Mechatronics design for a programmable closed-loop mechanism

Abstract

As the demand increases for machines with high accuracy, high speed and high stiffness, programmable closed-loop linkages (PCLL) emerge. This paper presents further results obtained from a study of the mechatronics design approach to PCLL systems proposed by the authors elsewhere. In this approach, the system performances such as motion tracking and torque fluctuation are further improved after a suitable design of mass redistribution. In the present paper it is shown that a scheme called negative mass redistribution, which follows the principle of shaking force/shaking moment balancing, can achieve an excellent improvement in system performance. Furthermore, simultaneous variation in the length of the link and the gain of the PD controller is studied, which shows promise for further improvement in system performance. In general, these studies have shown that complex control algorithms may not achieve a better result than that achieved by a simple PD controller combined with a mass redistribution scheme.