传统燃油车的电动化改制方案研究

文章以前置后驱的传统燃油车改制为前置前驱的纯电动汽车案例,展开整车设计分析,在维持原型车的外形、长宽高、轴距和轮距等基本参数的基础上,提出了整车布置结构变化的改制设计方案,设定了电动车整车主要性能指标。在电动化设计中取消了传统燃油动力总成及其附属的燃油、进排气等系统,依据整车性能目标要求,结合车辆空间及整车结构原理,对驱动电机动力总成、电池PACK、VCU、PDC三合一等高压系统零部件进行选型及布置设计。     

纯电动公交车示范项目

在本项目中,临沂市公交总公司采用了铝合金全承载车身、三相异步电机驱动系统、磷酸铁锂动力电池组的纯电动车作为公交车,依靠当地电动汽车生产企业提供的车辆技术支持,从2010年2月起,先后在5条公交线路上进行了SDL6120EVG纯电动车的示范运行。通过合理使用电池、强化电池保养、加强驾驶员培训等管理手段。到目前为止,单车平均运行2万多公里,车辆运行平稳,节能环保效果良好。     

管道电流测绘系统中发射电路的设计与仿真

管道电流测绘系统(Pipeline Current Mapper)是一种用于地下管道外防腐层破损检测的装置,通过向地下管道发射一种用于管道检测的甚低频电流信号(接近直流)进行检测。针对检测的原理,开发出一种PCM发射电路。该发射电路采用超高运行速度的单片机和D/A转换器编程产生甚低频正弦波信号,再经有源低通滤波器滤波和OCL功率放大电路的调整,最终输出频率可调的甚低频正弦波信号。最后,将设计的发射电路放在Proteus7.4仿真软件中进行仿真,通过仿真得到的结果,分析得出该发射电路能非常精确地产生PCM系统所需的信号。     

一种声控直流无刷电机驱动器

本实用新型提供一种声控直流无刷电机驱动器,包括语音单元、控制单元、显示单元和电源模块;语音单元与控制单元信号电连接:显示单元与控制单元信号电连接;电源模块给系统提供工作电源;语音单元包括麦克风、滤波电路、单片机、功放、喇叭和键盘;控制单元包括DSP、过压过流检测电路、驱动电路、电流检测电路、霍尔传感器和IGBT逆变电路。本实用新型能够通过语音指令实现对无刷直流电机的正转、反转和停止等状态进行控制,电路设计简洁,稳定性好,语音识别率高且成本较低,可广泛用于电动自行车、电动汽车、智能机嚣人及工业控制等使用场合,适用性强。     

纯电动汽车应用现状分析及策略探讨

通过对知豆纯电动汽车的调查实践,文章简述了纯电动汽车的优势及其电驱动系统机构,分析了纯电动汽车的应用现状,提出了纯电动汽车应用存在的价格较高、基础设施不完善、电池性能及能量管理有待优化等问题。在此基础上,提出了要继续强化纯电动汽车的基础研究、加快充换电站等基础设施建设和政府政策继续引导支持的建议。     

折叠电动自行车

权利要求1.折叠电动自行车,包括折叠车架和电力驱动系统构成,所述的折叠车架由主横管、前把竖管、后座竖管,折叠支架构成,其特征在于,主横管的前端与前把竖管的下端枢接,主横管的后端设置枢接座,通过枢接座与后座竖管的下端枢接,折叠支架连接在主横管和后座竖管之间,连接处采用枢接方式,所述的电力驱动系统包括控制器、电池和驱动电机。     

工业管道声发射信号衰减测试及定位分析

简述了工业管道输送流体流动特性,以及声发射技术在管道检测中的应用。采用手持式声发射检测仪器配合不同频率传感器对在役工业管道进行检测,研究焊接有三通、法兰、阀门等外接接口的不规则管道的定位特征,对比分析规则管道与焊有外接接口的不规则管道衰减特征区别,通过对现场数据的分析,得到管道损伤定位与传播声速之间的相互关系以及不同传播速度条件下产生的定位误差,综合分析误差产生原因,作为对现场检测的经验。     

V型墩连续刚构桥动力特性分析

采用环境脉动试验对某V型墩连续剐构桥的模态进行测试,并进行有限元动力特性计算,通过试验结果与理论计算结果的比较,对该桥状态进行评定.计算结果可为桥梁的设计、施工以及使用阶段的健康检测和维护提供技术参数和依据.     

