Prototype Development of a Parallel-Link Robot Actuated by Pneumatic Linear Drives with Variable Inclination Mechanisms

Abstract

Parallel-link robots are generally high in power and precision because of their parallel arrangement of actuators. However, they have a workspace smaller than that of serial-link robots. In this paper, we develop a parallel-link robot prototype with pneumatic linear drives in which a mechanism for varying the actuator inclination is incorporated to enlarge the workspace. Our parallel-link robot realizes the rotational and translational motions of the end effector principally by means of the linear reciprocating motions of pneumatic linear drives mounted on the base. Auxiliary pneumatic actuators are used to adjust the inclination angles of those main pneumatic linear drives. The use of pneumatic actuators to realize the proposed parallel-link robot results in a lightweight, compact, and low-cost construction. The workspace and motion transmissibility of our parallel-link robot are analyzed through simulations based on kinematics; then, experimental investigations are carried out using the prototype.