存在饱和输入的欠驱动船舶航迹跟踪控制

针对控制输入存在饱和限制的欠驱动船舶的航迹跟踪问题,提出鲁棒饱和控制方法。以船舶纵向速度和艏向角速度为虚拟输入,设计饱和运动学控制器,并引入二阶滤波器形式对控制器进行简化;利用反步法并引入Nussbaum型函数,设计饱和动力学控制器,以实现对任意光滑航迹的跟踪控制,并保证跟踪误差收敛至零点附近的一个有界区域内。仿真算例验证了设计方法的有效性和鲁棒性。     

Course-keeping control of underactuated hovercraft

The course-keeping control of underactuated hovercraft with two aft propellers was considered. The control of the heading error and cross-track error was accomplished by the yaw torque merely in this case. The hovercraft dynamic model is nonlinear and underactuated. At first the Controllability of course-keeping control for hovercraft was proved, then a course-keeping control law was derived that keeps hovercraft heading constant as well as minimizes the lateral movement of hovercraft. The proposed law guarantees heading error and sway error all converge to zero exponentially. Simulation tests were carried out to illustrate the effectiveness of the proposed control law. For further research, the disturbance influence would be considered in the dynamic equations.     

基于快速终端滑模自抗扰的船舶曲线航迹跟踪控制

针对欠驱动船舶的曲线航迹跟踪问题,首先采用自抗扰控制技术,通过扩张状态观测器实时估计和补偿系统的内部和外界扰动,将非线性快速终端滑模引入误差反馈控制环节,并采用幂指数趋近律,设计出快速终端滑模-自抗扰控制律,提高系统的收敛速度和误差跟踪精度,减小系统的抖振;然后对野本船舶模型简化变形,构造降维方程,将航迹跟踪问题转化为航向镇定问题.Simulink仿真结果表明,控制器能够实现船舶对期望曲线航迹的快速、精确跟踪,具有良好控制效果.     

The stabilization control of underactuated surface vessels

The problem of stabilization control of underactuated surface vessels with two independent control inputs is in vestigated inthis paper. Through transformation, a cascade property of the system is revealed. And the original nonlinear system could be divided into two subsystems: a linear subsystem and a nonlinear subsystem. The stabilization laws are derived for the two subsystems separately. A smooth time - varying feedback stabilization law with exponentially convergence rate is obtained. The proposed stabilization law guarantees all the system states converge to the equilibrium exponentially. The aim of stabilization control of underactuated surface vessels is achieved. At last, the effectiveness of the proposed algorithm is illustrated by simulation tests.     

带有干扰观测器的欠驱动船舶路径跟踪非线性模型预测控制

针对欠驱动船舶提出了一种非线性路径跟踪控制器,使其能够在风、浪、流等环境干扰下驶入预定的航行路径.欠驱动船舶以恒定前进速度航行,并且其合速度与参考轨迹相切.该控制器的设计使用了解析模型预测控制和干扰观测器技术,其中非线性观测器用来估计环境干扰.在最优路径跟踪控制器的作用下,路径跟踪误差渐近收敛到零.数值仿真结果验证了该控制器的有效性.     

欠驱动船舶路径跟踪的神经滑模控制

为实现欠驱动船舶在存在风浪流外界干扰和参数摄动条件下的路径跟踪控制,提出一种基于可视距离的神经滑模路径跟踪鲁棒控制器。利用可视距离思想,根据期望路径与当前位置信息,分别设计船舶纵向速度和艏摇角的参考值,并视为镇定位置误差的虚拟控制律,将路径跟踪问题转化为纵向速度和艏摇角的镇定问题;结合神经网络和滑模方法,设计一种新的神经滑模鲁棒控制器,实现了对虚拟控制律的跟踪控制,无需确定参数摄动和外界干扰的上界,避免了控制器容易出现的饱和问题和抖振现象。仿真试验表明,设计的控制器对欠驱动船舶的模型摄动和外界干扰变化不敏感,可以实现路径的理想跟踪。     

欠驱动自主水下航行器的镇定及跟踪

针对仅带有轴向推力及偏航力矩的欠驱动自主水下航行器（AUV）,研究了其在水平面内的轨迹跟踪及定点调节问题。基于Lyapunov直接法及串接一反步技术,通过采用一种带有动力学震荡器的跟踪误差变换,设计了一种统一的连续时变状态反馈控制律,并给出了参数自适应更新律以估计AUV的非线性阻力参数,使得AUV的位置及方向角的跟踪误差全局渐近收敛于零点左右的一个邻域内,该区域可以为任意小,并且,AUV的跟踪性能与外界干扰的大小无关。仿真结果证明所提出的方法是有效的。     

欠驱动无人艇的全局时变反馈镇定控制

欠驱动水面船舶的镇定控制大多采用切换控制的方法,对该问题的研究普遍存在需要角速度持续激励的问题,时变控制可以有效解决该问题,但时变系统存在构造李雅普洛夫函数的困难,为此提出了一种时变状态变换,并基于反步法构造了该系统的李雅普洛夫函数,从而设计了一种全局时变反馈镇定控制器,取消了对初始条件角速度不能为零的约束。仿真结果验证了所提出方法的有效性。     

带不确定动态的欠驱动水面船舶鲁棒自适应路径跟踪控制(英文)

A robust adaptive control strategy was developed to force an underactuated surface vessel to follow a reference path,despite the presence of uncertain parameters and unstructured uncertainties including exogenous disturbances and measurement noise.The reference path can be a curve or a straight line.The proposed controller was designed by using Lyapunov’s direct method and sliding mode control and backstepping techniques.Because the sway axis of the vessel was not directly actuated,two sliding surfaces were introduced,the first one in terms of the surge motion tracking errors and the second one for the yaw motion tracking errors.The adaptive control law guaranteed the uniform ultimate boundedness of the tracking errors.Numerical simulation results were provided to validate the effectiveness of the proposed controller for path following of underactuated surface vessels.     

基于ESO和动态逆的欠驱动船舶航迹跟踪控制设计

针对欠驱动船舶航迹跟踪控制问题,考虑船舶动态不确定性、未知时变外部扰动和速度不可测的情况,将输出重定义方法、扩张状态观测器(extended state observer, ESO)和动态逆控制方法相结合,设计欠驱动船舶航迹跟踪控制律。输出重定义方法用来解决系统欠驱动问题;构造ESO,估计由船舶动态不确定性、未知时变外部扰动以及船舶各自由度运动状态变量间的耦合构成的总扰动和船舶速度;基于上述,采用动态逆控制方法,设计航迹跟踪控制律,使欠驱动船舶跟踪期望航迹,并保证航迹跟踪闭环控制系统所有信号最终一致有界。以一艘欠驱动船舶为例进行仿真研究,仿真结果验证了所设计的航迹跟踪控制律的有效性和优越性。