Study On Characteristic For Three Degree-of-freedom Power Shift Hybrid Transmission

In this paper,by taking a three degree-of-freedom power shift hybrid transmission for the study,the following contents are studied,including the establishment of the power shift process model of the three degree-of-freedom power shift hybrid transmission and the vehicle longitudinal dynamics model,the research of the dynamic problems of the power shift process and the applicability of the shift schedule of the three degree-of-freedom power shift hybrid transmission.The research has important significance to the vehicle dynamics and shift quality of the three degree-of-freedom power shift hybrid transmission.The research work can be summarized as the following points:By taking a three degree-of-freedom power shift hybrid transmission for the study,the paper describes the structure characteristic and function characteristic of the three degree-of-freedom power shift hybrid transmission.The power flow,the gear arrangement,the sequence of power shift and the synchronizer arrangement are focused on.The paper analyzes the structural advantage by comparing the speed of left-off synchronizer and the inertia during the gear shift.The dynamic characteristic is analyzed by calculating the maximum speed,acceleration time and the maximum gradeability.The paper also puts the quality of power shift as the research object.The evaluation of the shift quality is introduced in order to provide the basis for the study on the shift quality of the three degree-of-freedom power shift hybrid transmission.The paper analyzes the shift control process by analyzing the mechanical and electrical power shift.In order to verify that the three degree-of-freedom power shift hybrid transmission can improve the shift quality,the performance and comfort of vehicle,a simulation platform of the shift process based on Matlab/Simulink is bulit.The simulation platform focuses on the synchronizer model and the clutch model.The paper studies the shift schedule of the three degree-of-freedom power shift hybrid transmission.Two parameters optimal dynamic shift schedule of the multiple driving modes is study.Because state of charge(SOC)has an impact on the working state of the motor,the paper studies the regular of the gear selection when the motor generated the power and the braking energy recovery strategy.In order to verify the regular and the strategy,the paper built a simulation platform of the vehicle based on Matlab/Simulink.The paper simulation analyes the regular and the strategy under different operating conditions based on the simulation platform.