Robust output feedback cruise control for high-speed train movement with uncertain parameters

In this paper,the robust output feedback cruise control for high-speed train movement with uncertain parameters is investigated.The dynamic of a high-speed train is modeled by a cascade of cars connected by flexible couplers,which is subject to rolling mechanical resistance,aerodynamic drag and wind gust.Based on Lyapunov’s stability theory,the sufficient condition for the existence of the robust output feedback cruise control law is given in terms of linear matrix inequalities(LMIs),under which the high-speed train tracks the desired speed,the relative spring displacement between the two neighboring cars is stable at the equilibrium state,and meanwhile a small prescribed H∞ disturbance attenuation level is guaranteed.One numerical example is given to illustrate the effectiveness of the proposed methods.     

客货共运模式下高铁列车货运兼办方案优化

以当前高铁快递运输的客货共运模式为背景,研究高铁列车货运兼办方案优化问题.通过分析客货共运模式下货运办理站选择对货物运输、客运列车时刻表与停站方案的影响,以货运办理站选择、货物运输、列车时刻表与列车停站方案为主要决策变量,以极小化旅客旅行时间和未满足货物惩罚成本为目标,构建客货共运模式下基于货运办理站方案选择的货物运输与列车时刻表、列车停站方案一体化优化混合整数线性规划模型.当给定货运办理站选择方案时,本文所构建模型即可转化为传统的客货共运模式下货物运输方案优化模型.以武广高铁为例,设计数值实验,采用C++语言编写程序调用Cplex优化软件对模型进行求解,验证了模型的正确性与合理性.算例结果表明：通过对货运办理站、货物运输方案、列车时刻表和停站方案进行一体化优化,可在尽可能减小货物运输对客运影响的基础上,充分利用高铁线路列车时空上剩余能力,在旅客旅行时间仅增加0.68%、列车停站数量仅增加1.24%的情况下,运输近68%的货物需求,增加铁路部门收益.     

底板岩层破坏的有限元模拟

本文运用NCAP—2D非线性岩石力学有限元程序对某矿8号煤层开采过程中的底板破坏情况进行了模拟,并对模拟结果进行了分析。     

Discrete event model-based simulation for train movement on a single-line railway

The aim of this paper is to present a discrete event model-based approach to simulate train movement with the considered energy-saving factor. We conduct extensive case studies to show the dynamic characteristics of the traffic flow and demonstrate the effectiveness of the proposed approach. The simulation results indicate that the proposed discrete event model-based simulation approach is suitable for characterizing the movements of a group of trains on a single railway line with less iterations and CPU time. Additionally, some other qualitative and quantitative characteristics are investigated. In particular, because of the cumulative influence from the previous trains, the following trains should be accelerated or braked frequently to control the headway distance, leading to more energy consumption.     

全矿性突然停电的危害及应变措施

文章分析了全矿性突然停电后,由于处理不当,所造成的危害,提出了全矿突然停电后的应变措施。     

水泥胶砂抗压强度试验测量不确定度评定

测量不确定度是测量系统最基本也是最重要的特性指标,是测量质量的重要标志.通过水泥胶砂强度试验,对测量不确定度进行分析,建立测量不确定度的数学模式,可以使检测机构技术人员很快地估计出强度不确定度,更有效地进行检测控制.     

Discrete-time movement model of a group of trains on a rail line with stochastic disturbance

This paper presents a discrete-time model to describe the movements of a group of trains, in which some operational strategies, including traction operation, braking operation and impact of stochastic disturbance, are defined. To show the dynamic characteristics of train traffic flow with stochastic disturbance, some numerical experiments on a railway line are simulated. The computational results show that the discrete-time movement model can well describe the movements of trains on a rail line with the moving-block signalling system. Comparing with the results of no disturbance, it finds that the traffic capacity of the rail line will decrease with the influence of stochastic disturbance. Additionally, the delays incurred by stochastic disturbance can be propagated to the subsequent trains, and then prolong their traversing time on the rail line. It can provide auxiliary information for rescheduling trains when the stochastic disturbance occurs on the railway.     

模糊数无穷乘积

在定义了区间无穷乘积、模糊数无穷乘积及其收敛的基础上 ,利用 [3]中得到的关于模糊级数收敛的某些结论 ,得出模糊数无穷乘积与实数无穷乘积理论类似的结果 ,从而说明本文定义的模糊数无穷乘积确为实数无穷乘积的推广。     

T∞-测度分解定理的进一步讨论

在对T∞-测度做进一步研究的基础上,得到了(有限或无限)T∞-测度的Hahn分解定理和Jordan分解定理。同时,用一种新方法证明了有限T∞-测度的Lebesgue分解定理。此外,还得到了一些类似于经典测度的结论。