Control of a Single Link Robot Arm Actuated by Pneumatic Artificial Muscles Employing Active Force Control and Fuzzy Logic via Hardware-in-the-loop-simulation

Among the many types of actuation for robotic systems, Pneumatic Artificial Muscle (PAM) is one of the most credible and efficient classes providing high tension forces, high power density, rapid response and high power-to-weight ratio, as well as features like cleanliness and low cost. However, drawbacks such as high level of nonlinearity and time varying characteristics make this class of actuators difficult to control. In this paper, an intelligent Active Force Control(AFC) of a single-link PAM actuated robot arm employing Fuzzy Logic(FL) element has been applied and tested through simulation as well as experimental studies. The robot arm is desired to move along a one radian (about 60 degrees) circular trajectory as a joint angle tracking control in the wake of the introduced disturbances. To demonstrate the robot arm more industrially practical, a radial gripper has been physically developed and attached to the robot arm. The experiment was conducted using Hardware-in-the-Loop-Simulation (HILS) strategy, taking into account variations in the payload masses. The results clearly show the capability of the proposed controller to handle and eliminate the disturbances in the system effectively and robustly.