Research On Control Strategy Of The Double Synchronized Gear-shift For The Parallel Hybrid Electric Bus

Due to the energy crisis and environmental protection problems are becoming more and more serious causing by the traditional automobile, the electric vehicle has become the developing direction of the future automobile industry. The Hybrid Electric Vehicle (HEV) overcomes the problems of the short service life, the low energy density and poor life, which are the problems existing in pure electric vehicles battery, and is the main way of developing the electric vehicle. Because of the HEV integrates the engine and motor as the main power components, and increases the difficulty of the vehicle control. Therefore, this article separately studies the HEV energy management control strategy and the transmission shift control strategy.First of all, choosing the demonstration operation of the double-axis parallel hybrid electric bus as the research object, based on the research of autonomous development of electric bus remote monitoring and data collection system collected the real data of vehicle, and analyze the characteristics of the engine, motor, battery and transmission.Then, this paper established the simulation model of the hybrid electric bus, divides the work states of HEV for different working modes, optimizes the working range of engine and motor working condition by the electric auxiliary function, reduce the vehicle fuel consumption, and build the control model of every kind of work condition by using the simulation modeling tools. Compared with the numerical calculation results of the data acquisition system and the results of real vehicle statistics, the result shows that the control platform and control strategy of building can actually reflect the vehicle’s fuel economy.Finally, in the transient control condition for the shifting difficult problem caused by the rotational inertia of the transmission input shaft in automated mechanical transmission (AMT) of the parallel hybrid electric bus, this paper presents the control strategy of the double synchronized gear-shift. Through the coordinated control the torque of the motor and engine to shorten the time of power interruption in the shifting process; Match the target speed of the motor to reduce the shifting shock by keeping the transmission input shaft torque in zero when shifting; Match the target speed of the engine to reduce the speed difference of the friction plate and the wear of the clutch and the loss of power when shifting.Through the above study, the vehicle control model set up in this paper can realize the engine and motor torque distribution, braking energy recycling, keep the battery charged state of balance and other functions, reduce vehicle fuel consumption, verified the effectiveness of the platform, has practical significance to speed up the development of HEV. The proposed double synchronous transmission control method can reduce the power interruption time shift process, reduce the clutch wear, smooth shifting process, improve the performance of the clutch and the transmission and the vehicle comfort and performance.