Research On Diesel Engine Control Method Based On Electro-mechanical Transmission System

Hybrid electric vehicles(HEVs), which combine the advantages of electric vehicles and conventional vehicles, have raised wide public concern in the civil areas. In the military fields, all electrical combat vehicles(AECVs) stand for the future direction. Electro-mechanical transmission(EMT), similar with the hybrid drive system of power split, is a basic transmission form of the AECVs. In this paper, electro-mechanical transmission systems and turbocharged diesel engine was regarded as research object, and for the characteristics of Electro-mechanical transmission system, diesel engine control strategy was studied.Firstly, the composition of electro-mechanical transmission system and the definition of different modes were introduced, and according to the relationship of speed and that of torque in simple planetary gears, and the structure characters of four planet rows, this paper derived formulas about the speed relationship of the motor A, and motor B, enter axis, and output axis, and derived formulas about the torque relationship of that in EVT1_L mode, EVT1_H mode, and EVT2 mode, respectively.Secondly, this article established the vehicle model of Electro-mechanical transmission system, in which, acoording to study the engine control strategy, the mean-value model of the engine and the model of engine controller were established. With Matlab/Simulink model library, this paper established simulation models of mechanical transmission system and electric drive system, and also described the driver models and environmental models. And the vehicle basic control algorithm for Electro-mechanical transmission system was also studied in this paper, including the engine start control, mode switch control, power distribution control based on the rules and dynamic coordinating control.In addition, for meeting energy management target that are electric power supplying performance, driven performance, and fuel economic performance in the vehicle of Electro-mechanical transmission system, and resolving electric power balance problem in high electric power conditions, this paper carried out muliti-objective( electric power supplying performance, and driven performance, and fuel economic performance) in power-flow distribution optimization strategy and electric power balance strategy, which both composed energy management strategy in this article. The paper also designed high electric power conditions and verify the electric power balance strategy under the analysis of offline simulation.Finally, as aforementioned studies, this article proposed 3 kinds of engine control strategies based on Electro-mechanical transmission system, which are " torque control + speed regulation", " speed control with load feed forward + torque regulation", and " fuzzy-PID speed control with load feed forward + torque regulation", respectly. According to simulation analysis, " torque control + speed regulation" control strategy got better control effect than others, and this paper verify this control strategy in test bench.