four_wheel_steering_controller.h

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 *  Copyright (c) 2013, PAL Robotics, S.L.
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#pragma once
 
 
#include <controller_interface/multi_interface_controller.h>
#include <hardware_interface/joint_command_interface.h>
 
#include <nav_msgs/Odometry.h>
#include <four_wheel_steering_msgs/FourWheelSteeringStamped.h>
#include <tf/tfMessage.h>
 
#include <realtime_tools/realtime_buffer.h>
#include <realtime_tools/realtime_publisher.h>
 
#include <four_wheel_steering_controller/odometry.h>
#include <four_wheel_steering_controller/speed_limiter.h>
 
namespace four_wheel_steering_controller{
 
  class FourWheelSteeringController
      : public controller_interface::MultiInterfaceController<hardware_interface::VelocityJointInterface,
                                                              hardware_interface::PositionJointInterface>
  {
  public:
    FourWheelSteeringController();
 
    bool init(hardware_interface::RobotHW* robot_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> front_wheel_joints_;
    std::vector<hardware_interface::JointHandle> rear_wheel_joints_;
    std::vector<hardware_interface::JointHandle> front_steering_joints_;
    std::vector<hardware_interface::JointHandle> rear_steering_joints_;
 
    struct Command
    {
      ros::Time stamp;
 
      Command() : stamp(0.0) {}
    };
    struct CommandTwist : Command
    {
      double lin_x;
      double lin_y;
      double ang;
 
      CommandTwist() : lin_x(0.0), lin_y(0.0), ang(0.0) {}
    };
    struct Command4ws : Command
    {
      double lin;
      double front_steering;
      double rear_steering;
 
      Command4ws() : lin(0.0), front_steering(0.0), rear_steering(0.0) {}
    };
    realtime_tools::RealtimeBuffer<CommandTwist> command_twist_;
    CommandTwist command_struct_twist_;
    ros::Subscriber sub_command_;
 
    realtime_tools::RealtimeBuffer<Command4ws> command_four_wheel_steering_;
    Command4ws command_struct_four_wheel_steering_;
    ros::Subscriber sub_command_four_wheel_steering_;
 
    std::shared_ptr<realtime_tools::RealtimePublisher<nav_msgs::Odometry> > odom_pub_;
    std::shared_ptr<realtime_tools::RealtimePublisher<four_wheel_steering_msgs::FourWheelSteeringStamped> > odom_4ws_pub_;
    std::shared_ptr<realtime_tools::RealtimePublisher<tf::tfMessage> > tf_odom_pub_;
    Odometry odometry_;
 
    double track_;
    double wheel_steering_y_offset_;
 
    double wheel_radius_;
 
    double wheel_base_;
 
    double cmd_vel_timeout_;
 
    std::string base_frame_id_;
 
    bool enable_odom_tf_;
 
    bool enable_twist_cmd_;
 
    CommandTwist last1_cmd_;
    CommandTwist last0_cmd_;
    SpeedLimiter limiter_lin_;
    SpeedLimiter limiter_ang_;
 
  private:
 
    void updateOdometry(const ros::Time &time);
    void updateCommand(const ros::Time& time, const ros::Duration& period);
 
    void brake();
 
    void cmdVelCallback(const geometry_msgs::Twist& command);
 
    void cmdFourWheelSteeringCallback(const four_wheel_steering_msgs::FourWheelSteering &command);
 
    bool getWheelNames(ros::NodeHandle& controller_nh,
                       const std::string& wheel_param,
                       std::vector<std::string>& wheel_names);
 
    void setOdomPubFields(ros::NodeHandle& root_nh, ros::NodeHandle& controller_nh);
 
  };
 
} // namespace four_wheel_steering_controller