A New Method For Measuring The Rotary Speed Of A Car’s Engine Based On The Vehicle Vibration And The Discrete Spectrum Correction Theories And Its Implementation

With the rapid development of the automotive and increasing storage, detectingtest and diagnosis of vehicle arises, using the modern equipment, to adapt to themodern automotive technology. Motor testing is one of the important automotivetrails, and rotating speed is an important parameter, and also reflects the operatingstatus of a car. It is very significant to test instant speed in combustion motor.Using discrete spectrum correction theory in the high accuracy measurement ofengine speed, this paper proposes a new way of testing speed upon vibration anddiscrete spectrum correction theory which makes use of the theory of Four EnergyCentrobaric Orthosis and cepstrum. It can correct rotating speed taking advantage oforder analysis, and resolve the problem that cannot exactly measure the rotating speedduring the time of engine start and speeding up. According to the new algorithm, itputs the new algorithm into simulation analysis, in a signal-to-noise ratio is0dB ofwhite noise, the maximal relative error theory of the rotational speed is only0.5%between order time tracking speed and obtain speed, the error is very small, it verifiesthe correctness of the new algorithm. On the bench test and four typical vehicles tests,the results demonstrate that the new algorithm is accuracy. At last, it designs theengine speed system, and chooses TMS320F28335DSP of TI company as controller,using C++to realize the program,and it realizes the engine speed measurement inDSP.