pid.h

Go to the documentation of this file.

/*********************************************************************
 * Software License Agreement (BSD License)
 *
 *  Copyright (c) 2008, Willow Garage, Inc.
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *   * Neither the name of the Willow Garage nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 *  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 *  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 *********************************************************************/
#ifndef CONTROL_TOOLBOX__PID_H
#define CONTROL_TOOLBOX__PID_H
 
 
#include <string>
#include <ros/ros.h>
#include <control_msgs/PidState.h>
 
// Dynamic reconfigure
#include <dynamic_reconfigure/server.h>
#include <control_toolbox/ParametersConfig.h>
#include <boost/thread/mutex.hpp>
 
// Realtime buffer
#include <realtime_tools/realtime_buffer.h>
#include <realtime_tools/realtime_publisher.h>
 
class TiXmlElement;
 
namespace control_toolbox {
 
/***************************************************/
/***************************************************/
 
class Pid
{
public:
 
  struct Gains
  {
    // Optional constructor for passing in values without antiwindup
    Gains(double p, double i, double d, double i_max, double i_min)
      : p_gain_(p),
        i_gain_(i),
        d_gain_(d),
        i_max_(i_max),
        i_min_(i_min),
        antiwindup_(false)
    {}
    // Optional constructor for passing in values
    Gains(double p, double i, double d, double i_max, double i_min, bool antiwindup)
      : p_gain_(p),
        i_gain_(i),
        d_gain_(d),
        i_max_(i_max),
        i_min_(i_min),
        antiwindup_(antiwindup)
    {}
    // Default constructor
    Gains()
      : p_gain_(0.0),
        i_gain_(0.0),
        d_gain_(0.0),
        i_max_(0.0),
        i_min_(0.0),
        antiwindup_(false)
    {}
    double p_gain_;   
    double i_gain_;   
    double d_gain_;   
    double i_max_;    
    double i_min_;    
    bool antiwindup_; 
  };
 
  Pid(double p = 0.0, double i = 0.0, double d = 0.0, double i_max = 0.0, double i_min = -0.0, bool antiwindup = false);
 
  Pid(const Pid &source);
 
  ~Pid();
 
  void initPid(double p, double i, double d, double i_max, double i_min, bool antiwindup = false);
 
  void initPid(double p, double i, double d, double i_max, double i_min, const ros::NodeHandle& /*node*/);
  void initPid(double p, double i, double d, double i_max, double i_min, bool antiwindup, const ros::NodeHandle& /*node*/);
 
  bool initParam(const std::string& prefix, const bool quiet=false);
 
  bool init(const ros::NodeHandle &n, const bool quiet=false);
 
  bool initXml(TiXmlElement *config);
 
  void initDynamicReconfig(ros::NodeHandle &node);
 
  void reset();
 
  void reset(double d_error, double i_error);
 
  void getGains(double &p, double &i, double &d, double &i_max, double &i_min);
  void getGains(double &p, double &i, double &d, double &i_max, double &i_min, bool &antiwindup);
 
  Gains getGains();
 
  void setGains(double p, double i, double d, double i_max, double i_min, bool antiwindup = false);
 
  void setGains(const Gains &gains);
 
  void updateDynamicReconfig();
  void updateDynamicReconfig(Gains gains_config);
  void updateDynamicReconfig(control_toolbox::ParametersConfig config);
 
  void dynamicReconfigCallback(control_toolbox::ParametersConfig &config, uint32_t /*level*/);
 
  double computeCommand(double error, ros::Duration dt);
 
  double computeCommand(double error, double error_dot, ros::Duration dt);
 
  ROS_DEPRECATED double updatePid(double p_error, ros::Duration dt);
 
  ROS_DEPRECATED double updatePid(double error, double error_dot, ros::Duration dt);
 
  void setCurrentCmd(double cmd);
 
  double getCurrentCmd();
 
  void getCurrentPIDErrors(double *pe, double *ie, double *de);
 
 
  void printValues();
 
  Pid &operator =(const Pid& source)
  {
    if (this == &source)
      return *this;
 
    // Copy the realtime buffer to then new PID class
    gains_buffer_ = source.gains_buffer_;
 
    // Reset the state of this PID controller
    reset();
 
    return *this;
  }
 
private:
 
  // Store the PID gains in a realtime buffer to allow dynamic reconfigure to update it without
  // blocking the realtime update loop
  realtime_tools::RealtimeBuffer<Gains> gains_buffer_;
 
  boost::shared_ptr<realtime_tools::RealtimePublisher<control_msgs::PidState> > state_publisher_;
  bool publish_state_;
 
  bool valid_p_error_last_; 
  double p_error_last_; 
  double p_error_; 
  double i_error_; 
  double d_error_; 
  double cmd_;     
  // Dynamics reconfigure
  bool dynamic_reconfig_initialized_;
  typedef dynamic_reconfigure::Server<control_toolbox::ParametersConfig> DynamicReconfigServer;
  boost::shared_ptr<DynamicReconfigServer> param_reconfig_server_;
  DynamicReconfigServer::CallbackType param_reconfig_callback_;
 
  boost::recursive_mutex param_reconfig_mutex_;
 
};
 
}
 
#endif