/**
 * 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;
}
Esempio n. 2
0
/**
* This test verifies the use of BodyActuator for applying spatial forces to a selected
* body. It checks if using a BodyActuator generates equivalent acceleration compared 
* to when applying the forces via mobilityForce.
*
* @author Soha Pouya
*/
void testBodyActuator()
{
	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 body 1: Ground
	OpenSim::Body& ground = model->getGroundBody();

	// OpenSim body 2: A Block
	// Geometrical/Inertial properties for the block
	double blockMass = 1.0, blockSideLength = 1;
	Vec3 blockMassCenter(0);
	Inertia blockInertia = blockMass*Inertia::brick(blockSideLength/2,
		blockSideLength/2, blockSideLength/2); // for the halves see doxygen for brick 

	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");

	Vec3 locationInParent(0, blockSideLength / 2, 0), orientationInParent(0), 
		locationInBody(0), orientationInBody(0);
	FreeJoint *blockToGroundFree = new FreeJoint("blockToGroundBall", 
		ground, locationInParent, orientationInParent, 
		*block, locationInBody, orientationInBody);
	
	model->addBody(block);
	model->addJoint(blockToGroundFree);
	
	// specify magnitude and direction of applied force and torque
	double forceMag = 1.0;
	Vec3 forceAxis(1, 1, 1);
	Vec3 forceInG = forceMag * forceAxis;

	double torqueMag = 1.0;
	Vec3 torqueAxis(1, 1, 1);
	Vec3 torqueInG = torqueMag*torqueAxis;

	// ---------------------------------------------------------------------------
	// Use MobilityForces to Apply the given Torques and Forces to the body
	// ---------------------------------------------------------------------------
	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 6D spatial force:");

	model->getMatterSubsystem().addInBodyTorque(state, block->getIndex(),
		torqueInG, bodyForces);
	model->getMatterSubsystem().addInStationForce(state, block->getIndex(),
		Vec3(0), forceInG, bodyForces);

	bodyForces.dump("Body Forces after applying 6D spatial force to the block");

	model->getMultibodySystem().realize(state, Stage::Acceleration);
	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[i] = torqueInG[i];
		mobilityForces[i+3] = forceInG[i];
	}
	mobilityForces.dump("Mobility Forces after applying 6D spatial force to the block");


	model->getMultibodySystem().realize(state, Stage::Acceleration);
	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], SimTK::Eps);
	}

	// clear the mobility forces
	mobilityForces = 0;

	// ---------------------------------------------------------------------------
	// Use a BodyActuator to Apply the same given Torques and Forces to the body
	// ---------------------------------------------------------------------------

	// Create and add the body actuator to the model
	BodyActuator* actuator = new BodyActuator(*block);
	actuator->setName("BodyAct");
	model->addForce(actuator);

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

	// get a new system and state to reflect additions to the model
	State& state1 = model->initSystem();

	// -------------- Provide control signals for bodyActuator ----------
	// Get the default control vector of the model
	Vector modelControls = model->getDefaultControls();
	
	// Spedicfy a vector of control signals to include desired torques and forces
	Vector fixedControls(6);
	for (int i = 0; i < 3; i++){
		fixedControls(i) = torqueInG(i);
		fixedControls(i + 3) = forceInG(i);
	}
	fixedControls.dump("Spatial forces applied by body Actuator:");

	// Add control values and set their values
	actuator->addInControls(fixedControls, modelControls);
	model->setDefaultControls(modelControls);

	// ------------------- Compute Acc and Compare -------------
	// Compute the acc due to spatial forces applied by body actuator
	model->computeStateVariableDerivatives(state1);

	Vector udotBodyActuator = state1.getUDot();
	udotBodyActuator.dump("Accelerations due to body actuator");

	// First make sure that accelerations are not zero accidentally
	ASSERT(udotMobility.norm() != 0.0 || udotBodyActuator.norm() != 0.0);
	// Then verify that the BodyActuator also generates the same acceleration
	// as the equivalent applied mobility force
	for (int i = 0; i<udotBodyActuator.size(); ++i){
		ASSERT_EQUAL(udotMobility[i], udotBodyActuator[i], SimTK::Eps);
	}

	// -------------- Setup integrator and manager -------------------
	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(state1);

