半潜式海洋平台动力定位复合自抗扰控制方法研究

发布时间：2018-04-21 02:23

本文选题：半潜式海洋平台 + 动力定位　；参考：《江苏科技大学》2017年硕士论文

【摘要】：动力定位技术伴随着人们开发海洋资源的深入而不断发展,并广泛地运用于半潜式海洋平台及船舶上。控制方法的优劣对于动力定位系统至关重要,然而,半潜式海洋平台是一个非线性且伴有较大不确定性的系统,导致不能很精确地建立它的系统模型,同时海洋环境干扰较为复杂,因此人们需要寻找更加有效的控制方法以提高动力定位精度。自抗扰控制是近年来发展起来的一种先进控制技术,在处理非线性系统和大滞后被控对象的控制问题上效果显著,但自抗扰控制仍然存在一些弊端,需要加以改进。因此,本文着眼于引入其他控制方法与自抗扰控制相结合,构成复合自抗扰控制策略,并将其运用于动力定位领域。主要内容如下:1.对半潜式海洋平台三自由度低频模型及风、浪、流等外界海洋环境模型进行了探讨,为便于设计控制器,对平台低频模型作了变形转换,并做了仿真分析以检验所建立的模型是否符合平台一般运动规律。2.对自抗扰控制基本原理进行了介绍,指出其对多变量耦合系统的控制较为有效,在此基础上,对平台模型进行了解耦。此外,在海洋平台动力定位系统上进行了PID控制与自抗扰控制的仿真结果对比,以直观地阐述自抗扰控制相对PID的优势以及自抗扰控制自身的不足。3.针对自抗扰控制器的扰动估计能力不足问题,引入了一种新型连续光滑非线性函数对扩张状态观测器进行改进。同时,用非奇异终端滑模控制代替了非线性状态误差反馈控制律,以提高系统的快速响应能力与稳定性。仿真结果也表明了滑模自抗扰动力定位控制器的优良性能,且该方案对推力系统的要求较低,经济性较好。4.为实现动力定位控制器扰动估计能力的再提高,引入了动态面控制思想对扩张状态观测器进行改造。仿真结果表明,相对于用连续光滑非线性函数对扩张状态观测器进行改进的传统思路,动态面扩张状态观测器方案能大幅提高控制器扰动估计能力,增强了控制器对复杂海洋环境干扰的适应能力。
[Abstract]:With the development of marine resources, dynamic positioning technology has been widely used in semi-submersible offshore platforms and ships. The merits and demerits of the control method are very important for the dynamic positioning system. However, the semi-submersible offshore platform is a nonlinear and uncertain system, which makes it impossible to establish its system model accurately. At the same time, the marine environment interference is more complex, so people need to find more effective control methods to improve the dynamic positioning accuracy. Active disturbance rejection control (ADRC) is an advanced control technology developed in recent years. It is effective in dealing with nonlinear systems and large time-delay controlled objects, but there are still some drawbacks in ADRC, which need to be improved. Therefore, this paper focuses on the combination of other control methods and active disturbance rejection control to form a compound active disturbance rejection control strategy, and applies it to the field of dynamic positioning. The main content is as follows: 1. In this paper, the three degree of freedom low frequency model of semi-submersible offshore platform and the model of wind, wave and current are discussed. In order to design the controller, the low frequency model of the platform is deformed and converted. The simulation analysis is also done to verify whether the established model conforms to the general motion rule of the platform. 2. The basic principle of active disturbance rejection control is introduced, and it is pointed out that the control of multivariable coupling system is more effective. On this basis, the platform model is decoupled. In addition, the simulation results of PID control and active disturbance rejection control are compared on the offshore platform dynamic positioning system, in order to intuitively expound the advantages of active disturbance rejection control over PID and the disadvantages of auto disturbance rejection control. In order to solve the problem of insufficient disturbance estimation ability of ADRC, a new continuous smooth nonlinear function is introduced to improve the extended state observer. At the same time, the nonlinear state error feedback control law is replaced by the nonsingular terminal sliding mode control to improve the system's fast response ability and stability. The simulation results also show that the sliding mode active disturbance rejection dynamic positioning controller has good performance, and the requirement of the scheme for thrust system is lower and the economy is better. 4. In order to improve the disturbance estimation ability of the dynamic positioning controller, an extended state observer is modified by introducing the idea of dynamic surface control. The simulation results show that, compared with the traditional idea of improving the extended state observer with continuous smooth nonlinear function, the dynamic surface extended state observer scheme can greatly improve the disturbance estimation ability of the controller. The adaptive ability of the controller to complex marine environment disturbance is enhanced.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE95;TP273

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