Research On Parallel Hybrid Electric Bus Transmission System Control Technology

The invention of the car has brought great convenience to human life, but also caused a big problem at the same time, such as environmental pollution and energy crisis. Hybrid cars get the favors of the major manufacturers because of its excellent fuel economy and mission performance. Clutch and gearbox are the key components of a single-shaft parallel hybrid electric bus transmission system, the stand or fall of its control performance will not only have a huge impact on the mode switch process, and on the shift quality, also have a decisive role on the vehicle dynamic peace. Combined with the corpus of 863 "hybrid commercial vehicle development research", the mode switching control and shifting process of a single-shaft parallel hybrid electric bus with AMT are studied. Several aspects are researched as follows:1. In order to study the mode switching control strategy and the shift process control strategy, driving dynamic of a single-shaft parallel hybrid electric bus is analyzed and simulation platform of a single-shaft parallel hybrid electric bus powertrain is established. The model includes the ICE model, permanent magnet synchronous motor model, transmission model, battery model, clutch model, driver model and vehicle model.2. The mode switching process with the clutch action is to realize the power of the engine to be transmitted to the wheel through the engagement and separation of the clutch. Firstly, we introduced the clutch actuating mechanism and build the clutch actuator motor model. On this basis, Fuzzy Adaptive PID control strategy is developed to complete the process of mode switching.3. The driveline system of a single-shaft parallel hybrid electric bus has multiple power sources including the engine and the electrical motor. So the coordination control of each part is particularly important in the process of gear shifting and the mode switching of the vehicle. In the dynamic coordination of the mode switching including the control of the clutch, considering that the responds of motor speed and the motor torque are very speedy, we put forward a mode switching control strategy based on the torque compensation of the electrical motor, so the engagement and the disengagement of the clutch has a smaller impact. In the process of dynamic shifting coordination, to estimate the load we setup a neural network controller for the shifting actuator, the result shows that control accuracy of the shifting actuator and the shifting probability are improved obviously.4. In order to improve the vehicle’s power and economy. We study economy and power shift schedule in the various operating mode in this paper, and proposed comprehensive shift schedule based on the driver’s intention which identified by the fuzzy control algorithm.