	// ----------------- Test Copying the model -------------------
	// Before exiting lets see if copying the actuator works
	BodyActuator* copyOfActuator = actuator->clone();
	ASSERT(*copyOfActuator == *actuator);

	// Check that de/serialization works
	Model modelFromFile("TestBodyActuatorModel.osim");
	ASSERT(modelFromFile == *model, __FILE__, __LINE__,
		"Model from file FAILED to match model in memory.");

	std::cout << " ********** Test BodyActuator time = ********** " <<
		1.e3*(std::clock() - startTime) / CLOCKS_PER_SEC << "ms\n" << endl;
}
Esempio n. 3
0
/**
* This test verifies if using a BodyActuator generates equivalent result in the body
* acceleration compared to when using a combination of PointActuaor, TorqueActuaor 
* and BodyActuator. 
* It therefore also verifies model consistency when user defines and uses a 
* combination of these 3 actuators. 
* 
* @author Soha Pouya
*/
void testActuatorsCombination()
{
	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: 1) The ground
	OpenSim::Body& ground = model->getGroundBody();
	//ground.addDisplayGeometry("block.vtp");

	// OpenSim bodies: 2) A Block
	// Geometrical/Inertial properties for the block
	double blockMass = 1.0, blockSideLength = 1.0;
	Vec3 blockMassCenter(0);
	// Brick Inertia: for the halves see doxygen  
	Inertia blockInertia = blockMass*Inertia::brick(blockSideLength/2, 
									blockSideLength/2, blockSideLength/2);
	std::cout << "blockInertia: " << blockInertia << std::endl;

	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");

	// Make a FreeJoint from block to ground
	Vec3 locationInParent(0, blockSideLength/2, 0), orientationInParent(0), //locationInParent(0, blockSideLength, 0)
		 locationInBody(0), orientationInBody(0);
	FreeJoint *blockToGroundFree = new FreeJoint("blockToGroundFreeJoint", 
				ground, locationInParent, orientationInParent, 
				*block, locationInBody, orientationInBody);

	// Add the body and joint to the model
	model->addBody(block);
	model->addJoint(blockToGroundFree);

	// specify magnitude and direction of desired force and torque vectors to apply
	double forceMag = 1.0;
	Vec3 forceAxis(1, 1, 1);
	SimTK::UnitVec3 forceUnitAxis(forceAxis); // to normalize
	Vec3 forceInG = forceMag * forceUnitAxis;

	double torqueMag = 1.0;
	Vec3 torqueAxis(1, 2, 1);
	SimTK::UnitVec3 torqueUnitAxis(torqueAxis); // to normalize
	Vec3 torqueInG = torqueMag*torqueUnitAxis;

	// needed to be called here once to build controller for body actuator
	State& state = model->initSystem();
	
	// ---------------------------------------------------------------------------
	// Add a set of PointActuator, TorqueActuator and BodyActuator to the model
	// ---------------------------------------------------------------------------
	// Create and add a body actuator to the model
	BodyActuator* bodyActuator1 = new BodyActuator(*block);
	bodyActuator1->setName("BodyAct1");
	bodyActuator1->set_point(Vec3(0, blockSideLength/2, 0));
	model->addForce(bodyActuator1);
	
	// Create and add a torque actuator to the model
	TorqueActuator* torqueActuator =
		new TorqueActuator(*block, ground, torqueUnitAxis, true);
	torqueActuator->setName("torqueAct");
	model->addForce(torqueActuator);

	// Create and add a point actuator to the model
	PointActuator* pointActuator =
		new PointActuator("block");
	pointActuator->setName("pointAct");
	pointActuator->set_direction(forceUnitAxis);
	pointActuator->set_point(Vec3(0, blockSideLength/2,0));
	model->addForce(pointActuator);

	// ------ build the model -----
	model->print("TestActuatorCombinationModel.osim");
	model->setUseVisualizer(false);

	// get a new system and state to reflect additions to the model
	State& state1 = model->initSystem();

	// ------------------- Provide control signals for bodyActuator ----------------
	// Get the default control vector of the model
	Vector modelControls = model->getDefaultControls();

