teleop_twist deceleration

Hi, I have teleoptwistjoy driving my physical robot. so when I let go of joy stick, it slows down and stop. It doesn't slow down fast enough. How do i increase the deceleration?

Cant see a parameter and don't know witch file to look in so I can change the code.

Asked by TK hobby on 2022-07-25 02:30:41 UTC

Comments

I would suggest to describe the rest of the nodes on your robot. Are you using custom code to translate Twist to motor current/velocities? Or perhaps something from ros_control? An answer would depend on the precise details.

Asked by gvdhoorn on 2022-07-25 05:23:10 UTC

Answers

teleop_twist_joy, as far as I know, does not ramp down velocity slower than the input, it just produces the Twist message. Have a look at the output of /cmd_vel (or wherever the robot reads commands from) to make sure teleop_twist_joy is the culprit here. Make sure to look at both where you send the commands from and where you send them to. Personally, I suspect a few targets:

Overtuned motors. If you run the motors on full effect, then stop, and the motors keep running, you have a tuning problem.
Underpowered motors. If your robot is heavy, it will take longer to brake. (and, naturally, longer to accelerate)
Network problems. The messages you send from your host to the robot are throttled due to shaky networking, appearing as lag. If you experience a slow acceleration as well as a slow deceleration, this is likely it. Joysticks are typically quite sensitive, which can lead to large spikes of data. You can use ros2 topic bw <topic> to look at the bandwidth of a topic.

Asked by Per Edwardsson on 2022-07-25 03:23:11 UTC

Comments

I have not given up on this issue, just a bit side tracked to finish the robot built log. Then I will get back to the "tuning" bits. It does seem your are on to something. my pid controlled motor driver might be at fault.

Asked by TK hobby on 2022-08-09 07:21:12 UTC