针对小水线面双体船运动控制问题,设计了带有扩张状态观测器的终端滑模控制器。首先,针对小水线面双体船在随机海浪作用下的运动问题,建立了带有系统复合扰动的非线性运动模型;进而,考虑到系统存在的参数摄动和海浪扰动的复杂性、随机性,将系统分为内环观测器和外环控制器分别设计;利用一个线性扩张状态观测器对系统的复合扰动进行估计,并在外环终端滑模控制器中进行补偿;最后,利用Lyapunov理论得到了系统的渐进稳定结论。仿真结果表明,带有扩张状态观测器的终端滑模控制方法能够有效实现小水线面双体船的运动控制,线性扩张状态观测器能够准确估计出系统的复合扰动,且终端滑模控制器能够使系统状态快速收敛。
For the motion control problem of a SWATH ship, a terminal sliding mode controller is designed based on extended state observer (ESO). Firstly, considering the motion control problem under random wave disturbances, the nonlinear model of SWATH ship with compound disturbances is established. Then, considering the parameters perturbation, complexity and randomness of the wave, the control system is divided into inner loop observer and outer loop controller respectively. An ESO is implemented to estimate and compensate the compound disturbances in the terminal sliding mode controller. At last, the asymptotical stability is achieved based on Lyapunov theory. Simulations show the effectiveness of the proposed method Linear ESO can estimate the compound disturbances successfully, meanwhile, the terminal sliding mode controller can enable the system states converge quickly.