基于非线性无源观测器的动力定位船舶反步滑模控制(英文)

Backstepping-sliding Mode Control Based on Passive Nonlinear Observer for Dynamic Positioning Vessels

针对动力定位船舶的工作环境及特点,设计了基于无源非线性观测器的反步滑模控制器。船舶在海洋中的实际运动包含低频运动和高频运动两部分。高频运动部分控制器是很难补偿的并且也不需要加以控制,因为它引起船舶作往复周期性的运动。为了克服这一问题,采用带滤波功能的非线性无源观测器滤除船舶位置和艏向中的高频成分,同时观测器还能够重构船舶的低频运动。由于船舶运动模型是非线性的,采用鲁棒性较强的反步法进行控制器设计。为了保证系统误差在有限时间内收敛到零,在控制器的设计过程中引入了滑模技术。仿真结果证实了控制器良好的控制效果和较强的鲁棒性。

An observer Backstepping-sliding mode controller is presented for dynamic positioning ves- sels. The motions of the vessel in realistic world contain the low-frequency and high-frequency parts. The high-frequency （HF） motions are hardly compensated and fortunately, they need not to be because the HF motions are zero-mean and periodic. To overcome the problem, the passive nonlinear observer is adopted to eliminate the high-frequency data in the position and heading. Moreover, the observer can also reconstruct the low-frequency motions of the vessel. Since the model of the motion is strongly nonlinear, the backstepping method is appropriate because of its strong robustness. The slid- ing mode technique is introduced to guarantee that the error will converge to zero in finite time. In order to reduce the chattering of the controller, the sign function is replaced by the saturation function. The simulation shows it has good position tracking performance and high robustness.