交叉口绿闪信号行人过街行为模型

城市信号交叉口通过设置绿闪信号,在机动车获得通行权之前清空人行横道上的过街行人.为研究行人在此信号期间的过街行为,提出一种绿闪信号时行人过街运动模型.综合分析绿闪信号、周围过街行人、人行横道边界以及右转冲突车辆对行人过街的影响机理,基于社会力模型,建立绿闪后人行横道上行人过街行为模型,并根据实际调查所获得的人行横道尺寸、行人与车辆速度等数据,标定模型参数.基于模型仿真行人运动行为,产生行人分层现象以及与周围行人、冲突车辆避碰等行为,验证模型在宏观层面的有效性;对不同断面的仿真行人与实际过街行人的过街速率变化曲线进行拟合,拟合优度指标显示模型对人行横道前/后半段过街行人模拟精度分别为83% 和95%,验证了模型在微观层面的有效性.     

发动机燃用生物柴油-柴油-乙醇混合燃料的性能试验

为了降低柴油机燃用中等比例生物柴油-柴油混合燃料的污染物排放,在1 400r/min和2 000r/min不同负荷条件下,首先对比分析了发动机燃用生物柴油-柴油混合燃料与纯柴油的性能差异,然后在中等比例的生物柴油-柴油混合燃料中分别掺混10%和20%(体积比)的无水乙醇,测定了乙醇掺混比对发动机经济性、动力性和排放特性的影响。结果表明:与纯柴油相比,生物柴油-柴油混合燃料的有效燃油消耗率上升,动力性略有下降,炭烟排放降低,而NO_x排放升高。随着乙醇掺混比的增大,生物柴油-柴油-乙醇混合燃料的有效燃油消耗率升高,小负荷时受乙醇汽化潜热的影响导致有效热效率下降,中等负荷时乙醇对有效热效率的影响不大,而大负荷时乙醇的高含氧量能够提高发动机的有效热效率。1 400r/min和2 000r/min全负荷条件下,发动机的最大功率随乙醇掺混比的增大而下降。在不同负荷条件下,随着生物柴油-柴油-乙醇混合燃料中乙醇掺混比的增大,发动机的炭烟、NO_x和CO排放逐渐降低,小负荷时乙醇的高汽化潜热导致HC排放明显升高。     

Integrated evasive manoeuvre assist for collision mitigation with oncoming vehicles

Development and deployment of steering based collision avoidance systems are made difficult due to the complexity of dealing with oncoming vehicles during the evasive manoeuvre. A method to mitigate the collision risk with oncoming vehicles during such manoeuvres is presented in this work. A point mass analysis of such a scenario is first done to determine the importance of speed for mitigating the collision risk with the oncoming vehicle. A characteristic parameter was identified, which correlates well with the need to increase or decrease speed, in order to reduce the collision risk. This finding was then verified in experiments using a Volvo XC90 test vehicle. A closed-loop longitudinal acceleration controller for collision mitigation with oncoming vehicles is then presented. The longitudinal control is combined with yaw stability control using control allocation to form an integrated controller. Simulations in CarMaker using a validated XC90 vehicle model and the proposed controller showed consistent reductions in the collision risk with the oncoming vehicle.     

Feature-Based Cad System Buildup for Passenger Airbag Design

The passenger airbag (PAB) requires a large volume and fast deployment because of the large distance between the dashboard and the passenger. And various shapes and sizes of the PAB are required depending on the type of vehicle. However, since the PAB modeling process for each design change is complicated and time consuming, the design parameters of the PAB could not be well investigated. In this study, a unique feature-based CAD system has been proposed that easily constructs PAB CAD model and then generates PAB FE model for collision analysis. Main keypoints and widths of PAB that determine the shape and size have been extracted by analyzing the geometric-feature of airbag. The PAB CAD model can be easily constructed by inputting keypoints and widths information. Then, from the constructed PAB CAD model, the PAB FE model is automatically generated. Finally, the generated PAB FE model can be directly employed for collision analysis, thereby reducing the modeling time of the PAB and enabling efficient parametric studies on design.     

汽车导航用电子地图的高效路网模型

为了有效地描述实际道路网络，提高汽车导航系统的运行效率，建立了一种新的电子地图的路网模型。在分析了嵌入式系统特点的基础上，对路网的数据结构进行了简化。采用重整实体ID的方法，进一步提高了数据的处理效率。实践证明，该模型可以较好地表述实际的道路网络，结构精练，处理效率高，适合车载导航系统，特别是嵌入式车载导航系统的要求。     

具有模块化结构的汽车动力学仿真模型的初步研究

初步探讨了面向开发型驾驶模拟器的具有模块化结构的汽车动力学仿真模型建立方法，从而可以在此基础上进一步建立一套通用的面向结构的汽车动力学仿真程序，便捷地在开发型驾驶模拟器上实现对不同类型或同类型不同结构车辆性能的仿真。     

汽车精密成型技术现状与发展趋势刍议

简述了汽车精密成型技术的内涵、特点及其在汽车制造中的地位，较深入地分析了目前国内外精密冲压、精密铸造、精密锻造和精密焊接技术等汽车精密成型技术的发展现状，并指出汽车精密成型未来发展的主要趋势。     

RP900J型机械式多功能摊铺机

介绍了一种用于道路基层和面层施工的多功能摊铺机的研发思路、结构构造及性能特点，对摊铺机的设备选型及使用有所帮助。     

填石路基振动压实试验

通过选择压实设备来提高填石路基施工质量，探讨了施工过程中压实机具、铺层厚度、碾压遍数及沉降量等因素的相互关系以及影响填石路基施工质量的主要因素，为合理有效的填石路基压实工艺提供了依据。     

沥青混凝土路面施工机群智能调度与监控系统

根据沥青混凝土路面施工工艺及机械运行规律，分析了机群智能调度与监控系统的功能需求，提出了基于无线局域网的机群智能控制系统结构方案，对机群智能调度系统中的优化调度技术进行了探讨。