Regarding the inability to trace the global path？

[ju-mingyue]

Hello, I am using this package alone to follow the global path planned by myself, but the effect is very poor, mainly as follows:

1. The robot can only follow in a straight line, and it will deviate greatly when turning, and it will not even be able to track until the path will eventually stop.

2. The robot will stop when it approaches an obstacle, but when there is a new path, the robot will still stop and cannot move unless the robot is repositioned. The following are the parameters I configured:

   controllers.yaml

   controllers:

   • name: PathTrackingPID type: path_tracking_pid/TrackingPidLocalPlanner PathTrackingPID: holonomic_robot: false track_base_link: true estimate_pose_angle: false base_link_frame: base_link Kd_ang: 0.3 Kd_lat: 0.3 Ki_ang: 0.0 Ki_lat: 0.0 Kp_ang: 1.0 Kp_lat: 1.0 l: 1.0 feedback_ang: false feedback_lat: true feedforward_ang: false feedforward_lat: true controller_debug_enabled: true target_end_x_vel: 0.0 target_x_acc: 2.0 target_x_decc: 2.0 target_x_vel: 2.0 abs_minimum_x_vel: 0.0 max_error_x_vel: 1.0 max_yaw_vel: 2.0 max_yaw_acc: 2.0 min_turning_radius: 0.0

   use_mpc: false mpc_max_error_lat: 0.5 mpc_max_fwd_iter: 200 mpc_max_vel_optimization_iterations: 5 mpc_min_x_vel: 0.5 mpc_simulation_sample_time: 0.05

   anti_collision: true obstacle_speed_reduction: true collision_look_ahead_resolution: 1.0 # [m]

   global_frame_id: odom map_frame: map

   controller_frequency: 5.0 controller_max_retries: 0

[ju-mingyue]

@Timple

[Timple]

How is the tracking behavior of the robot itself?

Can you provide a plot with the cmd_vel angular.z value and the odom twist.rotational.z components during the tracking of a corner?

[ju-mingyue]

@Timple Hello, I just tested it and recorded a video, you can check the link below, the problem in the video may be more clear https://youtu.be/dRqwf_Ed-l4

My robot is not a cleaning robot, I just hope it can follow the global path more accurately, mainly for tracking or pure path tracking.

[Timple]

It should be able to do better than this. Video is clarifying.

However comparing the numbers in the terminal is tricky. Would you mind using plotjuggler to plot these to values?

In short:

sudo apt install ros-noetic-plotjuggler-ros
rosrun plotjuggler plotjuggler

[ju-mingyue]

@Timple I drew the curve of odom, but the curve of cmd_vel did not come out. The following video link includes the change of the curve: https://youtu.be/kYKbNohFzug

[Timple]

Still really hard to compare them. If you don't succeed adding it to plotjuggler, can you add odometry to the graph above?

[ju-mingyue]

@Timple Hello, I have added the cmd_vel curve, as shown in the figure above

[Timple]

Yes I see. The request was to add odometry to that graph. So both lines are in a single graph.

This way we can rule-out any strange turning behavior.