tutorial-franka-coppeliasim-joint-impedance-control.cpp

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/****************************************************************************
 *
 * ViSP, open source Visual Servoing Platform software.
 * Copyright (C) 2005 - 2021 by Inria. All rights reserved.
 *
 * This software is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * See the file LICENSE.txt at the root directory of this source
 * distribution for additional information about the GNU GPL.
 *
 * For using ViSP with software that can not be combined with the GNU
 * GPL, please contact Inria about acquiring a ViSP Professional
 * Edition License.
 *
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 *
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 * Inria Rennes - Bretagne Atlantique
 * Campus Universitaire de Beaulieu
 * 35042 Rennes Cedex
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#include <iostream>
 
#include <visp3/gui/vpPlot.h>
#include <visp_ros/vpROSRobotFrankaCoppeliasim.h>
 
int
main( int argc, char **argv )
{
  bool opt_coppeliasim_sync_mode = false;
  bool opt_verbose               = false;
  bool opt_save_data             = false;
 
  for ( int i = 1; i < argc; i++ )
  {
    if ( std::string( argv[i] ) == "--enable-coppeliasim-sync-mode" )
    {
      opt_coppeliasim_sync_mode = true;
    }
    else if ( std::string( argv[i] ) == "--verbose" || std::string( argv[i] ) == "-v" )
    {
      opt_verbose = true;
    }
    else if ( std::string( argv[i] ) == "--save" )
    {
      opt_save_data = true;
    }
    else if ( std::string( argv[i] ) == "--help" || std::string( argv[i] ) == "-h" )
    {
      std::cout << argv[0] << "[--enable-coppeliasim-sync-mode]"
                << " [--save]"
                << " [--verbose] [-v] "
                << " [--help] [-h]" << std::endl;
      return EXIT_SUCCESS;
    }
  }
 
  vpROSRobotFrankaCoppeliasim robot;
  try
  {
    //    ROS node    //
    ros::init( argc, argv, "visp_ros" );
    ros::NodeHandlePtr n = boost::make_shared< ros::NodeHandle >();
    ros::Rate loop_rate( 1000 );
    ros::spinOnce();
 
    robot.setVerbose( opt_verbose );
    if ( 0 )
    {
      // Instead of setting the tool from Coppeliasim topics, we can set its values manually to e.g. introduce errors in
      // the parameters This must be done before call robot.connect() The following are the parameters for the Panda
      // Hand as reported in the datasheet.
      double mass = 0.73; // [kg]
      vpHomogeneousMatrix flMe(
          vpTranslationVector( 0, 0, 0.1034 ),
          vpRotationMatrix( { std::cos( vpMath::rad( 45 ) ), -std::sin( vpMath::rad( 45 ) ), 0,
                              std::sin( vpMath::rad( 45 ) ), std::cos( vpMath::rad( 45 ) ), 0, 0, 0, 1 } ) );
      vpHomogeneousMatrix fMcom( vpTranslationVector( -0.01, 0.0, 0.03 ), vpRotationMatrix() );
      vpMatrix I_l( 3, 3 );
      I_l.diag( vpColVector( { 0.001, 0.0025, 0.0017 } ) ); // [kg*m^2]
      robot.add_tool( flMe, mass, fMcom, I_l );
    }
 
    robot.connect();
 
    std::cout << "Coppeliasim sync mode enabled: " << ( opt_coppeliasim_sync_mode ? "yes" : "no" ) << std::endl;
    robot.coppeliasimStopSimulation(); // Allows to reset simulation, moving the robot to initial position
    robot.setCoppeliasimSyncMode( false );
    robot.coppeliasimStartSimulation();
 
    // Move to a secure initial position
    vpColVector q_init( { 0, vpMath::rad( -45 ), 0, vpMath::rad( -135 ), 0, vpMath::rad( 90 ), vpMath::rad( 45 ) } );
 
    robot.setRobotState( vpRobot::STATE_POSITION_CONTROL );
    robot.setPosition( vpRobot::JOINT_STATE, q_init );
    vpTime::wait( 500 );
 
    vpPlot *plotter = nullptr;
 
    plotter = new vpPlot( 4, 800, 800, 10, 10, "Real time curves plotter" );
    plotter->setTitle( 0, "Joint positions [rad]" );
    plotter->initGraph( 0, 7 );
    plotter->setLegend( 0, 0, "q1" );
    plotter->setLegend( 0, 1, "q2" );
    plotter->setLegend( 0, 2, "q3" );
    plotter->setLegend( 0, 3, "q4" );
    plotter->setLegend( 0, 4, "q5" );
    plotter->setLegend( 0, 5, "q6" );
    plotter->setLegend( 0, 6, "q7" );
 
