非线性

On the basis of the conclusion above, the nonlinear weak controllable vectors can be obtained, which compose the second class of weak controllable matrix, by means of matrix transfermations of the first class of weak controllable matrix. Furthmore the second criterion of weak controllability, accessibility and strong accessibility, which is more standard, more succinct and more practical, is obtained. On the basis of the first criterion and the second criterion, several important problems about nonlinear controllability are discussed, which include 1 local controllability; 2 three classes of local controllable decomposition, separately by means of local coordinate changes in the neighborhood of a nonsingular point, a point on a singular surface or a designated point x〓 with a designated input u〓; 3 the character of controllability of the ith state variable x〓 in different controllable areas and their boundaries.

在第一判别定理和第二判别定理的基础上，我们分析了非线性系统受控性质中的几个重要问题，所得到的结论包括i得到了非线性系统在可平衡点附近的能控性判别定理；ii分别给出了非线性系统在非奇异点、s阶奇面以及在状态空间内给定的一点x〓和输入u〓上的三种状态分解形式以及相应的求解方法；利用系统的Ⅰ型弱能控矩阵与Ⅱ型弱能控矩阵秩相等的条件，得到了只用系统的前n个弱能控向量来判断系统的弱能控性的判别定理；iii通过引入系统状态分量的三类受控区域边界的定义及相应的求解方法，初步探讨了非线性系统各个状态分量在不同的受控区域及其边界上的受控性质。

It is a generalization of the nonlinear diffusion equation proposed by Perona-Malik and the method presented by Cuesta, and interpolates between the nonlinear parabolic equation and the nonlinear hyperbolic equation, thus can effectively control the diffusion process so that noises can be removed and details of the image such as edges can be preserved as much as possible simultaneously.

提出了一种包含对时间的分数阶导数的非线性扩散方程，它是对Perona-Malik的非线性扩散方程和Cuesta提出的方程的推广，介于非线性抛物方程和非线性双曲方程之间，从而能有效地控制扩散过程，使得在去除图像噪声的同时能够尽可能地保留图像的边缘等细节信息。

The nonlinear dynamic model was expressed based on the format of SISO affine nonlinear system. Then the system was represented into the standard Byres-Isidori format base on the diffeomorphism transform.

使用SISO仿射非线性系统描述了所建立的自行车机器人非线性动力学模型，利用非线性微分同胚变换将该系统化成了Byres-Isidori非线性系统的标准型形式。

The solution of some practical problems in engineering can be regarded as that of periodic solution of nonlinear autonomous systems according to the opinion of mathematics, The problems of this kind are analysed by means of the direct numerical method in this paper,The simple and convenient Draw Newton Method is applied for solving the parameter vectors in iteration course along with the calculation of a practical engineering problem.

日I崖旨J，'口工程中的一些实际问题往往可以归结为非线性自治系统，例如描述同步发电机暂态稳定性问题的转子摇摆方程，即是一典型的非线性自治系统。虽然可以用各种小参数摄动法求解非线性系统，但是这类方法是依据对线性系统的解进行"摄动"来逼近非线性系统解的。因而当系统

The main works in this paper are as follows:(1). In this thesis, a new method, continuous linearization model, is constructed for the non-linear dynamic systems. The precision Duhamel integration solution for the linearization equation is also given from the theory of linear differential equation. The calculating results show that the new method can improve the calculation precision greatly. In fact, the truncation error is not limited by this method, it can arrive the precision according to the requirement.

本文的主要工作有以下几个方面：(1)由于非线性项的存在，使得多数情况下难以得到非线性动力方程的解析解表达式，目前常使用数值积分方法来求解非线性动力学方程的解，但常规计算方法的计算精度不很理想，本文提出了含Taylor展开项中高阶余项的非线性动力方程的线性化数值计算方法，构造了瞬态线性化方程，给出了Duhamel积分的表达式。

According to the nonlinear finite element theory, the basic principle of the finite element method about geometrical nonlinearity and material nonlinearity is analyzed.

依据虚功原理和增量理论，研究了与几何非线性和材料非线性相关的有限元基本理论，并将其引入张弦梁的非线性力学分析中，建立该结构的非线性有限元分析理论和计算方法。

In our thesis, contents are organized as following In Chapter 1 we present our topic's internal and overseas research situations, theoretical and practical significance, and introduce the research object and contents, and the main contributions of this dissertation. Chapter 2 reviews the development of the stability results for nonlinear systems and some relevant recent results, which include Lyapunov and LaSalle-Yoshizawa theorems for nonlinear systems, and stochastic edition for stochastic nonlinear systems. Sontag's formula for systems affine in control is presented in the frame of CLF. The concepts of disturbance attenuation and the inverse optimality are also explained in this Chapter. In chapter 3 we present the solvable theorem of inverse optimal gain assignment problem, design the inverse optimal controller and the inverse optimal tracking controller for strict-feedback nonlinear continuous systems with unknown time-varing bounded disturbances and constant unknown parameters using an adaptive backstepping algorithm, which are nonlinear, continuous and are easier to realize. These designs are fully systematic and the algorithm can be directly coded in symbolic software. The results of simulation show the effectiveness of the control algorithms.

