超空泡航行体运动稳定性及切换控制研究

Supercavitation technology can reduce the resistance of underwater vehicle, which makes the speed of vehicle exceeding 200 knots or more become possible. Due to super high-speed vehicle is enveloped by cavity, the wetted area decreases, most of buoyancy force loses, and both force and motion mode of underwater vehicle are significantly different from common underwater body. Therefore, studying the control, guidance and stability of supercavitating vehicle is an important part of its engineering applications. To solve this key problem, this project takes basic theory as central point, theoretical research and semi-physical simulation as method, and studies dynamics model and control law of vehicle. The main contents include research on changing conditions and laws of planing force, integrated control strategy of vehicle cavitator and rudder, mathematical models and their different characteristics when the vehicle with or without planing force, stability of motion and control methods under two models switching conditions, and the stability of control system when cavity noise disturbance exists, finally carrying out semi-physical simulation experiment, validation and revising theoretical research..This project can provide robust control method for underwater supercavitating vehicle, offer theoretical basis for engineering applications, and can also supply a reference for theoretical study of related fields of supercavitation.

超空泡技术可以减小航行体的阻力，使水下航行体速度突破200节甚至更高成为可能。由于超高速航行体被空泡包裹而使沾湿面积减小，丧失大部分浮力，其受力及运动方式与普通水下运动体显著不同，因此超空泡航行体的控制、制导和稳定性是其工程应用的重要组成部分。本项目以解决此关键问题为宗旨，以基础理论为中心，以理论研究与半实物仿真为手段，研究航行体动力学模型及控制规律。包括研究滑行力变化条件及规律；研究超空泡航行体空化器与尾舵综合控制策略；研究航行体有无滑行力情况下的数学模型及其差异特性；研究两种模型切换条件下的运动稳定性及控制方法；研究空泡噪声干扰时控制系统稳定性；进行半实物仿真实验，验证并修正理论研究内容。.　　研究内容可以为水下超空泡航行体运动提供鲁棒控制方法，为水下超空泡航行体工程应用提供理论基础，也可以为超空泡相关领域的理论研究提供参考。

项目以水下超空泡航行体的动力学及运动稳定性为背景，研究航行体在超空泡条件下的动力学模型及强非线性滑行力,将航行体模型特性与非线性控制方法相结合,抑制航行体本身动力学参数摄动和外部环境扰动,达到较好的控制效果。项目从动力学模型中的滑行力非线性特性、系统稳定性、鲁棒控制、半实物仿真等方面开展研究，重要进展概括如下：（1）研究航行体纵向运动模型，给出三种滑行力模型与纵向速度的对应关系，将动力学模型经过转换后表示为线性环节与非线性环节反馈连接的形式，基于圆判据定理给出了航行体绝对稳定的充分条件，并依据该条件采用状态反馈极点配置方法设计控制器。通过设计反馈控制器可以保证滑行力建模不确定性及参数不确定性条件下的绝对稳定。（2）用线性变参数方法设计鲁棒变增益控制器，在理论上保证系统的全局稳定性和鲁棒性，克服了传统变增益控制的缺点。（3）针对航行体部分水动力参数存在摄动及外部环境的噪声干扰,提出一种基于时域绝对稳定性的鲁棒 绝对稳定控制器的综合方法,实现了闭环系统对于范数有界不确定行的绝对稳定。（4）搭建水下高速运动体半实物仿真平台，通过仿真试验结果，能够验证控制器控制算法的有效性，传感器和执行机构的可靠性等，达到预期控制目标。