Handling stability improvement through robust active front steering and active differential control

The design of the integrated active front steering and active differential control for handling improvement of road vehicles is undertaken. The controller design algorithm is based on the solution of a set of linear matrix inequalities that guarantee robustness against a number of vehicle parameters such as speed, cornering and braking stiffnesses. Vehicle plane dynamics are first expressed in the generic linear parameter-varying form, where the above-stated parameters are treated as interval uncertainties. Then, static-state feedback controllers ensuring robust performance against changing road conditions are designed. In a first series of simulations, the performance of the integrated controller is evaluated for a fishhook manoeuvre for different values of road adhesion coefficient. Then, the controller is tested for an emergency braking manoeuvre executed on a split-μ road. In all cases, it is shown that static-state feedback controllers designed by the proposed method can achieve remarkable road handling performance compared with uncontrolled vehicles.     

基于Simulink单相矩阵变换器畸变的改进措施研究

基于单相矩阵变换器原理图得到产生畸变的输出波形，并进一步分析了输出波形畸变的原因，提出了改进思路以及改进电路图，最终通过Simulink的建模仿真得到了单相矩阵变换器理想的输出波形，并发现这种变换器具有输出频率连续可调、输入输出电流接近正弦波等优点，发展前景大，值得进一步研究．     

基于GSM-R智能网的接入矩阵业务

介绍GSM—R智能网系统，简述GSM—R系统的编号方案，阐述接入矩阵业务的概念及其在铁路中的应用，详细分析了接入矩阵业务的信令消息，并且提出消息中的必选参数。     

基于弹性构架的地铁车辆动力学分析

为避免车辆弹性动力学分析中自由度数多、求解方程慢的问题,运用Guyan矩阵缩减理论选出模型中能描述动力学行为的部分。运用Ritz模态向量叠加理论考虑构架的弹性变形对地铁车辆动力学行为的影响。用车辆系统的位形坐标与构架的模态坐标建立刚—柔混合多体系统动力学模型,使自由度得到缩减。从而较快得到地铁车辆具有构架弹性振动的动力学响应,其结果与刚体动力学模型相比有明显差别。     

多跨弹性支座圆弧梁计算的传递矩阵法

以圆弧梁初参数方程的通解为基础,求得承受任意分布载荷的圆弧梁段的载荷函数,推得反映状态向量变化的传递矩阵式。根据变形协调条件和力的平衡条件推得圆弧梁在弹性支座作用处和集中载荷作用处的点矩阵,解决在这些截面两侧某些状态变量突变的问题。将多跨弹性支座圆弧梁的复杂计算变成一个利用一维矩阵连续相乘的简单问题。通过验证表明,这种方法的计算结果和理论解一致。通过对多跨弹性支座圆弧梁实例的计算表明,其结果与其他方法求得的结果也十分吻合。     

Alternative friction models for braking train dynamics

Braking dynamics plays an essential role in ensuring the comfort and running safety of trains. Due to the complexity of the phenomena involved and the presence of dry friction, studies have been carried out by numerical methods using smoothening. Based on the non-smooth dynamics framework, in the present paper, an efficient and comprehensive alternative model is defined. Set-valued friction of Coulomb's law type is accounted for and motion equations are formulated as a differential inclusion. Some of the fundamental issues of contact dynamics are briefly reviewed. Static friction forces which arise in buffers are computed in a very intuitive and efficient manner, using an original method involving generalised inverses of matrices. The corresponding algorithm is described. Numerical integration is done by an event-driven algorithm. Indeterminate system configurations can be appropriately handled. The number of vehicles on which tests have been carried out ranged from 5 to 50. Comparison with the smoothening method reveals significant differences. Computational efficiency is dramatically improved. Computation speed can rise by a few orders of magnitude. Specific phenomena such as stick–slip or persistent longitudinal forces can be evidenced. Computed values of the system states differ substantially. In addition to this, any wagon connection model can be embedded.     

基于比较矩阵法的沥青混合料路用性能权重研究

在评价沥青混合料的路用性能这一矛盾体时，权重是一关键因素，对方案优选起重要作用。如何相对客观地确定权重是评价模型中一个非常关键的问题。通过沥青混合料各路用性能的预估寿命这一相对客观的指标，结合比较矩阵法建立了权重模型，分别求取了沥青各面层各路用性能的权重。通过分析各路用性能的权重，可进一步指导各面层的沥青混合料的设计。     

广义Jacobi矩阵特征值问题

在科学工程运算中，很多实际问题感兴趣的是大规模矩阵的特征值求解问题，例如振动工程中的一些问题，往往可以归结为Jacobi矩阵的特征值求解问题．主要对广义Jacobi矩阵的特征值问题，也就是次对角线元素乘积为正的Jacobi矩阵的特征值问题，做了进一步的研究讨论，并得到一些重要结果．     

基于完全信息的车速建模及Moore-Penrose广义逆求解

针对交通事故中的车速估计，提出了基于事故中的完全信息建立车速估计数学模型，摒弃传统的仅根据未知量个数建立方程组的方法，意在构造出方程个数多于未知量个数的不相容线性方程组，利用Moore-Penrose广义逆求解未知参数，使与事故车速关联的信息在车速估计中充分体现，从而减小模型误差和数据误差对事故车速估计结果的影响，获得车速的最优估计值。     

矮塔斜拉桥塔高优化

本文以主梁弯曲应变能最小及塔高最小为目标函数 ,建立了矮塔斜拉桥塔高优化模型 ,探讨了通过调整拉索初张力优化 (降低 )矮塔斜拉桥塔高的可行性。本文以一矮塔斜拉桥为背景 ,分析了独塔两跨矮塔斜拉桥塔高变化时调整拉索初张力的效果 ,对进一步认识矮塔斜拉桥的结构性能及同类桥梁的塔高优化设计有一定的参考意义