Pepper right shoulder pitch wont respond in timeline ir inspector

Question

I'm trying to make some reach-grasp trajectories in timeline. They work fine with the virtual robot. On the real Pepper, sometimes they execute fine, then, next try, the right arm doesnt move in the complete trajectory. If I then use the inspector to move the right shoulder pitch, it gets stuck around 50°.

I wonder if there is some stiffness, or force, parameter: it is as if the robot does not have the strength to make the movement.

Answer 1

You may debug the hand movement with a simple command line Python script that we have made for us. See https://nlp.fi.muni.cz/trac/pepper/wiki/SetArmPosition with a link to souce code.

Answer 2

Pepper has barely the strength to lift its arms when stretched. When it does so, these motors get hot, and the power fed to them is reduced, to the point where the motion cannot be performed.

Prefer more complex motion, that requires less instantaneous strength to perform, for instance by using a bit of the roll motion, and by stretching the arms only at the last moment.