波纹管机械密封焊接金属膜片的有限元分析和结构优化

波纹管为焊接金属波纹管机械密封的关键零件，工作中常因反复的弹性变形而发生疲劳失效．本文以焊接金属波纹管的膜片为研究对象，对S型和V型两种膜片的应力场和变形场进行了详细的有限元法分析和计算，在对两种膜片进行比较的基础上对S型膜片进行了结构形状优化和计算．研究结果为焊接金属波纹管机械密封的改进和设计、提高疲劳强度和使用寿命提供了理论依据．     

一类时滞中立型系统的无记忆反馈H_∞控制

本文采用Lyapunov函数和LMI不等式方法,研究了一类输出方程亦带有不确定性的中立型时滞系统在控制律的作用下鲁棒H∞控制问题.     

具有受限转移率的跳变系统L2-L∞模糊控制

讨论了一类含不确定转移率的非线性Markov跳变系统的L2-L∞模糊控制问题。系统模态间转移概率所包含的不确定性是未知且有界的。通过Takagi Sugeno模型模糊建模，获取了整个闭环模糊动态方程。基于L2-L∞模糊控制理论，提出了使得系统随机稳定且满足一定输入输出L2-L∞特性的模态依赖的模糊控制器存在条件。利用构造的Lyapunov Krasovskii函数，结合线性矩阵不等式技术，给出了鲁棒L2-L∞模糊控制器的设计方法，并将其设计转化为一个优化问题。仿真示例说明了设计方法的有效性。     

Receding horizon H∞ control for discrete-time Markovian jump linear systems

Receding horizon H∞ control scheme which can deal with both the H∞ disturbance attenuation and mean square stability is proposed for a class of discrete-time Markovian jump linear systems when minimizing a given quadratic performance criteria. First, a control law is established for jump systems based on pontryagin’s minimum principle and it can be constructed through numerical solution of iterative equations. The aim of this control strategy is to obtain an optimal control which can minimize the cost function under the worst disturbance at every sampling time. Due to the difficulty of the assurance of stability, then the above mentioned approach is improved by determining terminal weighting matrix which satisfies cost monotonicity condition. The control move which is calculated by using this type of terminal weighting matrix as boundary condition naturally guarantees the mean square stability of the closed-loop system. A sufficient condition for the existence of the terminal weighting matrix is presented in linear matrix inequality (LMI) form which can be solved efficiently by available software toolbox. Finally, a numerical example is given to illustrate the feasibility and effectiveness of the proposed method.     

深层次动态优化设计理论及应用研究

随着技术的进步,传统的动态优化设计方法已经难以满足这些日益提高的要求,以非线性理论为基础的深层次动态优化设计理论的研究和应用已成为机械工程的一个重要的研究方向。     

给水管网系统优化设计方法

给水管网是供水系统的重要部分,必须确保其安全可靠。本文集中介绍了七种管网系统优化设计方法。     

基于粒子群优化算法的APU总体件能优化设计

本文采用粒子群优化算法（PSO），集成APU总体性能计算模型，以150座级和100座级的两款民用飞机辅助动力装置（APU）为例，在满足其设计要求的前提下，以耗油率为目标进行了多参数的优化设计。计算结果表明，基于PSO算法的APU总体性能优化方法能够获得最优解，可以克服其性能方案设计时人工经验依赖较重的缺点，其结论可为实际的APU设计研制提供依据并指导相关设计参数的选取。     

具有极点约束的δ算子不确定系统的鲁棒l2-l∞滤波

针对l2-l∞性能这一类扰动抑制度指标设计滤波器,使滤波误差系统是鲁棒D(a,r)-稳定的(当外部扰动恒为零时),且l2-l∞性能指标上界尽可能的小.采用线性矩阵不等式方法,给出了l2-l∞滤波器存在的充分条件,进而提出滤波器的设计方法.通过数值算例验证了该方法的可行性.     

1^∞型幂指函数极限的一种计算方法

微积分极限部分常遇见计算形如「ｆ（ｘ）＾ｇ（ｘ）（即幂指函数）的极限，本文将在教科书常用的计算方法之外，对于呈１＾∞型的害虫指函数给出一种便于应用的转化为求积」ｆ（ｘ）－１「ｇ（ｘ）的极限。     

H_∞ Control of a 5th- order Model of Synchronous Generators

1　IntroductionThe control of synchronous generators is one of the most important and widely studiedproblem in the area of power systems control.Such a problem is a non-trivial one,mainlybecause of the highly nonlinear behaviour of synchronous machines.As a matter of fact,their dynamic dramatically changes when passing from a working condition to another.Asa consequence,standard PID-based controllers can not guarantee high performances overthe entire working range.Among the various control a…