列车防护报警和客车列尾系统

介绍了列车防护报警和客车列尾系统的构成和主要功能,分析并指出该系统的无线数据传输应采用调频方式和800MHz频段工作频率.     

A structured flexible transit system for low demand areas

Public transit structure is traditionally designed to contain fixed bus routes and predetermined bus stations. This paper presents an alternative flexible-route transit system, in which each bus is allowed to travel across a predetermined area to serve passengers, while these bus service areas collectively form a hybrid “grand” structure that resembles hub-and-spoke and grid networks. We analyze the agency and user cost components of this proposed system in idealized square cities and seek the optimum network layout, service area of each bus, and bus headway, to minimize the total system cost. We compare the performance of the proposed transit system with those of comparable systems (e.g., fixed-route transit network and taxi service), and show how each system is advantageous under certain passenger demand levels. It is found out that under low-to-moderate demand levels, the proposed flexible-route system tends to have the lowest system cost.     

Energy efficiency optimization of electric vehicle driven by in-wheel motors

Electric vehicle is considered to be the solution for energy and environment crisis, but it’s still not competitive enough with conventional vehicles because of the limited energy density and high cost of the power battery. So the energy efficiency is of the most importance for the control of electric vehicles. This paper looks into the energy efficiency optimization problem of electric vehicle driven by four in-wheel motors by developing a comprehensive energy efficiency model of the permanent magnet synchronous motor including the inverter. The calculated efficiency agrees with the measured data quite well. Based on the power loss analysis, the conclusion is drawn that in all driving or braking conditions the total torque requirement should be distributed evenly to all the motors in order to maximize the energy efficiency for electric vehicles driven by permanent magnet synchronous in-wheel motors. Vehicle test results show that the energy efficiency of the evenly distributed torque control is higher than the control strategy proposed by control allocation in literature.     

永连公路滑坡加固与治理

结合永连公路两处较为典型的滑坡实例,通过对滑坡产生原因的分析,介绍了不同滑坡的治理办法,同时认为因地制宜、精心设计和认真作好施工管理是滑坡治理工作的关键。     

地铁地下线凹形竖曲线最低点位置及高程的确定

地铁地下线为设置排水泵站须寻求线路纵坡最低点位置及高程,论述地下线纵坡凹形变坡点处竖曲线地段最低点准确位置及高程计算方法,并列出计算成果表。     

GL Studio在飞机虚拟地勤训练中的应用

虚拟现实技术应用到飞机地勤人员培训是一种经济,高效的方法.针对飞机虚拟地勤维护训练系统中座舱视景仿真的难点问题,采用GL Studio仪表建模工具建立座舱仪表模型,Vega视景驱动软件进行实时驱动的方法.对GLStudio仪表建模的关键技术进行研究,并分析Vega的底层软件开发原理,解决GL Studio建模及把GL Studio模型植入Vega的难题.     

旋转整流器的换相过程分析

阐述了无刷励磁发电机的旋转整流器在正常工况下的工作原理和换相过程,根据换相电抗和负载电阻的关系将换相过程分类,并通过理论解析了旋转整流器在正常工况下的换相电流波形。通过仿真验证了理论分析的正确性,为无刷励磁发电机系统的相关研究提供一定的理论依据。     

电控燃油喷射用高速电磁阀驱动方式研究

对柴油机电控系统脉冲电磁阀的快速响应性进行了分析，从电磁铁结构设计和电路驱动技术两个方面进行了对比，提出并设计了一种基于充电泵的升压驱动电路。实验结果表明，这种驱动电路可以大大缩短电磁阀的响应时间。     

现代潜艇铅酸蓄电池放电模型研究

铅酸蓄电池是常规潜艇水下航行的核心动力，为优化动力系统工作性能，需要建立放电模型．在分析蓄电池放电特点的基础上，提出了建模需要解决的若干问题和神经网络的方法．基于前馈神经网络，模拟了任意放电率下的恒流放电规律．利用插值法、积分和坐标变换等方法，得到了蓄电池恒功率放电模型，解决了端电压、放电电流变化规律、放电起始点和放电率计算等同题．潜艇续航力核算表明所建立的放电模型可行。     

高速公路紧急事件管理系统实施效果评价

在阐述了高速公路紧急事件管理系统实施效果评价的含义和意义的基础上,分析系统结构特点及影响其实施效果的各因素,构建了多层次的评价指标体系,并针对此评价指标繁多且不易量化等特点,应用模糊数学理论建立了既全面考虑又兼顾重点的系统实施效果模糊综合评价模型。该模型应用集值统计法确定评价指标集,采用三角形隶属度函数,得到实施效果评价矩阵;通过层次分析法确定多层指标权重。算例中对北京某高速公路紧急事件管理系统实施效果评价的计算结果为77.21,实施效果综合评价结论为"较好",与实际相符,说明所提出的模型能对系统实施效果做出合理的评价。