城市轨道交通安全风险管理

介绍海外有关轨道交通安全风险管理的准则:英国轨道交通安全风险管理准则,轨道交通系统工程的安全保证,英、法、德国不同的风险接受标准.     

基于全寿命周期的建设项目成本风险管理探讨

基于全寿命周期的建设项目成本管理,在立项、设计、施工、运营、报废回收5个阶段都存在不同类别的不确定性,这种不确定性会增加项目成本管理中的风险。根据建设项目全寿命周期内各阶段的特点,对建设项目在不同阶段可能发生的成本风险因素进行识别与评价,根据评价结果提出各阶段可采取的应对风险的控制措施,可减少或避免可能发生的成本风险,达到实行项目成本风险管理的目的。     

An inverse design method for rail grinding profiles

Inspired by the optimisation design method for restoration of worn wheel profiles, an inverse design method based on optimal rail grinding profiles is presented in this paper. To improve grinding quality, vehicle dynamic performance is chosen as the main criteria and rolling radii difference function is selected as the key factor (also main target function) determining dynamic performance. Grinding material to be removed is chosen as the auxiliary target aimed at extending rail service life. Besides that, wheel–rail contact distribution is also taken into consideration as an auxiliary target preventing stress concentration and fatigue growth. By introducing certain presuppositions, all the design targets will form an inverse design problem. This problem can be solved using hybrid discrete numerical methods. Considering different grinding requirements, two examples of grinding profile design for straight and curved track will be discussed. Results show that the presented method is efficient and effective. Practical implementation has been carried out at several grinding sites in China.     

减少振动的尾部线型

本文主要介绍由船舶螺旋桨引起的激振力以及减少振动的尾部线型设计。     

汽车空间三万向节传动动态优化设计

本文从汽车实际行驶的动态工况出发，提出了对汽车空间三万向节传动量优布置的数学模型选择了合适的优化算法，编制了计算程序，实例计算表明，采用了动态优化方法比采用静态优化方法，对降低万向节传动引起的传动系统振动和噪声将会有更好的效果。     

新型混联式混合动力客车动力系统分析

分析了新型混联式混合动力客车动力系统的结构特点和总体布置,介绍了该系统的主要控制策略.根据汽车动力学原理,计算出了该混联式混合动力客车动力系统的基本参数,并分析了该方案在中国典型城市工况下的动力性能;建立了车辆的仿真模型,计算了车辆的动力性和经济性.仿真结果表明,采用该方案的车辆动力性较原车有一定程度提高,燃油经济性较原车有明显改善.     

论地被植物在绿化中的实际应用

地被植物在园林中的应用越来越广泛,它以草坪无法比拟的综合特性,已经成为园林植物造景中的优秀配角。该文就地被植物的种植,阐述地被植物在园林绿化实际应用中的原则、形式、方向以及种植地点与植物种类的正确选择等问题。     

Control of energy regeneration for electric vehicle

To extend electric vehicle (EV) running distance, the vehicle energy regeneration (ER) method and vehicle control strategy were designed based on the original vehicle braking system. The ER principle of direct current (DC) brushless motor was studied, the motor mathematical model and PI control method with torque close-loop were built. This control method was applied to pure EV and the real road tests were evaluated.The ER control does not make any significant uncomfortable influence brake feeling and can save about 10% battery energy based on 3 times economic commission for Europe (ECE) driving cycles.     

Torque distribution strategy for integrated starter/ generator hybrid bus implemented by fuzzy algorithm

A torque distribution strategy was designed by using fuzzy logic to realize the optimal control. Thevehicle load zones were dynamically divided into several zones by several torque lines to indicate the driversdemand and the high or low efficient operating areas of the diesel engine. The fuzzy logic controller withtrapezoid membership function and Mamdani rule reference mechanism was utilized. There are over 100 rulesused in this fuzzy-based torque distribution strategy which are sorted into four rule-bases. The fuel economyand acceleration tests were designed to test and validate the integrated starter/generator (ISG) bus perfor-mance using fuzzy-based torque distribution strategy. The fuel economy is improved 7.7% compared with therule-based strategy. Finally the road test results reveal that there is about 157% improvement of fuel economy.And the 0-50 km/h acceleration time is 9.5% shorter than the original bus.     

智能公交系统运营优化数据库建立方法探讨

城市公共交通运输是城市客流运输的主要形式之一,智能公交系统是公共交通的发展趋势.在分析智能公交系统数据处理流程和公共交通客流采集技术的基础上,研究了智能公交客流基本数据采集技术,探讨了常规公交、轨道交通和出租车交通客流的筛选分析方法.