Engine transient periodic torque simulating method of automobile transmission stand knocking test

Abstract

The invention discloses an engine transient periodic torque simulating method of an automobile transmission stand knocking test. The method comprises the following steps that 1) a throttle opening degree-rotating speed-torque model of an engine is established; 2) an inertia toque resolving module is established, an inertia torque TI is obtained, and a maximal amplitude A1 of the inertia torque is obtained; 3) an indicator diagram is drawn, and a maximal amplitude A2 of a combustion torque is obtained; and 4) a mean torque TM, the maximal amplitude A1 of the inertia torque and the maximal amplitude A2 of the combustion torque are fit, the number of cylinders in the simulated engine and the advance angle of igniting are considered, and a torsional oscillation curve of the engine is obtained, namely the total transient torque of the engine is obtained. The simulating method of the invention is high in accuracy and instantaneity and lower in computational complexity, and can satisfy high dynamic control response during transient periodic torque (torsional oscillation) simulation of the engine.

Description

technical field [0001] The invention relates to a method for simulating the performance test of an automobile engine, in particular to a method for simulating the transient period torque (torsional vibration) of an engine for an automobile transmission bench knock test. Background technique [0002] In recent years, the NVH problem of automobiles has attracted more and more attention from engineers. The periodic fluctuation of engine torque will cause torsional vibration of the drive train, which will generate noise and reduce the service life of parts. If the transmission gears are not properly designed, engine cycle torque ripple can cause transmission rattle, which can affect the NVH quality of the car. There are many disadvantages in using real engine to drive NVH test. 1) Engine fuel is flammable, and it is prone to fire and other dangerous factors during its working process. At the same time, the exhaust gas it emits is not conducive to environmental protection. 2) Th...

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Problems solved by technology

[0002] In recent years, the NVH problem of automobiles has attracted more and more attention from engineers. The periodic fluctuation of engine torque will cause torsional vibration of the drive train, resulting in noise and reducing the service life of components.

If the transmission gears are not properly designed, the engine cycle torque pulsation can cause transmission rattle, which can affect the NVH quality of the car

Carrying out NVH test with physical engine drive has many disadvantages, 1) The engine fuel is flammable, and it is easy to produce dangerous factors such as fire during its working process, and its exhaust gas is not conducive to environmental protection

2) The NVH test mainly measures the noise problem of the transmission under test, and the higher noise of the real engine in the test will affect the NVH test of the transmission

3) In the initial stage of powertrain development, usually the matching engine is also under development and testing, so it is difficult to obtain the engine as a drive to perform NVH and other performance tests on the powertrain on an indoor bench

Accurate engine models have been discussed in many literatures, such as black-box models and models based on physical structures, etc., because these models require a large amount of engine development data or detailed engine design parameters, these parameters are not easy to obtain in drive train tests, and Traditional physical models are difficult to meet the requirements of high dynamic control response when simulating engine combustion characteristics with complex mathematical calculations, so these models are not suitable for dynamic simulation of drive train benches

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