Research On The Gear Shifting Schedule Of AMT

Automated Mechanical Transmission (AMT) is an automatic mechanical transmission that made up of gearing mechanical transmission. AMT technology applies the modern automatic technology to the manual mechanical transmission. AMT not only has the advantages of Automatic Transmission, but also retains the gearing mechanical transmission’s advantages, such as efficiency, low price and simple structure. So it has a wide development prospects.Shift schedule is the basic characteristic of AMT. While the AMT is working, by comparing the states of the vehicle with the optimal shift schedules, the AMT decides the optimal shift time and achieves the shift automatically. This will lessen the tiredness of the driver and improve the safety. The relationships of acceleration and driving speed, traction force and driving speed, fuel consumption and driving speed between two gears on any throttle conditions are researched in this thesis. The change of traction force and fuel consumption in the gear shifting is also researched. Finally, the shift schedules which guarantee the best performance of vehicle are obtained in this thesis.This thesis aims to study the shift schedule which is one of the critical problems of the AMT. The achievements in this dissertation are as follows.Firstly, based on the general summary of development of AMT at home and abroad, the significance of the research of AMT is discussed; the structure, principle and critical problems on AMT are also studied.Secondly, the method of design on existing shift schedules is discussed; the shift schedules that suit the thesis are determined; the theory models of the automotive power train are built.Thirdly, the power ability and fuel economy of vehicle are studies;the optimal power shift schedule, the optimal fuel economy shift schedule and3-parameter comprehensive shift schedule are designed; the indexes of automobile power ability and fuel economy are analyzed. Building vehicle running equation and fuel consumption, the design process of shift schedule is described and improved.Fourthly, based on MATLAB/SIMULINK, the simulation models of vehicle power train are built; based on STATEFLOW, the logic of shift schedule is built. After the dynamic simulation for the optimal power shift schedule, the optimal fuel economy shift schedule and3-parameter comprehensive shift schedule, the driving characteristics for vehicle are analyzed.Finally, a feasible method of designing shift schedules, which meets the best performance of vehicle, is obtained by simulation via MATLAN/SIMULINK in this thesis. This thesis enriches the theory research for shift schedule and lays a foundation for practical application of shift schedule.