I am attempting to simulate a servo arm similar to those used in the Aloha kits, which do not have torque control and have a large gear ratio. From my understanding, Drake uses a force-based simulator. With that, simulating these types of arms with high PD gains might lead to numerical instability. Drake perfectly supports torque-based manipulators like Kuka and Franka Panda, but I am uncertain about the best approach for simulating and controlling these more basic servo-based arms, which typically exhibit larger control errors and gear ratios.

Any insights or resources would be greatly appreciated!

Currently, I am using JointStiffnessDriver in drake, but it didn’t match the real world so well.