Chai3d Point constraint interacting with haptic object

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dkchaisumdet
Posts: 12
Joined: 19 Mar 2023, 06:27

Chai3d Point constraint interacting with haptic object

Post by dkchaisumdet »

Hi,

When using a point constraint on the Chai3d Vrep module constrained to the End effector of my robot with the haptic tool cursor being fairly large how can i dampen the massive vibrations that there are when my cursor (close to the point contraint) and the mesh are close to each other.

https://imgur.com/u9t4255

I've tried changing the viscosity variable in the point constraint function ptKv thinking it would dampen large vibrations but that makes even more vibrations?

Is my simulation time step too slow or something (dt=0.0500)?

There is also nothing printing to the console window.

Ive tried to make the ptKp and ptKv variables change with the error between the cursor and the pt constraint too.

ptKp=kpgain*error
ptKv=kvgain/error

To make it so that the viscosity is high as the error comes close to zero and vice versa for the stiffness.

I have no other ideas about what to do.
Please help!

Thank you!

coppelia
Site Admin
Posts: 10339
Joined: 14 Dec 2012, 00:25

Re: Chai3d Point constraint interacting with haptic object

Post by coppelia »

Hello,

we are a little bit out of excercise with the CHAI3D usage...
The CHAI3D library will run its own high-frequency loop to provide a haptic function. That loop runs much more often that CoppeliaSim simulation loop. However: when you modify some properties within the CoppeliaSim loop, those modifications, only get picked up as the same speed as CoppeliaSim's loop, obviously.

Vibrations should thus be handled in the low-level, by CHAI3D directly (i.e. CHAI3D settings).

Cheers

dkchaisumdet
Posts: 12
Joined: 19 Mar 2023, 06:27

Re: Chai3d Point constraint interacting with haptic object

Post by dkchaisumdet »

Hi,

Do you know where abouts i can modify these settings?

Thanks

dkchaisumdet
Posts: 12
Joined: 19 Mar 2023, 06:27

Re: Chai3d Point constraint interacting with haptic object

Post by dkchaisumdet »

dkchaisumdet wrote: 17 May 2023, 12:44 Hi,

Do you know where abouts i can modify these settings?

Thanks
Hi,

Just asking this again.

Thanks

coppelia
Site Admin
Posts: 10339
Joined: 14 Dec 2012, 00:25

Re: Chai3d Point constraint interacting with haptic object

Post by coppelia »

Unfortunately no. Try to ask on the CHAI3D forum, they would be in a much better position to answer this.

Cheers

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