气体燃料/汽油两用燃料汽车自适应燃料点火器

气体燃料 /汽油两用燃料汽车燃用不同燃料时 ,最佳点火提前角相差悬殊。采用自适应燃料点火器可根据发动机使用燃料的不同自动改变点火提前角。论述了单片机控制自适应燃料点火器的软、硬件结构和工作原理。试验结果表明 ,加装自适应燃料点火器后 ,发动机动力性增加 2 .6%～3.1 % ,燃料消耗率下降 2 .6%～ 3.4%。     

丰田汽车电控系统自诊断功能分析

详细介绍了丰田汽车的诊断接口及其功能。分析了发电机、自动变速器、ABS/TRAC等部位电控系统的检测方法及故障诊断。最后指出了通过自诊断功能检测汽车故障时应注意的问题。     

择一定理及向量优化问题的Benson真有效性

在局部凸Hausdorff空间中，引入了近次似凸集值映射，建立了近次似凸集值映射下的择一定理．最后，获得了近次似凸集值映射向量优化问题标量下Benson真有效性的一个性质．     

智能控制技术在汽车AMT中的应用

针对汽车AMT系统中节气门控制、离合器接合点及最佳动力性换档规律的确定等问题 ,讨论了采用多模式控制、模糊控制和自学习控制等智能控制的具体方法 .实际应用表明 ,这些方法切实可行 ,同时 ,也体现了智能控制技术在车辆控制系统中的实用性和先进性     

CRTSⅢ型板式无砟轨道铺设技术

结合盘营客运专线CRTSⅢ型板式无砟轨道施工实例,详细介绍了其施工关键技术,尤其是自密实混凝土灌筑工装的改进,解决了灌筑速度慢的难题;同时节约了自密实混凝土,控制了施工质量。近2年的观察证明:自密实混凝土及轨道板外型美观,尺寸精确,自密实混凝土表面密实,内在质量好,使用情况良好。     

重锤夯实处理非自重湿陷性黄土地基的应用

非自重湿陷性黄土遇水后，在自重和荷载的共同作用下，其结构很快破坏，发生大量而剧烈的变形．强度也随之迅速降低，产生湿陷性。对于存在于天然地基上的路基，施工时应对其加以处理，消除或减少其湿陷性。汾柳高速公路路基施工中采用重锤夯实法对非自重湿陷性黄土路基基盘进行处理，实践证明该方法简单有效，值得推广。     

Modification of the Highway Capacity Manual two‐lane highway analysis procedure for Spanish conditions

The US Highway Capacity Manual (HCM) methodology is used in Spain to evaluate traffic operation and quality of service. The effect of passing manoeuvre on two‐lane highway operational performance is considered through adjustment factors to average travel speeds and percent time spent following. The procedure is largely based on simulations in TWOPAS and passing behaviours observed during US calibrations in the 1970s. It is not clear whether US driving behaviour and vehicles' performance are comparable with Spanish conditions. The objective of this research is to adapt the HCM 2010 methodology to Spanish driver behaviour, for base conditions (i.e. no passing restrictions). To do so, TWOPAS was calibrated and validated based on current Spanish passing field data. The calibration used a genetic algorithm. The case study included an ideal two‐lane highway with varying directional traffic flow rate, directional split and percentage of trucks. The updated methodology for base conditions is simpler than the current HCM 2010 and does not rely on interpolation from tables. Copyright © 2016 John Wiley & Sons, Ltd.     

Modeling delay at signalized intersections with channelized right‐turn lanes considering the impact of blockage

This paper presents a probabilistic delay model for signalized intersections with right‐turn channelization lanes considering the possibility of blockage. Right‐turn channelization is used to improve the capacity and to reduce delay at busy intersections with a lot of right‐turns. However, under heavy traffic conditions the through vehicles will likely block the channelization entrance that accrues delay to right‐turn vehicles. If the right‐turn channelization gets blocked frequently, its advantage in reducing the intersection delay is neglected and as a result the channelization lane becomes inefficient and redundant. The Highway Capacity Manual (HCM) neglects the blockage effect, which may be a reason for low efficiency during peak hours. More importantly, using HCM or other standard traffic control methods without considering the blockage effects would lead to underestimation of the delay. To overcome this issue, the authors proposed delay models by taking into account both deterministic and random aspects of vehicles arrival patterns at signalized intersections. The proposed delay model was validated through VISSIM, a microscopic simulation model. The results showed that the proposed model is very precise and accurately estimates the delay. In addition, it was found that the length of short‐lane section and proportion of right‐turn and through traffic significantly influence the approach delay. For operational purposes, the authors provided a step‐by‐step delay calculation process and presented approach delay estimates for different sets of traffic volumes, signal settings, and short‐lane section lengths. The delay estimates would be useful in evaluating adequacy of the current lengths, identifying the options of extending the short‐lane section length, or changing signal timing to reduce the likelihood of blockage. Copyright © 2016 John Wiley & Sons, Ltd.     

Modeling traffic operation at signalized intersections without explicit left‐turn yielding rules with an enhanced cell transmission model

This paper presents an enhanced cell transmission model (CTM) to capture traffic operation at signalized intersections without explicit permissive left‐turn yielding rules (i.e. aggressive permissive left‐turn maneuvers may not necessarily yield to opposing through traffic), which can be widely observed in many developing countries. Different from previous studies that focus on traffic dynamics on approaching links, this study contributes to modeling traffic operations within the intersection. A novel cell transmission framework with various types of virtual cells is proposed to model the dynamics of traffic movements from approach to exit. The unique phenomenon of competitive occupying of the conflict point between the left turn and opposing through movements is modeled. The cell state indicating its blockage is proposed to capture the dynamic queue formulation and dissipation and to evaluate the operational traffic performance at the intersection. Field validation results show that the proposed model can capture the operation of traffic at signalized intersections without explicit permissive left‐turn yielding rules with significantly higher level of accuracy than traditional traffic flow models. Copyright © 2016 John Wiley & Sons, Ltd.     

Finding time‐robust fuel‐efficient paths for a call‐taxi in a stochastic city road network

Intra‐city commuting is being revolutionized by call‐taxi services in many developing countries such as India. A customer requests a taxi via phone, and it arrives at the right time and at the right location for the pick‐up. This mode of intra‐city travel has become one of the most reliable and convenient modes of transportation for customers traveling for business and non‐business purposes. The increased number of vehicles on city roads and raising fuel costs has prompted a new type of transportation logistics problem of finding a fuel‐efficient and quickest path for a call‐taxi through a city road network, where the travel times are stochastic. The stochastic travel time of the road network is induced by obstacles such as the traffic signals and intersections. The delay and additional fuel consumption at each of these obstacles are calculated that are later imputed to the total travel time and fuel consumption of a path. A Monte‐Carlo simulation‐based approach is proposed to identify unique fuel‐efficient paths between two locations in a city road network where each obstacle has a delay distribution. A multi‐criteria score is then assigned to each unique path based on the probability that the path is fuel efficient, the average travel time of the path and the coefficient of variation of the travel times of the path. Copyright © 2016 John Wiley & Sons, Ltd.