基于前馈和滑模复合结构的飞行器电动舵机控制

针对飞行器电动舵机伺服系统的控制问题,提出了一种能够有效抑制传动机构非线性摩擦的控制方法,该方法由前馈补偿器、基于LQR的PID反馈控制器以及滑模控制器构成。前馈控制能够提高系统响应的快速性,PID反馈控制提高系统的抗干扰能力,针对非线性摩擦设计的滑模控制律,用来削弱非线性摩擦对舵机伺服的影响。在分析电动舵机伺服系统构成的基础上,给出了非线性摩擦的Stribeck模型;建立了系统数学模型,在此基础上分析得出前馈补偿器的结构和参数;引入参考给定量,建立基于误差的状态控制方程,设计了基于LQR的PID控制器以及抑制非线性摩擦扰动的滑模控制律。分别对含有滑模控制器和不含滑模控制器的控制方法进行了仿真实验,实验结果表明:含有滑模控制器的控制方法能够有效抑制非线性摩擦引起的速度抖动问题以及位置"平顶"现象。

Aircraft Electromechanical Actuator Control Based on Feedforward and Sliding Mode Composite Structure

Aimed at the problem of aircraft electromechanical actuator servo control system , the control method which can effec-tively suppress transmission mechanism of nonlinear friction was present .The method was constituted by feedforward compensator , pro-portion integration and differential ( PID) feedback controller based on linear quadratic regulator ( LQR) and the sliding mode control-ler.The system fast response could be improved by the feedforward control , and the system anti-interference ability could be enhanced by the PID feedback controller .Aimed at the nonlinear friction design , the sliding mode control was used to weaken the influence of nonlinear friction on the servo actuator .Based on analyzing the structure of the electromechanical actuator servo system , the Stribeck model of nonlinear friction was presented .The system mathematical model was establised , and then the feedforward compensator of structure and parameters were obtained through analysis .The reference input was introduced and state control equation was built based on errors, then the PID controller based on LQR and sliding model controller which supressed interference of nonlinear friction were de -signed.At last, the simulation experiment with sliding model control was carried out , and then the simulation experiment without slid-ing model control was also carried out .The experimental results show that by contrast , the control model with sliding model controller can effectively restrain the speed shake of the nonlinear friction and position “ceiling” phenomenon .