【作者】 王晓飞；

【导师】 邹早建；

【作者基本信息】 上海交通大学 ， 船舶与海洋结构物设计制造， 2009， 博士

【摘要】 现代造船业、航运业的蓬勃发展,对船舶的控制性能提出了越来越高的要求,传统的航向控制已远远不能满足实际需求,研究更精确的船舶运动控制技术日益受到人们的重视。本文以常规水面船舶为研究对象,研究了欠驱动船舶路径跟踪控制问题,设计了欠驱动船舶在不同控制要求下的路径跟踪控制器,使得欠驱动船舶在控制器的作用下能够跟踪并最终稳定在预定的参考路径上。欠驱动船舶路径跟踪控制系统具有欠驱动特性、强非线性、易受到模型参数变化及外界干扰影响等特点,是一个典型的非线性控制系统,对该控制系统的研究有助于探讨一般非线性系统的控制问题,具有重要的学术研究价值。同时,对欠驱动船舶路径跟踪控制的研究,也有助于解决船舶在复杂环境中的操纵控制、自动靠离泊等实际工程问题。本文采用解析模型预测控制这一先进的非线性控制方法对欠驱动船舶路径跟踪控制问题进行了深入的研究,针对船舶控制系统中存在的非线性、欠驱动特性、外界干扰、模型参数的不确定性,开发了具有鲁棒性能和自适应性能的欠驱动船舶路径跟踪控制器。本文主要完成了以下工作:1.建立了欠驱动船舶路径跟踪控制系统的数学模型。建模是控制器设计的基础,本文总结了前人的研究成果,建立了多种欠驱动船舶路径跟踪控制系统的数学模型,包括欠驱动船舶直线路径跟踪控制、曲线路径跟踪控制模型,有外界干扰及模型参数不确定的路径跟踪控制模型,基于非线性滤波的路径跟踪控制模型,为后面的控制器设计奠定了基础。2.针对一阶非线性K-T模型的欠驱动船舶直线路径跟踪控制系统,分别基于状态空间非线性(离散)广义预测控制(Generalized Predictive Control, GPC)和解析模型预测控制方法研究了欠驱动船舶直线路径跟踪控制算法。在基于(离散)GPC的控制算法中,控制模型中未考虑外界干扰的影响,控制算法能够使得欠驱动船舶渐近稳定在设定的直线参考路径上,并对设定的系统的输出变化具有一定的鲁棒性。在基于解析模型预测控制的路径跟踪控制算法中,首先考虑了无外界干扰的欠驱动船舶直线路径跟踪控制的数学模型,通过引入重定义输出变量,使得原单输入多输出控制系统转化为等价的单输入单输出控制系统,基于解析模型预测控制技术提出了具有全局渐近收敛能力的欠驱动船舶直线路径跟踪控制算法,该控制算法能够保证重定义变量及其组成元素渐近收敛到零,使得欠驱动船舶渐近稳定在给定的直线参考路径上。在此基础上,将解析模型预测控制方法与高增益观测器(High Gain Observer, HGO)技术相结合,研究了有外界干扰影响的欠驱动船舶直线路径跟踪控制问题,所提出的路径跟踪控制算法能够使得船舶在外界干扰的影响下最终稳定在给定的直线路径上。并系统的总结了解析模型预测控制与(离散)GPC、反馈线性化方法之间的联系与区别。3.针对欠驱动船舶曲线路径跟踪控制中存在的不确定相关度问题,提出了一种基于非切换解析模型预测控制方法的欠驱动船舶路径跟踪控制算法。该控制算法是连续的、非奇异的,避免了系统振荡,解决了不确定相关度问题。所提出的路径跟踪控制算法能够使得船舶跟踪并最终稳定在设定的曲线路径上。4.在Serret-Frenet标架下研究了欠驱动船舶曲线路径跟踪控制算法。将船舶运动模型转化到Serret-Frenet标架下进行研究,并通过引入重定义输出,将单输入多输出控制系统转化为等价的单输入单输出控制系统,简化了控制器设计。在Serret-Frenet标架下,首先,研究了模型参数确定且无外界干扰情况的欠驱动船舶曲线路径跟踪控制问题,基于解析模型预测控制、Serret-Frenet标架以及重定义输出技术提出的控制算法能够使得欠驱动船舶跟踪并稳定在设定的曲线参考路径上,路径跟踪误差(包括位置误差和方位误差)及其对应的重定义输出能够渐近收敛到零。其次,研究了风浪等有界干扰、均匀流干扰影响下的欠驱动船舶路径跟踪控制问题,应用解析模型预测控制与非线性观测器方法设计了欠驱动船舶路径跟踪控制器,提出了对外界干扰具有鲁棒性的路径跟踪算法,使得欠驱动船舶能够抵抗风浪、均匀流的干扰,跟踪并收敛到设定的参考路径。最后,针对模型中参数不确定的情况,采用解析模型预测控制与模型参考自适应辨识联合控制的方法,提出了具有自适应性能的欠驱动船舶路径跟踪控制器,该控制器由两部分组成,即针对对象标称模型设计的解析模型预测控制器和针对对象不确定参数设计的模型参考自适应辨识算法,在模型参数发生变化甚至是“突变”时,该控制器能够保证船舶稳定在设定的参考路径上,不确定参数的估计值以及控制输入平稳变化,避免了系统由于参数“突变”发生剧烈振荡。5.针对欠驱动船舶路径跟踪控制系统中存在的随机干扰以及模型参数的不确定性,应用UKF(Unscented Kalman Filter)方法对状态和不确定参数进行联合估计,并结合解析模型预测控制技术,设计了对随机干扰和不确定参数具有鲁棒性能的欠驱动船舶自适应路径跟踪控制算法。同已有的研究相比,本文的创新点在于:1.首次将解析模型预测控制方法应用于欠驱动船舶路径跟踪控制的研究。2.针对欠驱动船舶曲线路径跟踪控制中存在的不确定相关度问题,提出了一种基于连续非切换解析模型预测控制方法的欠驱动船舶路径跟踪控制算法。3.在Serret-Frenet标架下研究了欠驱动船舶路径跟踪控制,并通过引入重定义输出,使得单输入多输出控制系统转化为等价的单输入单输出控制系统,简化了控制器设计;将解析模型预测控制方法与非线性干扰观测器、模型参考自适应辨识方法相结合,提出了对外界干扰、不确定参数具有鲁棒性、自适应性的欠驱动船舶路径跟踪控制算法。4.将解析模型预测控制方法与UKF相结合,其中UKF用于对控制系统中的状态和参数进行联合估计,所提出的欠驱动船舶路径跟踪控制算法对控制系统中存在的随机干扰和不确定参数具有鲁棒性和自适应性。通过本文的研究,验证了解析模型预测控制方法用于欠驱动船舶路径跟踪控制器设计的有效性,为研究精确的船舶运动控制提供了一种新的非线性控制方法。更多还原

【Abstract】 The rapid development of modern shipbuilding and shipping has brought higher and higher requirement of ships’control performances. The conventional course control is far from satisfying the practical requirements. Therefore, the research on more precise ship motion control techniques has received increasing attention in recent years. The problem of path following control for underactuated surface ships is studied in this thesis. For the different control aims, path following controllers are designed to drive the underactuated ships to follow and stabilize onto the desired reference path. The control system is a typical nonlinear control system which has characters such as underactuated, strong nonlinear, susceptible to varying parameters and environmental disturbances. The study of the subject is contributive to study the general nonlinear system control problem and has great significance in academic study. It will benefit the practical engineering applications such as manoeuvring motion control, automatic mooring and unmooring of ships in