基于扩张状态观测器和反步法的非线性超空泡航行体纵向控制

Longitudinal control of nonlinear supercavitating vehicle based on extended state observer and backstepping method

考虑空泡记忆效应的超空泡航行体控制难度较大,主要体现在滑行力的强非线性、模型中的时延特性以及运动中的未知扰动.对于此类多输入多输出的复杂非线性系统,利用传统反步法控制器设计思想,将其改进以适用于超空泡航行体的纵向运动控制.为了对系统模型中存在的未知扰动进行观测补偿,本文设计了线性扩张状态观测器(LESO),将扰动估计值与控制器设计相结合,使用Lyapunov方法分析系统稳定性.最后在不同条件下进行仿真,结果验证了所设计的LESO估计未知扰动的准确性,以及所提控制方法对超空泡航行体纵向控制的有效性.

The control of a supercavitating vehicle considering the cavitation memory effect is difficult,which is mainly reflected in the strong nonlinearity of the planing force,time-delay properties in models and unknown perturbations in motion.For this kind of complex nonlinear system with multiple inputs and multiple outputs,the traditional backstepping controller is improved to be suitable for longitudinal motion control of supercavitational vehicle.In order to compensate the unknown disturbances in the system model,a linear extended state observer(LESO)is designed to combine the disturbance estimation with the controller design,and the system stability is analyzed by using the Lyapunov method.Finally,simulations are carried out under different conditions.The results verify the accuracy of the designed LESO for estimating unknown disturbances,and the effectiveness of the proposed control method for the longitudinal control of supercavitating vehicles.