No abstract

As the demand increases for machines with high accuracy, high speed and high stiVness, 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¯uctuation 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.

Hydro-pneumatic suspension is the important part of running system of vehicle, with wider working frequency band, frequent reciprocating motion and heavy impact load, whose important indicator is sealing performance. The heat generation law of hydro-pneumatic suspension is obtained under the sinusoidal excitation by calculating method, and the bench test of the temperature suppression is successfully achieved.