Using Custom Integrated Force Sensing Mechanisms for Interaction Control in Rehabilitation Robots
O'Malley, Marcia K.
Master of Science
This thesis presents the implementation of interaction controllers on two custom integrated force sensing mechanisms and demonstrates their suitability for applications to the field of rehabilitation robotics. One condition in which interaction control is beneficial occurs when the robot's dynamics are significant and need to be compensated through force-feedback. To address this need, a grip force sensor that measures forces in three planes by using force sensing resistors was developed. The device readily integrates with most rehabilitation robots at the end effector. Additionally, if a robot is non-backdrivable, force measurement is required to render transparent environments during evaluation mode as well as for interaction control. Here, interaction controllers are implemented in a 1DOF MR-compatible actuation module. The MR-compatible device uses a non-backdrivable actuator with series elasticity for force sensing. Experimental implementation of interaction controllers on both devices demonstrates the advantages of closed-loop force control.