	// Spedicfy a vector of control signals for desired torques and forces
	Vector bodyActuator1Controls(6,0.0); 
	for (int i=0; i<3; i++) bodyActuator1Controls(i) = torqueInG(i); // torque in 3 axes
	for (int i=0; i<3; i++) bodyActuator1Controls(i+3) = forceInG(i); // force along 3 axes
	
	
	bodyActuator1Controls.dump("Spatial forces applied by first Body Actuator:");

	// Add control values and set their values
	bodyActuator1->addInControls(bodyActuator1Controls, modelControls);
	model->setDefaultControls(modelControls);

	// ---------------- Provide control signals for torqueActuator -----------------
	Vector torqueActuatorControls(1); // input to addInControl should be a Vector
	torqueActuatorControls(0) = torqueMag; // axis already defined when initializing 

	Vector torqueActuatorVector(3); // to print out the 3D vector of applied torque
	for (int i = 0; i < 3; i++){
		torqueActuatorVector(i) = torqueInG(i);
	}
	torqueActuatorVector.dump("Torques applied by the Torque Actuator:");

	// Add control values and set their values
	torqueActuator->addInControls(torqueActuatorControls, modelControls);
	model->setDefaultControls(modelControls);

	// ------------------ Provide control signals for pointActuator ----------------
	Vector pointActuatorControls(1); // input to addInControl should be a Vector
	pointActuatorControls(0) = forceMag; // axis already defined when initializing

	Vector pointActuatorVector(3); // to print out the whole force vector
	for (int i = 0; i < 3; i++){
		pointActuatorVector(i) = forceInG(i);
	}
	pointActuatorVector.dump("Forces applied by the point Actuator:");

	// Add control values and set their values
	pointActuator->addInControls(pointActuatorControls, modelControls);
	model->setDefaultControls(modelControls);

	
	// ----------------------- Compute the acc to Compare later --------------------
	// compare the acc due to forces/torques applied by all actuator
	model->computeStateVariableDerivatives(state1);

	Vector udotActuatorsCombination = state1.getUDot();
	udotActuatorsCombination.dump("Accelerations due to all 3 actuators");


	// -----------------------------------------------------------------------------
	// Add a BodyActuator to enclose all of the above spatial forces in one Actuator 
	// -----------------------------------------------------------------------------
	// Create and add a body actuator to the model
	BodyActuator* bodyActuator_sum = new BodyActuator(*block);
	bodyActuator_sum->setName("BodyAct_Sum");
	model->addForce(bodyActuator_sum);
	bodyActuator_sum->set_point(Vec3(0, blockSideLength / 2, 0));


	State& state2 = model->initSystem();
	model->setUseVisualizer(true);

	// Get the default control vector of the model
	Vector modelControls_2 = model->getDefaultControls();

	// Spedicfy a vector of control signals for desired torques and forces
	Vector bodyActuatorSum_Controls(6,0.0);

	// make the torque component as the sum of body, torque and point actuators used 
	// in previous tets case
	for (int i = 0; i < 3; i++){
		bodyActuatorSum_Controls(i)   = 2*torqueInG(i);
		bodyActuatorSum_Controls(i+3) = 2*forceInG(i);
	}	

	bodyActuatorSum_Controls.dump("Spatial forces applied by 2nd Body Actuator:");
	std::cout <<"(encloses sum of the above spatial forces in one BodyActuator)"<< std::endl;

	// Add control values and set their values
	bodyActuator_sum->addInControls(bodyActuatorSum_Controls, modelControls_2);
	model->setDefaultControls(modelControls_2);

	// --------------------------- Comptue Acc and Compare -------------------------
	// now compare the acc due to forces/torques applied by this body actuator
	model->computeStateVariableDerivatives(state2);

	Vector udotOnlyBodyActuator = state2.getUDot();
	udotOnlyBodyActuator.dump("Accelerations due to only-one body actuator");

	// Verify that the bodyActuator_sum also generates the same acceleration
	// as the equivalent applied by 3 Actuators in previous test case
	// Also make sure that accelerations are not zero accidentally
	ASSERT(udotOnlyBodyActuator.norm() != 0.0 || udotActuatorsCombination.norm() != 0.0);
	for (int i = 0; i<udotActuatorsCombination.size(); ++i){
		ASSERT_EQUAL(udotOnlyBodyActuator[i], udotActuatorsCombination[i], 1.0e-12);
	}
	
