srh_joint_velocity_controller.cpp

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#include "sr_mechanism_controllers/srh_joint_velocity_controller.hpp"
#include "angles/angles.h"
#include "pluginlib/class_list_macros.h"
#include <sstream>
#include <math.h>
#include "sr_utilities/sr_math_utils.hpp"

#include <std_msgs/Float64.h>

PLUGINLIB_DECLARE_CLASS(sr_mechanism_controllers, SrhJointVelocityController, controller::SrhJointVelocityController, pr2_controller_interface::Controller)

using namespace std;

namespace controller {

  SrhJointVelocityController::SrhJointVelocityController()
    : SrController(), velocity_deadband(0.015)
  {
  }

  SrhJointVelocityController::~SrhJointVelocityController()
  {
    sub_command_.shutdown();
  }

  bool SrhJointVelocityController::init(pr2_mechanism_model::RobotState *robot, const std::string &joint_name,
                                        boost::shared_ptr<control_toolbox::Pid> pid_velocity)
  {
    ROS_DEBUG(" --------- ");
    ROS_DEBUG_STREAM("Init: " << joint_name);

    assert(robot);
    robot_ = robot;
    last_time_ = robot->getTime();

    if( joint_name.substr(3,1).compare("0") == 0)
    {
      has_j2 = true;
      std::string j1 = joint_name.substr(0,3) + "1";
      std::string j2 = joint_name.substr(0,3) + "2";
      ROS_DEBUG_STREAM("Joint 0: " << j1 << " " << j2);

      joint_state_ = robot_->getJointState(j1);
      if (!joint_state_)
      {
        ROS_ERROR("SrhVelocityController could not find joint named \"%s\"\n",
                  j1.c_str());
        return false;
      }

      joint_state_2 = robot_->getJointState(j2);
      if (!joint_state_2)
      {
        ROS_ERROR("SrhVelocityController could not find joint named \"%s\"\n",
                  j2.c_str());
        return false;
      }
      if (!joint_state_2->calibrated_)
      {
        ROS_ERROR("Joint %s not calibrated for SrhVelocityJointController", j2.c_str());
        return false;
      }
    }
    else
    {
      has_j2 = false;
      joint_state_ = robot_->getJointState(joint_name);
      if (!joint_state_)
      {
        ROS_ERROR("SrhVelocityController could not find joint named \"%s\"\n",
                  joint_name.c_str());
        return false;
      }
      if (!joint_state_->calibrated_)
      {
        ROS_ERROR("Joint %s not calibrated for SrhJointVelocityController", joint_name.c_str());
        return false;
      }
    }

    friction_compensator = boost::shared_ptr<sr_friction_compensation::SrFrictionCompensator>(new sr_friction_compensation::SrFrictionCompensator(joint_name));

    pid_controller_velocity_ = pid_velocity;

    serve_set_gains_ = node_.advertiseService("set_gains", &SrhJointVelocityController::setGains, this);
    serve_reset_gains_ = node_.advertiseService("reset_gains", &SrhJointVelocityController::resetGains, this);

    after_init();
    return true;
  }

  bool SrhJointVelocityController::init(pr2_mechanism_model::RobotState *robot, ros::NodeHandle &n)
  {
    assert(robot);
    node_ = n;

    std::string joint_name;
    if (!node_.getParam("joint", joint_name)) {
      ROS_ERROR("No joint given (namespace: %s)", node_.getNamespace().c_str());
      return false;
    }

    boost::shared_ptr<control_toolbox::Pid> pid_velocity = boost::shared_ptr<control_toolbox::Pid>( new control_toolbox::Pid() );;
    if (!pid_velocity->init(ros::NodeHandle(node_, "pid")))
      return false;


    controller_state_publisher_.reset(
      new realtime_tools::RealtimePublisher<pr2_controllers_msgs::JointControllerState>
      (node_, "state", 1));

    return init(robot, joint_name, pid_velocity);
  }


  void SrhJointVelocityController::starting()
  {
    if( has_j2 )
      command_ = (joint_state_->velocity_ + joint_state_2->velocity_) / 2.0;
    else
      command_ = joint_state_->velocity_;
    pid_controller_velocity_->reset();
    read_parameters();

    ROS_WARN("Reseting PID");
  }

  bool SrhJointVelocityController::setGains(sr_robot_msgs::SetPidGains::Request &req,
                                            sr_robot_msgs::SetPidGains::Response &resp)
  {
    pid_controller_velocity_->setGains(req.p,req.i,req.d,req.i_clamp,-req.i_clamp);
    max_force_demand = req.max_force;
    friction_deadband = req.friction_deadband;
    velocity_deadband = req.deadband;