皮带机双机启动、单机助力降耗运行

文章对原皮带机系统的控制方式及改造后的皮带机系统控制方式进行对比分析。得出结论为节约的主要源头在于时皮带机系统耗电量的控制,文章提出对皮带驱动电机采取双机启动、单机助力运行的运行方式,以降低电能的消耗。     

我国电动汽车技术应用与发展趋势的研究

阐述了我国发展电动汽车技术重要意义,通过对各类电动汽车的技术特性和局限性加以概括,列举其市场应用范例,并将其技术特点与我国的实际条件相结合,对其近期、中期和长期发展趋势进行了分析、评估和预测。     

On-road emissions from urban buses with SCR + Urea and EGR + DPF systems using diesel and biodiesel

Due to growing concerns about NO_x and particulate matter (PM) emissions from diesel engines, stricter regulations are being introduced requiring advanced emission control technology. In response the diesel industry has begun testing various emission control technologies and applying them. To assess vehicle renewal policies of bus companies, two exhaust after-treatment technologies are compared: the combination of a diesel particulate filter and an exhaust gas re-circulation system and the combination of a selective catalytic reduction and urea. On-board emission measurements were conducted under real-world driving conditions on a specific bus route in the city of Madrid.     

交流杂散电流干扰对管道直流电位的影响

文中利用杂散电流测试仪器,在城市管道受到杂散电流干扰区域进行了杂散电流的详细测试。选取同一条管线的4个点进行了测试,通过测试结果分析杂散电流的大小和方向,判断交流杂散电流对燃气管道直流电位的影响,确定电流流入与流出位置,确定出管线最容易遭受到腐蚀的位置。利用测试结果的分析结论确定施加排流措施方案,并测试排流后的效果。测试结果表明：排流措施施加得当,排流效果良好,能够使阴极保护系统保持正常运行状态。     

Methodology and results of the evaluation of alternative short tests applied in inspection and maintenance programmes

The aim of this paper is to present a methodology for the evaluation of the effectiveness of alternative short tests that could be applied in an inspection and maintenance programme. The basis for the evaluation, apart from the environmental benefits, is the social and political acceptance that constitutes crucial parameters in the implementation of a short test. The methodology has been applied to a large sample of three way catalyst equipped vehicles representative of the European fleet and the effectiveness of 10 alternative short tests has been evaluated. The short tests include transient and steady state (both loaded and unloaded) procedures, as well as the idle test of the current European legislation. The steady state tests find it difficult to identify high emitters, approximately 15% are detected, and as a result the predicted potential for environmental benefit is less than 5% for all pollutants. The transient tests, on the other hand, seem to be able to identify approximately 70% of gross emitters and therefore the emission reduction potential is predicted to be as high as 20% for all pollutants.     

Characteristics of gaseous and particulate pollutants exhaust from logistics transportation vehicle on real-world conditions

On-road vehicle tests of three heavy duty diesel trucks were conducted by a portable emission measurement system (PEMS) in Chengdu, China. SEMTECH-ECOSTAR provided by Sensors Inc. was employed to detect gaseous emissions and MI2, an emissions measuring instrument powered by the Pegasor Particulate Sensor (PPS) was used to detect particulate emissions during the tests. The impacts of speed, acceleration and engine load on emissions were analyzed. The average nitrogen oxides (NOx) emission factors of the heavy duty diesel truck (HDDT), medium-duty diesel truck (MDDT), light duty diesel truck (LDDT) were 7.29, 5.29 and 5.53 g/km. The particulate emission factors were 0.60, 0.30 and 0.14 g/km respectively, higher than the similar reported in the previous studies. Both gaseous and particulate emission exhibit significant correlations with the change in vehicle speed, acceleration and power demand. The highest emission was generally in high VSPs and higher loads. High engine load caused by aggressive driving was the main factor of high emissions for the vehicles on real-world conditions.     

Impact of control strategies on the emissions in a city bus equipped with power-split transmission

The continuously variable hydromechanical transmission is an interesting solution for high power vehicles subject to frequent changes of speed, in which the comfort is a significant requirement.Despite their low average efficiency with respect to the mechanical transmissions, the hydromechanical transmissions allow to release the engine speed by the vehicle speed, and to open the possibility for the optimal control of the engine. It follows that the performance and emissions of the powertrain is heavily affected by the logic control.The aim of the paper is to investigate the emission reductions that can be obtained using a Power-Split transmission.Therefore, a hydromechanical transmission has been sized and tested on a 12-ton-city bus by using a one-dimensional model developed in an AMESim environment. Four different control strategies of the powertrain were applied to the model. The CUEDC-ME standard cycle for the characterization of emissions in heavy vehicles was used as a reference mission.The simulation results showed that the hydromechanical transmission reduces consumption or the emission levels with respect to the traditional transmission when managed according to appropriate control strategies. By means of emission values normalized with respect to the standard limits, it is possible to identify a control strategy that allows the reduction of emissions in every usage condition of the vehicle at the expense of a slight increase of consumption.The suggested procedure could help the manufacturer to satisfy the emission standard requirements.     

