Estimation Of Vehicle Mass And Road Slope And Their Influence On Shift Schedule

In recent years the rapid development of auto industry bring great convenience to people’s production and life, it has also promoted the social development effectively. As the number of vehicle increases year after year, its exhaust pollution to the environment is becoming more and more serious. Compared with the traditional vehicle, pure electric vehicle don’t make harm to the environment at all. In order to improve the worsening environmental problems, large-scale popularization of pure electric vehicles has got a consensus around the world. The same as the conventional vehicles, pure electric vehicles also need excellent automatic transmission system to promote its dynamic performance and economic efficiency. In addition, the vehicle mass and road slope can also influence the performance of pure electric vehicles, it is necessary to carry out their accurate estimations.The medium-sized pure electric vehicle in this paper carried a 4 gear AMT gearbox, considering the efficiency of the motor, the new shift schedule is established and compared with the shift schedule based on vehicle’s dynamic performance. The paper analyzes the change of the vehicle mass and road slope’s influence on pure electric vehicle shift schedule and modify it using interpolation method. The main research content of this article is as follows:(1) The development of pure electric vehicles and the necessity of the popularization of pure electric vehicles are expounded; Current research status at home and abroad of shift schedule for automatic transmission, vehicle mass and road slope estimation problems are summed up and summarized;(2) Analyses and compares the advantages and disadvantages of all kinds of common-used automatic transmission and introduces the application of AMT on pure electric vehicle; The structure and principle of pure electric vehicles are introduced; The detailed formula of Recursive least square method is derived and proved, and its advantages when applied to real time parameter estimation are summarized;(3) Shift schedule for automatic transmission is introduced in detail, the new shift schedule considering the efficiency of the motor is established;(4) The necessity of estimating the vehicle mass and road slope is introduced, the vehicle longitudinal equation is established and the estimation using the Recursive least squares is completed;(5) Found the co-simulation platform of AMESim/Simulink and verifies the rationality of the new shift schedule by real vehicle tests, the estimation of vehicle mass and road slope are verified, modify the new shift schedule using interpolation method.