The ARGoS Forum

Hi everybody,

I've made this simple code showing a possible bug in ARGoS physics. Very simple: a footbot and a huge and heavy box (mass: 750 kg) are located in an arena.
The footbot go straight on and pushes the box for a while. As soon as the bot stops moving (and therefore to push the box), the box mysteriously continues to slide across the floor. This bug happens both with and without a floor entity.

Attached you can find the .cpp, .h and .xml of this weird phenomenon

Thanks in advance!

Hi Nicola,

I have prepared a test distribution of ARGoS for you. It contains a couple of fixes to the 2D dynamics physics engine that (in my tests) solve the problem that you mention. The distribution is for Ubuntu 10.04LTS and newer.

With these fixes, the foot-bot is able to push/pull an object weighing up 100kg when the wheel speed is set to 5cm/s.
With an object of 1kg the robot has no problem pushing, and no sliding happens.
With an object of 10kg the robot can move the object, albeit slowly, and again no sliding happens.

Could you please give it a try and confirm it? Thanks a lot!

Thanks,

I wasn't able to install the package because of a "wrong architecture" error... :\
I should have mentioned I was using the argos2-amd64-20120130 version :S
sorry for the bothering...

No problem, here you go with the amd64 version.

Ok, now it works.

I tested the same code I posted in the first post and it is just working perfectly.
The box does not move with a 750 kg mass. With reasonable values for masses the box can be pushed and no sliding occurs.

Thank you very much again!

Ok great. Tonight I'll make a new ARGoS distribution with this fix included.
Thanks a lot for spotting the bug!