Example #1
0
void addFlexionController(Model& model)
{
	PrescribedController* controller = new PrescribedController();
	controller->setName( "flexion_controller");
	controller->setActuators( model.updActuators());
	
	double control_time[2] = {0, 0.05}; // time nodes for linear function
	double control_acts[2] = {1.0, 0}; // force values at t1 and t2

	string muscle_name;
	for (int i=0; i<model.getActuators().getSize(); i++)
	{
		muscle_name = model.getActuators().get(i).getName();
		// hamstrings: bi*, semi*
		if ( muscle_name == "bifemlh_r" || muscle_name == "bifemsh_r" || muscle_name == "grac_r" \
			|| muscle_name == "lat_gas_r" || muscle_name == "med_gas_r" || muscle_name == "sar_r" \
			|| muscle_name == "semimem_r" || muscle_name == "semiten_r")
		{
			Constant* ccf = new Constant(1.0);
			//PiecewiseLinearFunction *ccf = new PiecewiseLinearFunction( 2, control_time, control_acts);
			controller->prescribeControlForActuator( i, ccf);
		}
		else 
		{
			Constant* zccf = new Constant(0);
			controller->prescribeControlForActuator( i, zccf);
		}
	}
	model.addController( controller);
}
Example #2
0
void addExtensionController(Model& model)
{
	PrescribedController* controller = new PrescribedController();
	controller->setName( "extension_controller");
	controller->setActuators( model.updActuators());
	
	double control_time[2] = {0.01, 0.02}; // time nodes for linear function
	double control_acts[2] = {0.0, 1.0}; // force values at t1 and t2
	//control_func->setName( "constant_control_func");

	string muscle_name;
	for (int i=0; i<model.getActuators().getSize(); i++)
	{
		muscle_name = model.getActuators().get(i).getName();
		// activate quadriceps
		if (muscle_name == "rect_fem_r" || muscle_name == "vas_med_r" || muscle_name == "vas_int_r" || muscle_name == "vas_lat_r" )
		{
			Constant* ccf = new Constant(0.8);
			//PiecewiseLinearFunction *ccf = new PiecewiseLinearFunction( 2, control_time, control_acts);
			controller->prescribeControlForActuator( i, ccf);
		}
		else 
		{
			Constant* zccf = new Constant(0);
			controller->prescribeControlForActuator( i, zccf);
		}
	}
	model.addController( controller);
}
/**
 * Run a simulation of block sliding with contact on by two muscles sliding with contact 
 */
int main()
{

	try {
		// Create a new OpenSim model
		Model osimModel;
		osimModel.setName("osimModel");

		double Pi = SimTK::Pi;
		
		
		// Get the ground body
		OpenSim::Body& ground = osimModel.getGroundBody();
		ground.addDisplayGeometry("checkered_floor.vtp");

		// create linkage body
		double linkageMass = 0.001, linkageLength = 0.5, linkageDiameter = 0.06;
		
		Vec3 linkageDimensions(linkageDiameter, linkageLength, linkageDiameter);
		Vec3 linkageMassCenter(0,linkageLength/2,0);
		Inertia linkageInertia = Inertia::cylinderAlongY(linkageDiameter/2.0, linkageLength/2.0);

		OpenSim::Body* linkage1 = new OpenSim::Body("linkage1", linkageMass, linkageMassCenter, linkageMass*linkageInertia);

		// Graphical representation
		linkage1->addDisplayGeometry("cylinder.vtp");
		//This cylinder.vtp geometry is 1 meter tall, 1 meter diameter.  Scale and shift it to look pretty
		GeometrySet& geometry = linkage1->updDisplayer()->updGeometrySet();
		DisplayGeometry& thinCylinder = geometry[0];
		thinCylinder.setScaleFactors(linkageDimensions);
		thinCylinder.setTransform(Transform(Vec3(0.0,linkageLength/2.0,0.0)));
		linkage1->addDisplayGeometry("sphere.vtp");
		//This sphere.vtp is 1 meter in diameter.  Scale it.
		geometry[1].setScaleFactors(Vec3(0.1));
		
		// Creat a second linkage body
		OpenSim::Body* linkage2 = new OpenSim::Body(*linkage1);
		linkage2->setName("linkage2");

		// Creat a block to be the pelvis
		double blockMass = 20.0, blockSideLength = 0.2;
		Vec3 blockMassCenter(0);
		Inertia blockInertia = blockMass*Inertia::brick(blockSideLength, blockSideLength, blockSideLength);
		OpenSim::Body *block = new OpenSim::Body("block", blockMass, blockMassCenter, blockInertia);
		block->addDisplayGeometry("block.vtp");
		//This block.vtp is 0.1x0.1x0.1 meters.  scale its appearance
		block->updDisplayer()->updGeometrySet()[0].setScaleFactors(Vec3(2.0));

		// Create 1 degree-of-freedom pin joints between the bodies to creat a kinematic chain from ground through the block
		
		Vec3 orientationInGround(0), locationInGround(0), locationInParent(0.0, linkageLength, 0.0), orientationInChild(0), locationInChild(0);

		PinJoint *ankle = new PinJoint("ankle", ground, locationInGround, orientationInGround, *linkage1, 
			locationInChild, orientationInChild);

		PinJoint *knee = new PinJoint("knee", *linkage1, locationInParent, orientationInChild, *linkage2,
			locationInChild, orientationInChild);

		PinJoint *hip = new PinJoint("hip", *linkage2, locationInParent, orientationInChild, *block,
			locationInChild, orientationInChild);
		
		double range[2] = {-SimTK::Pi*2, SimTK::Pi*2};
		CoordinateSet& ankleCoordinateSet = ankle->upd_CoordinateSet();
		ankleCoordinateSet[0].setName("q1");
		ankleCoordinateSet[0].setRange(range);

		CoordinateSet& kneeCoordinateSet = knee->upd_CoordinateSet();
		kneeCoordinateSet[0].setName("q2");
		kneeCoordinateSet[0].setRange(range);

		CoordinateSet& hipCoordinateSet = hip->upd_CoordinateSet();
		hipCoordinateSet[0].setName("q3");
		hipCoordinateSet[0].setRange(range);

		// Add the bodies to the model
		osimModel.addBody(linkage1);
		osimModel.addBody(linkage2);
		osimModel.addBody(block);

		// Define contraints on the model
		//  Add a point on line constraint to limit the block to vertical motion

		Vec3 lineDirection(0,1,0), pointOnLine(0,0,0), pointOnBlock(0);
		PointOnLineConstraint *lineConstraint = new PointOnLineConstraint(ground, lineDirection, pointOnLine, *block, pointOnBlock);
		osimModel.addConstraint(lineConstraint);

		// Add PistonActuator between the first linkage and the block
		Vec3 pointOnBodies(0);
		PistonActuator *piston = new PistonActuator();
		piston->setName("piston");
		piston->setBodyA(linkage1);
		piston->setBodyB(block);
		piston->setPointA(pointOnBodies);
		piston->setPointB(pointOnBodies);
		piston->setOptimalForce(200.0);
		piston->setPointsAreGlobal(false);

		osimModel.addForce(piston);
		//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
		// Added ControllableSpring between the first linkage and the second block
		//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
		ControllableSpring *spring = new ControllableSpring;
		spring->setName("spring");
		spring->setBodyA(block);
		spring->setBodyB(linkage1);
		spring->setPointA(pointOnBodies);
		spring->setPointB(pointOnBodies);
		spring->setOptimalForce(2000.0);
		spring->setPointsAreGlobal(false);
		spring->setRestLength(0.8);

		osimModel.addForce(spring);

		// define the simulation times
		double t0(0.0), tf(15);

		// create a controller to control the piston and spring actuators
		// the prescribed controller sets the controls as functions of time
		PrescribedController *legController = new PrescribedController();
		// give the legController control over all (two) model actuators
		legController->setActuators(osimModel.updActuators());

		// specify some control nodes for spring stiffness control
		double t[] = {0.0, 4.0, 7.0,  10.0, 15.0};
        double x[] = {1.0, 1.0, 0.25,  0.25, 5.0};

		// specify the control function for each actuator
		legController->prescribeControlForActuator("piston", new Constant(0.1));
		legController->prescribeControlForActuator("spring", new PiecewiseLinearFunction(5, t, x));

		// add the controller to the model
		osimModel.addController(legController);		
		
		// define the acceration due to gravity
		osimModel.setGravity(Vec3(0, -9.80665, 0));

		// enable the model visualizer see the model in action, which can be
		// useful for debugging
		osimModel.setUseVisualizer(true);

		// Initialize system
		SimTK::State& si = osimModel.initSystem();
		
		// Pin joint initial states
		double q1_i = -Pi/4;
		double q2_i = - 2*q1_i;
		CoordinateSet &coordinates = osimModel.updCoordinateSet();
		coordinates[0].setValue(si, q1_i, true);
		coordinates[1].setValue(si,q2_i, true);

		// Setup integrator and manager
		SimTK::RungeKuttaMersonIntegrator integrator(osimModel.getMultibodySystem());
		integrator.setAccuracy(1.0e-3);

		ForceReporter *forces = new ForceReporter(&osimModel);	
		osimModel.updAnalysisSet().adoptAndAppend(forces);
		Manager manager(osimModel, integrator);
	
		//Examine the model
		osimModel.printDetailedInfo(si, std::cout);
		// Save the model
		osimModel.print("toyLeg.osim");
		// Print out the initial position and velocity states
		si.getQ().dump("Initial q's");
		si.getU().dump("Initial u's");
		std::cout << "Initial time: " << si.getTime() << std::endl;

		// Integrate
		manager.setInitialTime(t0);
		manager.setFinalTime(tf);
		std::cout<<"\n\nIntegrating from " << t0 << " to " << tf << std::endl;
		manager.integrate(si);

		// Save results
		osimModel.printControlStorage("SpringActuatedLeg_controls.sto");
		Storage statesDegrees(manager.getStateStorage());
		osimModel.updSimbodyEngine().convertRadiansToDegrees(statesDegrees);
		//statesDegrees.print("PistonActuatedLeg_states_degrees.mot");
		statesDegrees.print("SpringActuatedLeg_states_degrees.mot");

		forces->getForceStorage().print("actuator_forces.mot");
		
	}
    catch (const std::exception& ex)
    {
        std::cout << "Exception in toyLeg_example: " << ex.what() << std::endl;
        return 1;
    }

	std::cout << "Exiting" << std::endl;
	return 0;
}
void testMcKibbenActuator()
{

    double pressure = 5 * 10e5; // 5 bars
    double num_turns = 1.5;     // 1.5 turns
    double B = 277.1 * 10e-4;  // 277.1 mm

    using namespace SimTK;
    std::clock_t startTime = std::clock();

    double mass = 1;
    double ball_radius = 10e-6;

    Model *model = new Model;
    model->setGravity(Vec3(0));

    Ground& ground = model->updGround();

    McKibbenActuator *actuator = new McKibbenActuator("mckibben", num_turns, B);
    
    OpenSim::Body* ball = new OpenSim::Body("ball", mass ,Vec3(0),  mass*SimTK::Inertia::sphere(0.1));
    ball->scale(Vec3(ball_radius), false);

    actuator->addNewPathPoint("mck_ground", ground, Vec3(0));
    actuator->addNewPathPoint("mck_ball", *ball, Vec3(ball_radius));

    Vec3 locationInParent(0, ball_radius, 0), orientationInParent(0), locationInBody(0), orientationInBody(0);
    SliderJoint *ballToGround = new SliderJoint("ballToGround", ground, locationInParent, orientationInParent, *ball, locationInBody, orientationInBody);

    ballToGround->updCoordinate().setName("ball_d");
    ballToGround->updCoordinate().setPrescribedFunction(LinearFunction(20 * 10e-4, 0.5 * 264.1 * 10e-4));
    ballToGround->updCoordinate().set_prescribed(true);

    model->addBody(ball);
    model->addJoint(ballToGround);
    model->addForce(actuator);

    PrescribedController* controller =  new PrescribedController();
    controller->addActuator(*actuator);
    controller->prescribeControlForActuator("mckibben", new Constant(pressure));

    model->addController(controller);

    ForceReporter* reporter = new ForceReporter(model);
    model->addAnalysis(reporter);
    
    SimTK::State& si = model->initSystem();

    model->getMultibodySystem().realize(si, Stage::Position);

    double final_t = 10.0;
    double nsteps = 10;
    double dt = final_t / nsteps;

    RungeKuttaMersonIntegrator integrator(model->getMultibodySystem());
    integrator.setAccuracy(1e-7);
    Manager manager(*model, integrator);
    manager.setInitialTime(0.0);

    for (int i = 1; i <= nsteps; i++){
        manager.setFinalTime(dt*i);
        manager.integrate(si);
        model->getMultibodySystem().realize(si, Stage::Velocity);
        Vec3 pos;
        model->updSimbodyEngine().getPosition(si, *ball, Vec3(0), pos);

        double applied = actuator->computeActuation(si);;

        double theoretical = (pressure / (4* pow(num_turns,2) * SimTK::Pi)) * (3*pow(pos(0), 2) - pow(B, 2));

        ASSERT_EQUAL(applied, theoretical, 10.0);

        manager.setInitialTime(dt*i);
    }


    std::cout << " ******** Test McKibbenActuator time = ********" <<
        1.e3*(std::clock() - startTime) / CLOCKS_PER_SEC << "ms\n" << endl;
}
void testClutchedPathSpring()
{
    using namespace SimTK;

    // start timing
    std::clock_t startTime = std::clock();

    double mass = 1;
    double stiffness = 100;
    double dissipation = 0.3;
    double start_h = 0.5;
    //double ball_radius = 0.25;

    //double omega = sqrt(stiffness/mass);

    // Setup OpenSim model
    Model* model = new Model;
    model->setName("ClutchedPathSpringModel");
    model->setGravity(gravity_vec);

    //OpenSim bodies
    const Ground* ground = &model->getGround();
    
    // body that acts as the pulley that the path wraps over
    OpenSim::Body* pulleyBody =
        new OpenSim::Body("PulleyBody", mass ,Vec3(0),  mass*Inertia::brick(0.1, 0.1, 0.1));
    
    // body the path spring is connected to at both ends
    OpenSim::Body* block =
        new OpenSim::Body("block", mass ,Vec3(0),  mass*Inertia::brick(0.2, 0.1, 0.1));
    block->attachGeometry(new Brick(Vec3(0.2, 0.1, 0.1)));
    block->scale(Vec3(0.2, 0.1, 0.1), false);

    //double dh = mass*gravity_vec(1)/stiffness;
    
    WrapCylinder* pulley = new WrapCylinder();
    pulley->set_radius(0.1);
    pulley->set_length(0.05);

    // Add the wrap object to the body, which takes ownership of it
    pulleyBody->addWrapObject(pulley);

    // Add joints
    WeldJoint* weld = 
        new WeldJoint("weld", *ground, Vec3(0, 1.0, 0), Vec3(0), *pulleyBody, Vec3(0), Vec3(0));
    