    plotter->setTitle( 1, "Joint position error [rad]" );
    plotter->initGraph( 1, 7 );
    plotter->setLegend( 1, 0, "e_q1" );
    plotter->setLegend( 1, 1, "e_q2" );
    plotter->setLegend( 1, 2, "e_q3" );
    plotter->setLegend( 1, 3, "e_q4" );
    plotter->setLegend( 1, 4, "e_q5" );
    plotter->setLegend( 1, 5, "e_q6" );
    plotter->setLegend( 1, 6, "e_q7" );
 
    plotter->setTitle( 2, "Joint torque measure [Nm]" );
    plotter->initGraph( 2, 7 );
    plotter->setLegend( 2, 0, "Tau1" );
    plotter->setLegend( 2, 1, "Tau2" );
    plotter->setLegend( 2, 2, "Tau3" );
    plotter->setLegend( 2, 3, "Tau4" );
    plotter->setLegend( 2, 4, "Tau5" );
    plotter->setLegend( 2, 5, "Tau6" );
    plotter->setLegend( 2, 6, "Tau7" );
 
    plotter->setTitle( 3, "Joint error norm [rad]" );
    plotter->initGraph( 3, 1 );
    plotter->setLegend( 3, 0, "||qd - d||" );
 
    // Create joint array
    vpColVector q( 7, 0 ), qd( 7, 0 ), dq( 7, 0 ), dqd( 7, 0 ), ddqd( 7, 0 ), tau_d( 7, 0 ), C( 7, 0 ), q0( 7, 0 ),
        F( 7, 0 ), tau_d0( 7, 0 ), tau_cmd( 7, 0 ), tau( 7, 0 );
    vpMatrix B( 7, 7 );
 
    std::cout << "Reading current joint position" << std::endl;
    robot.getPosition( vpRobot::JOINT_STATE, q0 );
    std::cout << "Initial joint position: " << q0.t() << std::endl;
 
    robot.setRobotState( vpRobot::STATE_FORCE_TORQUE_CONTROL );
    robot.setCoppeliasimSyncMode( opt_coppeliasim_sync_mode );
 
    qd = q0;
 
    bool final_quit       = false;
    bool first_time       = false;
    bool start_trajectory = false;
 
    vpMatrix K( 7, 7 ), D( 7, 7 ), I( 7, 7 );
    K.diag( { 400.0, 400.0, 400.0, 400.0, 400.0, 400.0, 900.0 } );
    D.diag( { 20.0, 45.0, 45.0, 45.0, 45.0, 45.0, 60.0 } );
    I.diag( { 10.0, 10.0, 10.0, 10.0, 10.0, 10.0, 60.0 } );
 
    vpColVector integral( 7, 0 );
 
    double mu = 4;
    double dt = 0;
 
    double time_start_trajectory, time_prev, time_cur;
    double delay_before_trajectory = 0.5; // Start sinusoidal joint trajectory after this delay in [s]
 
    // Control loop
    while ( !final_quit )
    {
      time_cur = robot.getCoppeliasimSimulationTime();
 
      robot.getPosition( vpRobot::JOINT_STATE, q );
      robot.getVelocity( vpRobot::JOINT_STATE, dq );
      robot.getForceTorque( vpRobot::JOINT_STATE, tau );
      robot.getMass( B );
      robot.getCoriolis( C );
      robot.getFriction( F );
 
      if ( time_cur < delay_before_trajectory )
      {
        time_start_trajectory = time_cur; // To ensure exp() = 1
        first_time            = true;
      }
      else if ( !start_trajectory ) // After the delay we start joint trajectory
      {
        time_start_trajectory = time_cur;
        start_trajectory      = true;
      }
 
