Coupling Mechanism Design And The Mode-switch Control Of Full Hybrid Electric Vehicle

In calling "low carbon, green, environmental protection" era, not only requirespeople to pay attention to energy conservation, and pay more attention to theenvironmental protection, in order to realize the sustainable development of society.Compared with the traditional automobile, new energy vehicles have importantsignificance to solve the world resources and serious environmental problems, becauseit has the advantages of low energy consumption, low pollution. Since no breakthroughin key technology of fuel cell vehicle and pure electric vehicle, to develop hybridelectric vehicle has become the most effective solution to solve the problem.Hybrid coupling mechanism is the core of the hybrid electric vehicle parts, designof a compact structure, work mode is complete, easy to control the hybrid coupledmechanism is a key to the success of a hybrid car. In this article, through analysis ofdomestic and foreign existing dynamic coupling mechanism used in hybrids, designed anew type of coupling mechanism. Then according to the design of hybrid system, setthe mode switch control strategy, simulation and bench test, to determine the reliabilityof the coupling mechanism.Based on the single motor, the CVT transmission type heavy hybrid cars as theresearch object, to drive alone by pure electric mode switch to the engine controlstrategies and methods of the dynamic process is studied. When to start the engine, ISGmotor in driving the vehicle moving at the same time must provide proper torque forstarting the engine. This process involves the clutch engaging process, must controlcoordination of different parts, so that the motor star engine process could be completedrapidly and smoothly. In this paper, the research contents mainly embodied in thefollowing aspects:①First, this paper introduces several kinds of typical hybrid power couplingmechanism, the advantages and disadvantages of part of the coupling system areanalyzed. Then according the function of the hybrid system, designed a new kind ofcoupling mechanism, and the working mode of hybrid power system of the couplingcharacteristics were analyzed.②I made a part of the coupling mechanism design, including the couplingmechanism of the wet type multi-disc clutch, pressure plate, return spring and the inputshaft and output shaft components design, checking of bearing and spline, and3d modeling.③The hybrid electric vehicle structure was analyzed first, dynamic engine model,motor model, wet type multi-disc clutch model, the coupling mechanism model, speedmodel and a forward dynamics model was built.④In the mode switching control strategy, first of all, this paper introduces themethod to realize the control strategy. Divide the hybrid electric vehicle operation area,and determine the boundary of operation modes and the torque of power sources.Analyze the evaluation criteria of the mode switching processes; design the fuzzycontroller about the clutch engagement process; based on energy management developthe control strategy of mode switching processes.⑤In order to verify that the hybrid system can smoothly realize the process, buildthe vehicle and control strategy simulation model based on Matlab/Simulink, anddevelop simulation study for mode switching processes of the hybrid electric vehicle. Indynamometer load and different speed, different slope under different conditions,develop the bench test for the process of motor start engine. The results show that withusing the coordinated torque control strategy can effectively reduce the torquefluctuation and jerk value of mode switching processes, and improves the vehicledrivability.