High dynamics and high accuracy parallel robot for pick and place applications

摘要

In this paper, a 5R symmetrical parallel robot for pick and place applications is presented. It reaches an acceleration of 150 m·s~(-2) and a speed of 5 m·s~(-1) with high position repeatability, high position stability as well as low settling time. The robot is driven by two high power torque motors equipped with high resolution rotary encoders. In addition, a novel spatial encoder is mounted on the end effector, which measures five degrees of freedom and extrapolates to the position of the tool centre point. A novel dual feedback control strategy combines the position data of the rotary encoders and the spatial encoder. A prototype has been developed for a workspace of 300 mm × 300 mm. The design of the robot links has been optimized using coupled mechatronic simulations to minimize settling time. The dual feedback control scheme has been optimized for highest bandwidth in combination with high position accuracy of the tool centre point. Test results demonstrate the effectiveness of the mechanical design, the tool centre point measurement and the control strategy.