A control strategy for operating unknown constrained mechanisms

This work aims at the development of a versatile control strategy for operating unknown mechanically constrained devices such as drawers or doors. Few assumptions on the device's shape as well as the utilized hardware are required. Our approach is based on an on-line estimation of the constraint manifold which serves as a reference input for an admittance-type controller providing the compliance required. The direction estimation is obtained from the velocity signal in task space. An on-line adaptation of the admittance controller according to the estimated moving direction reduces contact forces. The functionality of the control strategy is demonstrated on a mobile manipulator in a kitchen environment.