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Problem with the robot model moving itself [closed]

asked 2015-08-17 20:18:22 -0600

updated 2015-08-19 18:50:18 -0600

I'm a beginner in the ROS/Gazebo/robotics world. I started to work in a robotics research lab in my university, and I have to model an Hexapod. Apparently, the URDF Xacro is alright: the visuals, collisions, inertia tensors, COM, mass, joint tags, etc..

But when I spawn the model on GazeboSim, it doesn't get immovable. Instead, it get agitated. I thought is was caused by a bad inertia tensor, so I fixed the meshes from the original solid parts, calculated the mass properties and replaced the faulty inertial tags and meshes. But this didn't solve the problem. When I was recording the screen to post this question, I have noticed that the most I increased the effort limit, the most it became agitated. Here's the video that shows this behavior. And you can see, in the rostopic terminal, that the effort value applied to the joint is the max value (positive or negative) defined in the robot URDF Xacro file, and I don't know why this is happening.

Here's the robot description.

What can be made to solve this problem? I'm getting crazy with this problem haha

Thanks :D

P.S.: Sorry for my English.

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Closed for the following reason the question is answered, right answer was accepted by emersonfs
close date 2015-08-19 20:19:11.273333

2 answers

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answered 2015-08-19 18:27:22 -0600

updated 2015-08-19 18:27:56 -0600

I made the same question in ROS Answers, and this answer helped me a lot. Like I said in the answer comments, the PID controllers wasn't properly tuned, so I dropped down the PID values and now the Hexapod is stable.

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answered 2015-08-19 10:51:27 -0600

I'm working in a similar problem.

Have you checked the joint damping values?

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The robot description does not have damping tags for now.

emersonfs gravatar imageemersonfs ( 2015-08-19 18:29:21 -0600 )edit

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Asked: 2015-08-17 20:18:22 -0600

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Last updated: Aug 19 '15