汽车电动助力转向系统控制策略的研究

文章系统阐述了电动助力转向系统的控制策略和控制方法。通过比较电压控制方式和电流控制方式,得出电流控制方式明显优于电压控制方式的结论;并重点分析了在电流控制方式下的控制策略(包括助力控制、回正控制和阻尼控制),并在SIMULINK中进行了仿真。     

Investigation of tailpipe and evaporative emissions from China IV and Tier 2 passenger vehicles with different gasolines

The limited understanding of vehicular emissions in China, especially evaporative emissions, is one obstacle to establishing tighter standards. To evaluate tailpipe and evaporative emissions, two typical China IV vehicles and one Tier 2 vehicle with an onboard refuelling vapour recovery (ORVR) system were selected and tested. One of the China IV vehicles was fuelled with gasoline, E10 and M15, respectively, to investigate the effect of fuel properties on vehicular emissions. For each vehicle, cold-start tailpipe emission tests were conducted first, followed by an evaporation test. Based on the emission factors and real-world vehicle activity data, the annual tailpipe and evaporative hydrocarbon (HC) emissions of each vehicle were calculated and compared. The results show that E10 and M15 significantly reduced the tailpipe CO and particle number (PN) emissions but seriously aggravated the NOx emissions, especially for M15. The hot soak losses (HSLs) and diurnal breathing losses (DBLs) were slightly impacted by the fuel properties. The annual evaporative emissions with E10 and M15 were higher than that with gasoline. The ORVR system effectively controlled the evaporative emissions, especially for DBLs. Evaporative emissions from the China IV vehicles were 1.1–1.4 times the tailpipe HC emissions. Additionally, the evaporative emission factors of the China IV vehicles were almost 50% lower than the standard (2.0 g/test), whereas their annual evaporative emissions were almost 1.8–2.8 times higher than those from the Tier 2 vehicle. Therefore, controlling evaporative emissions currently remains a great need in China, and the ORVR might be a recommended evaporative control technology.     

Optimally combined headway and timetable reliable public transport system

This paper presents a model-based multiobjective control strategy to reduce bus bunching and hence improve public transport reliability. Our goal is twofold. First, we define a proper model, consisting of multiple static and dynamic components. Bus-following model captures the longitudinal dynamics taking into account the interaction with the surrounding traffic. Furthermore, bus stop operations are modeled to estimate dwell time. Second, a shrinking horizon model predictive controller (MPC) is proposed for solving bus bunching problems. The model is able to predict short time-space behavior of public transport buses enabling constrained, finite horizon, optimal control solution to ensure homogeneity of service both in time and space. In this line, the goal with the selected rolling horizon control scheme is to choose a proper velocity profile for the public transport bus such that it keeps both timetable schedule and a desired headway from the bus in front of it (leading bus). The control strategy predicts the arrival time at a bus stop using a passenger arrival and dwell time model. In this vein, the receding horizon model predictive controller calculates an optimal velocity profile based on its current position and desired arrival time. Four different weighting strategies are proposed to test (i) timetable only, (ii) headway only, (iii) balanced timetable - headway tracking and (iv) adaptive control with varying weights. The controller is tested in a high fidelity traffic simulator with realistic scenarios. The behavior of the system is analyzed by considering extreme disturbances. Finally, the existence of a Pareto front between these two objectives is also demonstrated.     

不同车型FCW试验中TTC安全时间阈值分析

目前,在自动驾驶车辆技术中已实现量产的功能主要分布于L0-L2 (SAE标准)阶段,其中主要功能以前向碰撞预警(FCW)、车道偏离预警(LDW)、自适应巡航(ACC)以及紧急制动(AEB)等为主;针对前向碰撞预警(FCW)功能技术,目前的测试方法主要依据美国公路交通安全管理局(NHTSA)、欧盟(EU)以及国际标准化组织(ISO)制定的《FORWARD COLLISION WARNING SYSTEM CONFIRMATIONG TEST》、《ISO15623 Transport information and control systems-Forward vehicle collision warning systems-Performance Requirements and Test Procedures》等相关标准;而类似标准在设置TTC规避阈值时间(即安全碰撞时间)均设置为固定值,没有依据不同类型车辆设相关加权系数。本文根据不同车型的多次FCW试验发现,为了保证试验安全,汽车质量和TTC存在一定的相关性。本文依据不同类型车辆制动试验数据计算出相关系数,从而界定了安全的TTC阈值。     

A self-adaptive method to equalize headways: Numerical analysis and comparison

In uncontrolled bus systems, buses tend to bunch due to the stochastic nature of traffic flows and passenger demand at bus stops. Although schedules and priori target methods introduce slack time to delay buses at control points to maintain constant headways between successive buses, too much slack required delay passengers on-board. In addition, these methods focus on regular headways and do not consider the rates of convergence of headways after disturbances. We propose a self-adaptive control scheme to equalize the headways of buses with little slack in a single line automatically. The proposed method only requires the information from the current bus at the control point and both its leading and following buses. This elegant method is shown to regulate headways faster than existing methods. In addition, compared to previous self-equalizing methods, the proposed method can improve the travel time of buses by about 12%, while keeping the waiting time of passengers almost the same.