	// ------------------------ Setup integrator and manager -----------------------
	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(state2);


	std::cout << " ********** Test Actuator Combination time = ********** " <<
		1.e3*(std::clock() - startTime) / CLOCKS_PER_SEC << "ms\n" << endl;
}
Esempio n. 4
0
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
    OpenSim::Body* ground = &model->getGroundBody();
	
	// 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->addDisplayGeometry("box.vtp");
	block->scale(Vec3(0.2, 0.1, 0.1), false);

	double dh = mass*gravity_vec(1)/stiffness;
	
	WrapCylinder* pulley = new WrapCylinder();
	pulley->setRadius(0.1);
	pulley->setLength(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
	CoordinateSet &slider_coords = slider->upd_CoordinateSet();
	slider_coords[0].setName("block_h");
	slider_coords[0].setRange(positionRange);
	slider_coords[0].setMotionType(Coordinate::Translational);

	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;
}
int main(int argc, char **argv) {
  cout << "--------------------------------------------------------------------------------" << endl;
  cout << " Multi-Body System Benchmark in OpenSim" << endl;
  cout << " Benchmark reference url: http://lim.ii.udc.es/mbsbenchmark/" << endl;
  cout << " Problem A03: Andrew's Mechanism Model Creator" << endl;
  cout << " Copyright (C) 2013-2015 Luca Tagliapietra, Michele Vivian, Elena Ceseracciu, and Monica Reggiani" << endl;
  cout << "--------------------------------------------------------------------------------" << endl;

  if (argc != 2){
    cout << " ******************************************************************************" << endl;
    cout << " Multi-Body System Benchmark in OpenSim: Creator for Model A03" << endl;
    cout << " Usage: ./AndrewsMechanismCreateModel dataDirectory" << endl;
    cout << "       dataDirectory must contain a vtpFiles folder" << endl;
    cout << " ******************************************************************************" << endl;
    exit(EXIT_FAILURE);
  }

  const std::string dataDir = argv[1];
  cout << "Data directory: " + dataDir << endl;

  OpenSim::Model andrewsMechanism;
  andrewsMechanism.setName("Andrew's Mechanism");
  andrewsMechanism.setAuthors("L.Tagliapietra, M. Vivian, M.Reggiani");

  // Get a reference to the model's ground body
  OpenSim::Body& ground = andrewsMechanism.getGroundBody();
  andrewsMechanism.setGravity(gravityVector);

  //******************************
  // Create OF element
  //******************************
  SimTK::Inertia OFbarInertia(0.1,0.1,OFinertia);
  OpenSim::Body *OF = new OpenSim::Body("OF", OFmass, OFMassCenter, OFbarInertia);

  //Set transformation for visualization pourpose
  SimTK::Rotation rot(SimTK::Pi/2, SimTK::UnitVec3(0,0,1));
  SimTK::Transform trans = SimTK::Transform(rot);

  //Set visualization properties
  OF->addDisplayGeometry(rodGeometry);
  OpenSim::VisibleObject* visOF = OF->updDisplayer();
  visOF -> updTransform() =  trans;
  visOF -> setScaleFactors(SimTK::Vec3(0.001,OFlength, 0.001));
  visOF -> setDisplayPreference(OpenSim::DisplayGeometry::DisplayPreference(1));

  SimTK::Vec3 orientationInParent(0), orientationInBody(0);
  OpenSim::PinJoint *OJoint = new OpenSim::PinJoint("joint_O", ground, SimTK::Vec3(0), orientationInParent, *OF, SimTK::Vec3(-OFlength/2,0,0), orientationInBody);
  OpenSim::CoordinateSet& OCoordinateSet = OJoint -> upd_CoordinateSet();
  OCoordinateSet[0].setName("joint_O");
  OCoordinateSet[0].setDefaultValue(OAngleAtZero);
  andrewsMechanism.addBody(OF);

  //********************************
  // Create FE element
  //********************************
  SimTK::Inertia EFbarInertia(0.1,0.1,EFinertia);
  OpenSim::Body *EF = new OpenSim::Body("EF", EFmass, EFMassCenter, EFbarInertia);

