[iWholeBodyActuactors] Actuator interface design issues

robotology-legacy / codyco-modules

Whole-body Compliant Dynamical Contacts in Cognitive Humanoids

www.codyco.eu

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[iWholeBodyActuactors] Actuator interface design issues #36

Closed traversaro closed 5 years ago

traversaro commented 10 years ago

Just opened this issue to track every problem that we find in the design of iWholeBodyActuactors.

traversaro commented 10 years ago

Position, velocity and torque control mode are related to joints, while motor pwm control mode is related to motors. In case of coupled actuation this can leads to inconsistency in the interface.

francesco-romano commented 10 years ago

I think we can link to this discussion also the following issues:

traversaro commented 10 years ago

We think that for the time being we can assume that the number of motors is equal to the number of joints. This greatly simplifies the design of the actuator class. Having said that, we though about the following thing:

if not explicitly specified, a joint is actuated directly by a motor
otherwise, at configuration time, one can specify a "mapping" or group between joints. This is taken in consideration when the proper references are sent to the control board.

traversaro commented 5 years ago

We are currently using directly YARP motor interfaces in place of the wholeBodyInterface, and interesting the problem of clearly separating "motor" interfaces from "joint" interfaces, and exposing their eventual couplings is an open problem.

Interestingly, this is one of the aspects covered by the OPC UA information Model for robotics, see https://robotik.vdma.org/documents/105999/27176383/Draft_VDMA_40010-1_2018-11_%28en%29_1542967016029.pdf/c2e189e4-28ce-ebc6-1e79-b91c9efcbf8f Section B.1.8 .