void testCoordinateCouplerConstraint()
{
using namespace SimTK;
cout << endl;
cout << "=================================================================" << endl;
cout << " OpenSim CoordinateCouplerConstraint vs. FunctionBasedMobilizer " << endl;
cout << "=================================================================" << endl;
// Define spline data for the custom knee joint
int npx = 12;
double angX[] = {-2.094395102393, -1.745329251994, -1.396263401595, -1.047197551197, -0.698131700798, -0.349065850399, -0.174532925199, 0.197344221443, 0.337394955864, 0.490177570472, 1.521460267071, 2.094395102393};
double kneeX[] = {-0.003200000000, 0.001790000000, 0.004110000000, 0.004100000000, 0.002120000000, -0.001000000000, -0.003100000000, -0.005227000000, -0.005435000000, -0.005574000000, -0.005435000000, -0.005250000000};
int npy = 7;
double angY[] = {-2.094395102393, -1.221730476396, -0.523598775598, -0.349065850399, -0.174532925199, 0.159148563428, 2.094395102393};
double kneeY[] = {-0.422600000000, -0.408200000000, -0.399000000000, -0.397600000000, -0.396600000000, -0.395264000000, -0.396000000000 };
for(int i = 0; i<npy; i++) {
// Spline data points from experiment w.r.t. hip location. Change to make it w.r.t knee location
kneeY[i] += (-kneeInFemur[1]+hipInFemur[1]);
}
SimmSpline tx(npx, angX, kneeX);
SimmSpline ty(npy, angY, kneeY);;
// Define the functions that specify the FunctionBased Mobilized Body.
std::vector<std::vector<int> > coordIndices;
std::vector<const SimTK::Function*> functions;
std::vector<bool> isdof(6,false);
// Set the 1 spatial rotation about Z-axis
isdof[2] = true; //rot Z
int nm = 0;
for(int i=0; i<6; i++){
if(isdof[i]) {
Vector coeff(2);
coeff[0] = 1;
coeff[1] = 0;
std::vector<int> findex(1);
findex[0] = nm++;
functions.push_back(new SimTK::Function::Linear(coeff));
coordIndices.push_back(findex);
}
else if(i==3 || i ==4){
std::vector<int> findex(1,0);
if(i==3)
functions.push_back(tx.createSimTKFunction());
else
functions.push_back(ty.createSimTKFunction());
coordIndices.push_back(findex);
}
else{
std::vector<int> findex(0);
functions.push_back(new SimTK::Function::Constant(0, 0));
coordIndices.push_back(findex);
}
}
// Define the Simbody system
MultibodySystem system;
SimbodyMatterSubsystem matter(system);
GeneralForceSubsystem forces(system);
SimTK::Force::UniformGravity gravity(forces, matter, gravity_vec);
//system.updDefaultSubsystem().addEventReporter(new VTKEventReporter(system, 0.01));
// Thigh connected by hip
MobilizedBody::Pin thigh(matter.Ground(), Transform(hipInGround),
SimTK::Body::Rigid(MassProperties(femurMass, femurCOM, femurInertiaAboutCOM.shiftFromMassCenter(femurCOM, femurMass))), Transform(hipInFemur));
//Function-based knee connects shank
MobilizedBody::FunctionBased shank(thigh, Transform(kneeInFemur), SimTK::Body::Rigid(tibiaMass), Transform(kneeInTibia), nm, functions, coordIndices);
//MobilizedBody::Pin shank(thigh, SimTK::Transform(kneeInFemur), SimTK::Body::Rigid(tibiaMass), SimTK::Transform(kneeInTibia));
// Simbody model state setup
system.realizeTopology();
State state = system.getDefaultState();
matter.setUseEulerAngles(state, true);
system.realizeModel(state);
//==========================================================================================================
// Setup OpenSim model
Model *osimModel = new Model;
