摘 要

随着海洋资源的重要性日益提高，如何有效地开发和利用海洋资源成为各国研究人员关注的焦点。水下航行器作为一种先进的海洋工程装备，可以代替或辅助人类进行海洋资源勘查和水下作业，在复杂的海洋环境下具有较高的使用价值。为了提高其操纵性，水下航行器通常配备多个冗余的推进器构成过驱动推进系统，然而，冗余的推进器增加了将推力合理分配到每个推进器上的难度，因此，推力优化分配对于水下航行器而言是一项关键技术。本文主要针对多推进器水下航行器的推力优化分配算法开展了以下研究工作：

（1）多推进器水下航行器推力分配需要考虑六自由度上力/力矩的合理分配，但由于水下航行器六自由度运动之间存在强耦合性，直接进行推力分配可能会分配失败，导致其运动的失衡，使得水下航行器的安全性降低。本文针对上述问题，采用六自由度解耦分配策略，该策略通过将六自由度上的控制力/力矩划分为水平向和垂直向分开进行分配的方式，有效地将六自由度运动解耦。依据该解耦策略和水下航行器推进器的布局，建立了多推进器水下航行器推力优化分配模型。

（2）水下航行器通常配备多个冗余的推进器构成过驱动推进系统，多推进器的采用使得推力分配中所考虑的约束条件增多，分配难度提高，因而分配方法的选用不当可能会导致分配失败，影响水下航行器的安全性。传统的推力分配方法主要包括直接解法和迭代解法，直接解法如伪逆法，通过直接求解的方式，可以很快地求出分配结果，具有良好的实时性，然而计算过程没有考虑不等式约束，部分情况下会分配失败。迭代解法如序列二次规划法（SQP），综合考虑了目标函数和约束条件的要求，通过迭代求解的方式，可以得到满足要求的最优解，然而算法设计复杂，而且实时性难以保证。随着智能优化方法的发展，分配方法的研究有了新的内容。与传统分配算法相比，智能算法具有通用性强，全局寻优以及自适应求解等优点。本文针对水下航行器推力分配问题，以配备多推进器的过驱动水下航行器为研究对象，首先采用传统推力分配方法中的伪逆法、序列二次规划法进行了水下航行器推力分配研究，通过数值仿真验证了两种算法的适用性。然后采用智能算法中的遗传算法设计了推力优化分配算法，通过数值仿真验证了该优化分配算法的有效性。

关键词：水下航行器；过驱动推进系统；解耦分配策略；优化分配方法

Abstract

With the increasing importance of Marine resources, how to effectively exploit and utilize marine resources has become the focus of researchers all over the world. As a kind of advanced marine engineering equipment, underwater vehicle can replace or assist human beings to carry out marine resources exploration and underwater operations. In order to improve its maneuverability, underwater vehicles are usually equipped with multiple redundant thrusters to form a driving propulsion system. However, redundant thrusters increase the difficulty of reasonably distributing thrust to each thruster. Therefore, optimal thrust distribution is a key technology for underwater vehicles. In this paper, the thrust optimization allocation algorithm of multi-propeller underwater vehicle is studied as follows:

(1) The thrust distribution of multiple thrusters’ underwater vehicle needs to consider the reasonable distribution of force/torque on the six degrees of freedom. However, due to the strong coupling between the six degrees of freedom motions of the underwater vehicle, direct thrust distribution may fail to distribute, resulting in the imbalance of its motion, which reduces the safety of the underwater vehicle. Aiming at the above problems, this paper adopts the decoupling distribution strategy of six degrees of freedom, which effectively decouples the motion of six degrees of freedom by dividing the control force/torque on the six degrees of freedom into horizontal direction and vertical direction. According to the decoupling strategy and the layout of AUV thrusters, the thrust optimization distribution model of multiple thrusters AUV was established.

(2) Underwater vehicles are usually equipped with multiple redundant thrusters to form a drive propulsion system. The use of multiple thrusters increases the constraint conditions considered in the thrust distribution and makes the distribution more difficult. Therefore, improper selection of the distribution method may lead to the distribution failure and affect the safety of underwater vehicles. The traditional thrust distribution method mainly includes direct solution and iterative solution. The direct solution method is like the pseudo-inverse method. Through direct solution, the distribution result can be obtained quickly with good real-time performance. Iterative solutions, such as sequential quadratic programming (SQP), comprehensively consider the requirements of the objective function and constraint conditions. Through iterative solutions, the optimal solution that meets the requirements of the objective function and constraint conditions can be obtained. However, the design of the algorithm is complex and the real-time performance cannot be guaranteed. With the development of intelligent optimization method, the research of distribution method has a new content. Compared with the traditional algorithm, the intelligent algorithm has the advantages of strong universality, global optimization and adaptive solution. Aiming at the thrust distribution problem of underwater vehicle, this paper takes the over-driven underwater vehicle equipped with multiple thrusters as the research object. Firstly, the pseudo-inverse method and sequential quadratic programming method in the traditional thrust distribution method are adopted to conduct the thrust distribution research of underwater vehicle. The applicability of the two algorithms is verified by numerical simulation. Then the genetic algorithm in the intelligent algorithm is used to design the thrust optimization allocation algorithm. The effectiveness of the optimization allocation method is verified by numerical simulation.

Keywords: Underwater vehicle; Overdrive propulsion system; Decoupling allocation strategy; Optimal allocation method

目 录

第一章 绪论 1

1.1研究背景与意义 1

1.2国内外研究现状 1

1.2.1水面船舶推力分配研究现状 2

1.2.2水下航行器推力分配研究现状 3

1.3研究内容安排 3

第二章 推力优化分配 4

2.1引言 4

2.2目标函数 4

2.2.1功率消耗 4

2.1.2惩罚项 5

2.3约束条件 5

2.3.1等式约束条件 5

2.3.2不等式约束条件 6

2.4推进器数学模型 7

2.4.1槽道推进器 7

2.4.2全回转推进器 7

2.4.3主推进器带舵 7

2.5水下航行器推力分配数学模型 8

2.5.1推进器空间布置 8

2.5.2水平向推进器建模 9

2.5.3垂直向推进器建模 10

2.5.4水下航行器推力分配数学模型 10

2.6本章小结 11

第三章 基于伪逆法和SQP的推力优化分配算法 12

3.1引言 12

3.2伪逆法 12

3.2.1基本原理 12

3.2.2算法流程 13

3.3序列二次规划法 13

3.3.1基本原理 14

3.3.2算法流程 15

3.3.3基于SQP的水下航行器推力分配问题求解 17

3.4仿真结果与分析 18

3.4.1仿真条件 18

3.4.2仿真结果 20

3.5本章小结 26

第四章 基于遗传算法的推力优化分配算法 27

4.1 引言 27