Actuator inertia

[nielsvd]

Actuators used in industrial robotic arms typically have a reasonably low inertia, which can be included in the link inertia. However, the actuator inertia has another important effect on the rigid body dynamics; namely, due to the gear ratio between the motor and the joint, the actuator inertia significantly contributes to the required torque to achieve a certain requested motion.

At the moment it seems that the URDF specification does not support the specification of such contribution of motor inertia. I think it could be well-placed in the tag.

Some relevant questions for the discussion:

• Am I missing out on something (actuator inertia is supported)?
• If not, is it in accordance to the philosophy behind URDF to include actuator inertia in the specification?
• If so, do you agree it should be place in the element?

Thanks in advance for your input.

[nielsvd]

Issue in wrong repository. Moved to: ros/urdfdom#78