带扰动观测器的船舶轨迹跟踪自适应动态面滑模控制

Adaptive Dynamic Surface Sliding Mode Control for Ship Trajectory Tracking with Disturbance Observer

针对遭受未知外部环境扰动的三自由度全驱动船舶轨迹跟踪控制问题,设计一种带扰动观测器的自适应动态面滑模控制方法。该方法构造扰动观测器估计未知扰动,并对控制量进行前馈补偿,采用σ修正泄漏项的自适应律估计扰动观测误差的界以提高控制精度,结合动态面技术解决传统反演法的微分爆炸问题,并选取李雅普诺夫函数证明该控制器可保证闭环系统内所有信号的一致最终有界性。基于一艘供给船舶进行仿真试验,结果表明,所设计的控制器输出合理有效且跟踪精度高,在工程实际中具有一定的参考价值。

Aiming at the trajectory tracking problem of three DOF full actuated ship with unknown external environment disturbances, an adaptive dynamic surface sliding mode control method with disturbance observer is designed. The disturbance observer is constructed to provide estimations of unknown disturbances and feedforward compensations for control amounts, the adaptive laws based on leakage terms of σ-modification are used to estimate bounds of disturbance observer errors so as to improve the control accuracy. The dynamic surface control technique is combined to solve the expansion problem of traditional backstepping method. The application of Lyapunov function proves that all signals in the closed-loop system can be guaranteed uniformly ultimate boundedness by using proposed control method. The simulation results show that control output is reasonable and effective, and tracking accuracy is high. The proposed controller has a certain reference value in engineering practice.