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Humanoid robot leg moves randomly without setting joint poisition

asked 2020-05-29 17:19:41 -0600

hossamamr gravatar image

Whenever I spawn the robot into gazebo and start the simulation with or without the joint controllers running, the left leg starts moving facing upwards and if I publish any message for the joint to move it does not respond and keeps moving in this unknown trajectory.

This only happens to the left leg so I thought it might be a problem with the URDF or the controllers. I decided to check where the problem is so I tried spawning each leg alone and it totally went fine with the joint controllers active and the legs moving to where they should.

Right now, I am stuck with comparing the links and joints in the URDF to figure out where the problem is but I have no clue.

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answered 2020-12-04 23:02:01 -0600

guru_florida gravatar image

I had a the same issue of a "break-dancing" robot and it was largely due to my joint limits being set to 0. I have no idea why 0 limits would be such trouble but when I set <limit effort...="" lower="-3.14" upper="3.14" velocity...=""> it stopped. I also had to play with the mu1, mu2, kp and kd parameters to get a good simulation. I did a video of my process: https://www.youtube.com/watch?v=Gp3DF...</limit>

I actually ended up doing automated hyper-parameter tuning of mu1, mu2, kp and kd using Hyperopt library over 400 simulation episodes since it seems it's mostly a trial and error process.

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I know it's been too long since you answered that question and till very recently I was not very active in the ROS community but after seeing your answer and checking the video out I really wanted to thank you so much for that effort and for such detailed video.

hossamamr gravatar image hossamamr  ( 2023-03-14 05:05:09 -0600 )edit

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Asked: 2020-05-29 17:19:41 -0600

Seen: 241 times

Last updated: Dec 04 '20