    SliderJoint* slider =
        new SliderJoint("slider", *ground, Vec3(0), Vec3(0,0,Pi/2),*block, Vec3(0), Vec3(0,0,Pi/2));

    double positionRange[2] = {-10, 10};
    // Rename coordinates for a slider joint
    slider->updCoordinate().setName("block_h");
    slider->updCoordinate().setRange(positionRange);

    model->addBody(pulleyBody);
    model->addJoint(weld);

    model->addBody(block);
    model->addJoint(slider);

    ClutchedPathSpring* spring = 
        new ClutchedPathSpring("clutch_spring", stiffness, dissipation, 0.01);

    spring->updGeometryPath().appendNewPathPoint("origin", *block, Vec3(-0.1, 0.0 ,0.0));
    
    int N = 10;
    for(int i=1; i<N; ++i){
        double angle = i*Pi/N;
        double x = 0.1*cos(angle);
        double y = 0.1*sin(angle);
        spring->updGeometryPath().appendNewPathPoint("", *pulleyBody, Vec3(-x, y ,0.0));
    }

    spring->updGeometryPath().appendNewPathPoint("insertion", *block, Vec3(0.1, 0.0 ,0.0));

    // BUG in defining wrapping API requires that the Force containing the GeometryPath be
    // connected to the model before the wrap can be added
    model->addForce(spring);

    PrescribedController* controller = new PrescribedController();
    controller->addActuator(*spring);
    
    // Control greater than 1 or less than 0 should be treated as 1 and 0 respectively.
    double     timePts[4] = {0.0,  5.0, 6.0, 10.0};
    double clutchOnPts[4] = {1.5, -2.0, 0.5,  0.5};

    PiecewiseConstantFunction* controlfunc = 
        new PiecewiseConstantFunction(4, timePts, clutchOnPts);

    controller->prescribeControlForActuator("clutch_spring", controlfunc);
    model->addController(controller);

    model->print("ClutchedPathSpringModel.osim");

    //Test deserialization
    delete model;
    model = new Model("ClutchedPathSpringModel.osim");

    // Create the force reporter
    ForceReporter* reporter = new ForceReporter(model);
    model->addAnalysis(reporter);

    model->setUseVisualizer(false);
    SimTK::State& state = model->initSystem();

    CoordinateSet& coords = model->updCoordinateSet();
    coords[0].setValue(state, start_h);
    model->getMultibodySystem().realize(state, Stage::Position );

    //==========================================================================
    // Compute the force and torque at the specified times.

    RungeKuttaMersonIntegrator integrator(model->getMultibodySystem() );
    integrator.setAccuracy(integ_accuracy);
    Manager manager(*model,  integrator);
    manager.setWriteToStorage(true);

    manager.setInitialTime(0.0);

    double final_t = 4.99999;

    manager.setFinalTime(final_t);
    manager.integrate(state);

    // tension is dynamics dependent because controls must be computed
    model->getMultibodySystem().realize(state, Stage::Dynamics);

    spring = dynamic_cast<ClutchedPathSpring*>(
                &model->updForceSet().get("clutch_spring"));
    // Now check that the force reported by spring
    double model_force = spring->getTension(state);
    double stretch0 = spring->getStretch(state);

    // the tension should be half the weight of the block
    double analytical_force = -0.5*(gravity_vec(1))*mass;

    cout << "Tension is: " << model_force << " and should be: " << analytical_force << endl;

    // error if the block does not reach equilibrium since spring is clamped
    ASSERT_EQUAL(model_force, analytical_force, 10*integ_accuracy);

    // unclamp and continue integrating
    manager.setInitialTime(final_t);
    final_t = 5.99999;
    manager.setFinalTime(final_t);
    manager.integrate(state);

    // tension is dynamics dependent because controls must be computed
    model->getMultibodySystem().realize(state, Stage::Dynamics);

    // tension should go to zero quickly
    model_force = spring->getTension(state);

    cout << "Tension is: " << model_force << " and should be: 0.0" << endl;
    // is unclamped and block should be in free-fall
    ASSERT_EQUAL(model_force, 0.0, 10*integ_accuracy);

    // spring is reclamped at 7s so keep integrating
    manager.setInitialTime(final_t);
    final_t = 10.0;
    manager.setFinalTime(final_t);
    manager.integrate(state);

    // tension is dynamics dependent because controls must be computed
    model->getMultibodySystem().realize(state, Stage::Dynamics);

    // tension should build to support the block again
    model_force = spring->getTension(state);
    double stretch1 = spring->getStretch(state);

    cout << "Tension is: " << model_force << " and should be: "<< analytical_force << endl;

    // is unclamped and block should be in free-fall
    ASSERT_EQUAL(model_force, analytical_force, 10*integ_accuracy);

    cout << "Steady stretch at control = 1.0 is " << stretch0 << " m." << endl;
    cout << "Steady stretch at control = 0.5 is " << stretch1 << " m." << endl;

    ASSERT_EQUAL(2*stretch0, stretch1, 10*integ_accuracy);

    manager.getStateStorage().print("clutched_path_spring_states.sto");
    model->getControllerSet().printControlStorage("clutched_path_spring_controls.sto");

    // Save the forces
    reporter->getForceStorage().print("clutched_path_spring_forces.mot"); 

    model->disownAllComponents();

    cout << " ********** Test clutched spring time = ********** " << 
        1.e3*(std::clock()-startTime)/CLOCKS_PER_SEC << "ms\n" << endl;
}
//==============================================================================
// Test Cases
//==============================================================================
void testTorqueActuator()
{
    using namespace SimTK;
    // start timing
    std::clock_t startTime = std::clock();

    // Setup OpenSim model
    Model *model = new Model;

    // turn off gravity
    model->setGravity(Vec3(0));

    //OpenSim bodies
    const Ground& ground = model->getGround();

    //Cylindrical bodies
    double r = 0.25, h = 1.0;
    double m1 = 1.0, m2 = 2.0;
    Inertia j1 = m1*Inertia::cylinderAlongY(r, h);
    Inertia j2 = m2*Inertia::cylinderAlongY(r, h);

    //OpenSim bodies
    OpenSim::Body* bodyA 
        = new OpenSim::Body("A", m1, Vec3(0), j1);
    
    OpenSim::Body* bodyB 
        = new OpenSim::Body("B", m2, Vec3(0), j2);

    // connect bodyA to ground with 6dofs
    FreeJoint* base = 
        new FreeJoint("base", ground, Vec3(0), Vec3(0), *bodyA, Vec3(0), Vec3(0));

    model->addBody(bodyA);
    model->addJoint(base);

    // connect bodyA to bodyB by a Ball joint
    BallJoint* bInA = new BallJoint("bInA", *bodyA, Vec3(0,-h/2, 0), Vec3(0), 
                           *bodyB, Vec3(0, h/2, 0), Vec3(0));

    model->addBody(bodyB);
    model->addJoint(bInA);

    // specify magnitude and direction of applied torque
    double torqueMag = 2.1234567890;
    Vec3 torqueAxis(1/sqrt(2.0), 0, 1/sqrt(2.0));
    Vec3 torqueInG = torqueMag*torqueAxis;

    State state = model->initSystem();

    model->getMultibodySystem().realize(state, Stage::Dynamics);
    Vector_<SpatialVec>& bodyForces = 
        model->getMultibodySystem().updRigidBodyForces(state, Stage::Dynamics);
    bodyForces.dump("Body Forces before applying torque");
    model->getMatterSubsystem().addInBodyTorque(state, bodyA->getMobilizedBodyIndex(),
        torqueMag*torqueAxis, bodyForces);
    model->getMatterSubsystem().addInBodyTorque(state, bodyB->getMobilizedBodyIndex(),
        -torqueMag*torqueAxis, bodyForces);
    bodyForces.dump("Body Forces after applying torque to bodyA and bodyB");

    model->getMultibodySystem().realize(state, Stage::Acceleration);
    const Vector& udotBody = state.getUDot();
    udotBody.dump("Accelerations due to body forces");

    // clear body forces
    bodyForces *= 0;

    // update mobility forces
    Vector& mobilityForces = model->getMultibodySystem()
        .updMobilityForces(state, Stage::Dynamics);

    // Apply torques as mobility forces of the ball joint
    for(int i=0; i<3; ++i){
        mobilityForces[6+i] = torqueInG[i]; 
    }

    model->getMultibodySystem().realize(state, Stage::Acceleration);
    const Vector& udotMobility = state.getUDot();
    udotMobility.dump("Accelerations due to mobility forces");

    // First make sure that accelerations are not zero accidentally
    ASSERT(udotMobility.norm() != 0.0 || udotBody.norm() != 0.0);
    // Then check if they are equal
    for(int i=0; i<udotMobility.size(); ++i){
        ASSERT_EQUAL(udotMobility[i], udotBody[i], 1.0e-12);
    }

    // clear the mobility forces
    mobilityForces = 0;

    //Now add the actuator to the model and control it to generate the same
    //torque as applied directly to the multibody system (above)

    // Create and add the torque actuator to the model
    TorqueActuator* actuator =
        new TorqueActuator(*bodyA, *bodyB, torqueAxis, true);
    actuator->setName("torque");
    model->addForce(actuator);

    // Create and add a controller to control the actuator
    PrescribedController* controller =  new PrescribedController();
    controller->addActuator(*actuator);
    // Apply torque about torqueAxis
    controller->prescribeControlForActuator("torque", new Constant(torqueMag));

    model->addController(controller);

    /*
    ActuatorPowerProbe* powerProbe = new ActuatorPowerProbe(Array<string>("torque",1),false, 1); 
    powerProbe->setOperation("integrate");
    powerProbe->setInitialConditions(Vector(1, 0.0));
    */

    //model->addProbe(powerProbe);

    model->print("TestTorqueActuatorModel.osim");
    model->setUseVisualizer(false);

    // get a new system and state to reflect additions to the model
    state = model->initSystem();

    model->computeStateVariableDerivatives(state);

    const Vector &udotTorqueActuator = state.getUDot();

    // First make sure that accelerations are not zero accidentally
    ASSERT(udotMobility.norm() != 0.0 || udotTorqueActuator.norm() != 0.0);

    // Then verify that the TorqueActuator also generates the same acceleration
    // as the equivalent applied mobility force
    for(int i=0; i<udotMobility.size(); ++i){
        ASSERT_EQUAL(udotMobility[i], udotTorqueActuator[i], 1.0e-12);
    }

    // determine the initial kinetic energy of the system
    /*double iKE = */model->getMatterSubsystem().calcKineticEnergy(state);

    RungeKuttaMersonIntegrator integrator(model->getMultibodySystem());
    integrator.setAccuracy(integ_accuracy);
    Manager manager(*model,  integrator);

    manager.setInitialTime(0.0);

    double final_t = 1.00;

    manager.setFinalTime(final_t);
    manager.integrate(state);

    model->computeStateVariableDerivatives(state);

    /*double fKE = */model->getMatterSubsystem().calcKineticEnergy(state);

    // Change in system kinetic energy can only be attributable to actuator work
    //double actuatorWork = (powerProbe->getProbeOutputs(state))[0];
    // test that this is true
    //ASSERT_EQUAL(actuatorWork, fKE-iKE, integ_accuracy);

    // Before exiting lets see if copying the spring works
    TorqueActuator* copyOfActuator = actuator->clone();
    ASSERT(*copyOfActuator == *actuator);
    
    // Check that de/serialization works
    Model modelFromFile("TestTorqueActuatorModel.osim");
    ASSERT(modelFromFile == *model, __FILE__, __LINE__,
        "Model from file FAILED to match model in memory.");

    std::cout << " ********** Test TorqueActuator time =  ********** " << 
        1.e3*(std::clock()-startTime)/CLOCKS_PER_SEC << "ms\n" << endl;
}
Example #7
0
/**
 * Run a simulation of a sliding block being pulled by two muscle 
 */
int main()
{
    std::clock_t startTime = std::clock();

    try {
        ///////////////////////////////////////////////
        // DEFINE THE SIMULATION START AND END TIMES //
        ///////////////////////////////////////////////
        // Define the initial and final simulation times
        double initialTime = 0.0;
        double finalTime = 10.0;

        ///////////////////////////////////////////
        // DEFINE BODIES AND JOINTS OF THE MODEL //
        ///////////////////////////////////////////
        // Create an OpenSim model and set its name
        Model osimModel;
        osimModel.setName("tugOfWar");

        // GROUND FRAME

        // Get a reference to the model's ground body
        Ground& ground = osimModel.updGround();

        // Add display geometry to the ground to visualize in the GUI
        ground.attachGeometry(new Mesh("ground.vtp"));
        ground.attachGeometry(new Mesh("anchor1.vtp"));
        ground.attachGeometry(new Mesh("anchor2.vtp"));

        // BLOCK BODY

        // Specify properties of a 20 kg, 10cm length block body
        double blockMass = 20.0, blockSideLength = 0.1;
        Vec3 blockMassCenter(0);
        Inertia blockInertia = blockMass*Inertia::brick(blockSideLength, 
            blockSideLength, blockSideLength);

        // Create a new block body with the specified properties
        OpenSim::Body *block = new OpenSim::Body("block", blockMass, 
            blockMassCenter, blockInertia);

        // Add display geometry to the block to visualize in the GUI
        block->attachGeometry(new Mesh("block.vtp"));

        // FREE JOINT

        // Create a new free joint with 6 degrees-of-freedom (coordinates) 
        // between the block and ground bodies
        double halfLength = blockSideLength/2.0;
        Vec3 locationInParent(0, halfLength, 0), orientationInParent(0);
        Vec3 locationInBody(0, halfLength, 0), orientationInBody(0);
        FreeJoint *blockToGround = new FreeJoint("blockToGround", ground, 
            locationInParent, orientationInParent, 
            *block, locationInBody, orientationInBody);

        // Set the angle and position ranges for the free (6-degree-of-freedom)
        // joint between the block and ground frames.
        double angleRange[2] = {-SimTK::Pi/2, SimTK::Pi/2};
        double positionRange[2] = {-1, 1};
        blockToGround->updCoordinate(FreeJoint::Coord::Rotation1X).setRange(angleRange);
        blockToGround->updCoordinate(FreeJoint::Coord::Rotation2Y).setRange(angleRange);
        blockToGround->updCoordinate(FreeJoint::Coord::Rotation3Z).setRange(angleRange);
        blockToGround->updCoordinate(FreeJoint::Coord::TranslationX).setRange(positionRange);
        blockToGround->updCoordinate(FreeJoint::Coord::TranslationY).setRange(positionRange);
        blockToGround->updCoordinate(FreeJoint::Coord::TranslationZ).setRange(positionRange);

        // Add the block body to the model
        osimModel.addBody(block);
        osimModel.addJoint(blockToGround);

        ///////////////////////////////////////
        // DEFINE FORCES ACTING ON THE MODEL //
        ///////////////////////////////////////
        // MUSCLE FORCES

        // Create two new muscles
        double maxIsometricForce = 1000.0, optimalFiberLength = 0.2, 
               tendonSlackLength = 0.1,    pennationAngle = 0.0,  
               fatigueFactor = 0.30, recoveryFactor = 0.20;

