纯电动汽车动力锂电池SOC估计策略综述

电池管理系统(BMS)采用了防止电池过放电和过充,提供电池均衡控制,能够实现新能源汽车动力锂电池的最佳利用和保护。电池管理系统实时精准估算电池电荷状态(SOC)是提高电动汽车续航里程和延长寿命的关键。然而,SOC不能直接测量,动力电池的充、放电又是一个复杂过程,导致目前现有的SOC估算策略很难精确地估算出实时在线SOC值。因此,如何提高SOC估算精度是当下BMS领域的研究热点。本文通过对各种SOC估算方法进行文献综述,分析和总结各个SOC估算方法的原理及优缺点,提出SOC估计策略未来发展趋势。     

基于模型的进路建立过程测试用例自动生成

为了生成进路建立过程完备的测试案例,分析设备故障和人环因素的影响并结合对应的逻辑过程,建立了进路建立过程的状态机模型,并对模型解析得到状态与边的关系,将状态和边的关系抽象成图论中边和节点的关系进行存储。通过讨论3种覆盖准则的优劣,设计深度优先搜索算法遍历模型,得到抽象测试案例,采用Java反射机制对抽象案例进行反推,结果生成8种类型的测试片段,每种类型的片段进行组合生成所有的测试案例。最后分析进路正常建立所需的输入案例和引入的故障案例对建立过程的影响。     

船舶变频制冷系统中状态参数的控制研究

本文主要叙述船舶制冷系统采用变频调速情况下,当转速和给定温度发生改变时,制冷系统理论循环中各状态点的有关参数计算式及其中主要参数压力和温度的变化过程,以便于运行管理.     

水面舰艇鱼雷防御系统综述

综述了国外水面舰艇鱼雷防御系统的现状，分析了水面舰艇鱼雷防御系统的关键技术和发展趋势，对发展我国水面舰艇鱼雷防御系统具有一定的积极作用。     

国有企业模拟股份制——国有资产经营探索

国有企业“模拟股份制”是以资产增值为目标,以资产经营者的市场竞争方式产生为手段,将企业制度创新与国有资产经营管理相结合的一种资产经营体制。     

Robust state feedback stabilization of articulated steer vehicles

In this work, a full-state feedback controller is designed to prevent the oscillatory instability or snaking behaviour of an articulated steer vehicle. To design the controller, first, a linearized model of the vehicle is developed and analyzed to identify the most important uncertain tire parameters with regard to the snaking mode. By using this linearized model, the equations of motion are represented in the form of a polytopic system, which depends affinely on the most important uncertain tire parameters. Then, by solving some linear matrix inequalities, both the Lyapunov and state feedback matrices for the robust stabilization of the vehicle are found. The performance of the resulting controller is evaluated by conducting several simulations based on the linearized model. To verify the results from the linearized model analysis, some simulations are also done by a virtual prototype of the vehicle in ADAMS. The results based on the linearized model are reasonably consistent with those from the simulations in ADAMS. They show that the controller can effectively stabilize the vehicle during the snaking mode in different driving conditions.     

Campus parking supply impacts on transportation mode choice

Parking demand is a significant land-use problem in campus planning. The parking policies of universities and large corporations with facilities located in small urban areas shape the character of their campuses. These facilities will benefit from a simplified methodology to study the effects of parking availability on transportation mode mix and impacts on recruitment and staffing policies. This paper, based on a case study of North Dakota State University in the United States, introduces an analytical framework to provide planners with insights about how parking supply and demand affects campus transportation mode choice. The methodology relies only on aggregate mode choice data for the special generator zone and the average aggregate volume/capacity ratio projections for all external routes that access the zone. This reduced data requirement significantly lowers analysis cost and obviates the need for specialized modelling software and spatial network analysis tools. Results illustrate that the framework is effective for analysing mode choice changes under different scenarios of parking supply and population growth.     

清代中国嘉庆年间之东亚的朝贡国与互市国

作为传统的中华帝国,清政府一直保持着与东亚诸国的朝贡关系.但是嘉庆年间确立了新的朝贡体制,将之前的朝贡国家与之后开始贸易交往的国家区分开.东亚的朝鲜和琉球一直都是中国的朝贡国.由于日本施行闭关锁国政策,所以不是中国的朝贡国,但清朝嘉庆年间,日本被中国视作朝贡国中的贸易互市国加以对待.     

Short-Term Highway Traffic State Prediction Using Structural State Space Models

This research proposes a short-term highway traffic state prediction method based on a structural state space model, with the intention to provide a robust approach for obtaining accurate forecasts of traffic state under both recurring and non-recurring conditions. True traffic state is decomposed to three components, namely, regular traffic pattern, structural deviation, and random fluctuation. Particularly, the structural deviation term reflects the change of true traffic state from regular (historical) pattern, due to unexpected capacity reduction and/or demand variations. A polynomial trend is adopted to describe the temporal evolution of structural deviations across different time intervals. We derive an analytical form of structural deviations in a single bottleneck case based on cumulative flow count diagrams. The proposed model is incorporated in a Kalman filtering-based algorithmic framework, together with an adaptive scheme for determining the variances of random errors. A set of numerical experiments was conducted on two test beds in the northern Taiwan highway network. Experimental results show that the proposed approach is particularly superior to an ordinary Kalman filtering method presented in the literature under non-recurring conditions, highlighting the advantage of combining both the polynomial trend model and historical pattern into the proposed short-term traffic state prediction approach.     

道岔状态不良风险的故障树分析及控制研究

针对道岔状态不良,通过建立涵盖道岔全生命周期的故障树模型,计算最小割集、顶事件概率和基本事件的临界重要度,对道岔状态不良进行定量风险分析.围绕风险控制的消除、预防、减轻后果、事故应急4个方面,研究提出8项针对性的风险控制措施,并建立控制措施有效性评价矩阵,来评价措施有效性.结果表明,道岔状态不良属于风险程度较高的危害事...