diff_drive_controller.h

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/*
 * Author: Enrique Fernández
 */

#include <controller_interface/controller.h>
#include <hardware_interface/joint_command_interface.h>
#include <pluginlib/class_list_macros.h>

#include <nav_msgs/Odometry.h>
#include <tf/tfMessage.h>

#include <realtime_tools/realtime_buffer.h>
#include <realtime_tools/realtime_publisher.h>

#include <diff_drive_controller/odometry.h>
#include <diff_drive_controller/speed_limiter.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_;

    hardware_interface::JointHandle left_wheel_joint_;
    hardware_interface::JointHandle right_wheel_joint_;

    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_;

    boost::shared_ptr<realtime_tools::RealtimePublisher<nav_msgs::Odometry> > odom_pub_;
    boost::shared_ptr<realtime_tools::RealtimePublisher<tf::tfMessage> > tf_odom_pub_;
    Odometry odometry_;
    geometry_msgs::TransformStamped odom_frame_;

    double wheel_separation_;

    double wheel_radius_;

    double wheel_separation_multiplier_;
    double wheel_radius_multiplier_;

    double cmd_vel_timeout_;

    std::string base_frame_id_;

    // speed limiters
    Commands last_cmd_;
    SpeedLimiter limiter_lin_;
    SpeedLimiter limiter_ang_;

  private:
    void brake();

    void cmdVelCallback(const geometry_msgs::Twist& command);

    bool setOdomParamsFromUrdf(ros::NodeHandle& root_nh,
                               const std::string& left_wheel_name,
                               const std::string& right_wheel_name);

    void setOdomPubFields(ros::NodeHandle& root_nh, ros::NodeHandle& controller_nh);

  };

  PLUGINLIB_EXPORT_CLASS(diff_drive_controller::DiffDriveController, controller_interface::ControllerBase);
} // namespace diff_drive_controller