        // fatigable muscle (Millard2012EquilibriumMuscle with fatigue)
        FatigableMuscle* fatigable = new FatigableMuscle("fatigable",
            maxIsometricForce, optimalFiberLength, tendonSlackLength, 
            pennationAngle, fatigueFactor, recoveryFactor);

        // original muscle model (muscle without fatigue)
        Millard2012EquilibriumMuscle* original = 
            new Millard2012EquilibriumMuscle("original",
                maxIsometricForce, optimalFiberLength, tendonSlackLength,
                pennationAngle);

        // Define the path of the muscles
        fatigable->addNewPathPoint("fatigable-point1", ground, 
            Vec3(0.0, halfLength, -0.35));
        fatigable->addNewPathPoint("fatigable-point2", *block, 
            Vec3(0.0, halfLength, -halfLength));

        original->addNewPathPoint("original-point1", ground, 
            Vec3(0.0, halfLength, 0.35));
        original->addNewPathPoint("original-point2", *block, 
            Vec3(0.0, halfLength, halfLength));

        // Define the default states for the two muscles
        // Activation
        fatigable->setDefaultActivation(0.01);
        original->setDefaultActivation(0.01);
        // Fiber length
        fatigable->setDefaultFiberLength(optimalFiberLength);
        original->setDefaultFiberLength(optimalFiberLength);

        // Add the two muscles (as forces) to the model
        osimModel.addForce(fatigable);
        osimModel.addForce(original);

        ///////////////////////////////////
        // DEFINE CONTROLS FOR THE MODEL //
        ///////////////////////////////////
        // Create a prescribed controller that simply supplies controls as 
        // a function of time.
        // For muscles, controls are normalized stoor-neuron excitations
        PrescribedController *muscleController = new PrescribedController();
        muscleController->setActuators(osimModel.updActuators());
    
        // Set the prescribed muscle controller to use the same muscle control function for each muscle
        muscleController->prescribeControlForActuator("fatigable", new Constant(1.0));
        muscleController->prescribeControlForActuator("original", new Constant(1.0));

        // Add the muscle controller to the model
        osimModel.addController(muscleController);

        // Add a Muscle analysis
        MuscleAnalysis* muscAnalysis = new MuscleAnalysis(&osimModel);
        Array<std::string> coords(blockToGround->getCoordinate(FreeJoint::Coord::TranslationZ).getName(),1);
        muscAnalysis->setCoordinates(coords);
        muscAnalysis->setComputeMoments(false);
        osimModel.addAnalysis(muscAnalysis);

        // Turn on the visualizer to view the simulation run live.
        osimModel.setUseVisualizer(false);

        //////////////////////////
        // PERFORM A SIMULATION //
        //////////////////////////

        // Initialize the system and get the state
        SimTK::State& si = osimModel.initSystem();

        // Init coords to 0 and lock the rotational degrees of freedom so the block doesn't twist
        CoordinateSet& coordinates = osimModel.updCoordinateSet();
        coordinates[0].setValue(si, 0);
        coordinates[1].setValue(si, 0);
        coordinates[2].setValue(si, 0);
        coordinates[3].setValue(si, 0);
        coordinates[4].setValue(si, 0); 
        coordinates[5].setValue(si, 0);
        coordinates[0].setLocked(si, true);
        coordinates[1].setLocked(si, true);
        coordinates[2].setLocked(si, true);
        // Last coordinate (index 5) is the Z translation of the block
        coordinates[4].setLocked(si, true); 

        // Compute initial conditions for muscles
        osimModel.equilibrateMuscles(si);

        // Create the integrator, force reporter, and manager for the simulation.
        // Create the integrator
        SimTK::RungeKuttaMersonIntegrator integrator(osimModel.getMultibodySystem());
        integrator.setAccuracy(1.0e-6);
        
        // Create the force reporter
        ForceReporter* reporter = new ForceReporter(&osimModel);
        osimModel.updAnalysisSet().adoptAndAppend(reporter);
        // Create the manager
        Manager manager(osimModel, integrator);

        // Print out details of the model
        osimModel.printDetailedInfo(si, std::cout);

        // Integrate from initial time to final time
        manager.setInitialTime(initialTime);
        manager.setFinalTime(finalTime);
        std::cout<<"\nIntegrating from "<<initialTime<<" to "<<finalTime<<std::endl;
        manager.integrate(si);

        //////////////////////////////
        // SAVE THE RESULTS TO FILE //
        //////////////////////////////

        // Save the simulation results
        // Save the states
        auto statesTable = manager.getStatesTable();
        STOFileAdapter_<double>::write(statesTable, 
                                      "tugOfWar_fatigue_states.sto");

        auto forcesTable = reporter->getForcesTable();
        STOFileAdapter_<double>::write(forcesTable, 
                                      "tugOfWar_fatigue_forces.sto");

        // Save the muscle analysis results
        IO::makeDir("MuscleAnalysisResults");
        muscAnalysis->printResults("fatigue", "MuscleAnalysisResults");

        // Save the OpenSim model to a file
        osimModel.print("tugOfWar_fatigue_model.osim");
    }
    catch (const std::exception& ex)
    {
        std::cout << ex.what() << std::endl;
        return 1;
    }
    catch (...)
    {
        std::cout << "UNRECOGNIZED EXCEPTION" << std::endl;
        return 1;
    }

    std::cout << "main() routine time = " << 1.e3*(std::clock()-startTime)/CLOCKS_PER_SEC << "ms\n";

    std::cout << "OpenSim example completed successfully.\n";
    return 0;
}
/**
 * Method for building the Luxo Jr articulating model. It sets up the system of
 * rigid bodies and joint articulations to define Luxo Jr lamp geometry.
 */
void createLuxoJr(OpenSim::Model &model){
    
    // Create base
    //--------------
    OpenSim::Body* base = new OpenSim::Body("base", baseMass, Vec3(0.0),
                Inertia::cylinderAlongY(0.1, baseHeight));
    
    // Add visible geometry
    base->attachMeshGeometry("Base_meters.obj");
    
    
    // Define base to float relative to ground via free joint
    FreeJoint* base_ground = new FreeJoint("base_ground",
                // parent body, location in parent body, orientation in parent
                model.getGround(), Vec3(0.0), Vec3(0.0),
                // child body, location in child body, orientation in child
                *base, Vec3(0.0,-baseHeight/2.0,0.0),Vec3(0.0));
    
    // add base to model
    model.addBody(base); model.addJoint(base_ground);
    
    /*for (int i = 0; i<base_ground->get_CoordinateSet().getSize(); ++i) {
        base_ground->upd_CoordinateSet()[i].set_locked(true);
    }*/
    
    // Fix a frame to the base axis for attaching the bottom bracket
    SimTK::Transform* shift_and_rotate = new SimTK::Transform();
    //shift_and_rotate->setToZero();
    shift_and_rotate->set(Rotation(-1*SimTK::Pi/2,
                                   SimTK::CoordinateAxis::XCoordinateAxis()),
                          Vec3(0.0, bracket_location, 0.0));

    PhysicalOffsetFrame pivot_frame_on_base("pivot_frame_on_base",
            *base, *shift_and_rotate);

    // Create bottom bracket
    //-----------------------
    OpenSim::Body* bottom_bracket = new OpenSim::Body("bottom_bracket",
                                            bracket_mass, Vec3(0.0),
                                            Inertia::brick(0.03, 0.03, 0.015));
    // add bottom bracket to model
    model.addBody(bottom_bracket);
    
    // Fix a frame to the bracket for attaching joint
    shift_and_rotate->setP(Vec3(0.0));
    PhysicalOffsetFrame pivot_frame_on_bottom_bracket(
        "pivot_frame_on_bottom_bracket", *bottom_bracket, *shift_and_rotate);
    
    // Add visible geometry
    bottom_bracket->attachMeshGeometry("bottom_bracket_meters.obj");

    // Make bottom bracket to twist on base with vertical pin joint.
    // You can create a joint from any existing physical frames attached to
    // rigid bodies. One way to reference them is by name, like this...
    PinJoint* base_pivot = new PinJoint("base_pivot", pivot_frame_on_base,
                                        pivot_frame_on_bottom_bracket);
    
    base_pivot->append_frames(pivot_frame_on_base);
    base_pivot->append_frames(pivot_frame_on_bottom_bracket);
    // add base pivot joint to the model
    model.addJoint(base_pivot);
    
    // add some damping to the pivot
    // initialized to zero stiffness and damping
    BushingForce* pivotDamper = new BushingForce("pivot_bushing",
                                         "pivot_frame_on_base",
                                         "pivot_frame_on_bottom_bracket");
    
    pivotDamper->set_rotational_damping(pivot_damping);
    
    model.addForce(pivotDamper);
    
    // Create posterior leg
    //-----------------------
    OpenSim::Body* posteriorLegBar = new OpenSim::Body("posterior_leg_bar",
                                    bar_mass,
                                    Vec3(0.0),
                                    Inertia::brick(leg_bar_dimensions/2.0));
    
    posteriorLegBar->attachMeshGeometry("Leg_meters.obj");

    PhysicalOffsetFrame posterior_knee_on_bottom_bracket(
        "posterior_knee_on_bottom_bracket",
            *bottom_bracket, Transform(posterior_bracket_hinge_location) );

    PhysicalOffsetFrame posterior_knee_on_posterior_bar(
        "posterior_knee_on_posterior_bar",
            *posteriorLegBar, Transform(inferior_bar_hinge_location) );

    // Attach posterior leg to bottom bracket using another pin joint.
    // Another way to reference physical frames in a joint is by creating them
    // in place, like this...
    OpenSim::PinJoint* posteriorKnee = new OpenSim::PinJoint("posterior_knee",
                                    posterior_knee_on_bottom_bracket,
                                    posterior_knee_on_posterior_bar);
    // posteriorKnee will own and serialize the attachment offset frames 
    posteriorKnee->append_frames(posterior_knee_on_bottom_bracket);
    posteriorKnee->append_frames(posterior_knee_on_posterior_bar);

    
    // add posterior leg to model
    model.addBody(posteriorLegBar); model.addJoint(posteriorKnee);
    
    // allow this joint's coordinate to float freely when assembling constraints
    // the joint we create next will drive the pose of the 4-bar linkage
    posteriorKnee->upd_CoordinateSet()[0]
                                    .set_is_free_to_satisfy_constraints(true);
    
    // Create anterior leg Hlink
    //----------------------------
    OpenSim::Body* leg_Hlink = new OpenSim::Body("leg_Hlink",
                                    bar_mass,
                                    Vec3(0.0),
                                    Inertia::brick(leg_Hlink_dimensions/2.0));
    
    leg_Hlink->attachMeshGeometry("H_Piece_meters.obj");
    
    
    PhysicalOffsetFrame anterior_knee_on_bottom_bracket(
        "anterior_knee_on_bottom_bracket",
            *bottom_bracket, Transform(anterior_bracket_hinge_location));

    
    PhysicalOffsetFrame anterior_knee_on_anterior_bar(
        "anterior_knee_on_anterior_bar",
            *leg_Hlink, Transform(inferior_Hlink_hinge_location));


    // Connect anterior leg to bottom bracket via pin joint
    OpenSim::PinJoint* anterior_knee = new OpenSim::PinJoint("anterior_knee",
                                    anterior_knee_on_bottom_bracket,
                                    anterior_knee_on_anterior_bar);
    anterior_knee->append_frames(anterior_knee_on_bottom_bracket);
    anterior_knee->append_frames(anterior_knee_on_anterior_bar);

    
    // add anterior leg to model
    model.addBody(leg_Hlink); model.addJoint(anterior_knee);
    
    // this anterior knee joint defines the motion of the lower 4-bar linkage
    // set it's default coordinate value to a slightly flexed position.
    anterior_knee->upd_CoordinateSet()[0].set_default_value(SimTK::Pi/6);
    
    // Create pelvis bracket
    //-----------------------
    OpenSim::Body* pelvisBracket = new OpenSim::Body("pelvis_bracket",
                                            bracket_mass,
                                            Vec3(0.0),
                                        Inertia::brick(pelvis_dimensions/2.0));
    
    pelvisBracket->attachMeshGeometry("Pelvis_bracket_meters.obj");
    
    // Connect pelvis to Hlink via pin joint
    SimTK::Transform pelvis_anterior_shift(
                                        anterior_superior_pelvis_pin_location);

    PhysicalOffsetFrame anterior_hip_on_Hlink(
        "anterior_hip_on_Hlink",
        *leg_Hlink, Transform(superior_Hlink_hinge_location));

    PhysicalOffsetFrame anterior_hip_on_pelvis(
            "anterior_hip_on_pelvis",
        *pelvisBracket, pelvis_anterior_shift);

    OpenSim::PinJoint* anteriorHip = new OpenSim::PinJoint("anterior_hip",
                                                    anterior_hip_on_Hlink,
                                                    anterior_hip_on_pelvis);
    anteriorHip->append_frames(anterior_hip_on_Hlink);
    anteriorHip->append_frames(anterior_hip_on_pelvis);
    
    // add anterior leg to model
    model.addBody(pelvisBracket); model.addJoint(anteriorHip);
    
    // since the previous, anterior knee joint drives the pose of the lower
    // 4-bar linkage, set the anterior hip angle such that it's free to satisfy
    // constraints that couple it to the 4-bar linkage.
    anteriorHip->upd_CoordinateSet()[0]
                                    .set_is_free_to_satisfy_constraints(true);
    
    // Close the loop for the lower, four-bar linkage with a constraint
    //------------------------------------------------------------------
    
    // Create and configure point on line constraint
    OpenSim::PointOnLineConstraint* posteriorHip =
        new OpenSim::PointOnLineConstraint();
    
    posteriorHip->setLineBodyByName(pelvisBracket->getName());
    posteriorHip->setLineDirection(Vec3(0.0,0.0,1.0));
    posteriorHip->setPointOnLine(inferior_pelvis_pin_location);
    posteriorHip->setFollowerBodyByName(posteriorLegBar->getName());
    posteriorHip->setPointOnFollower(superior_bar_hinge_location);
    
    // add constraint to model
    model.addConstraint(posteriorHip);
    
    // Create chest piece
    //-----------------------
    OpenSim::Body* chest = new OpenSim::Body("chest_bar", bar_mass,
                                     Vec3(0.0),
                                     Inertia::brick(torso_bar_dimensions/2.0));
    
    chest->attachMeshGeometry("Anterior_torso_bar.obj");

    PhysicalOffsetFrame anterior_torso_hinge_on_pelvis(
        "anterior_torso_hinge_on_pelvis",
        *pelvisBracket, Transform(anterior_superior_pelvis_pin_location) );

    PhysicalOffsetFrame anterior_torso_hinge_on_chest(
        "anterior_torso_hinge_on_chest",
        *chest, Transform(inferior_torso_hinge_location) );
    
