Automotive Multi-performance Optimal Individualized Shift Schedule Based On Driving Intention Identification

Shift schedule is one of the key technologies of automatic transmissions,and it is also one of the most important factors affecting the performance of vehicles.With the development of intelligent control technologies and people’s increasing requirements of intelligent vehicles,the vehicle with automatic transmission is no longer limited in the purpose of automatic shift,and requires more intelligent and multi-type shift schedules to suit different drivers’ driving demands.In this paper,an inference method based on fuzzy logic has been used to map drivers’ manipulating behaviors and the vehicle operating status to the weights corresponding to each performance which can be used directly in the shift schedule optimization.The main contents are as follows:(1)The technical characteristics of the common automatic transmission are summarized;the development process of the shift schedule of automatic transmission is outlined;this paper makes a detailed induction and analysis of the research results and the present situation of drivers’ driving intention.(2)By making a comprehensive analysis the relationship between the driving control parameters,the vehicle running status and the corresponding performances,combining with the control experiences of excellent drivers and the test data of the throttle opening,engine speed and the driver’s expectation on power performance,fuzzy inference rules for power performance expectation are developed.Based on these rules,taking the engine speed,the throttle opening as inputs and the driver’s expectations of the power performance as output,a fuzzy inference system of power performance with two inputs and one output is established.Driver’s expectation of power is quantified and verified.(3)Analyzing the original characteristics,the input characteristics of torque converter and the engine torque characteristics,the mathematical models of TC and engine are established.According to the matching principle,the engine and TC co-working has been studied on,and the lock rules of TC are established.(4)According to the quantified drivers’ shifting performance expectations,the square and weighted ideal point method has been applied to establish the comprehensive evaluation function of multi-performance integrated optimal shift schedule.Based on the output characteristics of co-working,this paper has used the evaluation function as optimization goal,two-parameter as design variables to calculate the shift schedule which reflect driving intention by using genetic algorithm.(5)A simulation-based evaluation system for shift schedule,which consists of the models of engine performances,the simulation model of AT,the shift logic simulation model and the simulation model of vehicle longitudinal dynamics,has been built using MATLAB/Simulink/Stateflow platform.The formulated shift schedule has been evaluated through simulation results of dynamic performances and driving cycles.The simulation results show that: the fuzzy inference method of driving intention proposed in this paper is reasonable,the shift schedule can reflect the driver’s expectations which reflect the personalized intelligent shift.