void init(void* separator, const std::map<std::string, Moby::BasePtr>& read_map, double time)
{
// wipe out existing files
std::ofstream out("rke.dat");
out.close();
out.open("telemetry.box");
out.close();
out.open("manifold.change");
out.close();
// get a reference to the TimeSteppingSimulator instance
for (std::map<std::string, Moby::BasePtr>::const_iterator i = read_map.begin();
i !=read_map.end(); i++)
{
// Find the simulator reference
if (!sim)
sim = boost::dynamic_pointer_cast<TimeSteppingSimulator>(i->second);
if (i->first == "box")
box = boost::dynamic_pointer_cast<RigidBody>(i->second);
if (!grav)
grav = boost::dynamic_pointer_cast<GravityForce>(i->second);
}
sim->post_step_callback_fn = &post_step_callback;
sim->constraint_callback_fn = &post_contact_callback;
srand(0);
// set the position, orientation, and velocities to some random values
Pose3d x = *box->get_pose();
rand_pose(x);
// add 2.0 to the initial pose for the box
x.x[1] += 2.0;
box->set_pose(x);
// set random velocity for the box
shared_ptr<const Pose3d> P = box->get_velocity().pose;
box->set_velocity(rand_velocity(P));
}
void init(void* separator, const std::map<std::string, Moby::BasePtr>& read_map, double time)
{
const unsigned Z = 2;
// overwrite the energy and velocity files
std::ofstream out("energy.dat");
out.close();
out.open("velocity.dat");
out.close();
out.open("cvio.dat");
out.close();
// If use robot is active also init dynamixel controllers
// get a reference to the TimeSteppingSimulator instance
for (std::map<std::string, Moby::BasePtr>::const_iterator i = read_map.begin();
i !=read_map.end(); i++)
{
// Find the simulator reference
if (!sim)
sim = boost::dynamic_pointer_cast<TimeSteppingSimulator>(i->second);
if (i->first == "WHEEL")
wheel = boost::dynamic_pointer_cast<RigidBody>(i->second);
if (i->first == "GROUND")
ground = boost::dynamic_pointer_cast<RigidBody>(i->second);
if (!grav)
grav = boost::dynamic_pointer_cast<GravityForce>(i->second);
}
sim->post_step_callback_fn = &post_step_callback;
sim->post_mini_step_callback_fn = &post_ministep_callback;
// initialize the system to the fixed point
// double theta = M_PI/N_SPOKES;
double theta = 0.0;
const double ALPHA = 0.2;
const double LAMBDA_SQ = 2.0/3;
const double MU = 1.0 + LAMBDA_SQ * (std::cos(2*M_PI/N_SPOKES) - 1.0);
assert(MU > 0.0 && MU < 1.0);
// double theta_dot = std::sqrt((4.0*MU*MU*LAMBDA_SQ*std::sin(M_PI/N_SPOKES)*std::sin(ALPHA))/(1.0 - MU*MU));
// get theta dot
char* theta_dot_str = getenv("RIMLESS_WHEEL_THETAD");
if (!theta_dot_str)
{
std::cerr << "RIMLESS_WHEEL_THETAD not defined!" << std::endl;
exit(-1);
}
double theta_dot = std::atof(theta_dot_str);
out.open("system.state", std::ostream::app);
out << theta_dot << " ";
out.close();
// get the distance per revolution
const double DIST_PER_REV = 2*M_PI*R;
const double REV_PER_SEC = theta_dot / (M_PI*2.0);
const double DIST_PER_SEC = DIST_PER_REV * REV_PER_SEC;
// set the rotation about y
Quatd q_wheel = Matrix3d::rot_Y(theta);
Vector3d lvel(DIST_PER_SEC, 0.0, 0.0, wheel->get_velocity().pose);
Vector3d avel(0, theta_dot, 0, wheel->get_velocity().pose);
Pose3d P;
P.x.set_zero();
P.x[Z] = 0.866025403784439;
P.q = q_wheel;
wheel->set_pose(P);
SVelocityd v;
v.set_angular(avel);
v.set_linear(lvel);
wheel->set_velocity(v);
/*
// Set initial conditions from ruina paper
Ravelin::VectorNd x,xd;
part->get_generalized_coordinates( Moby::DynamicBody::eEuler,x);
part->get_generalized_velocity( Moby::DynamicBody::eSpatial,xd);
x[1] = 0; // x
x[2] = 0; // y
x[3] = 0.1236; // z
// 9.866765986740000e-002
// -9.248610676160000e-003
// -1.601658349552200e-001
// 3.435833890385830e+000
// -1.322096551035500e-001
// -1.990961987794000e-002
// 4.712423746697700e-001
// -3.925591686648300e-001
double PHI = 9.866765986740000e-002, // yaw
THE = -1.601658349552200e-001, // pitch + alpha
PSI = -9.248610676160000e-003; // roll
Ravelin::Matrix3d Rz = Ravelin::Matrix3d::rot_Z(PHI),
Ry = Ravelin::Matrix3d::rot_Y(THE),
Rx = Ravelin::Matrix3d::rot_X(PSI),
Rzxy = Ry.mult(Rx).mult(Rz);
Quatd q = Quatd(Rzxy);
x[4] = q[0];
x[5] = q[1];
x[6] = q[2];
x[7] = q[3];
x[0] = 3.435833890385830e+000 + THETA_SW_OFFSET; // Theta_sw
// Convert Time derivative of RPY to angular velocity (w)
double dPHI = -1.322096551035500e-001, // d yaw / dt
dTHE = 4.712423746697700e-001, // d pitch / dt
dPSI = -1.990961987794000e-002; // d roll / dt
// a_dot is time derivative of RPY
// Numerically derive skew symmetric
// angular velocity tensor matrix W
double h = 1e-6;
Matrix3d
Rz2 = Ravelin::Matrix3d::rot_Z(PHI + h*dPHI),
Rx2 = Ravelin::Matrix3d::rot_X(PSI + h*dPSI),
Ry2 = Ravelin::Matrix3d::rot_Y(THE + h*dTHE);
Matrix3d
Rzxy2 = Ry2.mult(Rx2).mult(Rz2);
Matrix3d
W = ((Rzxy2-Rzxy)/h).mult_transpose(Rzxy);
// w is angular velocity
Vector3d w((W(2,1)-W(1,2))/2,(W(0,2)-W(2,0))/2,(W(1,0)-W(0,1))/2);
xd.set_zero();
xd.set_sub_vec(4,w);
xd[0] = -3.925591686648300e-001; // Theta_sw
part->set_generalized_coordinates( Moby::DynamicBody::eEuler,x);
part->set_generalized_velocity( Moby::DynamicBody::eSpatial,xd);
*/
}