电动轮自卸车电传动系统试验平台的可行性研究

文章依托科技部＂十五＂科研项目——＂交流驱动百吨级矿用自卸车的研制＂,介绍了电动轮自卸车的发展、原理和技术特点。为了满足电传动系统的试验需求,特别是对由柴油发动机、发电机、驱动电机及其测试和控制系统等构成的动力总成进行试验,建立了一个拥有不同驱动电机试验功能的试验平台。平台由变频异步电动机、交流同步发电机、驱动电机、测功机等机械设备和整流器、逆变器、励磁器等电气设备组成,采用CAN总线串行通信协议实现各电控单元之间的信息交换。通过发电机空载特性、外特性、驱动电机稳态运行性能等试验证明,该平台基本满足电动轮自卸车的各种试验条件,为驱动性能研究提供了良好的实验环境。     

虚拟人机关系在越野群车加油车设计中的应用

在装备设计中,利用计算机建立的虚拟人机关系指导设计值得关注。以越野群车加油车设计为例,应用CATIA人机工程模块对该车数字模型引入虚拟人体模型,建立虚拟人机关系,通过虚拟人机关系指导相关零部件的精确设计和优化设计,并合理安排这些零部件的位置。通过虚拟人机关系的应用,使所设计的越野群车加油车在满足功能的前提下尽量符合人的生理和心理特征,便于操作和维修,达到人机的最佳匹配和统一。     

叉车的选择与应用

系统介绍了目前普遍使用的手动托盘车、电动托盘车、平衡重叉车、前伸式叉车等8种类型的叉车,并分析各类型叉车的特点及其适用的环境场合.同时例举了叉车运搬能力的测试与计算方法.叉车的选择有很多影响因素,包括地坪、出入库频率等.     

汽车运输型物流企业规避油价风险的策略研究

燃油成本是汽车运输型物流企业运营成本的重要组成部分,针对目前油价持续上涨的背景,本文提出通过加强路线管理策略、提高装载率策略、市场运作策略及加强内部管理来规避油价上涨给汽车运输型物流企业带来的成本压力,并提出了上述策略下的一些具体措施.     

论自卸车副车架的功能与设计

随着各地基础建设不断增加,自卸车近年来一直保持较高产量,但目前我国的自卸车生产技术仍然处于较低水平,主要表现在材料、结构、工艺、技术含量、耐久性、舒适性乃至安全性等方面。文章从设计角度和理论方面对自卸车副车架结构进行了分析和探讨。自卸车副车架是自卸车的关键总成件,除了要固定液压系统外,还要承担重载和路面产生的动载荷。     

RFID技术在铁路集装箱堆场进出口的应用

利用射频识别技术（RFID）可以实现集装箱箱号及其属性的自动识别,大大提高铁路集装箱运输作业的自动化水平。论文首先分析了目前铁路集装箱运输作业中存在的主要问题及RFID在集装箱运输中的应用现状,提出了铁路集装箱办理站出入口自动管理系统的功能设计并详细规划了在集卡出入口和铁路出入口的应用方案。该方案可改变原有落后低效的工作方式,有效加快集装箱进出堆场的速度,提高管理的自动化水平,实现自动出入管理。     

Recreation vehicles : A perspective

The growth and popularity of recreation vehicles in the United States and other countries has implications for the travel and tourism industry. Owners of these vehicles require no separate lodging facilities while traveling and rarely patronize hotels or motels. They often perceive that they spend less for their vacations by staying at travel parks and campgrounds, but survey results and comparative cost analysis reveal that they spend more than automobile travelers when total fixed and variable costs are taken into account. Recreation vehicle (RV) preferences by income category suggest alternative modes of recreation travel and a vacation life style which has considerable appeal. This “RV life style” is characterized by a strong desire to experience the outdoors and socialize with other campers while still retaining the comforts and conveniences of a familiar domicile. Limiting characteristics include the provincial nature of recreation vehicle travel and the impact of mandatory fuel conservation measures.     

How do authenticity and quality perceptions affect dining experiences and recommendations of food trucks? The moderating role of perceived risk

A growing number of food trucks differentiate themselves in the competitive market by serving ethnic foods. The purpose of the study was to investigate the effect of customers’ authenticity and quality perceptions of ethnic food trucks on their memorable dining experience (MDE) and, consequently, word of mouth (WOM) while considering customers’ perceived risk. Data were collected from 540 customers who had dined at ethnic food trucks in the U.S. Structural equation modeling and hierarchical regression were employed to test the proposed hypotheses. The results indicated that authenticity perceptions influence quality perceptions and dining satisfaction directly, and MDE indirectly through dining satisfaction. Moreover, dining satisfaction affects WOM directly as well as indirectly through MDE. Among the three dimensions of perceived risk, hygienic risk mitigates both of the relationships between authenticity perceptions and dining satisfaction as well as between quality perceptions and dining satisfaction. Implications and suggestions for future research were discussed.     

Development of air pollutant emission factors under real-world truck driving cycle

The truck driving cycle was developed in Thailand using actual speed-time profile from trucks in suburban area. Driving data were separated into micro trips and the representative driving cycle was selected by matching micro trips statistics and target statistics. The Performance Value (PV) was considered for selecting the representative driving cycle. This selected driving cycle was then used as input data for estimating emission factors of 4 air pollutants and 3 greenhouse gases by the International Vehicle Emission (IVE) model. Results were then compared with emission factors developed using the European Transient Cycle (ETC). Additionally, a comparison was made between emission factors calculated in this study and direct measurements of emissions from truck driven on chassis dynamometer under the European driving cycle. Comparison results revealed that CO, NO_x and CO₂ emission factor were about 2.05, 2.24 and 1.78 times lower than those obtained from direct measurements. PM emission factor was about 0.89 times higher than measured data. This study confirms the need to considered actual fleets and characteristics of vehicular sources when calculating their emission rates for further use in development of emission inventory.     

Antecedents of consumers’ intention to visit food trucks

The food truck industry has become a national phenomenon in the United States by gaining attention and praise. However, there has been limited attention on how and why consumers decide to patronize food trucks. The purpose of the study is to investigate determinants of consumers’ intention to patronize food trucks by applying the model of goal-directed behavior. Structural equation modeling was employed to assess the relationships among constructs in the proposed research model. This study contributes significant theoretical and practical implications by first attempting to examine what specific psychological variables influence the decision-making process regarding consumers’ intention to visit food trucks.