基于多模态快速非奇异终端滑模的船舶航迹跟踪自抗扰控制

为解决欠驱动船舶航迹直线和曲线跟踪控制问题,设计基于多模态快速非奇异终端滑模(Fast Nonsingular Terminal Sliding Mode,FNTSM)的自抗扰控制器(Active Disturbance Rejection Control,ADRC)。引入ADRC技术,利用跟踪微分器快速提取跟踪期望信号的微分信号,通过可在线性与非线性之间切换的扩张状态观测器实时估计船舶外部和内部的总干扰;将根据多模态思想设计的非奇异终端滑模和一种新型双幂次趋近律引入状态误差反馈环节中,设计基于多模态FNTSM的ADRC控制律,在保证ADRC优点的同时,提高收敛速度和稳态跟踪精度;构造期望艏向角方程,将航迹控制问题转化为易于实现的航向控制问题。Simulink仿真结果表明:利用该控制器的船舶能快速、准确地跟踪期望直线和曲线航迹,说明其具有优良的控制品质。

Active Disturbance Rejection Control for Ship Trajectory Tracking with Multimodal Fast Nonsingular Terminal Sliding Mode Strategy

The ADRC(Active Disturbance Rejection Controller)based on FNTSM(Fast Nonsingular Terminal Sliding Mode)is designed to improve the straight-line and curve-following control of underactuated ships.In the active disturbance rejection control system,a tracking-differentiator is used to extract differential signal of the desired track signal quickly and an extended state observer that can switch between linear and nonlinear is used to estimate the total external and internal disturbances on the ship in real time.The nonsingular terminal sliding mode control strategy that is designed according to the multimodal idea and a new dual power approach law is introduced to the state errors feedback to improve the convergence speed and steady-state tracking accuracy of the system.The equation of desired heading is formulated so that the trajectory tracking problem is transformed into a course control problem that gives executable manipulating directions.The design is verified as accurate and quick in trajectory tracking through simulation.