The Improvement Of The Non-steady-state Dynamic Model Of Engine

Vehicle dynamic simulation technique is a powerful tool for auto design and production. As a general technique to increase national competition, it's the international research focus for decades.The simulation technique key part is that vehicle dynamic model has RTS (real time simulation) and high fidelity. The engine is not only the source of power but also the primary NVH source of the car. So we must build a real time engine dynamic model before building a precise vehicle dynamic model.When driving the driving simulator, the driver will change the accelerate pedal and shift leveler according to the traffic conditions subconsciously, so the engine run randomly and continuously. At the same time, the working cycle of the engine is a transient course of which the periodicity is 720 degrees of the crank angle and in one working cycle, the engine output and rotator speed will change with the change of the crank angle. So only when building the transient engine model, can we supply the vehicle dynamic model with precise power and simulate the influence of the engine vibration on the vehicle dynamic with transient excitation force which the engine acts on the car body or frame.The dynamic model of the complex system can be built using multi-body dynamic theory, and there are lots of commercial soft wares like ADAMS, DADS. But multi-body programs employ nonlinear differential-algebraic equations that require iterative solution methods that run slowly and with variable time steps. It usually wastes some weeks to solve one condition. So this kind model is not suitable for full vehicle dynamic design and optimization. So the dissertation tries to build a non-steady engine dynamic model that can real-time simulate and is suitable for our Driving-Simulator. The main contents and conclusions of the dissertation are as follows:(1) The development of dynamic model of engine and the dynamic...