//OpenSim bodies
const Ground& ground = osimModel->getGround();;
OpenSim::Body osim_thigh("thigh", femurMass, femurCOM, femurInertiaAboutCOM);
// create hip as a pin joint
PinJoint hip("hip",ground, hipInGround, Vec3(0), osim_thigh, hipInFemur, Vec3(0));
// Rename hip coordinates for a pin joint
hip.getCoordinateSet()[0].setName("hip_flex");
// Add the thigh body which now also contains the hip joint to the model
osimModel->addBody(&osim_thigh);
osimModel->addJoint(&hip);
// Add another body via a knee joint
OpenSim::Body osim_shank("shank", tibiaMass.getMass(),
tibiaMass.getMassCenter(), tibiaMass.getInertia());
// Define knee coordinates and axes for custom joint spatial transform
SpatialTransform kneeTransform;
string knee_q_name = "knee_q";
string tx_name = "knee_tx";
string ty_name = "knee_ty";
Array<string> indepCoords(knee_q_name, 1, 1);
// knee flexion/extension
kneeTransform[2].setCoordinateNames(indepCoords);
kneeTransform[2].setFunction(new LinearFunction());
// translation X
kneeTransform[3].setCoordinateNames(OpenSim::Array<std::string>(tx_name, 1, 1));
kneeTransform[3].setFunction(new LinearFunction());
// translation Y
kneeTransform[4].setCoordinateNames(OpenSim::Array<std::string>(ty_name, 1, 1));
kneeTransform[4].setFunction(new LinearFunction());
// create custom knee joint
CustomJoint knee("knee", osim_thigh, kneeInFemur, Vec3(0), osim_shank, kneeInTibia, Vec3(0), kneeTransform);
// Add the shank body which now also contains the knee joint to the model
osimModel->addBody(&osim_shank);
osimModel->addJoint(&knee);
// Constrain the knee translations to follow the desired manifold
CoordinateCouplerConstraint knee_tx_constraint;
CoordinateCouplerConstraint knee_ty_constraint;
knee_tx_constraint.setName("knee_tx_coupler");
knee_ty_constraint.setName("knee_ty_coupler");
knee_tx_constraint.setIndependentCoordinateNames(indepCoords);
knee_ty_constraint.setIndependentCoordinateNames(indepCoords);
knee_tx_constraint.setDependentCoordinateName(tx_name);
knee_ty_constraint.setDependentCoordinateName(ty_name);
knee_tx_constraint.setFunction(tx);
knee_ty_constraint.setFunction(ty);
// Add the constraints
osimModel->addConstraint(&knee_tx_constraint);
osimModel->addConstraint(&knee_ty_constraint);
//Add analyses before setting up the model for simulation
Kinematics *kinAnalysis = new Kinematics(osimModel);
kinAnalysis->setInDegrees(false);
osimModel->addAnalysis(kinAnalysis);
// OpenSim model must realize the topology to get valid osim_state
osimModel->setGravity(gravity_vec);
PointKinematics *pointKin = new PointKinematics(osimModel);
// Get the point location of the shank origin in space
pointKin->setBodyPoint("shank", Vec3(0));
osimModel->addAnalysis(pointKin);
// Model cannot own model components created on the stack in this test program
osimModel->disownAllComponents();
// write out the model to file
osimModel->print("testCouplerConstraint.osim");
//wipe-out the model just constructed
delete osimModel;
// reconstruct from the model file
osimModel = new Model("testCouplerConstraint.osim");
ForceReporter *forceReport = new ForceReporter(osimModel);
forceReport->includeConstraintForces(true);
osimModel->addAnalysis(forceReport);
// Need to setup model before adding an analysis since it creates the AnalysisSet
// for the model if it does not exist.
