Characteristics and adaptive control of pneumatic muscle actuators for a robotic elbow

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. This paper considers the development of a new high power/weight and power/volume braided pneumatic muscle actuator (PMA) having considerable power output potential, combined with controllable motion and inherent compliance to prevent damage to handled objects. Control of these muscles is explored via adaptive pole-placement controllers. Experimental results indicate that accurate position control ±1° is feasible with power/weight outputs in excess of 1 kW/kg at 200 kPa being possible