| With the increase of automobile consumption, automobile retain capacities are increasing. The result is city environment become worse and worse. In China, the ratio of transportation gas pollution becomes bigger and bigger in some big city. It exceeds half of the total pollution. So reduce transportation gas pollution and control vehicle emission have became urgent affairs.However,at present in China the level of vehicle emission is low and the single vehicle emission factor is high. As well as some means of transportation are relatively behindhand,the measure of traffic control and management are disadvantageous, traffic demand contradiction makes vehicle operation conditions worse,all these aggravate emission. To change the condition in existence,optimize traffic control and management to improve vehicle emission,this measure has great disavantage under unchanging means of transportation on road. This method mainly provide logical measure of traffic control and management and seek the high efficiency of transportation and environment protect through study vehicle emission characteristic,mirco emission model and the effect factors of vehicle emission performance in traffic flow. The key technology is the research on mirco emission model in traffic flow. So research on the effect factors of vehicle emission performance and mirco emission modeling are significant.Now the study on vehicle emission models have developed for many years,especially macro models which predict emission in macro region have developed maturely. But in road net,intersection and some detailed region,the emission predict has no effective measure. So in recent years,the overseas investigators commit themselves to mirco emission model. And they acquired some fruits. However in China the studies on vehicle emission effect factors and emission models are focus on several colleges and research institute. Beacause of no enough valid data,the investigators only rectify models that have exit in oversea commonly. But because traffic condition,road establishment,vehicle condition and fuel quality in domestic are great different from them in overseas. Simplely copy and rectify them has no veracity. So it is necessary to make models fitting for China.One side the research on emission factor on road and micro emission modeling are of importance, the other side the foundation of vehicle emission model suit for China situation is of inevitability. Based on the above-mentioned two sides,study of Light-duty vehicle emission model on urban corridor has important significance in practice.Because the micro emission model is based on urban road,the model data should root in real the test on urban road. The on-board emission testing system in this paper can solve such question. The total system include four parts:emission testing module,exhaust collecting module, engine sensors module, vehicle run condition inspecting module. The emission measure instrument is OEM-2100, which is manufactured by Clean Air Technologies Inc. of USA. It goes without saying on the advancement of machinery. The on-board emission testing system collect emission data,engine rotate speed, intake pressure,intake temperature,vehicle operation condition parameter ect. Experiment collection data provide evidence for emission effection factors analysis and micro emission modeling. The on-board emission testing system provides a feasible methold.To set up Light-duty vehicle emission model on urban road,the author choose the typical road in ShenYang,such as : Renmin Street,Changchun Street,Yatai Street and Nanhu Road,aim at study object.On these roads, test Multi Light-Duty vehicle emission,collect a mass of data,pre-process the collection data. According to vehicle type,time,road ,gather and clean up the data respectively and calculate some relative data. It can offer well base on further analysis and modeling.In real road,the effection factors on emission rate are mulriple. In paper several relatively important factors are choosed and analysed. Analyse the emission rate change of operation conditions of Jetta and Hongqi century star these 3 types vehicle .The result shows : Emission of acceleration operation condition is much higher than that of others operation condition. The second is cruise operation condition,and the third is deceleration,then idle is least. The characteristic of vehicle operation condition distribution on urban road is the proportion of idle, acceleration, deceleration. The emission contribute rate of operation condition is cruise higher than acceleration, acceleration than deceleration, deceleration than idle. Through comprising emission of same vehicle on same road under traffic high and low peak and natural traffic flow,it can make a conclusion that vehicle operation period of time affect emission greatly. In detail, emission under high peak is the highest,traffic congestion is grave, the frequence of acceleration and deceleration, emission under low peak is the least, vehicle speed is high relatively, emission under natural traffic flow is medial. Experiments show in the first 5 seconds on acceleration, CO add rapidly, NOx hold the line basically, from 5 seconds to 10 seconds, NOx and HC also add rapidly. From deceleration to idle, about 10 seconds CO and NOx become stable,but HC keep high emission all along. Through the analysis of effection on emission rate of vehicle speed and acceleration shows that: acceleration is one of the most important effect factors of emission rate,high emission result in big acceleration,speed effect on NOx and CO emission rate rather because burning temperature and burning sufficient are main factors of them.Based on analysis the effection on emission of vehicle speed,acceleration and vehicle operation condition, Speed Regression Model, Cruise emission rate model, Idle emission rate model, Acceleration emission rate model, Deceleration emission rate model, Speed-acceleration two dimension high-hypo emission rate model and BP neural network emission rate model are set up by using regression and neural network methold. Models error are all within 30%.So it is effective to predict instantaneous emission on real road. Speed Regression Model, Idle emission rate model, Acceleration emission rate model integrate traffic simulation model can predict micro emission of urban road nets, provide some traffic control and management strategies. Two dimension model and neural network model are good universality. They fit for predicting light-duty vehicle micro emission on urban road. But all models are based on Jetta emission data,they are limited. If predicting other light-duty vehicle emission,you can use coefficient methold temporarily,i.e. multiply models by vehicle coefficient.In this paper,emission factors on road are analysed,Light-duty vehicle emission models on urban typical road are set up. These models can predict vehicle emission in urban traffic flow expediently ,accurately. They also integrate traffic simulation software to accurately predict emission condition of a section of road and optimize traffic control and management. They are an important role in particular road emission controling and ITS evaluation. The study fruits can provide theory basis of traffic environment evaluation for local government even nation,which effect on traffic environment father actively for our country.
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