Minimum jerk Cartesian trajectory following¶
Note
The source code for this example can be found in [orca_root]/examples/gazebo/06-trajectory_following.cc, or alternatively on github at: https://github.com/syroco/orca/blob/dev/examples/gazebo/06-trajectory_following.cc
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 | #include <orca/orca.h>
#include <orca/gazebo/GazeboServer.h>
#include <orca/gazebo/GazeboModel.h>
using namespace orca::all;
using namespace orca::gazebo;
class MinJerkPositionTrajectory {
private:
Eigen::Vector3d alpha_, sp_, ep_;
double duration_ = 0.0;
double start_time_ = 0.0;
bool first_call_ = true;
bool traj_finished_ = false;
public:
MinJerkPositionTrajectory (double duration)
: duration_(duration)
{
}
bool isTrajectoryFinished(){return traj_finished_;}
void resetTrajectory(const Eigen::Vector3d& start_position, const Eigen::Vector3d& end_position)
{
sp_ = start_position;
ep_ = end_position;
alpha_ = ep_ - sp_;
first_call_ = true;
traj_finished_ = false;
}
void getDesired(double current_time, Eigen::Vector3d& p, Eigen::Vector3d& v, Eigen::Vector3d& a)
{
if(first_call_)
{
start_time_ = current_time;
first_call_ = false;
}
double tau = (current_time - start_time_) / duration_;
if(tau >= 1.0)
{
p = ep_;
v = Eigen::Vector3d::Zero();
a = Eigen::Vector3d::Zero();
traj_finished_ = true;
return;
}
p = sp_ + alpha_ * ( 10*pow(tau,3.0) - 15*pow(tau,4.0) + 6*pow(tau,5.0) );
v = Eigen::Vector3d::Zero() + alpha_ * ( 30*pow(tau,2.0) - 60*pow(tau,3.0) + 30*pow(tau,4.0) );
a = Eigen::Vector3d::Zero() + alpha_ * ( 60*pow(tau,1.0) - 180*pow(tau,2.0) + 120*pow(tau,3.0) );
}
};
int main(int argc, char const *argv[])
{
if(argc < 2)
{
std::cerr << "Usage : " << argv[0] << " /path/to/robot-urdf.urdf (optionally -l debug/info/warning/error)" << "\n";
return -1;
}
std::string urdf_url(argv[1]);
orca::utils::Logger::parseArgv(argc, argv);
auto robot = std::make_shared<RobotDynTree>();
robot->loadModelFromFile(urdf_url);
robot->setBaseFrame("base_link");
robot->setGravity(Eigen::Vector3d(0,0,-9.81));
RobotState eigState;
eigState.resize(robot->getNrOfDegreesOfFreedom());
eigState.jointPos.setZero();
eigState.jointVel.setZero();
robot->setRobotState(eigState.jointPos,eigState.jointVel);
orca::optim::Controller controller(
"controller"
,robot
,orca::optim::ResolutionStrategy::OneLevelWeighted
,QPSolver::qpOASES
);
auto cart_task = std::make_shared<CartesianTask>("CartTask-EE");
controller.addTask(cart_task);
cart_task->setControlFrame("link_7"); //
Eigen::Affine3d cart_pos_ref;
cart_pos_ref.translation() = Eigen::Vector3d(1.,0.75,0.5); // x,y,z in meters
cart_pos_ref.linear() = Eigen::Quaterniond::Identity().toRotationMatrix();
Vector6d cart_vel_ref = Vector6d::Zero();
Vector6d cart_acc_ref = Vector6d::Zero();
Vector6d P;
P << 1000, 1000, 1000, 10, 10, 10;
cart_task->servoController()->pid()->setProportionalGain(P);
Vector6d D;
D << 100, 100, 100, 1, 1, 1;
cart_task->servoController()->pid()->setDerivativeGain(D);
const int ndof = robot->getNrOfDegreesOfFreedom();
auto jnt_trq_cstr = std::make_shared<JointTorqueLimitConstraint>("JointTorqueLimit");
controller.addConstraint(jnt_trq_cstr);
Eigen::VectorXd jntTrqMax(ndof);
jntTrqMax.setConstant(200.0);
jnt_trq_cstr->setLimits(-jntTrqMax,jntTrqMax);
