joint_position_controller.h

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/*
 Author: Dave Coleman
 Contributors: Jonathan Bohren, Wim Meeussen, Vijay Pradeep
 Desc: Velocity-based position controller using basic PID loop
*/

#ifndef VELOCITY_CONTROLLERS__JOINT_POSITION_CONTROLLER_H
#define VELOCITY_CONTROLLERS__JOINT_POSITION_CONTROLLER_H

#include <ros/node_handle.h>
#include <urdf/model.h>
#include <control_toolbox/pid.h>
#include <boost/scoped_ptr.hpp>
#include <boost/thread/condition.hpp>
#include <realtime_tools/realtime_publisher.h>
#include <hardware_interface/joint_command_interface.h>
#include <controller_interface/controller.h>
#include <control_msgs/JointControllerState.h>
#include <std_msgs/Float64.h>
#include <control_msgs/JointControllerState.h>
#include <realtime_tools/realtime_buffer.h>

namespace velocity_controllers
{

class JointPositionController: public controller_interface::Controller<hardware_interface::VelocityJointInterface>
{
public:

  struct Commands
  {
    double position_; // Last commanded position
    double velocity_; // Last commanded velocity
    bool has_velocity_; // false if no velocity command has been specified
  };

  JointPositionController();
  ~JointPositionController();

  bool init(hardware_interface::VelocityJointInterface *robot, ros::NodeHandle &n);

  void setCommand(double pos_target);

  void setCommand(double pos_target, double vel_target);

  void starting(const ros::Time& time);
  
  void update(const ros::Time& time, const ros::Duration& period);

  void getGains(double &p, double &i, double &d, double &i_max, double &i_min);

  void printDebug();

  void setGains(const double &p, const double &i, const double &d, const double &i_max, const double &i_min);

  std::string getJointName();

  double getPosition();

  hardware_interface::JointHandle joint_;
  boost::shared_ptr<const urdf::Joint> joint_urdf_;
  realtime_tools::RealtimeBuffer<Commands> command_;
  Commands command_struct_; // pre-allocated memory that is re-used to set the realtime buffer

private:
  int loop_count_;
  control_toolbox::Pid pid_controller_;       
  boost::scoped_ptr<
    realtime_tools::RealtimePublisher<
      control_msgs::JointControllerState> > controller_state_publisher_ ;

  ros::Subscriber sub_command_;

  void setCommandCB(const std_msgs::Float64ConstPtr& msg);

  void enforceJointLimits(double &command);

};

} // namespace

#endif