  //Set visualization properties
  EF->addDisplayGeometry(rodGeometry);
  OpenSim::VisibleObject* visEF = EF->updDisplayer();
  visEF -> updTransform() =  trans;
  visEF -> setScaleFactors(SimTK::Vec3(0.001,EFlength, 0.001));
  visEF -> setDisplayPreference(OpenSim::DisplayGeometry::DisplayPreference(1));

  OpenSim::PinJoint *FJoint = new OpenSim::PinJoint("joint_F", *OF, SimTK::Vec3(OFlength/2,0,0), orientationInParent, *EF, SimTK::Vec3(EFlength/2,0,0), orientationInBody);
  OpenSim::CoordinateSet& FCoordinateSet = FJoint -> upd_CoordinateSet();
  FCoordinateSet[0].setName("joint_F");
  FCoordinateSet[0].setDefaultValue(FAngleAtZero);
  andrewsMechanism.addBody(EF);

  //********************************
  // Create EG element
  //********************************
  SimTK::Inertia GEbarInertia(0.1,0.1,GEinertia);
  OpenSim::Body *GE = new OpenSim::Body("GE", GEmass, GEMassCenter, GEbarInertia);

  //Set visualization properties
  GE->addDisplayGeometry(rodGeometry);
  OpenSim::VisibleObject* visGE = GE->updDisplayer();
  visGE -> updTransform() =  trans;
  visGE -> setScaleFactors(SimTK::Vec3(0.001,GElength, 0.001));
  visGE -> setDisplayPreference(OpenSim::DisplayGeometry::DisplayPreference(1));

  OpenSim::PinJoint *E1Joint = new OpenSim::PinJoint("joint_E1", *EF, SimTK::Vec3(-EFlength/2,0,0), orientationInParent, *GE, SimTK::Vec3(GElength/2,0,0), orientationInBody);
  OpenSim::CoordinateSet& E1CoordinateSet = E1Joint -> upd_CoordinateSet();
  E1CoordinateSet[0].setName("joint_E1");
  E1CoordinateSet[0].setDefaultValue(E1AngleAtZero);
  andrewsMechanism.addBody(GE);

  //********************************
  // Create AG element
  //********************************
  SimTK::Inertia AGbarInertia(0.1,0.1,AGinertia);
  OpenSim::Body *AG = new OpenSim::Body("AG", AGmass, AGMassCenter, AGbarInertia);

  //Set visualization properties
  AG->addDisplayGeometry(rodGeometry);
  OpenSim::VisibleObject* visAG = AG->updDisplayer();
  visAG -> updTransform() =  trans;
  visAG -> setScaleFactors(SimTK::Vec3(0.001,AGlength, 0.001));
  visAG -> setDisplayPreference(OpenSim::DisplayGeometry::DisplayPreference(1));

  OpenSim::PinJoint *GJoint = new OpenSim::PinJoint("joint_G", *GE, SimTK::Vec3(-GElength/2,0,0), orientationInParent, *AG, SimTK::Vec3(AGlength/2,0,0), orientationInBody);
  OpenSim::CoordinateSet& GCoordinateSet = GJoint -> upd_CoordinateSet();
  GCoordinateSet[0].setName("joint_G");
  GCoordinateSet[0].setDefaultValue(GAngleAtZero);
  andrewsMechanism.addBody(AG);

  //********************************
  // Create point constraint between AG element and ground to simulate joint A
  //********************************
   createPointCostraint(andrewsMechanism, std::string("ground"), SimTK::Vec3(-0.06934, -0.00227,0), std::string("AG"), SimTK::Vec3(-AGlength/2,0,0));

  //********************************
  // Create HE element
  //********************************
  SimTK::Inertia HEbarInertia(0.1,0.1,GEinertia);
  OpenSim::Body *HE = new OpenSim::Body("HE", HEmass, HEMassCenter, HEbarInertia);

  //Set visualization properties
  HE->addDisplayGeometry(rodGeometry);
  OpenSim::VisibleObject* visHE = HE->updDisplayer();
  visHE -> updTransform() =  trans;
  visHE -> setScaleFactors(SimTK::Vec3(0.001,HElength, 0.001));
  visHE -> setDisplayPreference(OpenSim::DisplayGeometry::DisplayPreference(1));