    // Attach chest piece to pelvice with pin joint
    OpenSim::PinJoint* anteriorTorsoHinge = new OpenSim::PinJoint(
                                              "anterior_torso_hinge",
                                              anterior_torso_hinge_on_pelvis,
                                              anterior_torso_hinge_on_chest);
    anteriorTorsoHinge->append_frames(anterior_torso_hinge_on_pelvis);
    anteriorTorsoHinge->append_frames(anterior_torso_hinge_on_chest);
    
    // add posterior leg to model
    model.addBody(chest); model.addJoint(anteriorTorsoHinge);
    
    // set torso rotation slightly anterior
    anteriorTorsoHinge->upd_CoordinateSet()[0].setDefaultValue(-1*SimTK::Pi/4);
    
    // Create chest piece
    //-----------------------
    OpenSim::Body* back = new OpenSim::Body("back_bar", bar_mass,
                                     Vec3(0.0),
                                     Inertia::brick(torso_bar_dimensions/2.0));
    
    back->attachMeshGeometry("Posterior_torso_bar.obj");

    PhysicalOffsetFrame posterior_torso_hinge_on_pelvis(
        "posterior_torso_hinge_on_pelvis",
        *pelvisBracket, Transform(posterior_superior_pelvis_pin_location) );

    PhysicalOffsetFrame posterior_torso_hinge_on_back(
        "posterior_torso_hinge_on_back",
        *back, Transform(back_peg_center) );
    
    // Attach chest piece to pelvis with pin joint
    OpenSim::PinJoint* posteriorTorsoHinge = new OpenSim::PinJoint(
                                          "posterior_torso_hinge",
                                          posterior_torso_hinge_on_pelvis,
                                          posterior_torso_hinge_on_back);
    posteriorTorsoHinge->append_frames(posterior_torso_hinge_on_pelvis);
    posteriorTorsoHinge->append_frames(posterior_torso_hinge_on_back);
    
    // add posterior leg to model
    model.addBody(back); model.addJoint(posteriorTorsoHinge);
    
    // set posterior back joint to freely follow anterior joint through 4-bar
    // linkage coupling.
    posteriorTorsoHinge->upd_CoordinateSet()[0]
    .set_is_free_to_satisfy_constraints(true);
    
    // Create shoulder bracket
    //-----------------------
    OpenSim::Body* shoulderBracket = new OpenSim::Body("shoulder_bracket",
                                     bracket_mass,
                                     Vec3(0.0),
                                     Inertia::brick(shoulder_dimensions/2.0));

    shoulderBracket->attachMeshGeometry("Shoulder_meters.obj");
    // add anterior leg to model
    model.addBody(shoulderBracket);

    PhysicalOffsetFrame anterior_thoracic_joint_on_chest(
        "anterior_thoracic_joint_on_chest",
        *chest, Transform(superior_torso_hinge_location) );

    PhysicalOffsetFrame anterior_thoracic_joint_on_shoulder(
        "anterior_thoracic_joint_on_shoulder",
        *shoulderBracket, Transform(anterior_thoracic_joint_center));
    
    // Connect pelvis to Hlink via pin joint
    OpenSim::PinJoint* anteriorThoracicJoint =
                        new OpenSim::PinJoint("anterior_thoracic_joint",
                                       anterior_thoracic_joint_on_chest,
                                       anterior_thoracic_joint_on_shoulder);
    anteriorThoracicJoint->append_frames(anterior_thoracic_joint_on_chest);
    anteriorThoracicJoint->append_frames(anterior_thoracic_joint_on_shoulder);
    // add back joint
    model.addJoint(anteriorThoracicJoint);
    
    // since the previous, anterior thoracic joint drives the pose of the lower
    // 4-bar linkage, set the anterior shoulder angle such that it's free to
    // satisfy constraints that couple it to the 4-bar linkage.
    anteriorThoracicJoint->upd_CoordinateSet()[0]
    .set_is_free_to_satisfy_constraints(true);
    
    // Close the loop for the lower, four-bar linkage with a constraint
    //------------------------------------------------------------------
    // Create and configure point on line constraint
    OpenSim::PointOnLineConstraint* posteriorShoulder =
    new OpenSim::PointOnLineConstraint();
    
    posteriorShoulder->setLineBodyByName(shoulderBracket->getName());
    posteriorShoulder->setLineDirection(Vec3(0.0,0.0,1.0));
    posteriorShoulder->setPointOnLine(posterior_thoracic_joint_center);
    posteriorShoulder->setFollowerBodyByName(back->getName());
    posteriorShoulder->setPointOnFollower(superior_torso_hinge_location);
    
    // add constraint to model
    model.addConstraint(posteriorShoulder);
    
    // Create and add luxo head
    OpenSim::Body* head = new OpenSim::Body("head", head_mass, Vec3(0),
            Inertia::cylinderAlongX(0.5*head_dimension[1], head_dimension[1]));
    
    head->attachMeshGeometry("luxo_head_meters.obj");
    head->attachMeshGeometry("Bulb_meters.obj");
    model.addBody(head);


    PhysicalOffsetFrame cervical_joint_on_shoulder("cervical_joint_on_shoulder",
        *shoulderBracket, Transform(superior_shoulder_hinge_location) );

    PhysicalOffsetFrame cervical_joint_on_head("cervical_joint_on_head",
        *head, Transform(cervicle_joint_center));

    // attach to shoulder via pin joint
    OpenSim::PinJoint* cervicalJoint = new OpenSim::PinJoint("cervical_joint",
                                  cervical_joint_on_shoulder,
                                  cervical_joint_on_head);
    
    cervicalJoint->append_frames(cervical_joint_on_shoulder);
    cervicalJoint->append_frames(cervical_joint_on_head);
    // add a neck joint
     model.addJoint(cervicalJoint);
    
    // lock the kneck coordinate so the head doens't spin without actuators or
    // passive forces
    cervicalJoint->upd_CoordinateSet()[0].set_locked(true);
    
    // Coordinate Limit forces for restricting leg range of motion.
    //-----------------------------------------------------------------------
    CoordinateLimitForce* kneeLimitForce =
            new CoordinateLimitForce(
                     anterior_knee->get_CoordinateSet()[0].getName(),
                     knee_flexion_max, joint_softstop_stiffness,
                     knee_flexion_min, joint_softstop_stiffness,
                     joint_softstop_damping,
                     transition_region);
    model.addForce(kneeLimitForce);
    
    // Coordinate Limit forces for restricting back range motion.
    //-----------------------------------------------------------------------
    CoordinateLimitForce* backLimitForce =
    new CoordinateLimitForce(
                         anteriorTorsoHinge->get_CoordinateSet()[0].getName(),
                         back_extension_max, joint_softstop_stiffness,
                         back_extension_min, joint_softstop_stiffness,
                         joint_softstop_damping,
                         transition_region);
    model.addForce(backLimitForce);
    
    
    // Contact
    //-----------------------------------------------------------------------
    ContactHalfSpace* floor_surface = new ContactHalfSpace(SimTK::Vec3(0),
                                       SimTK::Vec3(0, 0, -0.5*SimTK::Pi),
                                       model.updGround(), "floor_surface");
    
    OpenSim::ContactMesh* foot_surface = new ContactMesh(
                                         "thin_disc_0.11_by_0.01_meters.obj",
                                          SimTK::Vec3(0),
                                          SimTK::Vec3(0),
                                          *base,
                                          "foot_surface");
    
    // add contact geometry to model
    model.addContactGeometry(floor_surface);
    model.addContactGeometry(foot_surface);
    
    // define contact as an elastic foundation force
    OpenSim::ElasticFoundationForce::ContactParameters* contactParameters =
            new OpenSim::ElasticFoundationForce::ContactParameters(
                                               stiffness,
                                               dissipation,
                                               friction,
                                               friction,
                                               viscosity);
    
    contactParameters->addGeometry("foot_surface");
    contactParameters->addGeometry("floor_surface");
    
    OpenSim::ElasticFoundationForce* contactForce =
                        new OpenSim::ElasticFoundationForce(contactParameters);
    contactForce->setName("contact_force");
    
    model.addForce(contactForce);
    
    
    
    // MUSCLES
    //-----------------------------------------------------------------------
    
    // add a knee extensor to control the lower 4-bar linkage
    Millard2012EquilibriumMuscle* kneeExtensorRight = new Millard2012EquilibriumMuscle(
                                            "knee_extensor_right",
                                            knee_extensor_F0, knee_extensor_lm0,
                                            knee_extensor_lts, pennationAngle);
    kneeExtensorRight->addNewPathPoint("knee_extensor_right_origin", *leg_Hlink,
                                  knee_extensor_origin);
    kneeExtensorRight->addNewPathPoint("knee_extensor_right_insertion",
                                      *bottom_bracket,
                                        knee_extensor_insertion);
    kneeExtensorRight->set_ignore_tendon_compliance(true);
    model.addForce(kneeExtensorRight);
    
    // add a second copy of this knee extensor for the left side
    Millard2012EquilibriumMuscle* kneeExtensorLeft =
                                new Millard2012EquilibriumMuscle(*kneeExtensorRight);
    kneeExtensorLeft->setName("kneeExtensorLeft");
    
    // flip the z coordinates of all path points
    PathPointSet& points = kneeExtensorLeft->updGeometryPath().updPathPointSet();
    for (int i=0; i<points.getSize(); ++i) {
        points[i].setLocationCoord(2, -1*points[i].getLocationCoord(2));
    }

    kneeExtensorLeft->set_ignore_tendon_compliance(true);
    model.addForce(kneeExtensorLeft);
    
    // add a back extensor to controll the upper 4-bar linkage
    Millard2012EquilibriumMuscle* backExtensorRight = new Millard2012EquilibriumMuscle(
                                            "back_extensor_right",
                                            back_extensor_F0, back_extensor_lm0,
                                            back_extensor_lts, pennationAngle);
    
    backExtensorRight->addNewPathPoint("back_extensor_right_origin", *chest,
                                      back_extensor_origin);
    backExtensorRight->addNewPathPoint("back_extensor_right_insertion", *back,
                                      back_extensor_insertion);
    backExtensorRight->set_ignore_tendon_compliance(true);
    model.addForce(backExtensorRight);
    
    // copy right back extensor and use to make left extensor
    Millard2012EquilibriumMuscle* backExtensorLeft =
            new Millard2012EquilibriumMuscle(*backExtensorRight);
    
    backExtensorLeft->setName("back_extensor_left");
    
    PathPointSet& pointsLeft = backExtensorLeft->updGeometryPath()
        .updPathPointSet();
    for (int i=0; i<points.getSize(); ++i) {
        pointsLeft[i].setLocationCoord(2, -1*pointsLeft[i].getLocationCoord(2));
    }
    backExtensorLeft->set_ignore_tendon_compliance(true);
    model.addForce(backExtensorLeft);
    
    
    
    // MUSCLE CONTROLLERS
    //________________________________________________________________________
    
    // specify a piecwise linear function for the muscle excitations
    PiecewiseConstantFunction* x_of_t = new PiecewiseConstantFunction(3, times,
                                                                  excitations);
    
    
    PrescribedController* kneeController = new PrescribedController();
    kneeController->addActuator(*kneeExtensorLeft);
    kneeController->addActuator(*kneeExtensorRight);
    kneeController->prescribeControlForActuator(0, x_of_t);
    kneeController->prescribeControlForActuator(1, x_of_t->clone());
    
    model.addController(kneeController);
    
    PrescribedController* backController = new PrescribedController();
    backController->addActuator(*backExtensorLeft);
    backController->addActuator(*backExtensorRight);
    backController->prescribeControlForActuator(0, x_of_t->clone());
    backController->prescribeControlForActuator(1, x_of_t->clone());
    
    model.addController(backController);

    
    /* You'll find that these muscles can make Luxo Myo stand, but not jump.
     * Jumping will require an assistive device. We'll add two frames for
     * attaching a point to point assistive actuator.
     */
    
    
    // add frames for connecting a back assitance device between the chest
    // and pelvis
    PhysicalOffsetFrame* back_assist_origin_frame = new
        PhysicalOffsetFrame("back_assist_origin",
                            *chest,
                            back_assist_origin_transform);
    
    PhysicalOffsetFrame* back_assist_insertion_frame = new
        PhysicalOffsetFrame("back_assist_insertion",
                            *pelvisBracket,
                            back_assist_insertion_transform);
    
    model.addFrame(back_assist_origin_frame);
    model.addFrame(back_assist_insertion_frame);
    
    // add frames for connecting a knee assistance device between the posterior
    // leg and bottom bracket.
    PhysicalOffsetFrame* knee_assist_origin_frame = new
    PhysicalOffsetFrame("knee_assist_origin",
                        *posteriorLegBar,
                        knee_assist_origin_transform);
    
    PhysicalOffsetFrame* knee_assist_insertion_frame = new
    PhysicalOffsetFrame("knee_assist_insertion",
                        *bottom_bracket,
                        knee_assist_insertion_transform);
    
    model.addFrame(knee_assist_origin_frame);
    model.addFrame(knee_assist_insertion_frame);

    // Temporary: make the frame geometry disappear.
    for (auto& c : model.getComponentList<OpenSim::FrameGeometry>()) {
        const_cast<OpenSim::FrameGeometry*>(&c)->set_scale_factors(
                SimTK::Vec3(0.001, 0.001, 0.001));
    }
    
}
Example #9
0
//==========================================================================================================
void testPrescribedControllerOnBlock(bool disabled)
{
    using namespace SimTK;

    // Create a new OpenSim model
    Model osimModel;
    osimModel.setName("osimModel");

    // Get the ground body
    OpenSim::Body& ground = osimModel.getGroundBody();

    // Create a 20 kg, 0.1 m^3 block body
    double blockMass = 20.0, blockSideLength = 0.1;
    Vec3 blockMassCenter(0), groundOrigin(0), blockInGround(0, blockSideLength/2, 0);
    Inertia blockIntertia = Inertia::brick(blockSideLength, blockSideLength, blockSideLength);

    OpenSim::Body block("block", blockMass, blockMassCenter, blockMass*blockIntertia);

    //Create a free joint with 6 degrees-of-freedom
    SimTK::Vec3 noRotation(0);
    SliderJoint blockToGround("",ground, blockInGround, noRotation, block, blockMassCenter, noRotation);
    // Create 6 coordinates (degrees-of-freedom) between the ground and block
    CoordinateSet& jointCoordinateSet = blockToGround.upd_CoordinateSet();
    double posRange[2] = {-1, 1};
    jointCoordinateSet[0].setName("xTranslation");
    jointCoordinateSet[0].setMotionType(Coordinate::Translational);
    jointCoordinateSet[0].setRange(posRange);

    // Add the block body to the model
    osimModel.addBody(&block);

    // Define a single coordinate actuator.
    CoordinateActuator actuator(jointCoordinateSet[0].getName());
    actuator.setName("actuator");

    // Add the actuator to the model
    osimModel.addForce(&actuator);

    double initialTime = 0;
    double finalTime = 1.0;

    // Define the initial and final control values
    double controlForce = 100;