auto jnt_pos_cstr = std::make_shared<JointPositionLimitConstraint>("JointPositionLimit");
controller.addConstraint(jnt_pos_cstr);
auto jnt_vel_cstr = std::make_shared<JointVelocityLimitConstraint>("JointVelocityLimit");
controller.addConstraint(jnt_vel_cstr);
Eigen::VectorXd jntVelMax(ndof);
jntVelMax.setConstant(2.0);
jnt_vel_cstr->setLimits(-jntVelMax,jntVelMax);
double dt = 0.001;
double current_time = 0.0;
GazeboServer gzserver(argc,argv);
auto gzrobot = GazeboModel(gzserver.insertModelFromURDFFile(urdf_url));
///////////////////////////////////////
///////////////////////////////////////
///////////////////////////////////////
///////////////////////////////////////
MinJerkPositionTrajectory traj(5.0);
int traj_loops = 0;
bool exit_control_loop = true;
Eigen::Vector3d start_position, end_position;
cart_task->onActivationCallback([](){
std::cout << "Activating CartesianTask..." << '\n';
});
bool cart_task_activated = false;
cart_task->onActivatedCallback([&](){
start_position = cart_task->servoController()->getCurrentCartesianPose().block(0,3,3,1);
end_position = cart_pos_ref.translation();
traj.resetTrajectory(start_position, end_position);
std::cout << "CartesianTask activated. Removing gravity compensation and begining motion." << '\n';
cart_task_activated = true;
});
cart_task->onComputeBeginCallback([&](double current_time, double dt){
if (cart_task->getState() == TaskBase::State::Activated)
{
Eigen::Vector3d p, v, a;
traj.getDesired(current_time, p, v, a);
cart_pos_ref.translation() = p;
cart_vel_ref.head(3) = v;
cart_acc_ref.head(3) = a;
cart_task->servoController()->setDesired(cart_pos_ref.matrix(),cart_vel_ref,cart_acc_ref);
}
});
cart_task->onComputeEndCallback([&](double current_time, double dt){
if (cart_task->getState() == TaskBase::State::Activated)
{
if (traj.isTrajectoryFinished() )
{
if (traj_loops < 5)
{
// flip start and end positions.
auto ep = end_position;
end_position = start_position;
start_position = ep;
traj.resetTrajectory(start_position, end_position);
std::cout << "Changing trajectory direction." << '\n';
++traj_loops;
}
else
{
std::cout << "Trajectory looping finished. Deactivating task and starting gravity compensation." << '\n';
cart_task->deactivate();
}
}
}
});
cart_task->onDeactivationCallback([&cart_task_activated](){
std::cout << "Deactivating task." << '\n';
cart_task_activated = false;
});
cart_task->onDeactivatedCallback([](){
std::cout << "CartesianTask deactivated. Stopping controller" << '\n';
});
gzrobot.setCallback([&](uint32_t n_iter,double current_time,double dt)
{
robot->setRobotState(gzrobot.getWorldToBaseTransform().matrix()
,gzrobot.getJointPositions()
,gzrobot.getBaseVelocity()
,gzrobot.getJointVelocities()
,gzrobot.getGravity()
);
// All tasks need the robot to be initialized during the activation phase
if(n_iter == 1)
controller.activateTasksAndConstraints();
controller.update(current_time, dt);
if (cart_task_activated)
{
if(controller.solutionFound())
{
gzrobot.setJointTorqueCommand( controller.getJointTorqueCommand() );
}
else
{
gzrobot.setBrakes(true);
}
}
else
{
gzrobot.setJointGravityTorques(robot->getJointGravityTorques());
}
});
std::cout << "Simulation running... (GUI with \'gzclient\')" << "\n";
gzserver.run();
return 0;
}
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