基于ESO的导引头稳定平台双积分滑模控制

Double integral sliding mode control based on ESO for stabilized platform of seeker

为了提高导引头稳定平台抗扰性及速度稳态跟踪性能,提出了一种基于扩张状态观测器(Extended State Observer,ESO)的双积分滑模控制器(Double Integral Sliding Mode Controller,DISMC)。首先,采用二阶扩张状态观测器对系统的未知扰动进行估计;然后,采用了双积分滑模控制器实现了系统的低稳态误差跟踪,同时采用了改进的幂次趋近律来削弱控制系统的抖振影响;最后,采用导引头稳定平台进行目标跟踪实验和隔离度性能测试。实验结果表明,与传统基于扰动观测器(Disturbance Observer,DOB)的PI控制方法相比,跟踪3(°)/s的梯形波时,在提出的控制器作用下速度跟踪快速性提高了48 ms,跟踪误差标准差提高了0.0131(°)/s。同时用转台模拟弹体扰动分别为sin(πt)°、3sin(5πt)°、7sin(2πt)°时,系统的隔离度分别提高了2.91%、0.45%、0.7%,表明基于扩张状态观测器的双积分滑模控制器对导引头稳定平台具有较强的抗扰性和较好的跟踪性能。

In order to reduce the influence of disturbances on the stabilized platform of seeker, an improved double integral sliding mode controller（DISMC） based on extended state observer（ESO） was proposed in this paper. Firstly, the second order extended state observer was used to estimate the unknown disturbances of the system. Secondly, a double integral sliding mode controller was adopted to achieve low steady-state error tracking; meanwhile, the improved power reaching law was adopted to reduce the chatting magnitude. Finally, the performances of tracking and disturbance rejection rate were carried out on the stabilized platform of seeker. The results showed that compared with the traditional PI controller based on disturbance observer（PI-DOB）, when the system tracked the trapezoidal wave at 3（°）/s, response time of LOS rate was reduced by 48 ms, and the standard deviation of tracking error was reduced by 0.013 1 （°）/s with the proposed controller. Meanwhile, the turntable generated a periodic motion with sin（πt）°, 3sin（5πt）° and 7sin（2πt）° respectively to simulate the motion of the carrier, the disturbance rejection rates were increased by 2.91%, 0.45%, 0.7% respectively. In conclusion, the DISMC-ESO has better performance in dynamic response and disturbance rejecting for stabilized platform of seeker.