complicated environment.A new advanced nonlinear control method, analytic model predictive control, is proposed to study the problem of path following control for underactuated ships. With respect to the nonlinear, underactuated characters, environmental disturbances and uncertain parameters of ship control system, some applicable algorithms are proposed which have the performances of both robustness and adaptiveness on path following control problem for underactuated ships. The main results achieved in this thesis are as follows:1. Mathematical models of path following system for underactuated ships are established. Modeling plays a key role in controller design. Based on the study of other researchers, this thesis has established some kinds of mathematical models of path following system for underactuated ships, including straight-line and curve path following control models, path following control models with environmental disturbances and uncertain parameters, path following control model based on nonlinear filter. These models are the base of the controller design.2. With respect to the straight-line path following control system based on first-order nonlinear K-T model for underactuated ships, the path following control algorithms are studied by using state space nonlinear (discrete) generalized predictive control (GPC) and analytic model predictive control methods respectively. In the control algorithm by using (discrete) GPC, environmental disturbance is not considered in the control model. The proposed control algorithm can asymptotically stabilize the underactuated ship onto the desired straight-line reference path, and is robust to the outputs’changes. In the control algorithm by using analytic model predictive control, the straight-line path following system for underactuated ships without environmental disturbance is considered first. By introducing the output-redefinition, the original SIMO system is transformed into an equivalent SISO system. Based on analytic model predictive control technique, the global asymptotically convergent straight-line path following algorithm is proposed. This control algorithm can guarantee the output-redefinition and its compositions all asymptotically converge to zero. The underactuated ship can be driven onto the desired straight-line reference path. And then, the high gain observer technique and the analytic model predictive control are combined, and the straight-line path following control system with environmental disturbance is studied. The proposed path following control algorithm can make the underactuated ship converge to the desired straight-line path in spite of environmental disturbance. Based on the study, the relations and differences of analytic model predictive control, (discrete) GPC, and feedback linearization techniques are systematically summarized.3. The problem of ill-defined relative degree is studied which occurrs in the curve path following control for underactuated ships. A path following control algorithm for underactuated ships is proposed by using non-switch analytic model predictive control method. This control algorithm is continuous, non-singular, and the system fluctuation is avoided. The problem of ill-defined relative degree is solved. The proposed path following control algorithm can drive the underactuated ship converge to the desired curve path.4. The curve path following control for underactuated ships is studied in the Serret-Frenet frame. By introducing the output-redefinition, the SIMO system is transformed into an equivalent SISO system which simplifies the controller