Research On Shift Control Technology Of Commercial Vehicle AMT

In recent years,China’s automobile industry has developed rapidly,and the car ownership has repeatedly reached a new high.As the transmission part of the vehicle,the influence of the transmission on the driving quality of the whole vehicle can’t be ignored.Due to the advantages of good production inheritance,low maintenance cost and high transmission efficiency of electronically controlled mechanical transmission(AMT),it is very suitable for the use needs of commercial vehicles.However,at present,AMT Vehicles have impact in the process of shifting,resulting in buffeting of the whole vehicle during shifting,resulting in poor driving quality and easy wear of synchronizer;In addition,in the process of AMT real vehicle development,the calibration work is cumbersome,which seriously affects the development cycle and progress.In view of the above problems,combined with the AMT real vehicle development project of an enterprise,this paper studies the AMT vehicle shift control and parameter self-tuning strategy,improves the existing control strategy,and solves the phenomenon of impact in the shift process;At the same time,the self-tuning strategy is designed for the synchronous force control in the shift process,which reduces the calibration workload of the synchronous force to a certain extent,and explores the application of the parameter self-tuning strategy in AMT.The details are as follows:Aiming at the problems of abnormal wear of synchronizer and shift impact in AMT Vehicles,the formula is deduced theoretically,the causes of the problems are found,and the shortcomings of the control strategy are deeply analyzed;Then,aiming at these technical problems,the control requirements of smoothness,power and low sliding wear in the shift process are clarified.Through the integrated and coordinated control of engine,clutch and transmission,the shift force control strategy of AMT vehicle with synchronizer is proposed;Synchronous impact control strategy to increase engine torque at the moment of clutch engagement;The clutch control strategy of fast synchronization through engine speed control makes the whole shift process meet the control requirements.Aiming at the cumbersome problem of calibration in the development of AMT real vehicle,a parameter self-tuning control strategy is proposed;Taking the gear synchronization process as the research object,aiming at the problems of abnormal wear of synchronizer caused by excessive shift force and long gear synchronization time caused by too small shift force,different from the traditional method of using advanced control algorithm to improve the shift quality at one time,a self-tuning strategy of synchronization force control parameters in gear process is proposed;By comparing the actual synchronization time with the ideal synchronization time,the shift quality is judged,so as to increase or reduce the synchronization force control parameters accordingly.After several parameter adjustments of the self-tuning strategy,the synchronization time is controlled within the ideal time range,and the calibration workload of the synchronization force is reduced.Taking the light commercial vehicle as the test platform,through the real vehicle road test,the lifting gear test of AMT sample vehicle with synchronizer is carried out,and the proposed gear force control strategy,synchronous impact control strategy,clutch control strategy and synchronous force control parameter self-tuning control strategy are fully tested and verified.The test results show that the above control strategy makes the shift process meet the control requirements,reduces the calibration workload to a certain extent,and solves some engineering problems.