Tire-Road Contact Stress Signal Denoising Method Based On CEEMDAN And Wavelet Thresholding

Measuring the contact stress between tires and road surfaces is the basis for studying the mechanism of road damage,road service life and vehicle driving safety.In the actual stress measurement process,the tire-way contact stress signal often contains a lot of noise due to factors such as the experimental environment and circuit noise.Therefore,in order to accurately analyze the contact stress between the tire and the road surface,it is particularly important to denoise the collected tire-road contact stress signal.The main work of this article is as follows:Firstly,the tire-road contact stress signal containing random noise is simulated by using the tire-road contact load experimental simulation platform,and the denoising effect of hard and soft thresholding functions under different wavelet basis functions and wavelet thresholds is studied for the noisy tire-road contact stress signals in X,Y and Z directions based on wavelet thresholding algorithm.The results show that the soft thresholding with heuristic thresholding works best for all three directions of tire-road contact stress signals,and the optimal wavelet basis for denoising the X-direction signal is sym5,and the optimal wavelet basis for denoising the Y-and Z-direction signals is sym8.Second,for the problems of modal confounding in empirical modal decomposition(EMD)and noise residual in complete empirical modal decomposition(EEMD),the complete ensemble empirical modal decomposition with adaptive noise(CEEMDAN)method is introduced to denoise the simulated signals.The results show that CEEMDAN has good adaptivity in processing noise-laden tire-road contact stress signals and can effectively suppress random noise,but some useful information will be lost.Finally,based on the characteristics and shortcomings of wavelet thresholding and CEEMDAN,this paper proposes a joint denoising method combining CEEMDAN and wavelet thresholding.The simulation results show that the joint denoising method has better denoising effect than wavelet threshold denoising method or CEEMDAN denoising method alone.Meanwhile,the measured tire-road contact stress signal is processed,and the wavelet threshold method,CEEMDAN method and the joint denoising method are used to denoise it respectively.The experimental results show that the signal-to-noise ratio of the tire-road contact stress signal obtained by the joint denoising method is the best and the root-mean-square error is the lowest,which indicates that the joint denoising method has better denoising effect on the tire-road contact stress signal.