灰色预测在FAST液压促动器中的应用

Application of Grey Predictor Based Algorithm to Hydraulic Actuator Used in FAST Project

为了满足500,m口径球面射电望远镜(FAST)工程主动反射面索网节点位置和速度控制的要求,对FAST用液压促动器进行了研究,将灰色预测模型应用到传统PID控制中,提出一种新型的步长调整机制,在简化了以往调整机制复杂性、不确定性和耗时性的同时,很好地解决了传统PID控制策略下难以获得理想跟踪精度的问题.通过与传统PID控制策略进行仿真和实验对比,结果表明,变步长灰色预测PID控制策略提高了促动器的速度跟踪精度和位置跟踪精度,速度跟踪误差由0.100,mm/s减小到0.048,mm/s,位置跟踪误差由1.5,mm减小到0.2,mm,可满足FAST工程主动反射面索网节点位置控制精度和响应速度的要求.

In order that the cable net node of active reflector has a good performance in speed control and position control which is used in the 500,m aperture spherical radio telescope（FAST）project,a study on hydraulic actuator of the project was conducted.The grey predictor model was applied to the traditional PID control strategy,and a new step adjustment mechanism was presented.The mechanism not only simplifies the complexity,uncertainty and time consumption in the previous adjustment mechanisms,but also solves the problem that it is difficult to obtain the ideal position tracking accuracy by using the conventional PID control strategy.By means of comparing the simulations and experiments between the conventional PID control strategy and the switching grey prediction PID control strategy, the results show that the switching grey prediction PID control strategy improves the velocity tracking accuracy and the position tracking accuracy.The velocity tracking error is reduced from 0.100,mm/s to 0.048,mm/s,while the po-sition tracking error is reduced from 1.5,mm to 0.2,mm,which meets the requirements of the FAST project well.