Exoskeletal master device for dual arm robot teaching

Abstract Dual arm robots are used as humanoid or industrial robots for assembly work. Each arm of these robots is generally composed of 7-DOF to mimic the human arm. For motion teaching of this 7-DOF robot arm, upper limb exoskeletal master devices can be used, and each arm of the upper limb exoskeletal master device can also be composed of 7-DOF. However, the motions of the human shoulder are complex and the lack of DOF in the exoskeletal master device limits the wearer's motions and makes the wearer feel uncomfortable. We propose a compact-sized exoskeletal master device, each of whose arms are composed of two serially connected parts. One is a 6-DOF shoulder–elbow mechanism and the other is a 3-DOF wrist mechanism. The 6-DOF mechanism serially connects the base frame near the shoulder to a point on the forearm, and the center of rotation of the shoulder joint is shifted to the outside of the human shoulder. In addition, the 6-DOF mechanism includes a long stroke but short reduced-length prismatic joint. This 6-DOF mechanism enables unconstrained and comfortable shoulder motions. The 3-DOF wrist mechanism corresponds to forearm pronation/supination, wrist flexion/extension, and wrist adduction/abduction. The closed-loop inverse kinematic scheme is applied for the dual arm robot control in the task space. The performance of the exoskeletal master devices and control strategies are verified through experiments using a 14-DOF dual arm slave robot.