汽车配气机构的动力学模型的分析

配气机构是内燃机中重要的辅助控制机构,要求准确地控制气缸中进、排气门的启闭,随着内燃机朝着高速、精密化方向发展,研究其动力学性能非常必要.在分析汽车内燃机的配气机构的工作原理的基础上,利用动力学原理和集中参数法进行多元素系统的动力学分析,建立了构件的6自由度模型,并采用等效作用原理建立了简化的机构单自由度动力学模型,为进行机构的进一步研究奠定了基础.     

基于层次分析法的图书馆空调冷热源方案优选

从空调冷热源方案选择实际出发,建立了通用的AHP选优评价模型,并按初投资、运行费用、维护管理、环境影响、消防安全等指标对适合某图书馆空调工程的4种空调冷热源方案进行了定量分析,选出了最优方案．应用结果表明,AHP法为空调冷热源方案选择提供了一种有效的定量分析方法,可辅助工程师对备选方案进行综合分析、评比并作出决策,避免了决策的主观片面性,增强了决策的客观性、科学性．     

中、德智能网联汽车的战略选择及主要特征

 新一轮科技革命蓄势待发,引发全球汽车产业深刻变革。智能网联汽车成为汽车产业转型升级的重要突破口。梳理了中德智能网联汽车发展的背景条件和战略选择,分析了中德智能网联汽车发展的主要特征,提出中德双方应从行业管理、关键技术、标准法规、测试示范等方面持续深化合作,共同推动智能网联汽车发展。     

汽车半主动磁流变悬架的自适应相对控制研究

为了提高汽车的运行平顺性和操纵稳定性,以磁流变减振器为控制对象,提出了采用自适应神经网络相对控制方法的半主动悬架系统。在试验测试和理论分析的基础上,通过数据拟合得到磁流变减振器阻尼力的非线性Bingham模型,建立了基于该磁流变减振器的半主动悬架模型,并用该模型进行了自适应神经网络相对控制方法的研究。以模拟道路谱作为输入,以车身俯仰角加速度和车辆悬架前、后侧弹簧的垂向变形量之差作为控制量,把车身质心垂向加速度、前后悬架动行程作为评价指标来进行仿真研究。仿真结果表明,设计的半主动悬架与被动悬架相比,其平顺性与稳定性均得到了良好的改善,且对运行工况的改变有一定的适应性,对系统参数摄动也具有很强的鲁棒性。     

Experimental Study of Air Conditioning Unit of Evaporative Cooling Assisted Mechanical Refrigeration

The evaporative cooling,which assists the refrigeration machinery air-conditioning systems test-rig,has been designed.Its structure and working principle were described,and the performance test was con-ducted and analyzed.The test shows that making full use of the evaporative cooling"free cooling" in Spring and Autumn seasons can fully meet the requirements of air-conditioned comfort through the switch of the function in different seasons.Taking into account the evaporative cooling fan and pump energy consumption,compared with the traditional mechanical refrigeration system,more than 80 percent of energy can be saved,and the ener-gY efficiency ratio of the Unit(EER) is as high as 7.63.Using the two stages of indirect evaporative cooling to pre-cool the new wind in summer,under the conditions of the same air supply temperature requirements,0.83 kg/s chilled water saved can be equivalent to the traditional mechanical refrigeration system,and when the newwind ratio up to 50 percent.more than 10 percent load was reduced in mechanical refrigeration system.The overall EER increased about 35 percent.     

PEMFC边框密封结构的仿真与优化

质子交换膜燃料电池的边框一般通过黏结剂黏接在质子交换膜上，在保护质子交换膜的同时，还起到密封作用。燃料电池长期工作在复杂的环境下，边框和黏结剂的性能均会发生疲劳衰减，导致被剥离或破坏，进而影响燃料电池的气密性。因此，以边框和黏结剂的搭接试件为对象，结合内聚力模型和有限元软件设计了多种边框结构，研究了新结构对黏结性能的影响。结果表明：在低弹性模量的边框表面做三角形或梯形的凸形结构，将有效提升黏结结构的分离位移，但对于高弹性模量的边框，新结构反而会降低黏结性能；此外，优化结构的尺寸、形状对搭接模型黏结性能也有影响，当凸三角形底边长为1.5 mm时，搭接模型有最好的黏结性能。     

基于改进MPC的协同自适应巡航控制策略研究

针对环境干扰、传感器噪声和跟随时变车速稳定性较差等问题，提出一种基于KF(kalman filtering)的改进MPC(model predictive control)算法。搭建CACC(cooperative adaptive cruise control)车辆间纵向运动学模型，并建立离散状态空间方程；利用KF对状态变量降噪，同时对预测模型进行鲁棒性设计；对不同工况下CACC控制目标进行分析，分别建立目标优化函数。通过搭建Simulink与CarSim联合仿真模型进行验证，结果表明，改进MPC算法能够提高城市与市郊工况下车辆的燃油经济性与驾乘舒适性，实现公路工况下对时变车速的稳定跟随。     

Entropy Assessment on Environmental Influence of Condense Heat in Recovery System in Air-Conditioning Refrigerating Machine

This paper presented an entropy evaluation method for the influences of condense heat recovery system on the environment.Aiming at the damage of the condense heat to the environment,an entropy of re-source loss and an emission entropy from the condense heat recovery system in the air conditioning refrigerating machine were introduced.For the evaluation of the entropies,we developed a new algorithm for the parameter i-dentifieation.called the composite influence coefficient,based on the Least Squares Support Vector Machine method.By simulation,the numerical experiments shows that the Least Squares Support Vector Machine method is one of the powerful methods for the parameter identification to compute the damage entropy of the condense heat,with the largest training error being-0.025(the relative error being-3.56%),and the biggest test error being 0.015(the relative error being 2.5%).     

Selection of Weather Parameters for Air-Conditioning System Design for Buildings with Long Thermal Lag

Two building factors-a longer thermal lag of more than one hour for building envelops and a lag of indoor radiation to convert into cooling load-have impact on the instantaneous heat input and instantaneous cooling load.So the two factors should be taken into account when selecting the weather parameters for air-con-ditioning system design.This paper developed a new statistic method for the rational selection of coincident solar irradiance,dry-bulb and wet-bulb temperatures.The method was applied to historic weather records of 25 years in Hong Kong to generate coincident design weather data.And the results show that traditional design solar irra-diance,dry-bulb and wet-bulb temperatures may be significantly overestimated in many conditions,and the de-sign weather data for the three different constructions is not kept constant.     

基于改进区域生长和小波变换的非结构化道路检测

针对于在复杂场景的非结构化道路中,由于众多的环境干扰因素从而不能准确检测车道线的问题,提出了一种基于改进区域生长法和小波变换相结合的非结构化道路检测算法。根据大多数情况下道路区域在车载摄像头的正下前方及道路区域与道路两旁背景灰度值的一定差异,来有效的选取区域生长的种子点及生长原则进行区域生长道路初分割。同时结合基于小波变换的边缘检测来修正由于初分割道路受复杂环境导致道路检测不准确的情况。实验结果表明,该算法能够较准确的检测出受光照等因素影响的道路区域,且具有较高的准确性。