基于ESO的船舶航向鲁棒自适应控制

针对具有内部未建模动态和外部不确定扰动的水面船舶设计一种鲁棒自适应航向控制器,并同时解决转向过程中的漂角补偿问题.基于二阶非线性Nomoto模型和一阶漂角模型,建立非积分链结构的漂角-航向非线性状态空间模型,将航向控制系统未建模动态与外部不确定扰动合并为复合扰动,应用扩张状态观测器估计模型中的未测量状态和系统复合扰动.基于Lyapunov稳定性理论和自适应反步法设计航向状态反馈控制规律,为避免反步法控制过程中的微分爆炸问题,采用动态面控制技术获取虚拟控制信号的近似导数.所提出的扩张状态观测器和航向控制算法能够保证闭环系统内所有误差信号一致最终有界,提高航向保持和转向过程中的航向跟踪精度.仿真结果验证了所提出的航向控制规律的有效性.

NESO based ship heading robust adaptive control

A robust adaptive heading controller is designed for surface ships considering the internal un-modelled dynamics and the external uncertain disturbances, and the drift angle compensation problem is solved. Based on the second order Nomoto model and the first order drift angle model, the non-integral chain drift angle-heading nonlinear state space model is established, the heading control system un-modelled dynamics and the external uncertain disturbances are considered as a lumped uncertainty, and the unmeasured states and the lumped uncertainty in the model are estimated by a extended state observer(ESO). Based on the Lyapunov stability theory and the adaptive backstepping methodology, the heading state feedback control law is designed. In order to avoid the explosion of complexity problem in the backstepping control process, the derivative of the virtual control signal is approximated by the dynamic surface control technique. The proposed ESO and heading control scheme can ensure all error signals are uniformly ultimately bounded in the closed-loop system, the tracking accuracy is improved in course keeping and course changing processes. Simulation results illustrate the effectiveness of the proposed heading control law.