基于改进扩张状态观测器的船舶动力定位系统控制

Ship dynamic positioning system control based on improved extended state observers

针对船舶动力定位系统存在的模型非线性及外扰不确定性等导致的定位误差问题,将自抗扰控制器(active disturbance rejection controller,ADRC)应用于船舶动力定位系统。建立船舶低频运动模型,并对ADRC中的扩张状态观测器(extended state observer,ESO)的非线性fal函数进行改进,构成一个faln函数,通过非线性函数组合构造误差反馈率,对船舶运动进行控制。用改进前和改进后的ESO分别对船舶的位置和速度进行观测,对改进前与改进后的控制结果进行对比。仿真结果表明,改进后的ESO比传统的ESO具有更好的抗干扰性能。

Aiming at the error of the ship dynamic positioning system caused by nonlinearity of model and uncertainty of external disturbances,the active disturbance rejection controller(ADRC)is applied to the ship dynamic positioning system.A low-frequency motion model of ships is established,and the nonlinear fal function of the extended state observer(ESO)in the ADRC is improved to form a faln function.The error feedback rate is constructed by combining the nonlinear functions to control the ship motion.The ESOs before and after the improvement are used to observe the position and speed of ships,and the control results before and after the improvement are compared.The simulation results show that the improved ESO is of better anti-interference performance than the traditional ESO.