A servocontrolled pneumatic actuator for small movement-application to an adaptive gripper

An actuator capable of providing continuous controllable micro-movement is indispensable to realize compliant devices required in advanced robot applications. This paper presents a new servo-controlled pneumatic actuator that is composed of a low friction cylinder using a metallic bellows and a PWM pneumatic servomechanism. By considering the opening and closing delay properties, an equivalent mass flow rate model for the PWM solenoid valve device is established. Based on this model, a nonlinear control method is developed to overcome the nonlinear and the dissymmetric problems in the PWM pneumatic servomechanism. The result of applying the actuator to an adaptive gripper is also presented.<>