State& osim_state = osimModel->initSystem();
//==========================================================================================================
// Compare Simbody system and OpenSim model simulations
compareSimulations(system, state, osimModel, osim_state, "testCoordinateCouplerConstraint FAILED\n");
// Forces were held in storage during simulation, now write to file
forceReport->printResults("CouplerModelForces");
}
// test sphere to sphere contact using elastic foundation with and without
// meshes and their combination
int testBallToBallContact(bool useElasticFoundation, bool useMesh1, bool useMesh2)
{
// Setup OpenSim model
Model *osimModel = new Model;
//OpenSim bodies
OpenSim::Body& ground = *new OpenSim::Body("ground", SimTK::Infinity,
Vec3(0), Inertia());
osimModel->addBody(&ground);
OpenSim::Body ball;
ball.setName("ball");
ball.setMass(mass);
ball.setMassCenter(Vec3(0));
ball.setInertia(Inertia(1.0));
// Add joints
FreeJoint free("free", ground, Vec3(0), Vec3(0), ball, Vec3(0), Vec3(0));
osimModel->addBody(&ball);
osimModel->addJoint(&free);
// Create ContactGeometry.
OpenSim::ContactGeometry *ball1, *ball2;
if (useElasticFoundation && useMesh1)
ball1 = new ContactMesh(mesh_file, Vec3(0), Vec3(0), ground, "ball1");
else
ball1 = new ContactSphere(radius, Vec3(0), ground, "ball1");
if (useElasticFoundation && useMesh2)
ball2 = new ContactMesh(mesh_file, Vec3(0), Vec3(0), ball, "ball2");
else
ball2 = new ContactSphere(radius, Vec3(0), ball, "ball2");
osimModel->addContactGeometry(ball1);
osimModel->addContactGeometry(ball2);
OpenSim::Force* force;
std::string prefix;
if (useElasticFoundation){
}
else{
}
if (useElasticFoundation)
{
// Add an ElasticFoundationForce.
OpenSim::ElasticFoundationForce::ContactParameters* contactParams = new OpenSim::ElasticFoundationForce::ContactParameters(1.0e6/(2*radius), 0.001, 0.0, 0.0, 0.0);
contactParams->addGeometry("ball1");
contactParams->addGeometry("ball2");
force = new OpenSim::ElasticFoundationForce(contactParams);
prefix = "EF_";
prefix += useMesh1 ?"Mesh":"noMesh";
prefix += useMesh2 ? "_to_Mesh":"_to_noMesh";
}
else
{
// Add a Hertz HuntCrossleyForce.
OpenSim::HuntCrossleyForce::ContactParameters* contactParams = new OpenSim::HuntCrossleyForce::ContactParameters(1.0e6, 0.001, 0.0, 0.0, 0.0);
contactParams->addGeometry("ball1");
contactParams->addGeometry("ball2");
force = new OpenSim::HuntCrossleyForce(contactParams);
prefix = "Hertz";
}
force->setName("contact");
osimModel->addForce(force);
osimModel->setGravity(gravity_vec);
osimModel->setName(prefix);
osimModel->clone()->print(prefix+".osim");
Kinematics* kin = new Kinematics(osimModel);
osimModel->addAnalysis(kin);
ForceReporter* reporter = new ForceReporter(osimModel);
osimModel->addAnalysis(reporter);
SimTK::State& osim_state = osimModel->initSystem();
osim_state.updQ()[4] = height;
osimModel->getMultibodySystem().realize(osim_state, Stage::Position );
//==========================================================================================================
// Simulate it and see if it bounces correctly.
cout << "stateY=" << osim_state.getY() << std::endl;
RungeKuttaMersonIntegrator integrator(osimModel->getMultibodySystem() );
integrator.setAccuracy(integ_accuracy);
integrator.setMaximumStepSize(100*integ_accuracy);
Manager manager(*osimModel, integrator);
manager.setInitialTime(0.0);
manager.setFinalTime(duration);
manager.integrate(osim_state);
kin->printResults(prefix);
reporter->printResults(prefix);
osimModel->disownAllComponents();
// model takes ownership of components unless container set is told otherwise
delete osimModel;
return 0;
}