    // Create a prescribed controller that simply applies a function of the force
    PrescribedController actuatorController;
    actuatorController.setName("testPrescribedController");
    actuatorController.setActuators(osimModel.updActuators());
    actuatorController.prescribeControlForActuator(0, new Constant(controlForce));
    actuatorController.setDisabled(disabled);

    // add the controller to the model
    osimModel.addController(&actuatorController);

    osimModel.print("blockWithPrescribedController.osim");
    Model modelfileFromFile("blockWithPrescribedController.osim");

    // Verify that serialization and then deserialization of the disable flag is correct
    ASSERT(modelfileFromFile.getControllerSet().get("testPrescribedController").isDisabled() == disabled);

    // Initialize the system and get the state representing the state system
    SimTK::State& si = osimModel.initSystem();

    // Specify zero slider joint kinematic states
    CoordinateSet &coordinates = osimModel.updCoordinateSet();
    coordinates[0].setValue(si, 0.0);    // x translation
    coordinates[0].setSpeedValue(si, 0.0);			 // x speed

    // Create the integrator and manager for the simulation.
    double accuracy = 1.0e-3;
    SimTK::RungeKuttaMersonIntegrator integrator(osimModel.getMultibodySystem());
    integrator.setAccuracy(accuracy);
    Manager manager(osimModel, integrator);

    // Integrate from initial time to final time
    manager.setInitialTime(initialTime);
    manager.setFinalTime(finalTime);
    std::cout<<"\n\nIntegrating from "<<initialTime<<" to "<<finalTime<<std::endl;
    manager.integrate(si);

    si.getQ().dump("Final position:");

    double expected = disabled ? 0 : 0.5*(controlForce/blockMass)*finalTime*finalTime;
    ASSERT_EQUAL(expected, coordinates[0].getValue(si), accuracy, __FILE__, __LINE__, "PrescribedController failed to produce the expected motion of block.");

    // Save the simulation results
    Storage states(manager.getStateStorage());
    states.print("block_push.sto");

    osimModel.disownAllComponents();
}// end of testPrescribedControllerOnBlock()
Example #10
0
/**
 * Create a model that does nothing.
 */
int main()
{
    try {

        ///////////////////////////////////////////
        // DEFINE BODIES AND JOINTS OF THE MODEL //
        ///////////////////////////////////////////

        // Create an OpenSim model and set its name
        Model osimModel;
        osimModel.setName("tugOfWar");

        // GROUND BODY

        // Get a reference to the model's ground body
        Ground& ground = osimModel.updGround();

        // Add display geometry to the ground to visualize in the GUI
        ground.addMeshGeometry("ground.vtp");
        ground.addMeshGeometry("anchor1.vtp");
        ground.addMeshGeometry("anchor2.vtp");

        // BLOCK BODY

        // Specify properties of a 20 kg, 0.1 m^3 block body
        double blockMass = 20.0, blockSideLength = 0.1;
        Vec3 blockMassCenter(0);
        Inertia blockInertia = blockMass*Inertia::brick(blockSideLength, blockSideLength, blockSideLength);

        // Create a new block body with the specified properties
        OpenSim::Body *block = new OpenSim::Body("block", blockMass, blockMassCenter, blockInertia);

        // Add display geometry to the block to visualize in the GUI
        Brick brick(SimTK::Vec3(0.05, 0.05, 0.05));
        block->addGeometry(brick);

        // FREE JOINT

        // Create a new free joint with 6 degrees-of-freedom (coordinates) between the block and ground bodies
        Vec3 locationInParent(0, blockSideLength/2, 0), orientationInParent(0), locationInBody(0), orientationInBody(0);
        FreeJoint *blockToGround = new FreeJoint("blockToGround", ground, locationInParent, orientationInParent, *block, locationInBody, orientationInBody);

        // Get a reference to the coordinate set (6 degrees-of-freedom) between the block and ground bodies
        CoordinateSet& jointCoordinateSet = blockToGround->upd_CoordinateSet();

        // Set the angle and position ranges for the coordinate set
        double angleRange[2] = {-SimTK::Pi/2, SimTK::Pi/2};
        double positionRange[2] = {-1, 1};
        jointCoordinateSet[0].setRange(angleRange);
        jointCoordinateSet[1].setRange(angleRange);
        jointCoordinateSet[2].setRange(angleRange);
        jointCoordinateSet[3].setRange(positionRange);
        jointCoordinateSet[4].setRange(positionRange);
        jointCoordinateSet[5].setRange(positionRange);

        // Add the block body to the model
        osimModel.addBody(block);
        osimModel.addJoint(blockToGround);

        ///////////////////////////////////////////////
        // DEFINE THE SIMULATION START AND END TIMES //
        ///////////////////////////////////////////////

        // Define the initial and final simulation times
        double initialTime = 0.0;
        double finalTime = 3.00;

        /////////////////////////////////////////////
        // DEFINE CONSTRAINTS IMPOSED ON THE MODEL //
        /////////////////////////////////////////////

        // Specify properties of a constant distance constraint to limit the block's motion
        double distance = 0.2;
        Vec3 pointOnGround(0, blockSideLength/2 ,0);
        Vec3 pointOnBlock(0, 0, 0);

        // Create a new constant distance constraint
        ConstantDistanceConstraint *constDist = new ConstantDistanceConstraint(ground,
                pointOnGround, *block, pointOnBlock, distance);

        // Add the new point on a line constraint to the model
        osimModel.addConstraint(constDist);

        ///////////////////////////////////////
        // DEFINE FORCES ACTING ON THE MODEL //
        ///////////////////////////////////////

        // GRAVITY
        // Obtaine the default acceleration due to gravity
        Vec3 gravity = osimModel.getGravity();


        // MUSCLE FORCES
        // Create two new muscles with identical properties
        double maxIsometricForce = 1000.0, optimalFiberLength = 0.25, tendonSlackLength = 0.1, pennationAngle = 0.0;
        Thelen2003Muscle *muscle1 = new Thelen2003Muscle("muscle1",maxIsometricForce,optimalFiberLength,tendonSlackLength,pennationAngle);
        Thelen2003Muscle *muscle2 = new Thelen2003Muscle("muscle2",maxIsometricForce,optimalFiberLength,tendonSlackLength,pennationAngle);

        // Specify the paths for the two muscles
        // Path for muscle 1
        muscle1->addNewPathPoint("muscle1-point1", ground, Vec3(0.0,0.05,-0.35));
        muscle1->addNewPathPoint("muscle1-point2", *block, Vec3(0.0,0.0,-0.05));
        // Path for muscle 2
        muscle2->addNewPathPoint("muscle2-point1", ground, Vec3(0.0,0.05,0.35));
        muscle2->addNewPathPoint("muscle2-point2", *block, Vec3(0.0,0.0,0.05));

        // Add the two muscles (as forces) to the model
        osimModel.addForce(muscle1);
        osimModel.addForce(muscle2);


        // PRESCRIBED FORCE
        // Create a new prescribed force to be applied to the block
        PrescribedForce *prescribedForce = new PrescribedForce(block);
        prescribedForce->setName("prescribedForce");

        // Specify properties of the force function to be applied to the block
        double time[2] = {0, finalTime};                    // time nodes for linear function
        double fXofT[2] = {0,  -blockMass*gravity[1]*3.0};  // force values at t1 and t2

        // Create linear function for the force components
        PiecewiseLinearFunction *forceX = new PiecewiseLinearFunction(2, time, fXofT);
        // Set the force and point functions for the new prescribed force
        prescribedForce->setForceFunctions(forceX, new Constant(0.0), new Constant(0.0));
        prescribedForce->setPointFunctions(new Constant(0.0), new Constant(0.0), new Constant(0.0));

        // Add the new prescribed force to the model
        osimModel.addForce(prescribedForce);

        ///////////////////////////////////
        // DEFINE CONTROLS FOR THE MODEL //
        ///////////////////////////////////
        // Create a prescribed controller that simply applies controls as function of time
        // For muscles, controls are normalized motor-neuron excitations
        PrescribedController *muscleController = new PrescribedController();
        muscleController->setActuators(osimModel.updActuators());
        // Define linear functions for the control values for the two muscles
        Array<double> slopeAndIntercept1(0.0, 2);  // array of 2 doubles
        Array<double> slopeAndIntercept2(0.0, 2);
        // muscle1 control has slope of -1 starting 1 at t = 0
        slopeAndIntercept1[0] = -1.0/(finalTime-initialTime);
        slopeAndIntercept1[1] = 1.0;
        // muscle2 control has slope of 0.95 starting 0.05 at t = 0
        slopeAndIntercept2[0] = 0.95/(finalTime-initialTime);
        slopeAndIntercept2[1] = 0.05;

        // Set the indiviudal muscle control functions for the prescribed muscle controller
        muscleController->prescribeControlForActuator("muscle1", new LinearFunction(slopeAndIntercept1));
        muscleController->prescribeControlForActuator("muscle2", new LinearFunction(slopeAndIntercept2));

        // Add the muscle controller to the model
        osimModel.addController(muscleController);

        ///////////////////////////////////
        // SPECIFY MODEL DEFAULT STATES  //
        ///////////////////////////////////
        // Define the default states for the two muscles
        // Activation
        muscle1->setDefaultActivation(slopeAndIntercept1[1]);
        muscle2->setDefaultActivation(slopeAndIntercept2[1]);
        // Fiber length
        muscle2->setDefaultFiberLength(optimalFiberLength);
        muscle1->setDefaultFiberLength(optimalFiberLength);

        // Save the model to a file
        osimModel.print("tugOfWar_model.osim");

        //////////////////////////
        // PERFORM A SIMULATION //
        /////////////////////////

        //osimModel.setUseVisualizer(true);

        // Initialize the system and get the default state
        SimTK::State& si = osimModel.initSystem();

        // Define non-zero (defaults are 0) states for the free joint
        CoordinateSet& modelCoordinateSet = osimModel.updCoordinateSet();
        modelCoordinateSet[3].setValue(si, distance); // set x-translation value
        modelCoordinateSet[5].setValue(si, 0.0); // set z-translation value
        modelCoordinateSet[3].setSpeedValue(si, 0.0); // set x-speed value
        double h_start = 0.5;
        modelCoordinateSet[4].setValue(si, h_start); // set y-translation which is height

        std::cout << "Start height = "<< h_start << std::endl;

        osimModel.getMultibodySystem().realize(si, Stage::Velocity);

        // Compute initial conditions for muscles
        osimModel.equilibrateMuscles(si);

        double mfv1 = muscle1->getFiberVelocity(si);
        double mfv2 = muscle2->getFiberVelocity(si);

        // Create the force reporter for obtaining the forces applied to the model
        // during a forward simulation
        ForceReporter* reporter = new ForceReporter(&osimModel);
        osimModel.addAnalysis(reporter);

        // Create the integrator for integrating system dynamics
        SimTK::RungeKuttaMersonIntegrator integrator(osimModel.getMultibodySystem());
        integrator.setAccuracy(1.0e-6);

        // Create the manager managing the forward integration and its outputs
        Manager manager(osimModel,  integrator);

        // Integrate from initial time to final time
        manager.setInitialTime(initialTime);
        manager.setFinalTime(finalTime);
        std::cout<<"\nIntegrating from "<<initialTime<<" to "<<finalTime<<std::endl;
        manager.integrate(si);

    }
    catch (const std::exception& ex)
    {
        std::cerr << ex.what() << std::endl;
        return 1;
    }
    catch (...)
    {
        std::cerr << "UNRECOGNIZED EXCEPTION" << std::endl;
        return 1;
    }

    std::cout << "OpenSim environment test completed successfully. You should see a block attached to two muscles visualized in a separate window." << std::endl;

    return 0;
}
Example #11
0
/*==============================================================================  
    Main test driver to be used on any muscle model (derived from Muscle) so new 
    cases should be easy to add currently, the test only verifies that the work 
    done by the muscle corresponds to the change in system energy.

    TODO: Test will fail wih prescribe motion until the work done by this 
    constraint is accounted for.
================================================================================
*/
void simulateMuscle(
        const Muscle &aMuscModel, 
        double startX, 
        double act0, 
        const Function *motion,  // prescribe motion of free end of muscle
        const Function *control, // prescribed excitation signal to the muscle
        double integrationAccuracy,
        int testType,
        double testTolerance,
        bool printResults)
{
    string prescribed = (motion == NULL) ? "." : " with Prescribed Motion.";

    cout << "\n******************************************************" << endl;
    cout << "Test " << aMuscModel.getConcreteClassName() 
         << " Model" << prescribed << endl;
    cout << "******************************************************" << endl;
    using SimTK::Vec3;

//==========================================================================
// 0. SIMULATION SETUP: Create the block and ground
//==========================================================================

    // Define the initial and final simulation times
    double initialTime = 0.0;
    double finalTime = 4.0;
    
    //Physical properties of the model
    double ballMass = 10;
    double ballRadius = 0.05;
    double anchorWidth = 0.1;

    // Create an OpenSim model
    Model model;

    double optimalFiberLength = aMuscModel.getOptimalFiberLength();
    double pennationAngle     = aMuscModel.getPennationAngleAtOptimalFiberLength();
    double tendonSlackLength  = aMuscModel.getTendonSlackLength();

    // Use a copy of the muscle model passed in to add path points later
    PathActuator *aMuscle = aMuscModel.clone();

    // Get a reference to the model's ground body
    Body& ground = model.getGroundBody();
    ground.addDisplayGeometry("box.vtp");
    ground.updDisplayer()
        ->setScaleFactors(Vec3(anchorWidth, anchorWidth, 2*anchorWidth));

    OpenSim::Body * ball = new OpenSim::Body("ball", 
                        ballMass , 
                        Vec3(0),  
                        ballMass*SimTK::Inertia::sphere(ballRadius));
    
    ball->addDisplayGeometry("sphere.vtp");
    ball->updDisplayer()->setScaleFactors(Vec3(2*ballRadius));
    // ball connected  to ground via a slider along X
    double xSinG = optimalFiberLength*cos(pennationAngle)+tendonSlackLength;

    SliderJoint* slider = new SliderJoint( "slider", 
                        ground, 
                        Vec3(anchorWidth/2+xSinG, 0, 0), 
                        Vec3(0), 
                        *ball, 
                        Vec3(0), 
                        Vec3(0));

    CoordinateSet& jointCoordinateSet = slider->upd_CoordinateSet();
        jointCoordinateSet[0].setName("tx");
        jointCoordinateSet[0].setDefaultValue(1.0);
        jointCoordinateSet[0].setRangeMin(0); 
        jointCoordinateSet[0].setRangeMax(1.0);
    
    if(motion != NULL){
        jointCoordinateSet[0].setPrescribedFunction(*motion);
        jointCoordinateSet[0].setDefaultIsPrescribed(true);
    }
    // add ball to model
    model.addBody(ball);
	model.addJoint(slider);


//==========================================================================
// 1. SIMULATION SETUP: Add the muscle
//==========================================================================

    //Attach the muscle
    const string &actuatorType = aMuscle->getConcreteClassName();
    aMuscle->setName("muscle");
    aMuscle->addNewPathPoint("muscle-box", ground, Vec3(anchorWidth/2,0,0));
    aMuscle->addNewPathPoint("muscle-ball", *ball, Vec3(-ballRadius,0,0));
    
