pose_tracking.h

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/*
   Author: Andy Zelenak
   Desc: Servoing. Track a pose setpoint in real time.
*/
 
#pragma once
 
#include <atomic>
#include <control_toolbox/pid.hpp>
#include <moveit_servo/make_shared_from_pool.h>
#include <moveit_servo/servo_parameters.h>
#include <moveit_servo/servo.h>
#include <optional>
#include <tf2_geometry_msgs/tf2_geometry_msgs.hpp>
#include <tf2_ros/transform_listener.h>
#include <rclcpp/rclcpp.hpp>
 
// Conventions:
// Calculations are done in the planning_frame_ unless otherwise noted.
 
namespace moveit_servo
{
struct PIDConfig
{
  // Default values
  double dt = 0.001;
  double k_p = 1;
  double k_i = 0;
  double k_d = 0;
  double windup_limit = 0.1;
};
 
enum class PoseTrackingStatusCode : int8_t
{
  INVALID = -1,
  SUCCESS = 0,
  NO_RECENT_TARGET_POSE = 1,
  NO_RECENT_END_EFFECTOR_POSE = 2,
  STOP_REQUESTED = 3
};
 
const std::unordered_map<PoseTrackingStatusCode, std::string> POSE_TRACKING_STATUS_CODE_MAP(
    { { PoseTrackingStatusCode::INVALID, "Invalid" },
      { PoseTrackingStatusCode::SUCCESS, "Success" },
      { PoseTrackingStatusCode::NO_RECENT_TARGET_POSE, "No recent target pose" },
      { PoseTrackingStatusCode::NO_RECENT_END_EFFECTOR_POSE, "No recent end effector pose" },
      { PoseTrackingStatusCode::STOP_REQUESTED, "Stop requested" } });
 
class PoseTracking
{
public:
  PoseTracking(const rclcpp::Node::SharedPtr& node, const ServoParameters::SharedConstPtr& servo_parameters,
               const planning_scene_monitor::PlanningSceneMonitorPtr& planning_scene_monitor);
 
  PoseTrackingStatusCode moveToPose(const Eigen::Vector3d& positional_tolerance, const double angular_tolerance,
                                    const double target_pose_timeout);
 
  void stopMotion();
 
  void updatePIDConfig(const double x_proportional_gain, const double x_integral_gain, const double x_derivative_gain,
                       const double y_proportional_gain, const double y_integral_gain, const double y_derivative_gain,
                       const double z_proportional_gain, const double z_integral_gain, const double z_derivative_gain,
                       const double angular_proportional_gain, const double angular_integral_gain,
                       const double angular_derivative_gain);
 
  void getPIDErrors(double& x_error, double& y_error, double& z_error, double& orientation_error);
 
  bool getCommandFrameTransform(geometry_msgs::msg::TransformStamped& transform);
 
  void resetTargetPose();
 
  // moveit_servo::Servo instance. Public so we can access member functions like setPaused()
  std::unique_ptr<moveit_servo::Servo> servo_;
 
private:
  void readROSParams();
 
  void initializePID(const PIDConfig& pid_config, std::vector<control_toolbox::Pid>& pid_vector);
 
  bool haveRecentTargetPose(const double timeout);
 
  bool haveRecentEndEffectorPose(const double timeout);
 
  bool satisfiesPoseTolerance(const Eigen::Vector3d& positional_tolerance, const double angular_tolerance);
 
  void targetPoseCallback(const geometry_msgs::msg::PoseStamped::ConstSharedPtr& msg);
 
  void updateControllerSetpoints();
 
  void updateControllerStateMeasurements();
 
  geometry_msgs::msg::TwistStamped::ConstSharedPtr calculateTwistCommand();
 
  void doPostMotionReset();
 
  rclcpp::Node::SharedPtr node_;
  moveit_servo::ServoParameters::SharedConstPtr servo_parameters_;
 
  planning_scene_monitor::PlanningSceneMonitorPtr planning_scene_monitor_;
  moveit::core::RobotModelConstPtr robot_model_;
  // Joint group used for controlling the motions
  std::string move_group_name_;
 
  rclcpp::WallRate loop_rate_;
 
  // ROS interface to Servo
  rclcpp::Publisher<geometry_msgs::msg::TwistStamped>::SharedPtr twist_stamped_pub_;
 
  std::vector<control_toolbox::Pid> cartesian_position_pids_;
  std::vector<control_toolbox::Pid> cartesian_orientation_pids_;
  // Cartesian PID configs
  PIDConfig x_pid_config_, y_pid_config_, z_pid_config_, angular_pid_config_;
 
  // Transforms w.r.t. planning_frame_
  Eigen::Isometry3d command_frame_transform_;
  rclcpp::Time command_frame_transform_stamp_ = rclcpp::Time(0, 0, RCL_ROS_TIME);
  geometry_msgs::msg::PoseStamped target_pose_;
  mutable std::mutex target_pose_mtx_;
 
  // Subscribe to target pose
  rclcpp::Subscription<geometry_msgs::msg::PoseStamped>::SharedPtr target_pose_sub_;
 
  tf2_ros::Buffer transform_buffer_;
  tf2_ros::TransformListener transform_listener_;
 
  // Expected frame name, for error checking and transforms
  std::string planning_frame_;
 
  // Flag that a different thread has requested a stop.
  std::atomic<bool> stop_requested_;
 
  std::optional<double> angular_error_;
};
 
// using alias
using PoseTrackingPtr = std::shared_ptr<PoseTracking>;
}  // namespace moveit_servo