基于自适应滑模的喷水推进船舶航向控制

Adaptive Sliding Mode for Course Tracking Control of a Waterjet Propulsion Ship

关于船舶航行优化控制,针对喷水推进船舶的航向稳定性控制问题,根据模型中非线性水动力不确定性和外界干扰,提出了基于PID增益调节的自适应滑模控制方法,并利用Lyapunov稳定性理论证明控制方法的稳定性。控制方法对于模型参数摄动和外界干扰有较好的鲁棒性,PID增益参数的选择可通过在线自适应学习获得,采用边界层方法对设计的滑模控制器的高频抖振加以合理抑制。以一艘喷水推进船舶为例,进行了航向改变的仿真,结果表明设计的控制器具有船舶操纵的良好动态性能,且具有超调小、鲁棒性强的优点,更加符合船舶航向实时控制的工程要求。

In this paper an adaptive sliding mode controller with PID gain tuning method is presented for a waterjet propulsion ship, the model＇ s nonlinear hydrodynamic uncertainties and environmental disturbances are also considered for controller design, and the stability property of proposed controller can be guaranteed according to the Lyapunov stability theorem. Moreover, system robustness against parameter variations and external disturbances are ob- tained by the proposed control method, and suitable PID control gain parameters can be systematically on-line com- puted based on adaptive law. The boundary layer condition is adopted to reduce the high frequency chattering in the switching part of the sliding mode controller. Finally, an example with a waterjet propulsion ship is shown to verify the effectiveness of the proposed controller. Simulations, with ship course changing 10°, illustrate that the design controller has good dynamic performances without little overshooting and strong robustness, and can meet the engineering requirement of the ship course real-time control.