Adaptive position control of antagonistic pneumatic muscle actuators

Problems with the control and compliance of pneumatic systems have prevented their widespread use in advanced robotics. However, their compactness, power/weight ratio and inherent safety are factors that could potentially be exploited in sophisticated dexterous manipulator designs. These advantages have lead to the development of novel actuators such as the McKibben Muscle, Rubbertuator, Flexator, Romac and pneumatic muscle actuators (PMA). However, the nonlinearities in these systems still limit their controllability. This paper considers the development of an adaptive controller for bi-muscular PMA system. Control of these muscles is explored via adaptive pole-placement controllers. Experimental results indicate that accurate position control ±2° is feasible, with power/weight outputs in excess of 1 kW/kg at 250 kPa being possible