A six degree-of-freedom wrist with pneumatic suspension

Abstract

This paper presents a new six-degree-of-freedom pneumatic fine-motion device that can be used as a robot wrist, a teleoperation master, or in other finemotion applications requiring high position resolution and force control. The device uses six pairs of externally pressurized mechanical bellows as a pneumatic suspension without actuator friction. Forces and torques are controlled by servoing differential pressure across each pair of bellows using novel high-flow flapper valves. Aspects of design and control are presented. Experimental results show that the valves employed have no hysteresis and have pow exceeding that of any single stage pneumatic valve currently available on the market, while the pneumatic-suspension device shows promise as a force-reflecting teleoperation master.

Toward a seven axis haptic device

“…As far as compressed air is concerned, some impressive performance figures have been reported [41]. This technique was nonet heless discarded on the grounds of application complexity.…”