基于状态反馈线性化和ESO的船舶航向跟踪控制

Ship course tracking control based on the state feedback linearization and ESO

针对船舶航向跟踪控制问题,考虑舵机伺服系统特性、船舶动态参数不确定以及未知时变环境扰动,利用状态反馈线性化原理与扩张状态观测器(ESO)的基本思想,设计船舶航向跟踪控制律.首先,对带有执行机构的船舶操纵数学模型进行非线性坐标变换;然后,构造ESO,实时估计动态参数不确定和未知时变环境扰动构成的总扰动.基于上述,根据状态反馈线性化原理设计船舶航向跟踪控制律.理论分析表明,所构造的ESO估计误差渐近收敛于零,所设计的船舶航向跟踪控制律保证船舶航向跟踪闭环系统是稳定的,且使得船舶航向跟踪误差渐近收敛于零.最后,以一艘军舰为例进行仿真研究,仿真结果显示了所设计的船舶航向跟踪控制律的有效性和对扰动的鲁棒性.

Aiming at the problem of the ship course tracking,considering the characteristics of the rudder servo system,the dynamic parameter uncertainties of ships and the unknown time-varying environmental disturbance,a ship course tracking control law was designed by using the state feedback linearization principle and the basic thought of the extended state observer(ESO).Firstly,the nonlinear coordinate transformation was carried out for the ship steering mathematical model with an actuator.Then,the ESO was constructed to estimate the total disturbance due to the dynamic parameter uncertainties and the unknown time-varying environmental disturbance.Based on the above,the ship course tracking control law was designed by using the state feedback linearization principle.The theoretical analysis shows that the estimation errors of the constructed ESO asymptotically converge to zero,and the designed ship course tracking control law makes the closed-loop course tracking system of ships be stable and the ship course tracking error asymptotically converge to zero.Finally,a warship was taken as an example for simulation.The simulation results show the effectiveness and the robustness against the disturbance of the designed ship course tracking control law.