不可建模故障且故障数目不确定的自适应容错控制

The projection is based on a class of fault tolerant flight control problem of near space vehicles (NSV), researches the problem of adaptive fault diagnosis and fault tolerant control for nonlinear systems with infinite number of un-modeled actuator/sensor faults. First of all, based on a novel general composite fault model that can deals with both time-varying gain and bias faults, fault mechanism is studied enough and the fault model with infinite number of faults is established; fault disgnosis and fault torlerant control for nonlinear systems with infinite number of faults occurred in one or multiple actuators/sensors are investigated, respectively. Then, "descriptor adaptive fuzzy/neural sliding mode observers" are designed to diagnose different types of faults simultaneously occurred both in actuators and sensors. Thirdly, by using barrier Lyapunov function（BLF）and some algebraic geometric theorems, some useful property of the basis function of the radial basis function of neural network are explored, and fault diagnosis and fault compensation for un-modeled faults are researched. Further, the fault folerant control for nonlinear systems with infinite number of un-modeled faults is studied. In addition, the time delay due to fault diagnosis and isolation and its influence on the controlled systems' performance are quantitatively analyzed. Finally, the flight control problem of NSV is deeply researched. Based on the proposed approaches, a new fault tolerant flight control framework as well is provided for NSV. This projection enlarges the research fields of adaptive fault diagnosis and fault tolerant control, which makes the project have the important academic value and practical meaning.

本项目以近空间飞行器容错飞行控制为背景，研究具有执行器/传感器不可建模故障且故障数目不确定的非线性系统的自适应故障诊断与容错控制问题.在提出一种能够同时处理增益和偏置故障的时变复合故障模型基础上,充分研究故障发生机理,建立不确定数目的故障模型；探索一个或多个执行器/传感器发生不确定数目故障的故障诊断与容错控制；构造"广义自适应模糊/神经网络滑模观测器"以研究多个执行器和传感器同时发生不同类型故障的诊断；利用BLF及有关代数几何理论,挖掘神经网络基函数的有关性质，研究不可建模故障的诊断与补偿，并进一步研究具有不可建模故障且故障数目不确定的非线性系统的容错控制；定量分析FDI诱导的时滞及其对系统性能的影响；深入研究近空间飞行器容错飞行控制问题，并运用所提出的非线性系统容错控制方法，建立一套该类飞行器飞行容错控制框架.本项目拓宽了自适应故障诊断和容错控制的研究领域，具有重要学术意义和实际价值.

本项目首先以近空间飞行器容错飞行控制为背景，研究非线性系统的自适应故障诊断与容错控制问题，针对多种故障类型，利用神经网络、模糊逻辑系统、自适应控制技术以及其它控制理论与技术，提出了一套非线性系统的自适应故障诊断算法和容错控制方案。在此基础上，针对一类具有执行器故障的系统，本项目定量分析FDI诱导的时滞及其对系统性能的影响，并提出减少其影响的措施。然后，本项目研究了不确定高阶非线性多智能体系统的协同控制以及故障补偿问题，分别针对跟随者具有与自身状态相关的未知控制系数、跟随者具有严格反馈的形式、死区与饱和执行器故障等的情况，设计了相应的分布容错控制方案与故障补偿算法。接着，针对各种不确定非线性系统，在出现状态、输入未建模动态以及状态可测与不可测的情况下，利用多种控制技术和方法，分别提出了集中与分散式、状态反馈、输出反馈自适应控制方案，证明闭环系统的稳定性。最后，研究了不确定非线性纯反馈切换系统在任意切换下的自适应跟踪控制问题, 基于指令滤波的backstepping设计，提出了一种鲁棒自适应神经网络控制方案，保证闭环系统是渐进有界。本项目拓宽了自适应故障诊断和容错控制的研究领域，具有重要学术意义和实际价值.