Research on Time Delay of MR Buffer System Under Impact Load

The primary purpose of this paper is to provide a comprehensive review on the time delay of impact MR buffer system. The phenomenon of time delay which occurs in most of the MR buffer systems has been given little attentions especially in the applications where little time delay is demanded. Furthermore, the methods of reducing time delay have not been discussed in detail. So, in this study, several efforts have been made to decrease or even eliminate the phenomenon of time delay. Firstly, we analyzed two kinds of power supply sources and coil winding patterns. Next, an advanced correcting circuit was designed and the parameters of transfer function were determined by experimental data. The results show that, compared with the original circuit, it only takes 5ms to achieve 95% of the final state after correction, which increases 75% immediately. Furthermore, to evaluate the effect of compensation control strategy on time delay, the adaptive Smith compensation control was adopted and tested. Using the open on-off control strategy, four operating start times of current were applied, ranging from 0 to 300ms in increments of 100ms. The results show that the original maximum time delay is more than 150ms and it can be reduced to less than 50ms by adaptive smith compensation. Further analysis illustrates that decreasing time delay improves the dynamic performance of MRD in the buffer process, such as decreased overshoot, less fluctuation etc.