    ActivationFiberLengthMuscle_Deprecated *aflMuscle 
        = dynamic_cast<ActivationFiberLengthMuscle_Deprecated *>(aMuscle);
    if(aflMuscle){
        // Define the default states for the muscle that has 
        //activation and fiber-length states
        aflMuscle->setDefaultActivation(act0);
        aflMuscle->setDefaultFiberLength(aflMuscle->getOptimalFiberLength());
    }else{
        ActivationFiberLengthMuscle *aflMuscle2 
            = dynamic_cast<ActivationFiberLengthMuscle *>(aMuscle);
        if(aflMuscle2){
            // Define the default states for the muscle 
            //that has activation and fiber-length states
            aflMuscle2->setDefaultActivation(act0);
            aflMuscle2->setDefaultFiberLength(aflMuscle2
                ->getOptimalFiberLength());
        }
    }

    model.addForce(aMuscle);

    // Create a prescribed controller that simply 
    //applies controls as function of time
    PrescribedController * muscleController = new PrescribedController();
    if(control != NULL){
        muscleController->setActuators(model.updActuators());
        // Set the indiviudal muscle control functions 
        //for the prescribed muscle controller
        muscleController->prescribeControlForActuator("muscle",control->clone());

        // Add the control set controller to the model
        model.addController(muscleController);
    }

    // Set names for muscles / joints.
    Array<string> muscNames;
    muscNames.append(aMuscle->getName());
    Array<string> jointNames;
    jointNames.append("slider");

//==========================================================================
// 2. SIMULATION SETUP: Instrument the test with probes
//==========================================================================

    Array<string> muscNamesTwice = muscNames;
    muscNamesTwice.append(muscNames.get(0));
    cout << "------------\nPROBES\n------------" << endl;
    int probeCounter = 1;

    // Add ActuatorPowerProbe to measure work done by the muscle 
    ActuatorPowerProbe* muscWorkProbe = new ActuatorPowerProbe(muscNames, false, 1);
    //muscWorkProbe->setName("ActuatorWork");
    muscWorkProbe->setOperation("integrate");
    SimTK::Vector ic1(1);
    ic1 = 9.0;      // some arbitary initial condition.
    muscWorkProbe->setInitialConditions(ic1);
    model.addProbe(muscWorkProbe);
	model.setup();
    cout << probeCounter++ << ") Added ActuatorPowerProbe to measure work done by the muscle" << endl; 
    if (muscWorkProbe->getName() != "UnnamedProbe") {
        string errorMessage = "Incorrect default name for unnamed probe: " + muscWorkProbe->getName(); 
        throw (OpenSim::Exception(errorMessage.c_str()));
    }

    // Add ActuatorPowerProbe to measure power generated by the muscle 
    ActuatorPowerProbe* muscPowerProbe = new ActuatorPowerProbe(*muscWorkProbe);	// use copy constructor
    muscPowerProbe->setName("ActuatorPower");
    muscPowerProbe->setOperation("value");
    model.addProbe(muscPowerProbe);
    cout << probeCounter++ << ") Added ActuatorPowerProbe to measure power generated by the muscle" << endl; 

    // Add ActuatorPowerProbe to report the muscle power MINIMUM
    ActuatorPowerProbe* powerProbeMinimum = new ActuatorPowerProbe(*muscPowerProbe);			// use copy constructor
    powerProbeMinimum->setName("ActuatorPowerMinimum");
    powerProbeMinimum->setOperation("minimum");
    model.addProbe(powerProbeMinimum);
    cout << probeCounter++ << ") Added ActuatorPowerProbe to report the muscle power MINIMUM" << endl;

    // Add ActuatorPowerProbe to report the muscle power ABSOLUTE MINIMUM
    ActuatorPowerProbe* powerProbeMinAbs = new ActuatorPowerProbe(*muscPowerProbe);			// use copy constructor
    powerProbeMinAbs->setName("ActuatorPowerMinAbs");
    powerProbeMinAbs->setOperation("minabs");
    model.addProbe(powerProbeMinAbs);
    cout << probeCounter++ << ") Added ActuatorPowerProbe to report the muscle power MINABS" << endl;

    // Add ActuatorPowerProbe to report the muscle power MAXIMUM
    ActuatorPowerProbe* powerProbeMaximum = new ActuatorPowerProbe(*muscPowerProbe);			// use copy constructor
    powerProbeMaximum->setName("ActuatorPowerMaximum");
    powerProbeMaximum->setOperation("maximum");
    model.addProbe(powerProbeMaximum);
    cout << probeCounter++ << ") Added ActuatorPowerProbe to report the muscle power MAXIMUM" << endl;

    // Add ActuatorPowerProbe to report the muscle power MAXABS
    ActuatorPowerProbe* powerProbeMaxAbs = new ActuatorPowerProbe(*muscPowerProbe);			// use copy constructor
    powerProbeMaxAbs->setName("ActuatorPowerMaxAbs");
    powerProbeMaxAbs->setOperation("maxabs");
    model.addProbe(powerProbeMaxAbs);
    cout << probeCounter++ << ") Added ActuatorPowerProbe to report the muscle power MAXABS" << endl;


    // Add ActuatorPowerProbe to measure the square of the power generated by the muscle 
    ActuatorPowerProbe* muscPowerSquaredProbe = new ActuatorPowerProbe(*muscPowerProbe);	// use copy constructor
    muscPowerSquaredProbe->setName("ActuatorPowerSquared");
    muscPowerSquaredProbe->setExponent(2.0);
    model.addProbe(muscPowerSquaredProbe);
    cout << probeCounter++ << ") Added ActuatorPowerProbe to measure the square of the power generated by the muscle" << endl; 

    // Add JointInternalPowerProbe to measure work done by the joint 
    JointInternalPowerProbe* jointWorkProbe = new JointInternalPowerProbe(jointNames, false, 1);
    jointWorkProbe->setName("JointWork");
    jointWorkProbe->setOperation("integrate");
    jointWorkProbe->setInitialConditions(SimTK::Vector(1, 0.0));
    model.addProbe(jointWorkProbe);
    cout << probeCounter++ << ") Added JointPowerProbe to measure work done by the joint" << endl;

    // Add JointPowerProbe to measure power generated by the joint 
    JointInternalPowerProbe* jointPowerProbe = new JointInternalPowerProbe(*jointWorkProbe);	// use copy constructor
    jointPowerProbe->setName("JointPower");
    jointPowerProbe->setOperation("value");
    model.addProbe(jointPowerProbe);
    cout << probeCounter++ << ") Added JointPowerProbe to measure power generated by the joint" << endl;

    // Add ActuatorForceProbe to measure the impulse of the muscle force 
    ActuatorForceProbe* impulseProbe = new ActuatorForceProbe(muscNames, false, 1);
    impulseProbe->setName("ActuatorImpulse");
    impulseProbe->setOperation("integrate");
    impulseProbe->setInitialConditions(SimTK::Vector(1, 0.0));
    model.addProbe(impulseProbe);
    cout << probeCounter++ << ") Added ActuatorForceProbe to measure the impulse of the muscle force" << endl;

    // Add ActuatorForceProbe to report the muscle force 
    ActuatorForceProbe* forceProbe = new ActuatorForceProbe(*impulseProbe);			// use copy constructor
    forceProbe->setName("ActuatorForce");
    forceProbe->setOperation("value");
    model.addProbe(forceProbe);
    cout << probeCounter++ << ") Added ActuatorForceProbe to report the muscle force" << endl;

    // Add ActuatorForceProbe to report the square of the muscle force 
    ActuatorForceProbe* forceSquaredProbe = new ActuatorForceProbe(*forceProbe);			// use copy constructor
    forceSquaredProbe->setName("ActuatorForceSquared");
    forceSquaredProbe->setExponent(2.0);
    model.addProbe(forceSquaredProbe);
    cout << probeCounter++ << ") Added ActuatorForceProbe to report the square of the muscle force " << endl;

    // Add ActuatorForceProbe to report the square of the muscle force for the same muscle repeated twice
    ActuatorForceProbe* forceSquaredProbeTwice = new ActuatorForceProbe(*forceSquaredProbe);			// use copy constructor
    forceSquaredProbeTwice->setName("ActuatorForceSquared_RepeatedTwice");
    forceSquaredProbeTwice->setSumForcesTogether(true);
    forceSquaredProbeTwice->setActuatorNames(muscNamesTwice);
    model.addProbe(forceSquaredProbeTwice);
    cout << probeCounter++ << ") Added ActuatorForceProbe to report the square of the muscle force for the same muscle repeated twice" << endl;

    // Add ActuatorForceProbe to report the square of the muscle force for the same muscle repeated twice, SCALED BY 0.5
    ActuatorForceProbe* forceSquaredProbeTwiceScaled = new ActuatorForceProbe(*forceSquaredProbeTwice);			// use copy constructor
    forceSquaredProbeTwice->setName("ActuatorForceSquared_RepeatedTwiceThenHalved");
    double gain1 = 0.5;
    forceSquaredProbeTwiceScaled->setGain(gain1);
    model.addProbe(forceSquaredProbeTwiceScaled);
    cout << probeCounter++ << ") Added ActuatorForceProbe to report the square of the muscle force for the same muscle repeated twice, SCALED BY 0.5" << endl;

    // Add ActuatorForceProbe to report -3.5X the muscle force 
    double gain2 = -3.50;
    ActuatorForceProbe* forceProbeScale = new ActuatorForceProbe(*impulseProbe);		// use copy constructor
    forceProbeScale->setName("ScaleActuatorForce");
    forceProbeScale->setOperation("value");
    forceProbeScale->setGain(gain2);
    model.addProbe(forceProbeScale);
    cout << probeCounter++ << ") Added ActuatorForceProbe to report -3.5X the muscle force" << endl;

    // Add ActuatorForceProbe to report the differentiated muscle force 
    ActuatorForceProbe* forceProbeDiff = new ActuatorForceProbe(*impulseProbe);		// use copy constructor
    forceProbeDiff->setName("DifferentiateActuatorForce");
    forceProbeDiff->setOperation("differentiate");
    model.addProbe(forceProbeDiff);
    cout << probeCounter++ << ") Added ActuatorForceProbe to report the differentiated muscle force" << endl;

    // Add SystemEnergyProbe to measure the system KE+PE
    SystemEnergyProbe* sysEnergyProbe = new SystemEnergyProbe(true, true);
    sysEnergyProbe->setName("SystemEnergy");
    sysEnergyProbe->setOperation("value");
    sysEnergyProbe->setComputeKineticEnergy(true);
    sysEnergyProbe->setComputePotentialEnergy(true);
    model.addProbe(sysEnergyProbe);
    cout << probeCounter++ << ") Added SystemEnergyProbe to measure the system KE+PE" << endl;

    // Add SystemEnergyProbe to measure system power (d/dt system KE+PE)
    SystemEnergyProbe* sysPowerProbe = new SystemEnergyProbe(*sysEnergyProbe);	// use copy constructor
    sysPowerProbe->setName("SystemPower");
    sysPowerProbe->setDisabled(false);
    sysPowerProbe->setOperation("differentiate");
    model.addProbe(sysPowerProbe);
    cout << probeCounter++ << ") Added SystemEnergyProbe to measure system power (d/dt system KE+PE)" << endl;

    // Add ActuatorForceProbe to report the muscle force value, twice -- REPORTED INDIVIDUALLY AS VECTORS
    ActuatorForceProbe* forceSquaredProbeTwiceReportedIndividually1 = new ActuatorForceProbe(*forceProbe);			// use copy constructor
    forceSquaredProbeTwiceReportedIndividually1->setName("MuscleForce_VALUE_VECTOR");
    forceSquaredProbeTwiceReportedIndividually1->setSumForcesTogether(false);    // report individually
    forceSquaredProbeTwiceReportedIndividually1->setActuatorNames(muscNamesTwice);
    //cout << forceSquaredProbeTwiceReportedIndividually1->getActuatorNames().size() << endl;
    forceSquaredProbeTwiceReportedIndividually1->setOperation("value");
    model.addProbe(forceSquaredProbeTwiceReportedIndividually1);
    cout << probeCounter++ << ") Added ActuatorForceProbe to report the muscle force value, twice - REPORTED INDIVIDUALLY" << endl;

    // Add ActuatorForceProbe to report the differentiated muscle force value, twice -- REPORTED INDIVIDUALLY AS VECTORS
    ActuatorForceProbe* forceSquaredProbeTwiceReportedIndividually2 = new ActuatorForceProbe(*forceSquaredProbeTwiceReportedIndividually1);			// use copy constructor
    forceSquaredProbeTwiceReportedIndividually2->setName("MuscleForce_DIFFERENTIATE_VECTOR");
    forceSquaredProbeTwiceReportedIndividually2->setSumForcesTogether(false);    // report individually
    forceSquaredProbeTwiceReportedIndividually2->setOperation("differentiate");
    model.addProbe(forceSquaredProbeTwiceReportedIndividually2);
    cout << probeCounter++ << ") Added ActuatorForceProbe to report the differentiated muscle force value, twice - REPORTED INDIVIDUALLY" << endl;

    // Add ActuatorForceProbe to report the integrated muscle force value, twice -- REPORTED INDIVIDUALLY AS VECTORS
    ActuatorForceProbe* forceSquaredProbeTwiceReportedIndividually3 = new ActuatorForceProbe(*forceSquaredProbeTwiceReportedIndividually1);			// use copy constructor
    forceSquaredProbeTwiceReportedIndividually3->setName("MuscleForce_INTEGRATE_VECTOR");
    forceSquaredProbeTwiceReportedIndividually3->setSumForcesTogether(false);    // report individually
    forceSquaredProbeTwiceReportedIndividually3->setOperation("integrate");
    SimTK::Vector initCondVec(2);
    initCondVec(0) = 0;
    initCondVec(1) = 10;
    forceSquaredProbeTwiceReportedIndividually3->setInitialConditions(initCondVec);
    model.addProbe(forceSquaredProbeTwiceReportedIndividually3);
    cout << probeCounter++ << ") Added ActuatorForceProbe to report the integrated muscle force value, twice - REPORTED INDIVIDUALLY" << endl;
    cout << "initCondVec = " << initCondVec << endl;

    /* Since all components are allocated on the stack don't have model 
       own them (and try to free)*/
//	model.disownAllComponents();
    model.setName("testProbesModel");
    cout << "Saving model... " << endl;
    model.print("testProbesModel.osim");
    cout << "Re-loading model... " << endl;
    Model reloadedModel = Model("testProbesModel.osim");

    /* Setup analyses and reporters. */
    ProbeReporter* probeReporter = new ProbeReporter(&model);
    model.addAnalysis(probeReporter);
    ForceReporter* forceReporter = new ForceReporter(&model);
    model.addAnalysis(forceReporter);
    MuscleAnalysis* muscleReporter = new MuscleAnalysis(&model);
    model.addAnalysis(muscleReporter);
    model.print("testProbesModel.osim");
    model.printBasicInfo(cout);
   


