超空泡航行体的控制研究

Abstract

Abstract

Supercavitation can significantly reduce drag of underwater torpedo, which enabling a dramatic increase of velocity and attack power for underwater weapons. Therefore, study of the underwater high-speed supercavitating vehicle (HSSV) have great strategic significance and military application value. Because the HSSV is almost entire enveloped by a supercavity, the hydrodynamic problems of the HSSV is complex. The dynamic equtions of HSSV has coupling effect and lightly-damped characteristics, any small disturbances will make the HSSV drift away,so the HSSV must have feedback control to work. In this paper, the hydrodynamic forces including the cavitator, fin, and the planing force in the longitude plane of the underwater HSST are analyzed. According to the basic dynamic equtions of the longitude plane, this paper studyed about the control design of HSSV, and the specific work and results as follow:

Because of the coupling effect and lightly damped dynamics of the HSSV, a decoupling inner-outer loop design is proposed. In the design, the dynamic characteristics of the weak damping are stabilized by the pitch angle feedback fristly, and decoupled with the kinematics. And then the kinematic loop was designed in which the depth signal is used as the output. The Nyquist method is used to analyze the design of the system. This method of determining the feedback gain with loop and bandwidth can satisfy the good performance requirement of depth control and ensure the stability of the attitude loop. Each step of this design has a clear physical explanation, for the state feedback design provides a new idea, but also for the supercavity of the classic control law gives a perfect comment.

For the planing force when the tail of the the HSSV into contact with the cavity，the H∞control is proposed. The channel of the planing force is also taken into account in this control design to ensure that the system has good performance under sustained planing force disturbances. According to the two-input characteristics of the cavitator deflection and fins deflection and the special stability requirements of HSSV, and based on the considerations of the ill-conditioned problems in solving Riccati equations, the requirement in the low-frequency domain as well as the attitude stabilization problems, the choice of weighting coefficients is discussed in detail, a comprehensive solution to this weight slection problem is presented and the H∞ state feedback controller which satisfies the many requirements is given.

Because of delay characteristic of cavitation, the delay characteristic of planing force and the performance affect of delay characteristic in control is analyzed. It is

pointed out that the delay characteristic of supercavitating almost no affection in qualitative. Because the planing force with time-delay is a multivariable nonlinear function, in order to simplify the analysis, the banchmark model can be used in control design firstly, and then the time delay model can be use to verify in the simulation.

When the underwater high-speed supercavitation vehicle aft end pierces the bubble generated planing force, for the phenomenon of periodic collisions, planing avoid control mothod is discussed, based on observer will be used to compensate and eliminate the influence of constant disturbance. The disturbance observer equation was deduced and the compensator is given. The observer and compensation degined in this paper can avoid the problem of the HSSV slapping the cavity wall and actuator stroke too large. The predecessor's unsuccessful cases which use direct compensation is analyed, and provides a feasible scheme for the future control design for planing avoid control of HSSV.

Keywords:supercavitating vehicle; planing force; time-delay; state feedback; H∞ control;disturbance observer

目录

目录

摘要 .......................................................................................................................... I ABSTRACT ............................................................................................................... I II 第1章绪论. (1)

1.1课题背景和研究意义 (1)

1.2国内外的研究历史与现状分析 (3)

1.2.1 超空泡航行体流体动力学和建模研究现状 (3)

1.2.2 超空泡航行体控制技术研究现状 (5)

1.3本文的主要研究内容 (7)

第2章超空泡航行体的数学模型与分析 (9)

2.1引言 (9)

2.2超空泡航行体简介 (9)

2.2.1超空泡航行体的标准设计 (9)

2.2.2超空泡航行体的体坐标系和模型基本参数 (10)

2.3超空泡航行体纵向平面流体动力分析 (12)

2.3.1 空化器流体动力分析 (12)

2.3.2 尾翼流体动力分析 (13)

2.3.3 滑行力 (14)

2.4超空泡航行体控制模型 (15)

2.5超空泡航行体运动分析与仿真 (18)

2.6本章小结 (20)

第3章超空泡航行体的状态反馈控制设计 (21)

3.1引言 (21)

3.2反馈控制设计 (21)

3.2.1 超空泡航行体反馈控制性能的特殊要求 (21)

3.2.2 反馈控制设计思想 (22)

3.2.3 反馈增益设计 (25)

3.3反馈控制的稳定性分析 (31)

3.4超空泡航行体的实际运行性能分析 (32)

3.4.1 零初始条件下的稳定性能分析 (32)

3.4.2 扰动条件下的恢复性能分析 (35)

3.5本章小结 (38)

控制 (40)

第4章超空泡航行体的H

∞

4.1引言 (40)

4.2超空泡航行体的H∞状态反馈问题描述 (40)

4.2.1 H∞状态反馈简介 (40)

4.2.2 超空泡航行体的H∞状态反馈 (42)

4.3超空泡航行体H∞状态反馈设计 (44)

4.3.1总体设计思路 (44)