      // Compute joint trajectories
      // clang-format off
      qd[0]   = q0[0] + ( start_trajectory ? std::sin( 2 * M_PI * 0.1 * ( time_cur - time_start_trajectory ) ) : 0 );
      dqd[0]  = ( start_trajectory ? 2 * M_PI * 0.1 * std::cos( 2 * M_PI * 0.1 * ( time_cur - time_start_trajectory ) ) : 0 );
      ddqd[0] = ( start_trajectory ? - std::pow( 2 * 0.1 * M_PI, 2 ) * std::sin( 2 * M_PI * 0.1 * ( time_cur - time_start_trajectory ) ) : 0 );
 
      qd[2]   = q0[2] + ( start_trajectory ? ( M_PI / 16 ) * std::sin( 2 * M_PI * 0.2 * ( time_cur - time_start_trajectory ) ) : 0 );
      dqd[2]  = ( start_trajectory ? M_PI * ( M_PI / 8 ) * 0.2 * std::cos( 2 * M_PI * 0.2 * ( time_cur - time_start_trajectory ) ) : 0 );
      ddqd[2] = ( start_trajectory ? -M_PI * M_PI * 0.2 * ( M_PI / 4 ) * std::sin( 2 * M_PI * 0.2 * ( time_cur - time_start_trajectory ) ) : 0 );
 
      qd[3]   = q0[3] + ( start_trajectory ? 0.25 * std::sin( 2 * M_PI * 0.05 * ( time_cur - time_start_trajectory ) ) : 0 );
      dqd[3]  = ( start_trajectory ? 2 * M_PI * 0.05 * 0.25 * std::cos( 2 * M_PI * 0.05 * ( time_cur - time_start_trajectory ) ) : 0 );
      ddqd[3] = ( start_trajectory ? -0.25 * std::pow( 2 * 0.05 * M_PI, 2 ) * std::sin( 2 * M_PI * 0.05 * ( time_cur - time_start_trajectory ) ) : 0 );
 
      //qd[6]   = q0[6] + ( start_trajectory ? std::sin( 2 * M_PI * 0.1 * ( time_cur - time_start_trajectory ) ) : 0 );
      //dqd[6]  = ( start_trajectory ? 2 * M_PI * 0.1 * std::cos( 2 * M_PI * 0.1 * ( time_cur - time_start_trajectory ) ) : 0 );
      //ddqd[6] =  ( start_trajectory ? -std::pow( 2 * 0.1 * M_PI, 2 ) * std::sin( 2 * M_PI * 0.1 * ( time_cur - time_start_trajectory ) ) : 0 );
      // clang-format on
 
      dt = time_cur - time_prev;
      if ( start_trajectory )
      {
        integral += ( qd - q ) * dt;
      }
 
      // Compute the control law
      tau_d = B * ( K * ( qd - q ) + D * ( dqd - dq ) + I * ( integral ) + ddqd ) + C + F;
 
      if ( first_time )
      {
        tau_d0 = tau_d;
      }
 
      tau_cmd = tau_d - tau_d0 * std::exp( -mu * ( time_cur - time_start_trajectory ) );
 
      // Send command to the torque robot
      robot.setForceTorque( vpRobot::JOINT_STATE, tau_cmd );
 
      vpColVector norm( 1, vpMath::deg( std::sqrt( ( qd - q ).sumSquare() ) ) );
      plotter->plot( 0, time_cur, q );
      plotter->plot( 1, time_cur, qd - q );
      plotter->plot( 2, time_cur, tau );
      plotter->plot( 3, time_cur, norm );
      vpMouseButton::vpMouseButtonType button;
      if ( vpDisplay::getClick( plotter->I, button, false ) )
      {
        if ( button == vpMouseButton::button3 )
        {
          final_quit = true;
          tau_cmd    = 0;
          std::cout << "Stop the robot " << std::endl;
          robot.setRobotState( vpRobot::STATE_STOP );
        }
      }
 
      if ( opt_verbose )
      {
        std::cout << "dt: " << dt << std::endl;
      }
 
      time_prev = time_cur;
      robot.wait( time_cur, 0.001 ); // Sync loop at 1000 Hz (1 ms)
    }
 
    if ( opt_save_data )
    {
      plotter->saveData( 0, "sim-joint-position.txt", "# " );
      plotter->saveData( 1, "sim-joint-position-error.txt", "# " );
      plotter->saveData( 2, "sim-joint-torque-measure.txt", "# " );
      plotter->saveData( 3, "sim-joint-error-norm.txt", "# " );
    }
 
    if ( plotter != nullptr )
    {
      delete plotter;
      plotter = nullptr;
    }
 
    robot.coppeliasimStopSimulation();
  }
  catch ( const vpException &e )
  {
    std::cout << "ViSP exception: " << e.what() << std::endl;
    std::cout << "Stop the robot " << std::endl;
    robot.setRobotState( vpRobot::STATE_STOP );
    return EXIT_FAILURE;
  }
 
  return 0;
}