How to set the local respondable mask for the closed-loop legged robot

[xxm]

Hello,

I am making a legged robot model in vrep, but now I meet a difficult question in setting the local respondable mask and I don't know what I should do.

My robot is a closed-loop-legged robot. If I only adjust the global respondable mask without the local respondable mask, then my robot will shift to the right instead of straight-line if I adjust the same velocity of four joints for my quadruped robot. The trajectory curve is as follows：https://github.com/xxx-007/image/blob/m ... 20mask.png. Besides, if I do not set a local respondable mask, there are some phenomenons of interpenetrating. So I think it is necessary to set a local respondable mask for my robot.

But if I adjust the local respondable mask, then my quadruped robot will shift to the left instead of the straight line if I adjust the same velocity of four joints for my quadruped robot. The trajectory curve is as follows：https://github.com/xxx-007/image/blob/m ... 20mask.png.

So I think maybe it is the reason that I don't correctly set the local respondable mask. But I don't know how to set a local responable mask for the closed-loop-legged robot, could you give me any help or give me any models with closed-loop-legged robots?

There is another question about joints. In my robot, some joints will break apart when the velocity is very fast, so what should I do to avoid the question?

Thank you very much!

[coppelia]

Hello,

I think there are possibly several issues with your robot. Here a few thoughts:

• do not rely on collision response for the internal mechanics of your robot: only rely on joint constraints. This means, that you should be able to set all local respondable masks to 0 for your robot shapes, and your robot should operate fine by itself.
• could it be that your robot is quite small?
• how does your robot look like? Closed loops can often be modeled as open loops, i.e. you can cheat a bit for the same of stability and precision
• if your joints come apart, or your robot doesn't behave in a very stable manner, then it could also be that your masses and/or inertias are too small. Make sure to carefully read the design considerations 7 & 8

posting a link to your robot is often useful, since it can otherwise be difficult to assess what is really going on.

Cheers

[xxm]

Thanks for your advice! I will try it!