Construction And Research Of Vehicle Driving Cycle Of City Bus

The energy crisis and vehicle exhaust emission problem has been continuously deteriorated along with the rapid increase of automobile in China, which has become the key problem which is urgent to be solved in the field of traffic environment. Studying and developing vehicle driving cycles based on the traffic characteristic of our country cities will provide a theoretical basis for calculating the vehicle emission and fuel consumption, developing and assessing new vehicle types, as well as matching vehicle dynamic.The paper is taking the city bus of Wuhan city as object of research. First systematically analyzed the driving cycle, separately introduced the background, correlation concept and the principles of building process, which provided the rational foundation for the establishment of city bus driving cycle.After the determination of the experiment plan, GPS was designed to obtain data, which can reflect the real travel conditions. Data analyses processing takes the multivariate statistical analysis tools such as principal composition analysis and clustering analysis etc. Firstly the test data is divided into a series of micro-trips, and calculates 27 eigenvalue of every micro-trip (such as average speed, acceleration, maximum acceleration and speed standard deviation etc), and comes into being micro-trips database. Secondly several principal composition are drawn out from much eigenvalue, in this way, clustering analysis comes out according to several extracted principal composition. Finally the more than 5000 micro-trips are divided into three categories. One has represented crowded road traffic condition; another has represented comparative unblocked road traffic condition; the other has represented unblocked suburbs road traffic condition.The entire micro-trip set and the three kinds of short trip is taken as four independences samples, to arriving three difference driving cycles. With the aid of MATLAB software, we have gotten four kinds of Wuhan city bus diving cycle. That is, crowded road, comparative unblocked road, unblocked suburbs road as well as synthesize driving cycle. Finally we compared the Wuhan synthesize driving cycle and other typical driving cycle in and abroad our country. Show as result, driving cycle in other area can not reflect Wuhan actual traffic condition.