Control of a joint actuated by two pneumatic artificial muscles with fast switching on-off valves

Abstract

Abstract — The power to weight ratio of the actuators is an important design factor for running robots. In this re-gard pleated pneumatic artificial muscles are excellent ac-tuators. Another advantage is that they can actuate a joint directly, avoiding the additional weight and cost of a gear-box. Obviously the weight of the pressure control valves has to be taken into consideration as well. For this applica-tion, standard pressure regulating valves are rather heavy and slow. An intelligently controlled array of fast switching on-off valves was tested as an alternative. Ways to decrease the opening and closing times of these valves are discussed in this paper. Simulations and experimental results will be compared. The design of a modular rotational joint with an antagonistic set-up of two pleated pneumatic artificial muscles will be presented. I.