Imported humanoid from URDF fall aparts when start simulation

[Boby]

Hi guys,

I'm a newbie in robotics and I have some problems to create simulation. I have an URDF file which describes my robot model. This model was made in Solidworks. After importing the URDF file to CoppeliaSim I would like to make a simulation where my robot catches a cube with his grippers in Inverse kinematics mode. I studied this section: https://www.coppeliarobotics.com/helpFi ... torial.htm, but when I start my simulation, then my robot falls apart and I don't know what I'm doing wrong.

Can you help me with this problem please? I would accept any good advices or tutorials or researches which describe how to create simulations.

You can find my URDF file or scene: https://drive.google.com/open?id=1e1Bq- ... LE1utY22RL
Before the simulation I studied many tutorials as how to build a clean model https://www.coppeliarobotics.com/helpFiles/ or https://www.coppeliarobotics.com/helpFiles/


I have a second question which will refer to gripper. Do you have any ideas how to make closed loop chains in URDF which support CoppeliaSim? (If you look at my robot arm you will notice why I asked this question)
Now, I substitute loop chain with mimic joint. Lower fingers mimic upper fingers movement because I have a servo only at upper fingers.


Thanks

[coppelia]

Hello,

your model is collapsing because your joints are not dynamically enabled. Make sure to carefully read this page first.
As far as I know, there is no possibility to specify closed-loops in a URDF file.

Cheers

[Boby]

Thanks for your answer.