环境影响与参数摄动下船舶航速的非线性H_∞控制

Nonlinear H_∞ Control for Marine Speed with Parameter Perturbation and Ambient Interference

为了提高船舶的自动化水平,增强船舶的航行安全,对航速的稳定控制是重要的因素之一。由于船舶航速控制是一个参数时变、非线性,且其动态特性受环境因素的影响,因此常规的控制方法难以获得良好的控制效果。在建立船舶运动的非线性数学模型时,考虑了环境因素如风、浪、流的影响和系统参数不确定性。在此基础上,利用微分几何的方法对模型进行了精确线性化,然后利用线性H∞控制理论,设计了船舶航速的非线性H∞控制器。仿真结果表明非线性H∞控制器能有效的抑制环境扰动,提高系统的稳定性,保证控制精度,具有较强的鲁棒性。

In order to improve the automation level and enhance the navigation safety of ships, stable control for ship speed is very important. Good control effect is difficult to obtain based on the conventional control method since the marine speed control system is a time-varying parameters and nonlinear complicated propulsion system. The uncertainty of the system parameters and the effect of environment such as winds, waves and currents were considered adequately in ship motion mathematical model with disturbing force. The mathematic model was linearized accurately with the differential geometry method. Then the nonlinear Hoo controller was designed according to the linear H∞ theory. The simulation results show that the H∞ controller could effectively restrain the effect of the environment disturbance, improve the stability of the control system, ensure the accuracy of control and enhance the systems＇ robustness.