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My model does not going straight

My platform: OS: Ubuntu 16.04 LTS with 4.15.0-52-generic kernel. Gazebo Version: gazebo-7

I have a differential drive model that I've created from scratch. It has 4 wheel and it's a differential drive robot. I have just create a box for chassis. It has cylindrical wheels. I didn't specify any mass or inertial info.

I put the model to the an empty gazebo world. I applied velocity to the hinges. For all hinges I applied 0,2 m/s Velocity with P(1) I(0,1) D(0,01) gains. The problem is, it is not going straight perfectly. I've tried to apply force as well. And I tried to give velocity with using a model plugin.

I've discovered that the contact points are not symmetrical. I've tried to make the wheels too thin to get rid of this thing. But it didn't work. Can you see the problem or a mistake that I did?

Here is my sdf file: C:\fakepath\model.sdf

Here is the contact points, It should be like this:0 It should be like this

But I see that contact points But I see like this

Asked by ermanas on 2019-07-25 07:41:51 UTC

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Answers

Hello again, is there anybody who has any idea about it?

Asked by ermanas on 2019-07-26 08:24:33 UTC

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This may not solve your problem, but either way you should definitely specify mass and inertial properties. Otherwise your physics simulation cannot possible be realistic.

This is a helpful page for doing this https://en.wikipedia.org/wiki/List_of_moments_of_inertia

don't forget gazebo let's you visualize momets of inertia, the purple shapes should closely match the collision shape

Asked by Peter Mitrano on 2019-07-28 19:25:34 UTC

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