电液力伺服系统的反馈线性化滑模控制研究

Feedback linearization sliding mode control of electrohydraulic force servo system

针对电液力伺服系统具有参数不确定性、不确定非线性和外部干扰等问题,将反馈线性化理论与滑模控制理论相结合,提出了一种基于反馈线性化的滑模控制方法,实现了对电液力伺服系统进行较高精度跟踪的目的。首先,建立了电液力伺服系统的非线性数学模型,采用微分几何理论将非线性系统中的动态特性变换为线性的动态特性,实现了输入—状态的精确线性化;然后,在控制器中引入了滑模变结构控制,设计了反馈线性化滑模控制器,基于李雅普诺夫稳定性原理,证明了基于反馈线性化控制器的稳定性;最后,利用MATLAB/Simulink软件建立了电液力伺服系统及控制器的仿真模型,对设计的基于反馈线性化控制器进行了仿真验证,分析了不同幅值的信号、随机干扰对系统控制效果的影响。仿真实验结果表明:与PID控制算法相比,采用基于反馈线性化控制算法力使跟踪误差缩小了96.7%,调整时间缩短了90%。研究结果表明:基于反馈线性化控制算法能有效降低非线性因素对跟踪精度的影响,提高系统的力跟踪精度,具有更好的鲁棒性和更优的控制效果。

Aiming at the characteristics of electro-hydraulic force servo system,such as parametric uncertainties,uncertain nonlinearities and external disturbances,combining feedback linearization theory with sliding mode control theory,a sliding mode control method based on feedback linearization was proposed to realize the high precision tracking of electro-hydraulic force servo system.Firstly,the nonlinear mathematical model of the electro-hydraulic force servo system was established.The differential geometry theory was used to transform the dynamic characteristics of the nonlinear system into linear dynamic characteristics,and the input-state accurate linearization was realized.Then,the sliding mode variable structure control was introduced into the controller,and the feedback linearization sliding mode controller was designed.The stability of the proposed controller based on feedback linearization was proved by Lyapunov stability principle.Finally,the simulation model of electro-hydraulic force servo system and controller was established by using MATLAB/Simulink software,and the sliding mode controller based on feedback linearization was simulated and verified.The influence of different amplitude signals and random interference on the control effect was studied.The simulate experiment results show that comparing with the PID control algorithm,the force tracking error is reduced by 96.7%and the adjustment time is reduced by 90%by using sliding mode control method based on feedback linearization.The result shows that the control algorithm effectively reduces the influence of nonlinear factors on the tracking accuracy,improves the force tracking accuracy of the system,and has better robustness and better control effect.