为改善船舶舵机电静液作动器(Electro Hydrostatic Actuator,EHA)的抗扰性能,提出一种基于线性自抗扰控制和分数阶PD控制的融合控制方法。在建立驱动电机和液压系统数学模型的基础上,利用线性扩张状态观测器(Linear Extended State Observer,LESO)估计EHA在不同工况下所受的内外总扰动,并证明LESO的有界稳定性;进一步采用分数阶PD控制作为控制律对所估计的总扰动予以主动抑制,控制参数由剪切频率和相位裕度等频率响应指标决定。利用AMESim和Simulink联合建立EHA仿真模型,通过分析可知,所提出控制方法在船舶航速分别为6 kn和8 kn时位移控制精度均约为1 mm。利用自研EHA搭建船舶舵机半实物试验装置,进行来回摆舵和突然换向试验,结果表明在负载扰动下和有突变换向情况时,所提出控制方法对操舵指令的跟踪均具有较好的快速性和稳定性。
Fractional Order Linear Active Disturbance Rejection Control for Electro-hydrostatic Actuator of Ship Rudder
In order to improve the disturbance rejection performance of electro-hydrostatic actuator ( EHA) of ship rudder, a fusion control method based on linear active disturbance rejection control (LADRC) and fractional order proportional derivative (FOPD) control is proposed. The mathematical models of the drive motor and hydraulic system are established, respectively. On this basis, a linear extended state observer ( LESO ) is employed to estimate the total disturbances of EHA, including internal and external disturbances, under different operating conditions. The bounded stability of LESO is also proved. Furthermore, the FOPD control is used as the control law to actively suppress the estimated total disturbance, and the control parameters are determined by frequency response indicators such as shear frequency and phase margin. The joint simulation analysis of EHA model based on AMESim and Simulink shows that the displacement control accuracy of the proposed control method based on LADRC and FOPD is about 1mm when the ship speed is 6 kn or 8 kn. The self-developed EHA is used to build a semi-physical testing device, on which the reverse rudder and sudden reversal tests are carried out. The results show that the proposed control method has high speed and stability in tracking steering commands under load disturbances and sudden reversal situations.
ship rudderelectro-hydrostatic actuatorlinear active disturbance rejectionfractional order proportional derivative