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andreadelprete / consim

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computing frame acceleration dJv #2

Closed hammoudbilal closed 4 years ago

hammoudbilal commented 4 years ago

hi @andreadelprete returning frame acceleration from pinocchio as I understand requires you to call second order forward kinematics. i.e. FK(q, dq, ddq)

https://github.com/andreadelprete/consim/blob/fb4ed862b97d469c8444b299c317efd3552ddbff/script/robot_simulator_exponential_integrator.py#L48

is it called anywhere else, the only forward kinematics call I can find is https://github.com/andreadelprete/consim/blob/master/script/robot_simulator_exponential_integrator.py#L274

andreadelprete commented 4 years ago

Good point. For sure there's no call to 2nd-order FK (I think I've never used it). However, there's a call to computeAllTerms. My guess was that either computeAllTerms or FK computed link accelerations (assuming zero joint accelerations). I might be wrong, so we should check. Can you do it?

hammoudbilal commented 4 years ago

computeAllTerms computes only first order kinematics, had to call second order FK separately