4.3.2 LQR优化解的频率特性 (45)

4.3.3 H∞状态反馈权系数的选取 (47)

4.3.4 H∞状设计中数值求解的病态问题 (54)

4.4超空泡航行体H∞状态反馈下的性能 (55)

4.5与单位加权设计的性能对比分析 (57)

4.5.1 权矩阵为单位阵的H∞状态反馈 (58)

4.5.2 稳定性的对比 (58)

4.5.3 扰动抑制性能的对比 (62)

4.6本章小结 (67)

第5章超空泡航行体的时滞特性分析 (69)

5.1引言 (69)

5.2空泡的时滞效应及考虑时滞的滑行力 (70)

5.3常规状态反馈控制下的性能对比 (73)

5.4H∞控制下的性能对比分析 (76)

5.5本章小结 (80)

第6章超空泡航行体的观测器设计和补偿 (82)

6.1引言 (82)

6.2超空泡航行体的常值扰动分析 (82)

6.3超空泡航行体的扰动观测器设计 (84)

6.3.1 扰动观测器方程 (84)

6.3.2 超空泡航行体的扰动补偿 (85)

6.3.3 扰动观测补偿的性能分析 (86)

6.4补偿与系统设计的关系 (91)

6.5本章小结 (96)

结论 (97)

目录

参考文献 (99)

攻读博士学位期间发表的论文及其它成果 (107)

哈尔滨工业大学学位论文原创性声明和使用权限 (108)

致谢 (109)

个人简历 (111)

Contents

Abstract (In Chinese)........................................................................................?Abstract (In English)........................................................................................??Chapter 1 Introduction (1)

1.1 Background and significance of the subject (1)

1.2 Research history and status of home and abroad (3)

1.2.1 Development of hydrodynamics and modeling for supercavitating

vehicle (3)

1.2.2 Development of control technology for supercavitating vehicle (5)

1.3 Main research contents of this subject (7)

Chapter 2 Mathematical model and analysis for supercavitating vehicle (9)

2.1 Introduction (9)

2.2 Introduction for supercavitating vehicle (9)

2.2.1 A benchmark design for supercavitating vehicle (9)

2.2.2 Coordinate system and basic parameters for supercavitating vehicle.10 2.3 Hydrodynamic analysis of longitudinal for supercavitating vehicle..12

2.3.1 Hydrodynamic analysis for cavitator (12)

2.3.2 Hydrodynamic analysis for fin (14)

2.3.3 Planing force (14)

2.4 Model for control of supercavitating vehicle (15)

2.5 Introduction (18)

2.6 Motion analysis and simulation of supercavitating vehicle (20)

Chapter 3 feedback control design for supercavitating vehicle (21)

3.1 Introduction (21)

3.2 Feedback control design (21)

3.2.1 Special performance requirements for supercavitating vehicle (21)

3.2.2 Design ideas for feedback control design (22)

3.2.3 Feedback gain design (25)

3.3 Stability analysis of feedback control design (31)

3.4 Performance analysis for actual operation (32)

3.4.1 Stability performance analysis in zero initial conditions (32)

3.4.2 Recovery performance analysis under disturbance (35)

3.5 Brief summary (38)

Chapter 4 H∞ control design for supercavitating vehicle (40)

4.1 Introduction (40)

4.2 H∞ feedback problem of supercavitating vehicle (40)

4.2.1 Introduction of H∞ feedback control (41)

Contents

4.2.2 H∞ feedback control for supercavitating vehicle (42)

4.3 H∞ feedback control design for supercavitating vehicle (44)

4.3.1 Design idear totally (44)

4.3.2 Frequency characteristic of LQR optimal problem (45)

4.3.3 S election of weight factor for H∞ feedback (47)

4.3.4 Ill-conditioning problem in numerical solution for H∞ control (54)

4.4Performance analysis of H∞ control for supercavitating vehicle (55)

4.5 Comparative analysis between with unit weighting H∞ control (57)

4.5.1 Unit weighting H∞ feedback contr ol (58)

4.5.2 Comparative analysis of stability performance (58)

4.5.3 Performance comparative analysis under disturbance (62)

4.6 Brief summary (67)

Chapter 5 Time delay characteristic analysis for supercavitating vehicle (69)

5.1 Introduction (69)

5.2 Memory characteristic of cavitation and time-delay model for planning

f o r c e (70)

5.3 Performance contrast under conventional feedback control (73)

5.4Performance contrast under H∞ feedback control (76)

5.5 Brief summary (80)

Chapter 6 Observer and compensation design for supercavitating vehicle..82 6.1 Introduction (82)

6.2 Constant disturbance analysis for supercavitating vehicle (82)

6.3 Observer design for supercavitating vehicle (84)

6.3.1 Disturbance observer equation (84)

6.3.2 Perturbation compensation for supercavitating vehicle (85)

6.3.3 Performance analysis for disturbance observer and compensation (86)

6.4Relation between compensation and control design (91)

6.5 Brief summary (96)

Conclusions (97)

References (99)

Papers published in the period of Ph.D. education (107)

Statement of copyright and Letter of authorization (108)

Acknowledgements (109)

Resume (111)