Study On The Algorithm Of City Driving Cycle Construction

Faced with the pressure of energy and environment,the automobile enterprises all over the world started to develop new energy vehicles,including hybrid vehicles,pure electric passenger cars and buses,while the optimization of the dynamic system of new energy vehicles depends on the study of driving cycles.In fact,it’s rather difficult to acquire the driving cycles in a specific city if there isn’t enough time to do the driving test on road in a long enough distance during the process of vehicle development and optimization.Therefore it’s very important to develop a method to get the driving cycles of the vehicles running on the city road.Based on the existing study methods,the concept of kinematics interval is introduced to describe segments’ instantaneous characteristics,i.e.using the instantaneous characteristic parameters in eigenvalue analysis.Then,on the basis of the integrity and instantaneity described by eigenvalues,the clustering methodology is used to analyse the chosen segment,whose characteristic parameters are acquired from the integrated characteristic parameters of the segment and instantaneous characteristic parameters of the kinematics interval.Thus the kinematics interval is accurately exacted while constructing the driving cycle.For comparison,a driving cycle is also constructed through traditional method,to verify the rationality and effectiveness the two-stage clustering algorithm.Finally via comparing the probability distribution of velocity and acceleration,it’s proved that the driving cycle constructed by using two-stage clustering algorithm raised by this paper fits the actual driving cycle more closely.