    //Setting the new parameters in the parameter server
    node_.setParam("pid/p", req.p);
    node_.setParam("pid/i", req.i);
    node_.setParam("pid/d", req.d);
    node_.setParam("pid/i_clamp", req.i_clamp);

    node_.setParam("pid/max_force", max_force_demand);
    node_.setParam("pid/velocity_deadband", velocity_deadband);
    node_.setParam("pid/friction_deadband", friction_deadband);

    return true;
  }

  bool SrhJointVelocityController::resetGains(std_srvs::Empty::Request& req, std_srvs::Empty::Response& resp)
  {
    if( has_j2 )
      command_ = (joint_state_->velocity_ + joint_state_2->velocity_) / 2.0;
    else
      command_ = joint_state_->velocity_;

    if (!pid_controller_velocity_->init(ros::NodeHandle(node_, "velocity_pid")))
      return false;

    read_parameters();

    if( has_j2 )
      ROS_WARN_STREAM("Reseting controller gains: " << joint_state_->joint_->name << " and " << joint_state_2->joint_->name);
    else
      ROS_WARN_STREAM("Reseting controller gains: " << joint_state_->joint_->name);

    return true;
  }

  void SrhJointVelocityController::getGains(double &p, double &i, double &d, double &i_max, double &i_min)
  {
    pid_controller_velocity_->getGains(p,i,d,i_max,i_min);
  }

  void SrhJointVelocityController::update()
  {
    if( !has_j2 )
    {
      if (!joint_state_->calibrated_)
        return;
    }

    assert(robot_ != NULL);
    ros::Time time = robot_->getTime();
    assert(joint_state_->joint_);
    dt_= time - last_time_;

    if (!initialized_)
    {
      initialized_ = true;
      if( has_j2 )
        command_ = (joint_state_->velocity_ + joint_state_2->velocity_) / 2.0;
      else
        command_ = joint_state_->velocity_;
    }

    //Compute velocity demand from position error:
    double error_velocity = 0.0;
    if( has_j2 )
      error_velocity  = (joint_state_->velocity_ + joint_state_2->velocity_)/2.0 - command_;
    else
      error_velocity  = joint_state_->velocity_ - command_;

    double commanded_effort = 0.0;

    //don't compute the error if we're in the deadband.
    if( !hysteresis_deadband.is_in_deadband(command_, error_velocity, velocity_deadband) )
    {
      commanded_effort = pid_controller_velocity_->updatePid(error_velocity, dt_);

      //clamp the result to max force
      commanded_effort = min( commanded_effort, max_force_demand );
      commanded_effort = max( commanded_effort, -max_force_demand );

      if( has_j2 )
        commanded_effort += friction_compensator->friction_compensation( (joint_state_->position_ + joint_state_2->position_) ,(joint_state_->velocity_ + joint_state_2->velocity_), int(commanded_effort), friction_deadband );
      else
        commanded_effort += friction_compensator->friction_compensation( joint_state_->position_, joint_state_->velocity_, int(commanded_effort), friction_deadband );
    }
    if( has_j2 )
      joint_state_2->commanded_effort_ = commanded_effort;
    else
      joint_state_->commanded_effort_ = commanded_effort;

    if(loop_count_ % 10 == 0)
    {
      if(controller_state_publisher_ && controller_state_publisher_->trylock())
      {
        controller_state_publisher_->msg_.header.stamp = time;
        controller_state_publisher_->msg_.set_point = command_;
        if( has_j2 )
          controller_state_publisher_->msg_.process_value = ( joint_state_->velocity_ + joint_state_2->velocity_) / 2.0;
        else
          controller_state_publisher_->msg_.process_value = joint_state_->velocity_;
        controller_state_publisher_->msg_.error = error_velocity;
        controller_state_publisher_->msg_.time_step = dt_.toSec();
        controller_state_publisher_->msg_.command = commanded_effort;

        double dummy;
        getGains(controller_state_publisher_->msg_.p,
                 controller_state_publisher_->msg_.i,
                 controller_state_publisher_->msg_.d,
                 controller_state_publisher_->msg_.i_clamp,
                 dummy);
        controller_state_publisher_->unlockAndPublish();
      }
    }
    loop_count_++;

    last_time_ = time;
  }

  void SrhJointVelocityController::read_parameters()
  {
    node_.param<double>("pid/max_force", max_force_demand, 1023.0);
    node_.param<double>("pid/velocity_deadband", velocity_deadband, 0.015);
    node_.param<int>("pid/friction_deadband", friction_deadband, 5);
  }
}

/* For the emacs weenies in the crowd.
Local Variables:
   c-basic-offset: 2
End:
*/