Force-Based Compliant Behaviors to Augment Telerobotics

Analysis of direct teleoperation with force feedback indicates that humans have difficulties perceiving the direction and amount of reflected force. Locally implemented force-based reactive behaviors provide accurate and timely feedback to assist in replicating human skills and dexterity. The contact forces between the slave arm tool and the environment is analyzed using three settings. First, the user-controlled teleoperation with networked force feedback. Analysis of contact with the environment indicates that the use of high force gain improves operator sensitivity but may cause instability in pre-contact and postcontact phases. Second, programmed compliance at slave arm is used to selectively convert sensed forces into corrective motion to minimize contact forces. Third, a supervisory mechanism based on a user-controlled active compliance behavior is proposed for teleoperation. A user-controlled compliance loop at the slave arm improved contact stability and provided an effective supervisory control. Light and stiff arms are highly recommended to reduce the degradation in telerobotic synchronization caused by elasticity in linkage transmission and by the network delays. Force based compliance behaviors provide controllable compliance both in amount and direction and (2) shorten feedback delays.