基于FTESO和漂角补偿的船舶航向滑模控制

目的]为提高水面欠驱动船舶的航向跟踪性能,减小航向误差,研究一种基于有限时间扩张状态观测器(FTESO)的船舶航向滑模控制方法。方法]首先,采用预滤波器减小船舶转向时较大的航向变化率影响,利用扩张状态观测器对时变漂角进行估计,然后通过估计出的漂角及时修正航向误差。为简化控制器设计,艏摇方向上的外部扰动和内部不确定项由观测器同时估计,并在控制器设计中进行补偿。选取含积分项的滑模面,结合FTESO设计滑模控制律,并考虑输入饱和约束,最终通过李雅普诺夫理论证明控制系统的稳定性。结果]仿真结果显示,所研究的控制方法使水面船舶能够在较短的时间内减小航向跟踪误差并收敛至0。结论]研究成果可为水面船舶航向跟踪控制设计提供参考。

Ship course sliding mode control system based on FTESO and sideslip angle compensation

Objectives]To improve the performance of course tracking and reduce the course errors of an underactuated surface ship,a heading control method based on a finite-time extended state observer(FTESO)and sliding mode control algorithm is studied.Methods]A pre-filter is proposed to reduce the influence of the large rate of speed change when steering.The time-varying sideslip angle is estimated by FTESO,and course error is amended by the estimated sideslip angle in a timely manner.To simplify the design of the controller,external disturbance and internal uncertainty in the yaw direction are estimated by the observer simultaneously,and compensated for in the controller design.Considering input saturation,a sliding mode control law is designed by combining FTESO and a sliding mode surface with an integral term.The stability of the control system is proven by the Lyapunov theory.Results]The simulation results show that the proposed controller reduces course tracking error and makes it converge to zero in a shorter time.Conclusions]The results of this study can provide references for the course tracking control design of surface ships.