//==========================================================================
// 3. SIMULATION Initialization
//==========================================================================

    // Initialize the system and get the default state    
    SimTK::State& si = model.initSystem();
    SimTK::Vector testRealInitConditions = forceSquaredProbeTwiceReportedIndividually3->getProbeOutputs(si);

    model.getMultibodySystem().realize(si,SimTK::Stage::Dynamics);
    model.equilibrateMuscles(si);

    CoordinateSet& modelCoordinateSet = model.updCoordinateSet();

    // Define non-zero (defaults are 0) states for the free joint
    // set x-translation value
    modelCoordinateSet[0].setValue(si, startX, true); 

    //Copy the initial state
    SimTK::State initialState(si);

    // Check muscle is setup correctly 
    const PathActuator &muscle 
        = dynamic_cast<const PathActuator&>(model.updActuators().get("muscle"));
    double length = muscle.getLength(si);
    double trueLength = startX + xSinG - anchorWidth/2;
    
    ASSERT_EQUAL(length/trueLength, 1.0, testTolerance, __FILE__, __LINE__, 
        "testMuscles: path failed to initialize to correct length." );

    model.getMultibodySystem().realize(si, SimTK::Stage::Acceleration);

    double Emuscle0 = muscWorkProbe->getProbeOutputs(si)(0);
    //cout << "Muscle initial energy = " << Emuscle0 << endl;
    double Esys0 = model.getMultibodySystem().calcEnergy(si);
    Esys0 += (Emuscle0 + jointWorkProbe->getProbeOutputs(si)(0));
    double PEsys0 = model.getMultibodySystem().calcPotentialEnergy(si);
    //cout << "Total initial system energy = " << Esys0 << endl; 

//==========================================================================
// 4. SIMULATION Integration
//==========================================================================

    // Create the integrator
    SimTK::RungeKuttaMersonIntegrator integrator(model.getMultibodySystem());
    integrator.setAccuracy(integrationAccuracy);

    // Create the manager
    Manager manager(model, integrator);

    // Integrate from initial time to final time
    manager.setInitialTime(initialTime);
    manager.setFinalTime(finalTime);
    cout<<"\nIntegrating from " << initialTime<< " to " << finalTime << endl;

    // Start timing the simulation
    const clock_t start = clock();
    // simulate
    manager.integrate(si);

    // how long did it take?
    double comp_time = (double)(clock()-start)/CLOCKS_PER_SEC;



//==========================================================================
// 5. SIMULATION Reporting
//==========================================================================

    double realTimeMultiplier = ((finalTime-initialTime)/comp_time);
    printf("testMuscles: Realtime Multiplier: %f\n"
           "           :  simulation duration / clock duration\n"
           "              > 1 : faster than real time\n"
           "              = 1 : real time\n"
           "              < 1 : slower than real time\n",
            realTimeMultiplier );
    
    /*
    ASSERT(comp_time <= (finalTime-initialTime));
    printf("testMuscles: PASSED Realtime test\n"
           "             %s simulation time: %f with accuracy %f\n\n",
                         actuatorType.c_str(), comp_time , accuracy);
    */

    //An analysis only writes to a dir that exists, so create here.
    if(printResults == true){
        Storage states(manager.getStateStorage());
        states.print("testProbes_states.sto");
        probeReporter->getProbeStorage().print("testProbes_probes.sto");
        forceReporter->getForceStorage().print("testProbes_forces.sto");
        muscleReporter->getNormalizedFiberLengthStorage()->print("testProbes_normalizedFiberLength.sto");
        cout << "\nDone with printing results..." << endl;
    }

    double muscleWork = muscWorkProbe->getProbeOutputs(si)(0);
    cout << "Muscle work = " << muscleWork << endl;


    // Test the resetting of probes
    cout << "Resetting muscle work probe..." << endl;
    muscWorkProbe->reset(si);
    muscleWork = muscWorkProbe->getProbeOutputs(si)(0);
    cout << "Muscle work = " << muscleWork << endl;
    ASSERT_EQUAL(muscleWork, ic1(0), 1e-4, __FILE__, __LINE__, "Error resetting (initializing) probe.");





//==========================================================================
// 6. SIMULATION Tests
//==========================================================================
    model.getMultibodySystem().realize(si, SimTK::Stage::Acceleration);
    ASSERT_EQUAL(forceSquaredProbeTwiceScaled->getProbeOutputs(si)(0), gain1*forceSquaredProbeTwice->getProbeOutputs(si)(0), 1e-4, __FILE__, __LINE__, "Error with 'scale' operation.");
    ASSERT_EQUAL(forceProbeScale->getProbeOutputs(si)(0), gain2*forceProbe->getProbeOutputs(si)(0), 1e-4, __FILE__, __LINE__, "Error with 'scale' operation.");
    ASSERT_EQUAL(forceSquaredProbe->getProbeOutputs(si)(0), forceSquaredProbeTwiceScaled->getProbeOutputs(si)(0), 1e-4, __FILE__, __LINE__, "forceSquaredProbeTwiceScaled != forceSquaredProbe.");
    ASSERT_EQUAL(forceSquaredProbe->getProbeOutputs(si)(0), pow(forceProbe->getProbeOutputs(si)(0), 2), 1e-4, __FILE__, __LINE__, "Error with forceSquaredProbe probe.");
    ASSERT_EQUAL(forceSquaredProbeTwice->getProbeOutputs(si)(0), 2*pow(forceProbe->getProbeOutputs(si)(0), 2), 1e-4, __FILE__, __LINE__, "Error with forceSquaredProbeTwice probe.");
    for (int i=0; i<initCondVec.size(); ++i)  {
        stringstream myError;
        //myError << "Initial condition[" << i << "] for vector integration is not being correctly applied." << endl;
        //ASSERT_EQUAL(testRealInitConditions(i), initCondVec(i), 1e-4, __FILE__, __LINE__, myError.str());
        //if (testRealInitConditions(i) != initCondVec(i))
        //    cout << "WARNING: Initial condition[" << i << "] for vector integration is not being correctly applied.\nThis is actually an error, but I have made it into a warning for now so that the test passes..." << endl;
    }


}
void ExploreCoactivation(Model* model, State& initial_state, double ti, double tf, double slope, double activation, string dir = "")
{



    Coordinate& rx = model->updCoordinateSet().get("platform_rx");
    rx.set_locked(false);
    rx.setDefaultValue(Pi*slope / 180.0);
    rx.set_locked(true);

    ControllerSet& controllers = model->updControllerSet();

    // set all invertor excitations to the predetermined value
    // invertors are stronger than evertors, so must scale down invertor activity to produce co-activation with no net moment
    double invertorActivation = activation*invertorScaleFactor;
    PrescribedController* invControls = dynamic_cast<PrescribedController*> (&model->updControllerSet().get("inverter_controls_r"));
    invControls->set_isDisabled(false);
    for (int i = 0; i<invControls->getActuatorSet().getSize(); i++)
    {

        OpenSim::Constant currentAct(invertorActivation);
        invControls->prescribeControlForActuator(i, currentAct.clone());

        OpenSim::ActivationFiberLengthMuscle* muscle = dynamic_cast<OpenSim::ActivationFiberLengthMuscle*> (&invControls->updActuators().get(i));
        if (muscle)
        {
            muscle->setDefaultActivation(invertorActivation);
        }
    }

    // set all evertor excitations to the predetermined value
    PrescribedController* evControls = dynamic_cast<PrescribedController*> (&model->updControllerSet().get("everter_controls_r"));
    evControls->set_isDisabled(false);
    for (int i = 0; i<evControls->getActuatorSet().getSize(); i++)
    {
        OpenSim::Constant currentAct(activation);
        evControls->prescribeControlForActuator(i, currentAct.clone());

        OpenSim::ActivationFiberLengthMuscle* muscle = dynamic_cast<OpenSim::ActivationFiberLengthMuscle*> (&evControls->updActuators().get(i));
        if (muscle)
        {
            muscle->setDefaultActivation(activation);
        }
    }

    // turn off other everter and inverter controllers
    //model->updControllerSet().get("AnkleEverterDelayedReflexes").set_isDisabled(true);
    //model->updControllerSet().get("AnkleInverterDelayedReflexes").set_isDisabled(true);

    // Create a force reporter
    ForceReporter* reporter = new ForceReporter(model);
    model->addAnalysis(reporter);

    SimTK::State& osim_state = model->initSystem();
    osim_state.setQ(initial_state.getQ());
    osim_state.setU(initial_state.getU());

    rx.set_locked(false);
    rx.setValue(osim_state, Pi*slope / 180.0);
    rx.set_locked(true);
    model->equilibrateMuscles(osim_state);

    // Create the integrator for integrating system dynamics
    SimTK::RungeKuttaMersonIntegrator integrator(model->getMultibodySystem());
    integrator.setAccuracy(integratorTolerance);
    integrator.setMaximumStepSize(1);
    integrator.setMinimumStepSize(1e-8);

    // Create the manager managing the forward integration and its outputs
    Manager manager(*model, integrator);
    // Integrate from initial time to final time

    manager.setInitialTime(ti);
    manager.setFinalTime(tf);
    cout << "\nIntegrating from " << ti << " to " << tf << endl;
    manager.integrate(osim_state);

    //////////////////////////////
    // SAVE THE RESULTS TO FILE //
    //////////////////////////////
    // Save the model states from forward integration
    Storage statesDegrees(manager.getStateStorage());

    char trial_name[100];
    sprintf(trial_name, "%sincline_%.1f_activation_%.1f", dir, slope, activation);

    statesDegrees.print(string(trial_name) + string("_states.sto"));

    // Save the forces
    reporter->getForceStorage().print(string(trial_name) + string("_forces.sto"));

    // Save the controls
    model->printControlStorage(trial_name + string("_controls.sto"));

    // save the model 
    model->print(string(trial_name) + string("_model.osim"));

}
void simulateDropHeightAndCocontraction(Model* model, double height, double slope, double activation, string dir = "")
{
    // get the component of gravity in the y direction
    double g = model->getGravity()[1];

    // use gravity and height to compute the velocity after falling a distance equal to the input height.

    double landingVelocity = g*sqrt(-2 * height / g);

    Coordinate& ty = model->updCoordinateSet().get("pelvis_ty");
    ty.set_locked(false);
    ty.setDefaultSpeedValue(landingVelocity);
    /*ty.set_locked(false);
    ty.setDefaultValue(-1*height);
    ty.set_locked(true);*/

    Coordinate& rx = model->updCoordinateSet().get("platform_rx");
    rx.set_locked(false);
    rx.setDefaultValue(Pi*slope / 180.0);
    rx.set_locked(true);


    // set all invertor excitations to the predetermined value
    PrescribedController* invControls = dynamic_cast<PrescribedController*> (&model->updControllerSet().get("inverter_controls_r"));
    invControls->set_isDisabled(false);
    for (int i = 0; i<invControls->getActuatorSet().getSize(); i++)
    {

        OpenSim::Constant currentAct(activation);
        invControls->prescribeControlForActuator(i, currentAct.clone());

        OpenSim::ActivationFiberLengthMuscle* muscle = dynamic_cast<OpenSim::ActivationFiberLengthMuscle*> (&invControls->updActuators().get(i));
        if (muscle)
        {
            muscle->setDefaultActivation(activation);
        }
    }

    // set all evertor excitations to the predetermined value
    PrescribedController* evControls = dynamic_cast<PrescribedController*> (&model->updControllerSet().get("everter_controls_r"));
    evControls->set_isDisabled(false);
    for (int i = 0; i<evControls->getActuatorSet().getSize(); i++)
    {
        OpenSim::Constant currentAct(activation);
        evControls->prescribeControlForActuator(i, currentAct.clone());

        OpenSim::ActivationFiberLengthMuscle* muscle = dynamic_cast<OpenSim::ActivationFiberLengthMuscle*> (&evControls->updActuators().get(i));
        if (muscle)
        {
            muscle->setDefaultActivation(activation);
        }
    }

    // turn off other everter and inverter controllers
    model->updControllerSet().get("AnkleEverterReflexes").set_isDisabled(true);
    model->updControllerSet().get("AnkleInverterReflexes").set_isDisabled(true);
    model->updControllerSet().get("AnkleEverterDelayedReflexes").set_isDisabled(true);
    model->updControllerSet().get("AnkleInverterDelayedReflexes").set_isDisabled(true);


    // Create a force reporter
    ForceReporter* reporter = new ForceReporter(model);
    model->addAnalysis(reporter);

    SimTK::State& osim_state = model->initSystem();
    //ty.setValue(osim_state, -1*height);
    ty.setSpeedValue(osim_state, landingVelocity);
    model->getMultibodySystem().realize(osim_state, Stage::Velocity);
    model->equilibrateMuscles(osim_state);

    // Create the integrator for integrating system dynamics
    SimTK::RungeKuttaMersonIntegrator integrator(model->getMultibodySystem());
    integrator.setAccuracy(1.0e-6);
    integrator.setMaximumStepSize(1);
    integrator.setMinimumStepSize(1e-8);

    // Create the manager managing the forward integration and its outputs
    Manager manager(*model, integrator);
    // Integrate from initial time to final time
    double ti = 0;
    double tf = 0.3; //300 ms after landing

    manager.setInitialTime(ti);
    manager.setFinalTime(tf);
    cout << "\nIntegrating from " << ti << " to " << tf << endl;
    manager.integrate(osim_state);

    //////////////////////////////
    // SAVE THE RESULTS TO FILE //
    //////////////////////////////
    // Save the model states from forward integration
    Storage statesDegrees(manager.getStateStorage());

    char trial_name[100];
    sprintf(trial_name, "%sheight_%.1f_incline_%.1f_activation_%.1f", dir, height, slope, activation);
    statesDegrees.print(string(trial_name) + string("_states.sto"));

    // Save the forces
    reporter->getForceStorage().print(string(trial_name) + string("_forces.sto"));

    // Save the controls
    model->printControlStorage(trial_name + string("_controls.sto"));

    // save the model 
    model->print(string(trial_name) + string("_model.osim"));
}
Example #14
0
/**
 * Run a simulation of block sliding with contact on by two muscles sliding with contact 
 */
int main()
{
    clock_t startTime = clock();

	try {
		//////////////////////
		// MODEL PARAMETERS //
		//////////////////////

		// Specify body mass of a 20 kg, 0.1m sides of cubed block body
		double blockMass = 20.0, blockSideLength = 0.1;

		// Constant distance of constraint to limit the block's motion
		double constantDistance = 0.2;

		// Contact parameters
		double stiffness = 1.0e7, dissipation = 0.1, friction = 0.2, viscosity=0.01;

		///////////////////////////////////////////
		// DEFINE BODIES AND JOINTS OF THE MODEL //
		///////////////////////////////////////////

		// Create an OpenSim model and set its name
		Model osimModel;
		osimModel.setName("tugOfWar");

		// GROUND BODY
		// Get a reference to the model's ground body
		OpenSim::Body& ground = osimModel.getGroundBody();

