基于状态误差趋近率的自适应滑模控制器设计

Design of Adaptive Sliding Mode Controller Based on State Error Approach Rate

首先,针对光电稳定平台滑模控制中普通滑模趋近率对系统造成的抖振、收敛较慢的问题以及对于系统转动惯量摄动的抑制问题,提出了一种在指数趋近率基础上引入系统状态和跟踪误差的状态误差趋近率,系统状态点在滑动过程中使误差减小,从而控制增益逐渐减小,误差满足允许误差范围内时稳定在原点附近,减小了抖动,加快了收敛速度。其次,又针对光电稳定平台跟踪时框架系统的低速性造成不可避免的转矩扰动,提出了一种基于LurGre摩擦模型的自适应滑模控制方法,建立了包含该摩擦模型的机电伺服控制模型。最后,利用李雅普诺夫函数验证了控制器的稳定性,通过Matlab仿真加以证明该控制器比传统的控制方法具有较强的鲁棒性和较好的跟踪精度及抗干扰能力。

Firstly,aiming at the chattering and slow convergence caused by the common sliding mode approach rate in the sliding mode control of the photoelectric stabilized platform and the suppression of the perturbation of the system moment of inertia,a state error approach rate based on the exponential approach rate is proposed,which introduces the system state and tracking error.The system state point reduces the error in the sliding process,so the control gain gradually decreases,when the error is within the allowable error range,it is stable near the origin,which reduces the jitter and accelerates the convergence speed.Secondly,aiming at the inevitable torque disturbance caused by the low speed of the frame system when tracking the photoelectric stabilized platform,an adaptive sliding mode control method based on LurGre friction model is proposed,and an electromechanical servo control model including the friction model is established.Finally,the stability of the controller is verified by Lyapunov function,and Matlab simulation shows that the controller has stronger robustness,better tracking accuracy and anti-interference ability than that of the traditional control method.