Fully omnidirectional compliance in mobile robots via drive-torque sensor feedback

In order to make unintentional physical interaction with robots safer for humans, we consider compliant control of an omnidirectional wheeled base. In this paper we present a fully holonomic mobile robot system which achieves compliant motion via force control, improving over previous pseudo-omnidirectional mobile systems by being fully omnidirectional. We explain our robot's drive train, and present an experimental validation of our actuator control strategy. Using a smith predictor and a simple delay-based plant model, we demonstrate compliance and safe interaction in both the mobile system alone and as the base of a wheeled mobile manipulator style system.