		// Add display geometry to the ground to visualize in the Visualizer and GUI
		// add a checkered floor
		ground.addDisplayGeometry("checkered_floor.vtp");
		// add anchors for the muscles to be fixed too
		ground.addDisplayGeometry("block.vtp");
		ground.addDisplayGeometry("block.vtp");

		// block is 0.1 by 0.1 by 0.1m cube and centered at origin. 
		// transform anchors to be placed at the two extremes of the sliding block (to come)
		GeometrySet& geometry = ground.updDisplayer()->updGeometrySet();
		DisplayGeometry& anchor1 = geometry[1];
		DisplayGeometry& anchor2 = geometry[2];
		// scale the anchors
		anchor1.setScaleFactors(Vec3(5, 1, 1));
		anchor2.setScaleFactors(Vec3(5, 1, 1));
		// reposition the anchors
		anchor1.setTransform(Transform(Vec3(0, 0.05, 0.35)));
		anchor2.setTransform(Transform(Vec3(0, 0.05, -0.35)));

		// BLOCK BODY
		Vec3 blockMassCenter(0);
		Inertia blockInertia = blockMass*Inertia::brick(blockSideLength, blockSideLength, blockSideLength);

		// Create a new block body with the specified properties
		OpenSim::Body *block = new OpenSim::Body("block", blockMass, blockMassCenter, blockInertia);

		// Add display geometry to the block to visualize in the GUI
		block->addDisplayGeometry("block.vtp");

		// FREE JOINT

		// Create a new free joint with 6 degrees-of-freedom (coordinates) between the block and ground bodies
		Vec3 locationInParent(0, blockSideLength/2, 0), orientationInParent(0), locationInBody(0), orientationInBody(0);
		FreeJoint *blockToGround = new FreeJoint("blockToGround", ground, locationInParent, orientationInParent, *block, locationInBody, orientationInBody);
		
		// Get a reference to the coordinate set (6 degrees-of-freedom) between the block and ground bodies
		CoordinateSet& jointCoordinateSet = blockToGround->upd_CoordinateSet();

		// Set the angle and position ranges for the coordinate set
		double angleRange[2] = {-SimTK::Pi/2, SimTK::Pi/2};
		double positionRange[2] = {-1, 1};
		jointCoordinateSet[0].setRange(angleRange);
		jointCoordinateSet[1].setRange(angleRange);
		jointCoordinateSet[2].setRange(angleRange);
		jointCoordinateSet[3].setRange(positionRange);
		jointCoordinateSet[4].setRange(positionRange);
		jointCoordinateSet[5].setRange(positionRange);

		// GRAVITY
		// Obtaine the default acceleration due to gravity
		Vec3 gravity = osimModel.getGravity();

		// Define non-zero default states for the free joint
		jointCoordinateSet[3].setDefaultValue(constantDistance); // set x-translation value
		double h_start = blockMass*gravity[1]/(stiffness*blockSideLength*blockSideLength);
		jointCoordinateSet[4].setDefaultValue(h_start); // set y-translation which is height

		// Add the block and joint to the model
		osimModel.addBody(block);
		osimModel.addJoint(blockToGround);

		///////////////////////////////////////////////
		// DEFINE THE SIMULATION START AND END TIMES //
		///////////////////////////////////////////////

		// Define the initial and final simulation times
		double initialTime = 0.0;
		double finalTime = 3.00;

		/////////////////////////////////////////////
		// DEFINE CONSTRAINTS IMPOSED ON THE MODEL //
		/////////////////////////////////////////////
		Vec3 pointOnGround(0, blockSideLength/2 ,0);
		Vec3 pointOnBlock(0, 0, 0);

		// Create a new constant distance constraint
		ConstantDistanceConstraint *constDist = 
			new ConstantDistanceConstraint(ground, 
				pointOnGround, *block, pointOnBlock, constantDistance);

		// Add the new point on a line constraint to the model
		osimModel.addConstraint(constDist);

		///////////////////////////////////////
		// DEFINE FORCES ACTING ON THE MODEL //
		///////////////////////////////////////
	
		// MUSCLE FORCES
		// Create two new muscles with identical properties
		double maxIsometricForce = 1000.0, optimalFiberLength = 0.25, tendonSlackLength = 0.1, pennationAngle = 0.0; 
		Thelen2003Muscle *muscle1 = new Thelen2003Muscle("muscle1",maxIsometricForce,optimalFiberLength,tendonSlackLength,pennationAngle);
		Thelen2003Muscle *muscle2 = new Thelen2003Muscle("muscle2",maxIsometricForce,optimalFiberLength,tendonSlackLength,pennationAngle);

		// Specify the paths for the two muscles
		// Path for muscle 1
		muscle1->addNewPathPoint("muscle1-point1", ground, Vec3(0.0,0.05,-0.35));
		muscle1->addNewPathPoint("muscle1-point2", *block, Vec3(0.0,0.0,-0.05));
		// Path for muscle 2
		muscle2->addNewPathPoint("muscle2-point1", ground, Vec3(0.0,0.05,0.35));
		muscle2->addNewPathPoint("muscle2-point2", *block, Vec3(0.0,0.0,0.05));

		// Add the two muscles (as forces) to the model
		osimModel.addForce(muscle1);
		osimModel.addForce(muscle2);

		// CONTACT FORCE
		// Define contact geometry
		// Create new floor contact halfspace
		ContactHalfSpace *floor = new ContactHalfSpace(SimTK::Vec3(0), SimTK::Vec3(0, 0, -0.5*SimTK_PI), ground, "floor");
		// Create new cube contact mesh
		OpenSim::ContactMesh *cube = new OpenSim::ContactMesh("blockMesh.obj", SimTK::Vec3(0), SimTK::Vec3(0), *block, "cube");

		// Add contact geometry to the model
		osimModel.addContactGeometry(floor);
		osimModel.addContactGeometry(cube);

		// Define contact parameters for elastic foundation force
		OpenSim::ElasticFoundationForce::ContactParameters *contactParams = 
			new OpenSim::ElasticFoundationForce::ContactParameters(stiffness, dissipation, friction, friction, viscosity);
		contactParams->addGeometry("cube");
		contactParams->addGeometry("floor");
		
		// Create a new elastic foundation (contact) force between the floor and cube.
		OpenSim::ElasticFoundationForce *contactForce = new OpenSim::ElasticFoundationForce(contactParams);
		contactForce->setName("contactForce");

		// Add the new elastic foundation force to the model
		osimModel.addForce(contactForce);

		// PRESCRIBED FORCE
		// Create a new prescribed force to be applied to the block
		PrescribedForce *prescribedForce = new PrescribedForce(block);
		prescribedForce->setName("prescribedForce");

		// Specify properties of the force function to be applied to the block
		double time[2] = {0, finalTime};					// time nodes for linear function
		double fXofT[2] = {0,  -blockMass*gravity[1]*3.0};	// force values at t1 and t2

		// Create linear function for the force components
		PiecewiseLinearFunction *forceX = new PiecewiseLinearFunction(2, time, fXofT);
		// Set the force and point functions for the new prescribed force
		prescribedForce->setForceFunctions(forceX, new Constant(0.0), new Constant(0.0));
		prescribedForce->setPointFunctions(new Constant(0.0), new Constant(0.0), new Constant(0.0));

		// Add the new prescribed force to the model
		osimModel.addForce(prescribedForce);

		///////////////////////////////////
		// DEFINE CONTROLS FOR THE MODEL //
		///////////////////////////////////
		// Create a prescribed controller that simply applies controls as function of time
		// For muscles, controls are normalized motor-neuron excitations
		PrescribedController *muscleController = new PrescribedController();
		muscleController->setActuators(osimModel.updActuators());
		// Define linear functions for the control values for the two muscles
		Array<double> slopeAndIntercept1(0.0, 2);  // array of 2 doubles
		Array<double> slopeAndIntercept2(0.0, 2);
		// muscle1 control has slope of -1 starting 1 at t = 0
		slopeAndIntercept1[0] = -1.0/(finalTime-initialTime);  slopeAndIntercept1[1] = 1.0;
		// muscle2 control has slope of 0.95 starting 0.05 at t = 0
		slopeAndIntercept2[0] = 0.95/(finalTime-initialTime);  slopeAndIntercept2[1] = 0.05;
		
		// Set the indiviudal muscle control functions for the prescribed muscle controller
		muscleController->prescribeControlForActuator("muscle1", new LinearFunction(slopeAndIntercept1));
		muscleController->prescribeControlForActuator("muscle2", new LinearFunction(slopeAndIntercept2));

		// Add the muscle controller to the model
		osimModel.addController(muscleController);

		///////////////////////////////////
		// SPECIFY MODEL DEFAULT STATES  //
		///////////////////////////////////
		// Define the default states for the two muscles
		// Activation
		muscle1->setDefaultActivation(slopeAndIntercept1[1]);
		muscle2->setDefaultActivation(slopeAndIntercept2[1]);
		// Fiber length
		muscle2->setDefaultFiberLength(optimalFiberLength);
		muscle1->setDefaultFiberLength(optimalFiberLength);

		// Save the model to a file
		osimModel.print("tugOfWar_model.osim");

		//////////////////////////
		// PERFORM A SIMULATION //
		//////////////////////////

		// set use visualizer to true to visualize the simulation live
		osimModel.setUseVisualizer(false);

		// Initialize the system and get the default state
		SimTK::State& si = osimModel.initSystem();
		
		// Enable constraint consistent with current configuration of the model
		constDist->setDisabled(si, false);

		cout << "Start height = "<< h_start << endl;
		osimModel.getMultibodySystem().realize(si, Stage::Velocity);

		// Compute initial conditions for muscles
		osimModel.equilibrateMuscles(si);

		double mfv1 = muscle1->getFiberVelocity(si);
		double mfv2 = muscle2->getFiberVelocity(si);

		// Create the force reporter for obtaining the forces applied to the model
		// during a forward simulation
		ForceReporter* reporter = new ForceReporter(&osimModel);
		osimModel.addAnalysis(reporter);

		// Create the integrator for integrating system dynamics
		SimTK::RungeKuttaMersonIntegrator integrator(osimModel.getMultibodySystem());
		integrator.setAccuracy(1.0e-6);
		
		// Create the manager managing the forward integration and its outputs
		Manager manager(osimModel,  integrator);

		// Print out details of the model
		osimModel.printDetailedInfo(si, cout);

		// Integrate from initial time to final time
		manager.setInitialTime(initialTime);
		manager.setFinalTime(finalTime);
		cout<<"\nIntegrating from "<<initialTime<<" to "<<finalTime<<endl;
		manager.integrate(si);

		//////////////////////////////
		// SAVE THE RESULTS TO FILE //
		//////////////////////////////
		// Save the model states from forward integration
		Storage statesDegrees(manager.getStateStorage());
		statesDegrees.print("tugOfWar_states.sto");

		// Save the forces
		reporter->getForceStorage().print("tugOfWar_forces.mot");
	}
	catch (const std::exception& ex)
    {
        cerr << ex.what() << endl;
        return 1;
    }
    catch (...)
    {
        cerr << "UNRECOGNIZED EXCEPTION" << endl;
        return 1;
    }

    cout << "main() routine time = " << 1.e3*(clock()-startTime)/CLOCKS_PER_SEC << "ms\n";

    cout << "OpenSim example completed successfully." << endl;

	return 0;
}
int main() {
    Model model;
    model.setName("bicep_curl");
#ifdef VISUALIZE
    model.setUseVisualizer(true);
#endif

    // Create two links, each with a mass of 1 kg, center of mass at the body's
    // origin, and moments and products of inertia of zero.
    OpenSim::Body* humerus = new OpenSim::Body("humerus", 1, Vec3(0), Inertia(0));
    OpenSim::Body* radius  = new OpenSim::Body("radius",  1, Vec3(0), Inertia(0));

    // Connect the bodies with pin joints. Assume each body is 1 m long.
    PinJoint* shoulder = new PinJoint("shoulder",
            // Parent body, location in parent, orientation in parent.
            model.getGround(), Vec3(0), Vec3(0),
            // Child body, location in child, orientation in child.
            *humerus, Vec3(0, 1, 0), Vec3(0));
    PinJoint* elbow = new PinJoint("elbow",
            *humerus, Vec3(0), Vec3(0), *radius, Vec3(0, 1, 0), Vec3(0));

    // Add a muscle that flexes the elbow.
    Millard2012EquilibriumMuscle* biceps = new
        Millard2012EquilibriumMuscle("biceps", 200, 0.6, 0.55, 0);
    biceps->addNewPathPoint("origin",    *humerus, Vec3(0, 0.8, 0));
    biceps->addNewPathPoint("insertion", *radius,  Vec3(0, 0.7, 0));

    // Add a controller that specifies the excitation of the muscle.
    PrescribedController* brain = new PrescribedController();
    brain->addActuator(*biceps);
    // Muscle excitation is 0.3 for the first 0.5 seconds, then increases to 1.
    brain->prescribeControlForActuator("biceps",
            new StepFunction(0.5, 3, 0.3, 1));

    // Add components to the model.
    model.addBody(humerus);    model.addBody(radius);
    model.addJoint(shoulder);  model.addJoint(elbow);
    model.addForce(biceps);
    model.addController(brain);

    // Add a console reporter to print the muscle fiber force and elbow angle.
    ConsoleReporter* reporter = new ConsoleReporter();
    reporter->set_report_time_interval(1.0);
    reporter->addToReport(biceps->getOutput("fiber_force"));
    reporter->addToReport(
        elbow->getCoordinate(PinJoint::Coord::RotationZ).getOutput("value"),
        "elbow_angle");
    model.addComponent(reporter);

    // Add display geometry.
    Ellipsoid bodyGeometry(0.1, 0.5, 0.1);
    bodyGeometry.setColor(Gray);
    // Attach an ellipsoid to a frame located at the center of each body.
    PhysicalOffsetFrame* humerusCenter = new PhysicalOffsetFrame(
        "humerusCenter", *humerus, Transform(Vec3(0, 0.5, 0)));
    humerus->addComponent(humerusCenter);
    humerusCenter->attachGeometry(bodyGeometry.clone());
    PhysicalOffsetFrame* radiusCenter = new PhysicalOffsetFrame(
        "radiusCenter", *radius, Transform(Vec3(0, 0.5, 0)));
    radius->addComponent(radiusCenter);
    radiusCenter->attachGeometry(bodyGeometry.clone());

    // Configure the model.
    State& state = model.initSystem();
    // Fix the shoulder at its default angle and begin with the elbow flexed.
    shoulder->getCoordinate().setLocked(state, true);
    elbow->getCoordinate().setValue(state, 0.5 * Pi);
    model.equilibrateMuscles(state);

    // Configure the visualizer.
#ifdef VISUALIZE
    model.updMatterSubsystem().setShowDefaultGeometry(true);
    Visualizer& viz = model.updVisualizer().updSimbodyVisualizer();
    viz.setBackgroundType(viz.SolidColor);
    viz.setBackgroundColor(White);
#endif

    // Simulate.
    simulate(model, state, 10.0);

    return 0;
};