where did i go wrong? can someone help me.
Here's the source code
Code: Select all
#include <OpenSim/OpenSim.h>
using namespace SimTK;
using namespace OpenSim;
int main() {
Model model;
model.setName("bicep_curl");
model.setUseVisualizer(true);
// Create two links, each with a mass of 1 kg, center of mass at the body's
// origin, and moments and products of inertia of zero.
OpenSim::Body* humerus = new OpenSim::Body("humerus", 1, Vec3(0), Inertia(0));
OpenSim::Body* radius = new OpenSim::Body("radius", 1, Vec3(0), Inertia(0));
// Connect the bodies with pin joints. Assume each body is 1 m long.
PinJoint* shoulder = new PinJoint("shoulder",
// Parent body, location in parent, orientation in parent.
model.getGround(), Vec3(0), Vec3(0),
// Child body, location in child, orientation in child.
*humerus, Vec3(0, 1, 0), Vec3(0));
PinJoint* elbow = new PinJoint("elbow",
*humerus, Vec3(0), Vec3(0), *radius, Vec3(0, 1, 0), Vec3(0));
// Add a muscle that flexes the elbow.
Millard2012EquilibriumMuscle* biceps = new
Millard2012EquilibriumMuscle("biceps", 200, 0.6, 0.55, 0);
biceps->addNewPathPoint("origin", *humerus, Vec3(0, 0.8, 0));
biceps->addNewPathPoint("insertion", *radius, Vec3(0, 0.7, 0));
// Add a controller that specifies the excitation of the muscle.
PrescribedController* brain = new PrescribedController();
brain->addActuator(*biceps);
// Muscle excitation is 0.3 for the first 0.5 seconds, then increases to 1.
brain->prescribeControlForActuator("biceps",
new StepFunction(0.5, 3, 0.3, 1));
// Add components to the model.
model.addBody(humerus); model.addBody(radius);
model.addJoint(shoulder); model.addJoint(elbow);
model.addForce(biceps);
model.addController(brain);
// Add a console reporter to print the muscle fiber force and elbow angle.
ConsoleReporter* reporter = new ConsoleReporter();
reporter->set_report_time_interval(1.0);
reporter->addToReport(biceps->getOutput("fiber_force"));
reporter->addToReport(
elbow->getCoordinate(PinJoint::Coord::RotationZ).getOutput("value"),
"elbow_angle");
model.addComponent(reporter);
// Add display geometry.
Ellipsoid bodyGeometry(0.1, 0.5, 0.1);
bodyGeometry.setColor(Gray);
// Attach an ellipsoid to a frame located at the center of each body.
PhysicalOffsetFrame* humerusCenter = new PhysicalOffsetFrame(
"humerusCenter", "humerus", Transform(Vec3(0, 0.5, 0)));
humerus->addComponent(humerusCenter);
humerusCenter->attachGeometry(bodyGeometry.clone());
PhysicalOffsetFrame* radiusCenter = new PhysicalOffsetFrame(
"radiusCenter", "radius", Transform(Vec3(0, 0.5, 0)));
radius->addComponent(radiusCenter);
radiusCenter->attachGeometry(bodyGeometry.clone());
// Configure the model.
State& state = model.initSystem();
// Fix the shoulder at its default angle and begin with the elbow flexed.
shoulder->getCoordinate().setLocked(state, true);
elbow->getCoordinate().setValue(state, 0.5 * Pi);
model.equilibrateMuscles(state);
// Configure the visualizer.
model.updMatterSubsystem().setShowDefaultGeometry(true);
Visualizer& viz = model.updVisualizer().updSimbodyVisualizer();
viz.setBackgroundType(viz.SolidColor);
viz.setBackgroundColor(White);
// Simulate.
simulate(model, state, 10.0);
return 0;
};
github url: https://github.com/opensim-org/opensim-core