大口径射电望远镜伺服时滞因素分析及其预测补偿控制

Analysis and Prediction Compensation Control of Servo Time Delay Factors for Large Radio Telescopes

射电望远镜控制系统是一个多变量复杂系统,伺服系统中的摩擦、齿轮间隙等众多时滞因素严重影响着射电望远镜系统的精度和稳定性。文中针对大口径射电望远镜伺服控制系统中的时滞因素进行研究。以模型预测控制(Model Predictive Control,MPC)为主控器,利用模糊比例-积分(Proportional-Integral,PI)控制结合Smith预估器解决时滞因素带来的影响,并利用所提出的控制方法对射电望远镜的位置控制系统进行时域分析。研究结果表明,在时滞因素影响下,大口径射电望远镜伺服控制系统依旧可以保持稳定,超调量为0.6%,稳态误差小于0.15%,满足大口径天线1.39%的指向精度要求。

The radio telescope control system is a multivariable complex system,and many time delay factors such as friction and gear gap in the servo system seriously aflect the accuracy and stability of the radio telescope system.This paper studies the time delay factors in the servo control system of the large aperture radio telescope.The model predictive control(MPC)is used as the master controller,and the fuzzy PI control is combined with Smith predictive control to solve the impact of the time delay factors.The position control system of the radio telescope is analyzed in time domain by using the proposed control method.The study results show that under the influence of time delay factors,the servo control system of large aperture radio telescope can still maintain stability,the overshoot is 0.6%and the steady-state error is less than 0.15%,which meets the requirement of 1.39%pointing accuracy of large aperture antenna.