Pattern Recognition Of Abnormal Sound In The Rack And Pinion Steering Gear

The selection of this paper’s topic is from actual subject,the paper made a pattern recognition research about pinion and rack steering gear’s abnormal sound.First of all,it analyzed the structure of pinion and rack steering gear and its stress states in the C – EPS,determined the reason of abnormal sound and formulate research plan.Then the paper measured the vibration acceleration signal on the floating support nut of pinion and rack steering gear that carried on a test bed in factory,and completed these works of collection signal.It established steering gear sound waveform criterion which based on the measured vibration signal waveform analysis,and established the correlation coefficient of sound recognition criterion through the correlation analysis of vibration signal.Then use the wavelet analysis method to conduct the thorough research to the steering gear vibration signals.The paper use three different kinds of wavelet,dmey、coif1、sym2,to analyze the steering gear vibration signals.This paper used relative wavelet energy method to extract the three relative wavelet energy eigenvector of wavelet and established wavelet recognition criterion.It constructed the above three kinds of wavelet kernel function of support vector machine through vector machine(SVM)method,determined the sound recognition scheme and classification threshold by calculating and examined recognition rate through the recognition of the measured signal.This paper drew two conclusions: One is the steering gear sound waveform identification criterion and correlation coefficient of identification criteria can be used for artificial identification,but it is best to use wavelet recognition method for the abnormal sound of pinion and rack steering gear intelligent identification.The second is that dmey wavelet has the highest recognition rate in the use of three kinds of wavelet.The paper recommend using the relative small wavelet energy feature vector generated by this wavelet as the basis in the support vector machine(SVM).