The unreasonable shift phenomenon is analyzed

then

the direct cause is sudden change of pedal which gives occasion to shift hunting and the basic reason is the traditional shift schedule which is not satisfied with the dynamic state.The dynamic torque models of engine are built through support vector machine（SVM） identification.Based on that

a calculating method of dynamic shift schedule with 3-parameters is put forward.When the pedal sudden changed

the shift schedule real time changed too.A simulation model for shift is established using Matlab/Simulink

and tests have been made on bench test.Simulation and test results show that the shift schedule based on SVM model of engine can eliminate the improper shift in drive cycle and braking condition

and is superior to the shift schedule with traditional shift schedule in dynamic performance and fuel economy.