  OpenSim::PinJoint *E2Joint = new OpenSim::PinJoint("joint_E2", *EF, SimTK::Vec3(-EFlength/2,0,0), orientationInParent, *HE, SimTK::Vec3(HElength/2,0,0), orientationInBody);
  OpenSim::CoordinateSet& E2CoordinateSet = E2Joint -> upd_CoordinateSet();
  E2CoordinateSet[0].setName("joint_E2");
  E2CoordinateSet[0].setDefaultValue(E2AngleAtZero);
  andrewsMechanism.addBody(HE);

  //********************************
  //Create AH element
  //********************************
  SimTK::Inertia AHbarInertia(0.1,0.1,AHinertia);
  OpenSim::Body *AH = new OpenSim::Body("AH", AHmass, AHMassCenter, AHbarInertia);

  //Set visualization properties
  AH->addDisplayGeometry(rodGeometry);
  OpenSim::VisibleObject* visAH = AH->updDisplayer();
  visAH -> updTransform() =  trans;
  visAH -> setScaleFactors(SimTK::Vec3(0.001,AHlength, 0.001));
  visAH -> setDisplayPreference(OpenSim::DisplayGeometry::DisplayPreference(1));

  OpenSim::PinJoint *HJoint = new OpenSim::PinJoint("joint_H", *HE, SimTK::Vec3(-HElength/2,0,0), orientationInParent, *AH, SimTK::Vec3(AHlength/2,0,0), orientationInBody);
  OpenSim::CoordinateSet& HCoordinateSet = HJoint -> upd_CoordinateSet();
  HCoordinateSet[0].setName("joint_H");
  HCoordinateSet[0].setDefaultValue(HAngleAtZero);
  andrewsMechanism.addBody(AH);

  //********************************
  //Create point constraint between AH element and ground to simulate joint A
  //********************************
  createPointCostraint(andrewsMechanism, std::string("ground"), SimTK::Vec3(-0.06934, -0.00227,0), std::string("AH"), SimTK::Vec3(-AHlength/2,0,0));

  //********************************
  // Create BDE element
  //********************************
  SimTK::Inertia BDEInertia(0.1,0.1,BDEinertia);
  OpenSim::Body *BDE = new OpenSim::Body("BDE", BDEmass, BDEMassCenter, BDEInertia);

  //Set visualization properties
  BDE->addDisplayGeometry(triangleGeometry);
  OpenSim::VisibleObject* visBDE = BDE->updDisplayer();
  visBDE -> updTransform() =  trans;
  visBDE -> setScaleFactors(SimTK::Vec3(0.01, 0.01, 0.0005));
  visBDE -> setDisplayPreference(OpenSim::DisplayGeometry::DisplayPreference(1));

  OpenSim::PinJoint *E3Joint = new OpenSim::PinJoint("joint_E3", *EF, SimTK::Vec3(-EFlength/2,0,0), orientationInParent, *BDE, SimTK::Vec3(BElength/2,0,0), orientationInBody);
  OpenSim::CoordinateSet& E3CoordinateSet = E3Joint -> upd_CoordinateSet();
  E3CoordinateSet[0].setName("joint_E3");
  E3CoordinateSet[0].setDefaultValue(E3AngleAtZero);
  andrewsMechanism.addBody(BDE);

  //********************************
  // Create point constraint between BDE element and ground to simulate joint B
  //********************************
  createPointCostraint(andrewsMechanism, std::string("ground"), SimTK::Vec3(-0.03635, 0.03273,0), std::string("BDE"), SimTK::Vec3(-BElength/2,0,0));

  //********************************
  // Add the spring between BDE and ground
  //********************************
  OpenSim::PointToPointSpring *spring = new OpenSim::PointToPointSpring(std::string("ground"), SimTK::Vec3(0.014,0.072,0), std::string("BDE"), SimTK::Vec3(-BElength/2+0.018, 0.02,0), springK, springRestLength);
  andrewsMechanism.addComponent(spring);

  // Save to file the model
  andrewsMechanism.print((dataDir+"/"+modelName+std::string(".osim")).c_str());

  cout << "Model stored in: " << dataDir << "/" << modelName << ".osim" << endl;
}
Esempio n. 6
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;
    }


}
Esempio n. 7
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
		OpenSim::Body& ground = osimModel.getGroundBody();

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

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

		///////////////////////////////////////////////
		// 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;
}
Esempio n. 8
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;
}