Analyze The Ignition Signal Of Engine Based On Wavelet Transformation

With the rapid development of microelectronics, computer and control technique, it has been a new tendency in the automobile electronic technique to utilize electronic control techniques to raise engine performance, reduce energy consumption and meet the increasingly strict emission regulations. The power and the emissions are one of improving entire vehicle performance core questions, but the electronic fuel system of engine and the ignition control system are key installments which decide emissions and the power. In the test system of automobile ignition, the reliability and consistency of test system are not to be ensured because of electromagnetic interference in system of automobile ignition and dispersivity of products. On this issue, the paper discourse that process, analyze spark electric current signal and element of test system.The main contents of this paper are the followings:(1)Compare the advantages and disadvantages of Fourier transform short-time Fourier transform and wavelet transform in signal processing and analysis. Analyze all kinds of characteristics of function of the wavelet and applicability of the wavelet transform in the ignition system test.(2)Because there is electromagnetic interference in system of automobile ignition, need to use the wavelet transform to de-noise spark electric current signal. It has avoided weak point of the traditional filter method: smooth sharply changed the peak ingredient of signal, lost the important information which these point had.(3) Test several parametrics of engine system of ingite: the first, be to require that get and analyze characteristic points of ingite signal. Use the relationship between wavelet transformation and the singularity of signal to find out characteristic points of the spark electric current signal accurately.(4)Discourse that the elements of test system and the application of de-noise algorithm and getting characteristic points in the test system.Test shows that test system can be able to get the parameter of signal accurately; especially there is good robustnessthe in the different models and states.