diff_drive_controller.h

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/*
 * Author: Bence Magyar, Enrique Fernández
 */
 
#pragma once
 
 
#include <control_msgs/JointTrajectoryControllerState.h>
#include <controller_interface/controller.h>
#include <diff_drive_controller/DiffDriveControllerConfig.h>
#include <diff_drive_controller/odometry.h>
#include <diff_drive_controller/speed_limiter.h>
#include <dynamic_reconfigure/server.h>
#include <geometry_msgs/TwistStamped.h>
#include <hardware_interface/joint_command_interface.h>
#include <memory>
#include <nav_msgs/Odometry.h>
#include <realtime_tools/realtime_buffer.h>
#include <realtime_tools/realtime_publisher.h>
#include <tf/tfMessage.h>
 
namespace diff_drive_controller{
 
  class DiffDriveController
      : public controller_interface::Controller<hardware_interface::VelocityJointInterface>
  {
  public:
    DiffDriveController();
 
    bool init(hardware_interface::VelocityJointInterface* hw,
              ros::NodeHandle& root_nh,
              ros::NodeHandle &controller_nh);
 
    void update(const ros::Time& time, const ros::Duration& period);
 
    void starting(const ros::Time& time);
 
    void stopping(const ros::Time& /*time*/);
 
  private:
    std::string name_;
 
    ros::Duration publish_period_;
    ros::Time last_state_publish_time_;
    bool open_loop_;
 
    std::vector<hardware_interface::JointHandle> left_wheel_joints_;
    std::vector<hardware_interface::JointHandle> right_wheel_joints_;
 
    // Previous time
    ros::Time time_previous_;
 
    std::vector<double> vel_left_previous_;
    std::vector<double> vel_right_previous_;
 
    double vel_left_desired_previous_;
    double vel_right_desired_previous_;
 
    struct Commands
    {
      double lin;
      double ang;
      ros::Time stamp;
 
      Commands() : lin(0.0), ang(0.0), stamp(0.0) {}
    };
    realtime_tools::RealtimeBuffer<Commands> command_;
    Commands command_struct_;
    ros::Subscriber sub_command_;
 
    std::shared_ptr<realtime_tools::RealtimePublisher<geometry_msgs::TwistStamped> > cmd_vel_pub_;
 
    std::shared_ptr<realtime_tools::RealtimePublisher<nav_msgs::Odometry> > odom_pub_;
    std::shared_ptr<realtime_tools::RealtimePublisher<tf::tfMessage> > tf_odom_pub_;
    Odometry odometry_;
 
    std::shared_ptr<realtime_tools::RealtimePublisher<control_msgs::JointTrajectoryControllerState> > controller_state_pub_;
 
    double wheel_separation_;
 
    double wheel_radius_;
 
    double wheel_separation_multiplier_;
    double left_wheel_radius_multiplier_;
    double right_wheel_radius_multiplier_;
 
    double cmd_vel_timeout_;
 
    bool allow_multiple_cmd_vel_publishers_;
 
    std::string base_frame_id_;
 
    std::string odom_frame_id_;
 
    bool enable_odom_tf_;
 
    size_t wheel_joints_size_;
 
    Commands last1_cmd_;
    Commands last0_cmd_;
    SpeedLimiter limiter_lin_;
    SpeedLimiter limiter_ang_;
 
    bool publish_cmd_;
 
    bool publish_wheel_joint_controller_state_;
 
    // A struct to hold dynamic parameters
    // set from dynamic_reconfigure server
    struct DynamicParams
    {
      bool update;
 
      double left_wheel_radius_multiplier;
      double right_wheel_radius_multiplier;
      double wheel_separation_multiplier;
 
      bool publish_cmd;
 
      double publish_rate;
      bool enable_odom_tf;
 
      DynamicParams()
        : left_wheel_radius_multiplier(1.0)
        , right_wheel_radius_multiplier(1.0)
        , wheel_separation_multiplier(1.0)
        , publish_cmd(false)
        , publish_rate(50)
        , enable_odom_tf(true)
      {}
 
      friend std::ostream& operator<<(std::ostream& os, const DynamicParams& params)
      {
        os << "DynamicParams:\n"
           //
           << "\tOdometry parameters:\n"
           << "\t\tleft wheel radius multiplier: "   << params.left_wheel_radius_multiplier  << "\n"
           << "\t\tright wheel radius multiplier: "  << params.right_wheel_radius_multiplier << "\n"
           << "\t\twheel separation multiplier: "    << params.wheel_separation_multiplier   << "\n"
           //
           << "\tPublication parameters:\n"
           << "\t\tPublish executed velocity command: " << (params.publish_cmd?"enabled":"disabled") << "\n"
           << "\t\tPublication rate: " << params.publish_rate                 << "\n"
           << "\t\tPublish frame odom on tf: " << (params.enable_odom_tf?"enabled":"disabled");
 
        return os;
      }
    };
 
    realtime_tools::RealtimeBuffer<DynamicParams> dynamic_params_;
 
    typedef dynamic_reconfigure::Server<DiffDriveControllerConfig> ReconfigureServer;
    std::shared_ptr<ReconfigureServer> dyn_reconf_server_;
    boost::recursive_mutex dyn_reconf_server_mutex_;
 
  private:
    void brake();
 
    void cmdVelCallback(const geometry_msgs::Twist& command);
 
    bool getWheelNames(ros::NodeHandle& controller_nh,
                       const std::string& wheel_param,
                       std::vector<std::string>& wheel_names);
 
    bool setOdomParamsFromUrdf(ros::NodeHandle& root_nh,
                               const std::string& left_wheel_name,
                               const std::string& right_wheel_name,
                               bool lookup_wheel_separation,
                               bool lookup_wheel_radius);
 
    void setOdomPubFields(ros::NodeHandle& root_nh, ros::NodeHandle& controller_nh);
 
    void reconfCallback(DiffDriveControllerConfig& config, uint32_t /*level*/);
 
    void updateDynamicParams();
 
    void publishWheelData(const ros::Time& time,
                          const ros::Duration& period,
                          Commands& curr_cmd,
                          double wheel_separation,
                          double left_wheel_radius,
                          double right_wheel_radius);
  };
 
} // namespace diff_drive_controller