/**
* 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;
}
/**
* 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;
}
/**
* 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;
}
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;
}
/*==============================================================================
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;
}
}
/**
* 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;
}
/**
* 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;
}