论文的结构如下：在第1章中，给出了本文研究课题的研究现状、理论意义和实际应用，并介绍了本文的研究对象、研究内容以及主要贡献；在第2章中，针对确定性非线性系统和随机非线性系统，分别介绍了Lyapunov定理、LaSalle-Yoshizawa定理及其随机版本；对仿射系统，在控制Lyapunov函数框架下，给出了Sontag公式；同时给出了非线性系统扰动抑制和逆最优控制问题的基本概念；在第3章中，针对具有未知时变有界扰动和未知定常参数的一类不确定非线性系统，给出并证明了逆最优增益配置可解定理，使用自适应Backstepping算法和均值定理，系统地设计了自适应逆最优控制器和逆最优跟踪器，这种设计方法可同时获得逆最优控制策略和自适应律，简单明了，仿真结果表明该控制算法的有效性，并给出了性能估计。

Presents the design of longitudinal control for ASTOVL lift-fan aircraft, a multi-variable, strong-coupling, complicated nonlinear system to make the system nonlinear offset and decouple, and the method used for linear system in designing the system to gain expectant flying qualities and the combination of aerodynamic control surfaces with thrust vectors to delay the control surfaces getting into saturation, and the minimum N-norm generalized inverse theorem of weighted generalized inverse adopted to apportion the moments commands, which make the control surfaces gain appropriate deflection and the simulation results to verify the dynamic inverse control laws designed really make the system nonlinear offset and decouple; when one command is given, only this output will response, and others do not response; when all commands are given together, the responses will be just the linear superpose of the response of each command, therefore the operation of the pilot will be simplified greatly.

摘 要： ASTOVL升力风扇飞机是多变量、强耦合、复杂的非线性系统，采用非线性动态逆理论设计控制律以实现系统的非线性对消及解耦，然后，采用线性系统的设计方法对系统进行设计，以使系统获得期望的飞行品质。同时，考虑到ASTOVL升力风扇飞机是由气动舵面和推力矢量融合作用的，为了延缓各舵面进入饱和的时间，采用加权广义逆中的极小N-范数广义逆定理分配力矩指令，从而使各舵面达到适当的偏转角。并将所设计的控制律进行了仿真，结果验证了所设计的动态逆控制律使系统实现了非线性对消和解耦，单个指令作用时，只有该项响应，其余不受影响；所有指令作用时，其结果就等于单个指令作用时的线性叠加，这样使驾驶员的操纵大大简化而易于控制，从而大大降低了飞行事故率。

By the principle of penalt function, the irrotational fluid field is constrained, and author has proposed the Difference Method for distinguishing fluid vortex modes among the natural modes of coupled systems. Author has calculated the real frequencies with the extra deductive method, and discussed the influence of the numerical solution due to the irrotational constraint.

对于流体有限扰动时的非线性耦合系统的有限元分析作了一些探讨，给出了非线性系统的基本方程、变分原理及有限元方程，并具体地导出了三维几何非线性流体单元的切线刚度公式，采用增量形式的Newmark预报——校正逐步积分法计算系统的动力响应，由Newton-Raphson迭代法及其修正方法求解系统的非线性方程组，还列出了不平衡力余量检查和位移迭代增量检查等迭代收敛判断准则。

Considering the vehicular SG cruise integrating model under braking condition influenced by some factors of nonlinearity, time-delay and the disturbance, a new nonlinear SMITH predictor is designed to compensate the time delays of control variable in advance. Furthermore, with the resort of pure delay operator, extension of the Lie derivative and the Lie bracket, some issues of SISO nonlinear system with time delays in state variable are resolved, which cover the input-output linearization, invertability of coordinate transformation and the disturbance decoupling problem.the staged transformation and design technique, the vehicle deceleration tracking control and the SG cruise disturbance decoupling control under braking condition are carried out effectively using proposed control method.

在建立制动工况下车辆走-停巡航系统集成模型基础上，针对其非线性、时滞特性以及目标车减速度干扰的影响，提出一种改进的非线性SMITH预估补偿方法，以消除控制变量时滞，并结合时滞算子、扩展李导数和扩展李括号方法，研究并解决了SISO状态变量时滞非线性系统的输入输出线性化、坐标变换的可逆性以及输出干扰解耦问题，实现了SISO时滞非线性系统的综合控制。

Plunder melds and run with this jewel!

掠夺melds和运行与此宝石！

My dream is to be a crazy growing tree and extend at the edge between the city and the forest.

此刻，也许正是在通往天国的路上，我体验着这白色的晕旋。