An instrumented compliant wrist for robotics applications

The design and implementation of an instrumented compliant wrist is presented. The compliance helps reduce the impact effects of robot/environment interaction and improves force control performance. However, position accuracy of the end-effector degrades with increased compliance. Instrumentation of the compliant wrist enables it to serve as a compliant force/torque sensor which can be used to achieve both responsive force control and accurate position control. The wrist device uses rubber elements for compliance and damping, and a serial linkage, with potentiometers at each joint, is used for sensing deflections produced in the wrist. The wrist is connected in series between the end of the robot and the tool, and is designed to partially surround the tool, thus reducing the distance between the end-effector and the tool. A hybrid control scheme is implemented to enable the wrist to be used in a variety of applications. Example applications, including tool usage, are presented