三自由度波浪补偿舷梯串级自抗扰控制

Cascade linear active disturbance rejection controller for three degrees of freedom motion compensation gangway

本文对三自由度液压驱动波浪补偿舷梯进行建模,考虑到模型非线性、模型参数不确定、存在外部干扰等问题,设计一种串级线性自抗扰控制器对舷梯的升沉、横荡、纵荡3个自由度进行控制。首先根据拉格朗日方程建立舷梯的动力学模型,根据D-H参数法建立舷梯的运动学模型,根据阀控液压马达的流量方程、流量连续性方程和力平衡方程,建立液压力矩伺服模型。然后设计外环位置二阶线性自抗扰控制器和内环力矩二阶线性自抗扰控制器,并在位置自抗扰控制中引入模型辅助。最后搭建系统的仿真模型,对所设计的控制器进行仿真验证。仿真结果表明,三自由度波浪补偿舷梯控制系统对比带重力补偿的PID控制器,具有调节速度快、超调量小、抑制外界未知时变干扰和系统参数不确定性能力强等优点。

In this paper, the modeling method of the three-degree-of-freedom(3DOF) motion compensated gangway is analyzed, and a cascade linear active disturbance rejection controller for three degrees of freedom, heave, sway and surge, is proposed according to its nonlinear characteristics and uncertain model parameters. Firstly, the dynamic model of the gangway is established according to the Lagrange equation, the kinematic model of the gangway is established according to the D-H method, and the hydraulic torque servo model is established according to the flow equation, flow continuity equation and force balance equation of the hydraulic system. Then, the outer loop pose second-order linear active disturbance rejection controller(LADRC) and the inner loop moment second-order LADRC are designed, and model assistance is constructed in the outer loop to reduce the observer burden. The simulation model of the system is established, the simulation results show that, the designed controller has faster adjustment speed and smaller overshoot comparing with the PID controller with gravity compensation, and ADRC can suppress the unknown time-varying disturbance and the inconsistency of system parameters.