Research On The Objectives Evaluation Of Shift Quality For Automatic Transmission Of Passenger

Research on the objectives evaluation of shift quality is an important subject in the field ofvehicle transmission system, especially for the vehicle with automatic transmission. First of all,transmission system is on the central position of vehicle driving system, and shifting is a transientprocess which easily leads to vehicle dynamic performance changes. The study on the shift qualityhas a significant impact. Secondly, the shift quality is directly related to the driver andpassenger’s subjective experience. Shift quality directly affects the user’s satisfaction degree ofvehicle.The traditional objectives evaluation of shift quality is limited to the longitudinal impact ofvehicle, commonly used for: shifting time, vehicle longitudinal acceleration, work of slipping; orfrom the vehicle’s performance requirements, the evaluation indexes for: durability, economy,power performance and comfort. The former shifting characteristics are not enough for the drivingprocess of the vehicle. Evaluation index number is too small. The latter can obtain overallperformance from the vehicle’s point of view, but not comment on the properties of thetransmission system in detail.This paper studies vehicle automatic transmission shift quality evaluation, combined with theNational Natural Science Fund Project (50505014)" the vehicle shifting quality dynamiccomprehensive evaluation system research", and the major special "DCT development keytechnology" of Jilin province project as the background. The indexes of the objectives evaluationof shift quality are subdivided and defined. One reveals the mapping relationship between the shiftquality evaluation index and vehicle performance (power performance and so on). A prototypevehicle has road tests to establish the evaluation sample database for the objectives evaluation ofshift quality as database support. Establish the system of the objectives evaluation of shift qualityto evaluate shift quality.1. The construction of evaluation sample database and application in the objectivesevaluation of shift quality The construction of evaluation sample database provides database support for the system ofthe objectives evaluation of shift quality. On the one hand, databases can enhance evaluationsystem capacity; On the other hand, database can provide reference and comparison for thedevelopment of new system in the foundation of the current evaluation system. In the same time,database can display vehicle shift performance for virtual calibration, compared and analyzed withexisting model in the database. This can provides a more direct vehicle shift performance for thedevelopers. One can make further improvement for developing products based on the result ofevaluation model. This paper finally takes Microsoft SQL database as the evaluation system ofdatabase types through the comparison of several existing database types, advantages anddisadvantages.2. The subdivision and definition of indexes for the objectives evaluation of shift quality andmapping relationshipThe transient characteristic of shift process in automatic transmission will inevitably lead toproduce different degrees shifting impact, and impact on the ride comfort of shifting process whenbeing serious. The definition of evaluation index is very important for evaluating shift qualitycomprehensively. This article subdivides and defines indexes of the objectives evaluation of shiftquality, and extends the evaluation content; reveals the mapping relationship between theevaluation index and the vehicle performance. So, one can descript the vehicle shift quality morecomprehensively. This provide theoretical basis for the establishment of evaluation system.3. The system of the objectives evaluation of shift qualityThe system of the objectives evaluation of shift quality is based on SQL-MATLAB-CANoe.This paper introduces the function of evaluation system. Evaluation system makes full use ofCANoe graphics interface to integrate data acquisition and display the results of evaluation. Onecan reproduce the running state of vehicles and improve the evaluation system comprehensively.The advantages of MATLAB/Simulink in the modeling and database communicationcharacteristic provide a more powerful data processing, pattern recognition and state detectionfunction for establishing the evaluation system. The index extraction of the evaluation system isbased on the test data. The system can recognize driver intention and research mappingrelationship and weight distribution of the evaluation indexes based on different models and running conditions. The construction of sample database can provide reference and comparison forthe evaluation system.4．Experimental studyThis article proposes a test standard and method for shift quality evaluation. For differentmodels and conditions for the vehicle road test, one can solve the problem of thenon-synchronization data acquisition in the test process, because of the different signal acquisitiondevice. This provides data samples for the database construction and evaluation system.