Study On Driving Cycles Of City Vehicle

Along with the advanced study of environment protection and saving energy technology, vehicles with nontraditional energy come up. We need deeply representative driving cycles witch can describe regional vehicle driving character, in order to develop or certificate new automobile or take inspection/maintenance. The paper describes development method and relative research of vehicle driving cycle, according to 863 project-study of vehicle real driving cycles of typical city.Driving cycles research took two years to investigate passenger car and bus driving data of three typical city: Beijing, Shanghai and Guangzhou. As a result, we took investigation six times and obtained enough driving data. Representative driving cycles are formed after data processing, according to correlative statistical theory and using special program. At the same time, our research result is compared with international driving cycles.Confirming test routes is crucial step of driving investigation. Routes of city passenger car are confirmed by city street grade and traffic flow; witch of bus are decided by bus investigating information, beside with "route frequency and covering rate" that from traffic area. Vehicle real driving investigation comes up with time section cross method, and uses advanced instruments such as non-contacted speed sensor with tracking filter etc.Data analyses processing takes the multivariate statistical analysis tools such as principal composition analysis and clustering analysis etc. Firstly the processing partitions driving data into kinetic sequences, and calculates 36 eigenvalue of every sequence (such as driving distance, average speed, acceleration, speed standard deviation, acceleration standard deviation etc. ), and comes into being sequence database. Secondly several principal composition are drawn out from much eigenvalue, in this way, clustering analysis comes out according to several principal composition. Finally city driving cycles are formed by special sequences witch are drawn out by cluster rate and in accord with expected condition, at the same time, the cycles figure show. The special program VDCAP carry above function out that program with MATLAB.Result from different city show that vehicle driving condition belong to different city is diverse, and average speed and idle rate are not uniform, but their difference is small; and that every seasonal driving condition has their character. Generally speaking, we can establish uniform test cycles for our country.Speed-time curve is the showing result of driving cycles result. Because present cycles have two type: transient and modular type, this paper adopts theiradvantage and use local modular processing, in order that driving curve is true of real-world and operate expediently. Analyzing to our domestic curve shows that our driving cycles have private character, and that their eigenvalue are among international driving cycles(such as FTP75, ECE+EUDC and JapanlO. 15 as well as abroad other major city bus driving cycles).