design. In the Serret-Frenet frame, the curve path following control problem with fixed parameters and without environmental disturbances is studied first. Based on analytic model predictive control, Serret-Frenet frame and output-redefinition techniques, the proposed control algorithm can drive the underactuated ship converge onto the desired path. Path following errors including position error and orientation error all converge to zero; and the corresponding output-redefinition also asymptotically converge to zero. And then, robust path following control algorithms for underactuated ships are proposed with respect to the bounded disturbances induced by wind, waves and disturbance due to uniform current. Analytic model predictive control and nonlinear disturbance observer techniques are used to design the path following controllers. With help of the control algorithms, the underactuated ships can be driven asymptotically onto the desired path in spite of the environmental disturbances. Finally, aiming at the model with uncertain parameters, a joint control algorithm is adopted to get an adaptive path following controller of underactuated ships. The controller is made up of two parts: one is analytic model predictive controller with respect to the nominal system, the other is model reference adaptive identification algorithm with respect to the uncertain parameters. Even if the parameters change abruptly, the proposed controller can stabilize the underactuated ships onto the desired path. The estimation of uncertain parameters and the control input can change smoothly. The system’s fluctuation induced by the parameters’abrupt changes is avoided.5. With respect to the random disturbances and the parameters’uncertainty of underactuated ships, UKF (Unscented Kalman Filter) is used to estimate the states and uncertain parameters. By combining the analytic model predictive control technique with UKF, the adaptive path following controller is proposed which is robust to random disturbances and uncertain parameters.Comparing with the previous studies by other researchers, the main innovation points of this thesis can be summarized as follows:1. Analytic model predictive control method is used for the first time to study the path following control of underactuated ships.2. With respect to the problem of ill-defined relative degree which occurrs in the curve path following control for underactuated ships, a path following control algorithm for underactuated ships is proposed by using continuous non-switch analytic model predictive control method.3. The path following control problem is studied in the Serret-Frenet frame. By introducing Serret-Frenet frame and output-redefinition, the original SIMO system is transformed into an equivalent SISO system which simplifies the controller design. By combining analytic model predictive control with nonlinear disturbance observer and model reference adaptive identification, the path following control algorithms are proposed which are robust and adaptive to disturbances and uncertain parameters.4. The path following control algorithm is proposed by combining analytic model predictive control and UKF, where UKF is used to estimate the states and uncertain parameters. The proposed control algorithm is robust and adaptive to random disturbances and uncertain parameters.The study of this thesis has demonstrated that the proposed path following control algorithms by using analytic model predictive control and other methods are effective. It provides a new nonlinear control method to study the precise ship motion control technique.更多还原