AEB与可逆预紧安全带联合作用下乘员保护效果研究

针对自动紧急制动系统(AEB)导致乘员在碰撞前出现身体前倾和离位的现象,提出了使用可逆预紧安全带可以改善该现象,并且研究了在AEB和可逆预紧的联合作用下对不同坐姿乘员的保护效果.建立了某车型驾驶员侧包括正常坐姿和四种离位坐姿的约束系统仿真模型,并进行了验证.以五种坐姿乘员为研究对象,分别对比无AEB无可逆预紧,有AEB...     

一种适用于虚拟惯量优化控制研究的风电场等值建模方法

大型风电场的建模分析是研究风电参与电力系统频率调控的前提。风电场内机组众多且运行方式各异,根据风电机组的整体结构及虚拟惯量控制策略的基本原理,在直驱式风电机组单机详细模型的基础上进行简化,然后按典型风速将风电场内全部机组分为三群,同群机组采用聚合方法得到等值机组,从而形成最终的风电场多机并网等值模型。考虑风速扰动和负荷扰动两种情况,通过Matlab/Simulink软件对比校验所建模型,仿真结果显示了该建模方法的有效性。     

基于DSP的船舶电站监控系统设计

电站为船舶提供动力来源,在船舶航行中有非常重要的地位。对电站的监控现在也有比较成熟的技术,包括各种控制软件的应用。本系统结合实际情况及最新发展,提出基于DSP的船舶电站监控系统,芯片选用的是TI公司的TMS320F2812 DSP作为核心处理器,该型号DSP工作效率高,控制精度比较高,性能稳定,对于信号处理及硬件的控制都有很好的优势,可以使得监控系统稳定高效的工作。本系统配以MCGS组态软件作为监控软件,可以实时的从电脑终端对船舶中的各个设备及电站的工作状态进行可视化监控,以便做出及时决策。系统可以手动及自动的控制发电机开启、停止、加减速,并且系统可以在出现故障的时候进行报警提示。     

Shared autonomous electric vehicle (SAEV) operations across the Austin,Texas network with charging infrastructure decisions

Shared autonomous vehicles, or SAVs, have attracted significant public and private interest because of their opportunity to simplify vehicle access, avoid parking costs, reduce fleet size, and, ultimately, save many travelers time and money. One way to extend these benefits is through an electric vehicle (EV) fleet. EVs are especially suited for this heavy usage due to their lower energy costs and reduced maintenance needs. As the price of EV batteries continues to fall, charging facilities become more convenient, and renewable energy sources grow in market share, EVs will become more economically and environmentally competitive with conventionally fueled vehicles. EVs are limited by their distance range and charge times, so these are important factors when considering operations of a large, electric SAV (SAEV) fleet.This study simulated performance characteristics of SAEV fleets serving travelers across the Austin, Texas 6-county region. The simulation works in sync with the agent-based simulator MATSim, with SAEV modeling as a new mode. Charging stations are placed, as needed, to serve all trips requested (under 75 km or 47 miles in length) over 30 days of initial model runs. Simulation of distinctive fleet sizes requiring different charge times and exhibiting different ranges, suggests that the number of station locations depends almost wholly on vehicle range. Reducing charge times does lower fleet response times (to trip requests), but increasing fleet size improves response times the most. Increasing range above 175 km (109 miles) does not appear to improve response times for this region and trips originating in the urban core are served the quickest. Unoccupied travel accounted for 19.6% of SAEV mileage on average, with driving to charging stations accounting for 31.5% of this empty-vehicle mileage. This study found that there appears to be a limit on how much response time can be improved through decreasing charge times or increasing vehicle range.     

PCM+“短接法”在站场埋地管道定位中的应用

为了实现站场内埋地管道的非开挖定位,借鉴长输管道定位技术,采用PCM+探索实现站内管道定位的方法。站场内管道错综复杂,用电设备干扰大,按照正常信号加载方式,电流信号在埋地管道和用电设备之间无序流动,无法实现目标管道准确定位。采用PCM+"短接法",用金属导线将发射机与待检埋地管道直接相连,不经过地网,而形成"发射机-导线-管道-导线-发射机"的封闭回路,接收机可准确探测到埋地管道的位置,现场试验效果良好,经开挖验证后发现误差小于100 mm。     

新建地铁车站零距离下穿既有线区间影响分析

暗挖隧道下穿既有地铁施工,势必会引起既有地铁结构附加变形和差异沉降,影响其结构及运营安全,需要进行变形和内力分析,以便采取必要保护措施.文章以某暗挖车站密贴下穿既有地铁区间为例,采用FLAC3D和SAP 2000模拟,分析既有地铁区间变形和内力发展规律,评价结构和运营安全受影响的程度,为安全保护提供决策依据.     

基于壅塞理论的CNG加气管流量计算分析

为了计算CNG加气系统的高压胶管的流量,以气体动力学为基础,建立等截面一维定常绝热摩擦流动的数学模型.利用VC+ +语言编制界面计算程序对模型进行编程求解,对壅塞状态和非壅塞状态下流量以及出口压力进行计算和拟合.当天然气汽车储瓶内的压力小于临界压力时,加气流量最大,且与胶管两端的压差无关,并计算出最大流量与胶管管长的关...     

WT445电站故障实例剖析

通过对WT445电站监控系统主要任务和工作过程的阐述,分析该电站自动监控开关投入运行后自行停机的原因,给出故障分析的思路和排除故障的基本方法。     

内河沿线防汛泵站应急调度的对策研究

该文通过“麦莎”台风影响上海期间市区部分内河沿线泵站停止运行的实例,分析了排水设施和河道防汛设施间存在的差异,提出在紧急情况下合理调度排水泵站的预案。     

不停输原油管道大修时压降的计算

针对原油长输管线在不停输时,由于挖开段的传热系数增大影响到站阃的压强,采用分段法在稳定的热力条件下计算不停输原油管道大修时压降,用C语言编制了计算程序;并举例加以说明,对开挖与不开挖时出站压力相同时的压降进行对比分析;确定不出现凝油事故时的最低出站压力.