大众品牌汽车在华车型整车匹配性能统计分析

大众汽车集团是中国汽车工业最早、最成功的国际合作伙伴之一,除江淮大众外,其主要的合资公司为上汽大众和一汽大众,文章主要是统计一汽大众、上汽大众所有大众品牌在售乘用车车型信息、销量、动力性、经济性、整备质量等相关参数,从车机箱搭载维度、整车性能表现维度、发动机搭载形式和性能维度以及车辆整备质量维度等方面进行整车匹配性能统计分析。     

汽车技术性能状况的检测

检查车辆技术状况是车辆维护中必不可少的环节。文章介绍了车辆外观技术状况的检测方法，指出了汽车性能检测的主要内容及其意义，最后提出了汽车技术状态良好的标准。汽车在运行中所产生的故障虽然很复杂，但只要在反复实践中进行科学分析，不断总结经验，就能比较熟练地掌握判断排除故障的实际技能。     

Using census aggregates to proxy for household characteristics: an application to vehicle ownership

Traditionally, researchers studying transportation choice have used data either acquired from household surveys or broad, region-wide aggregates. At the disaggregate level, researchers usually do not have access to important variables or observations. This study investigates the potential usefulness of a proxy approach to modeling discrete choice vehicle ownership: substituting narrow area-based aggregate proxies for missing micro-level explanatory variables by accessing large, publicly maintained datasets. We use data from the 2000 Bay Area Travel Survey (BATS) and the contemporaneous U.S. Census file to compare three models of vehicle ownership, drawing area-wide proxies from increasing levels of aggregation. The models with proxies are compared with a parallel model that uses only survey data. The results indicate that the proxy models are preferred in terms of model selection criteria, and predict vehicle ownership as well or better than the survey model. Parameter values produced by the proxy method effectively approximate those returned by household survey models in terms of coefficient sign and significance, particularly when the aggregate variables are representative of their household-level counterparts. The proxy model with the narrowest level of aggregation achieved the best fit, coefficient precision, and percentage of correct prediction.

Residential location,vehicle ownership and travel in Asia: a comparative analysis of Kei-Han-Shin and Kuala Lumpur metropolitan areas

The study examines the relationships between residential location, vehicle ownership and mobility in two metropolitan areas of Asia, Kei-Han-Shin area of Japan and Kuala Lumpur area of Malaysia. It shows that, behind apparent similarities of household auto ownership and travel time expenditure per household member, there are many causal relationships that are distinct between the areas. The similarities and differences between the two areas point to the conjecture that the evolution of a metropolitan area may be unique and path dependent, being heavily influenced by the history and culture of the locale, spatial and geographical constraints, and historical progression in infrastructure development.

A structural analysis of vehicle design responses to Corporate Average Fuel Economy policy

The US Corporate Average Fuel Economy (CAFE) regulations are intended to influence automaker vehicle design and pricing choices. CAFE policy has been in effect for the past three decades, and new legislation has raised standards significantly. We present a structural analysis of automaker responses to generic CAFE policies. We depart from prior CAFE analyses by focusing on vehicle design responses in long-run oligopolistic equilibrium, and we view vehicles as differentiated products, taking demand as a general function of price and product attributes. We find that under general cost, demand, and performance functions, single-product profit maximizing firm responses to CAFE standards follow a distinct pattern: firms ignore CAFE when the standard is low, treat CAFE as a vehicle design constraint for moderate standards, and violate CAFE when the standard is high. Further, the point and extent of first violation depends upon the penalty for violation, and the corresponding vehicle design is independent of further standard increases. Thus, increasing CAFE standards will eventually have no further impact on vehicle design if the penalty for violation is also not increased. We implement a case study by incorporating vehicle physics simulation, vehicle manufacturing and technology cost models, and a mixed logit demand model to examine equilibrium powertrain design and price decisions for a fixed vehicle body. Results indicate that equilibrium vehicle design is not bound by current CAFE standards, and vehicle design decisions are directly determined by market competition and consumer preferences. We find that with increased fuel economy standards, a higher violation penalty than the current stagnant penalty is needed to cause firms to increase their design fuel economy at equilibrium. However, the maximum attainable improvement can be modest even if the penalty is doubled. We also find that firms’ design responses are more sensitive to variation in fuel prices than to CAFE standards, within the examined ranges.     

内河无人船局部路径规划和循迹控制

提出了内河无人船在水流中的局部路径规划算法,并在直线Line of Sight算法基础上设计了一般曲线路径的LOS循迹控制算法。将此算法结合完成了内河无人船的航行试验,实现了在落潮、涨潮等不同水流条件下的无人自主航行,验证了所提算法的有效性和实用性,对内河无人船的应用研究具有借鉴意义。     

气垫船垫升风机的振动试验研究及模态分析

垫升风机是气垫船的关键设备,是气垫船振动噪音的主要激励源之一。通过分析某气垫船左舷垫升风机的设计特点,选择关键位置开展振动响应频谱测量,分析不同测点位置、不同转速条件下测点的振动烈度响应。采用有限元方法分析单舷垫升风机的固有频率和振型,研究影响垫升风机振动的主要因素。在此基础上,提出降低垫升风机振动的措施,并基于试验评估实际降振效果,其可作为气垫船垫升风机设计的技术参考。     

Application of inductive loops as wheel detectors

This article presents the findings of model and field research into narrow inductive loop used as vehicle wheels detector in normal traffic conditions. The efficiency of the solution was compared with that of strip, polymeric piezoelectric detectors. The findings confirmed that narrow inductive loops can be successfully applied as wheel detectors.     

Impacts of driving patterns on tank-to-wheel energy use of plug-in hybrid electric vehicles

We evaluate the implications of a range of driving patterns on the tank-to-wheel energy use of plug-in hybrid electric vehicles. The driving patterns, which reflect short distance, low speed, and congested city driving to long distance, high speed, and uncongested highway driving, are estimated using an approach that involves linked traffic assignment and vehicle motion models. We find substantial variation in tank-to-wheel energy use of plug-in hybrid electric vehicles across driving patterns. Tank-to-wheel petroleum energy use on a per kilometer basis is lowest for the city and highest for the highway driving, with the opposite holding for a conventional internal combustion engine vehicle.