PyBullet: get dynamics information

[bdelhaisse]

Hi Erwin,

Is it possible to get dynamics information when using PyBullet? Specifically, I would like to get:

• the joint accelerations when calling getJointState(s).
• the link acceleration in the world frame when calling getLinkState.
• the moment around a contact point when calling getContactPoints.

If you don't have the time to implement it, could you point me how I can implement these features?

Thanks!

[erwincoumans]

We don't explicitly keep track of link/joint accelerations and torque around the contacts.
For accelerations, you could manually save the previous link/joint velocity and compute the accelerations using finite differencing.
We also don't store the applied torques at the contact points, we only expose the forces (normal, and 2 lateral friction directional forces). It could be added to pybullet.getContactPoints.

Explaining how is just as much work as doing the actual implementation.