导弹电动舵机系统离散自适应全程滑模控制

Discrete Adaptive Global Sliding Mode Control for Missile Electromechanical Actuator System

针对导弹电动舵机系统中参数摄动和外界干扰等不确定性对其性能的影响,提出一种离散自适应全程滑模控制器(AGSMC).通过设计非线性切换函数,使系统轨迹在初始时刻就落在滑模面上,大大缩短了初始到达时间.AGSMC的设计基于离散自适应趋近律,并且采用了线性外推法估计系统的不确定性,保证了系统在稳定情况下具有全程鲁棒性.通过对某电动舵机实验台的仿真表明,AGSMC方案与一般的指数趋近律法相比,不仅确保了系统对不确定性的鲁棒性以及舵机的位置跟踪精度,而且在很大程度上削弱了控制量的高频抖动现象.此外,所提出的控制方案不需要满足匹配条件,因此通用性较高.

For the influence of the uncertainties on the performance including parameters variations and external distur- bances in the missile electromechanical actuator system, a discrete adaptive global sliding mode controller （AGSMC） is proposed. By the design of nonlinear switching function, the initial state of system is set on the switching surface, which shortens the initial reaching time greatly. The AGSMC is designed based on a discrete adaptive reaching law, and a linear extrapolation method is used to estimate the uncertainties, which can guarantee the global robustness in the premise of system stability. With the computer simulations on an experiment plant of electromechanical actuator, it is shown that the proposed scheme not only ensures strong robustness against uncertainties and good tracking precision, but also suppresses the high- frequency chattering at control input effectively, compared with the conventional reaching law approach. In addition, it is dispensable to satisfy the matching condition, so the proposed control method possesses stronger generality.