Investigation Of The Driving Cycle Construction Of Mixed Roads In The City

With the rapid development of the national economy and the improvement of people's living standards, the cars are more and more widely used in our country, but a series of problems that the automobiles caused have appeared. For example, the cars in use have longer lives, the emission standard-reaching rate of new cars is low, traffic management and road infrastructure, etc, are not perfect, automobile emission pollutions are getting worse.In order to effectively control emission pollutants of urban vehicles, the vehicle emissions on real-road driving conditions must be mastered. The research of the driving cycle is basic work of vehicle emissions and fuel consumption and is also an important basis to determine vehicle emissions and environmental impacts of vehicle emissions.Standards of foreign driving cycles can not be mechanically transplanted for the real driving cycle research of cities of our country. The present research on the vehicle driving cycle is only theoretical and experimental at home and abroad, practical application in specific cities is rare, especially in our country although driving cycles of vehicles of some cities are studied, very few are used in practice, only limited to some theoretical analyses, and theoretical analyses often use traditional methods of multivariate statistical theory. Mainly because there are a lot of uncertainty during the research of actual vehicle driving cycle, driving cycles of each city and every vehicle type are different. Since the late 90s during the 20th century a number of theoretical research of the vehicle driving cycle are made by research institutions and universities. In this paper, learned from the design methods of the vehicle driving cycle at home and abroad, driving cycles are wholly studied and classified by the short trip method, the Markov method, the wavelet transform method and the cluster method, which provide the new thinking for the driving cycle research of mixed traffic in our country and improve the accuracy of the driving cycle construction. The research contents of this dissertation are listed as follow:(1) The experimental data are treated in typical road driving cycles by an example of Hefei.(2) The mathematic models of parameters of short trip are set up and the characteristics of driving cycle in Hefei are analyzed. The driving cycle is constructed by the traditional method of short trip, the parameters of the vehicle driving cycle are reflected, the constructed representative driving cycle is compared with the experimental data.(3) According to the characteristics of mixed traffic in China the experimental data of the vehicle driving cycle are compressed and reconstructed by the wavelet transform method, the reconstructed driving cycle data are constructed.(4) The vehicle driving cycle can be viewed as a random process, which is constructed by using the maximum likelihood estimation method and the Markov method. The constructed representative driving cycle is compared with the traditional method, wavelet transform method and foreign standard driving cycles.(5) The vehicle driving cycle is divided into crowded cycle and unblocked cycle by principle component analysis and cluster analysis, two groups of representative driving cycles are separately constructed.(6) Two factors related to fuel consumption are obtained using factor analysis, the total driving cycle is clustered and the low-speed, medium-speed and high-speed driving cycles related with fuel consumption are obtained. The driving cycle of each class is divided into different segments according to the Markov method and new classification criteria, the candidate driving cycles are constructed according to the transition probability and the specific power, the representative driving cycle is selected by the Composite Performance Measure.(7) The study work of the whole dissertation is concluded, and then the advice is given for the next step work.