Compliant Robot Wrist with Passive and Active Features

摘要

Interaction between a robot and the environment occurs in many tasks such as grasping, assembling, grinding and deburring. The transition between free motion and constrained motion - the impact - is especially difficult to control. Much research work is done on force control and passive compliance to solve this problem. For practical applications devices with passive compliance are mainly used.rnIn this paper we present a specially designed compliant device to support constrained robot motions with large and heavy work pieces. The device has 6 degrees of freedom. The deviations of the compliant device are measured and used for error compensation and control. The stiffness of three directions can be varied pneumatically. The developed system is used inside an industrial application, in which a robot handles sheet metal parts at a press brake. The sensor equipped compliant device supports fast positioning of metal sheets at mechanical backstops of the press brake.