Development of Delta-Type Parallel-Link Robot Using Pneumatic Artificial Muscles and MR Clutches for Force Feedback Device

Abstract

Force feedback devices have been recently adopted in virtual reality, rehabilitation, and medical training systems. Many of these devices convey the human forces sensed by the impedance control using motors; however, motorized actuators are disadvantaged by low output and backdrivability. To resolve these disadvantages, we developed a delta-type parallel-link robot using pneumatic artificial muscles and magnetorheological MR clutches. The artificial muscles deliver high output and backdrivability, while the MR clutches enable fast responses. Moreover, because the stiffness of its pneumatic artificial muscles directly responds to forces, our robot detects human forces without feedback from force sensors. This study introduces the prototype of our delta-type parallel-link robot, and evaluates its performance in elastic movement experiment. Finally, we confirmed that our prototype robot can obtain the stiffness and unloaded condition through its MR clutches without feedback from force sensors.