基于干扰观测的欠驱动无人艇自适应航迹跟踪控制算法

Adaptive course tracking control of underactuated USV based on disturbance observation

研究了欠驱动无人艇在外界干扰条件下的航迹跟踪控制问题,提出了一种基于干扰估计与补偿的航迹跟踪控制算法,实现了风浪流干扰环境下航迹的精确跟踪。算法引入纵向误差作为状态变量对扩张干扰观测器进行设计,实时估计干扰的稳态分量,相比于传统的基于输出反馈干扰估计算法,其灵活性、可控性更高;同时基于纵向跟踪误差的状态估计误差,设计扩张干扰观测器变增益因子,相比于基于常增益观测器的航迹跟踪算法其能够在实现干扰补偿的前提下,有效减小航迹跟踪收敛段的震荡。基于李雅普诺夫稳定性理论证明了级联控制系统与干扰观测系统在平衡点的半全局指数稳定性,通过仿真对比实验及分析证明了所提航迹跟踪算法的有效性和先进性。

In order to ensure accurate course tracking of underactuated unmanned surface vessels (USV) under wind, wave and flow interference, a course tracking control algorithm based on disturbance estimation is proposed. Compared with the traditional output-feedback interference estimation algorithm, the extended disturbance observer is more flexible and controllable, which is designed by the longitudinal error as the state variable. At the same time, the variable gain is designed based on the state estimation error of the longitudinal tracking error. Compared with the constant gain observer, it can effectively reduce the oscillation of course tracking when realizing the disturbance compensation. Based on the theory of Lyapunov and the cascade system, the semi global exponential stability of the control system and the interference observation system is proved. The effectiveness and advancement of the algorithm are proved by simulation and comparison experiments.