The position and vibration control of the artificial muscle manipulator by variable viscosity coefficient using MR brake

In this study, an artificial rubber muscle was selected as an actuator because it is safe to be used as a muscle manipulator that comes into contact with the human body. However, this actuator vibrates and can cause delayed responses because of the air pressure that is applied to the manipulation. We built a magnetorheological (MR) brake that uses MR fluid with a fast response into the joint to control the vibration. In this study, we focus on the variable damping of the MR brake. By variable damping of the MR brake, we could apply the brake torque depending on the rotational speed of the arm in response to the artificial muscle manipulator. Moreover, we could control the viscosity coefficient of the manipulator depending on its angle and calculate the optimum brake torque as an indicator. As a result, we found that the manipulator´s lifting operation was more stable without any sudden movement. We evaluated various aspects of the manipulator control to determine the best indicator of the viscosity coefficient, and studied the position control of an artificial muscle manipulator using these methods.