机械工程学报
機械工程學報
궤계공정학보
CHINESE JOURNAL OF MECHANICAL ENGINEERING
2014年
16期
155-161
,共7页
韩宗奇%王立强%王瑞林%王华宾
韓宗奇%王立彊%王瑞林%王華賓
한종기%왕립강%왕서림%왕화빈
轮速信号%傅里叶变换%频域滤波%信噪比
輪速信號%傅裏葉變換%頻域濾波%信譟比
륜속신호%부리협변환%빈역려파%신조비
wheel speed signal%fast Fourier transform(FFT)%frequency domain filtering%signal-to-noise ratio
汽车在高速行驶时，轮速传感器信号的信噪比降低以及由轮速信号计算数据的发散性是汽车安全有效控制的难题。将轮速传感器信号用快速傅里叶变换(Fast Fourier transform, FFT)到频域，在频域里研究真实信号和噪声的波形特点。在频域里，真实信号频域范围很窄但能量很强；而噪声频率范围很宽但能量很低。据此提出用FFT与傅里叶逆变换(Inverse fast Fourier transform, IFFT)处理轮速信号的新方法。将采集的轮速信号进行FFT变换，在频域里保持信号的能量不变，用曲线拟合的方法将噪声的能量进一步降低。经如此频域“滤波”后，再通过IFFT逆变换获得时域的真实信号。经过此FFT/IFFT处理后的轮速信号的信噪比(Signal-to-noise ratio, S/N)显著提高。在间接式轮胎气压监测系统(Tire pressure monitoring system, TPMS)的实车道路试验中，分别对轮速信号进行电路滤波、卡尔曼滤波与FFT/IFFT滤波效果进行比较，FFT/IFFT处理轮速信号能有效消除噪声，效果最好。
汽車在高速行駛時，輪速傳感器信號的信譟比降低以及由輪速信號計算數據的髮散性是汽車安全有效控製的難題。將輪速傳感器信號用快速傅裏葉變換(Fast Fourier transform, FFT)到頻域，在頻域裏研究真實信號和譟聲的波形特點。在頻域裏，真實信號頻域範圍很窄但能量很彊；而譟聲頻率範圍很寬但能量很低。據此提齣用FFT與傅裏葉逆變換(Inverse fast Fourier transform, IFFT)處理輪速信號的新方法。將採集的輪速信號進行FFT變換，在頻域裏保持信號的能量不變，用麯線擬閤的方法將譟聲的能量進一步降低。經如此頻域“濾波”後，再通過IFFT逆變換穫得時域的真實信號。經過此FFT/IFFT處理後的輪速信號的信譟比(Signal-to-noise ratio, S/N)顯著提高。在間接式輪胎氣壓鑑測繫統(Tire pressure monitoring system, TPMS)的實車道路試驗中，分彆對輪速信號進行電路濾波、卡爾曼濾波與FFT/IFFT濾波效果進行比較，FFT/IFFT處理輪速信號能有效消除譟聲，效果最好。
기차재고속행사시，륜속전감기신호적신조비강저이급유륜속신호계산수거적발산성시기차안전유효공제적난제。장륜속전감기신호용쾌속부리협변환(Fast Fourier transform, FFT)도빈역，재빈역리연구진실신호화조성적파형특점。재빈역리，진실신호빈역범위흔착단능량흔강；이조성빈솔범위흔관단능량흔저。거차제출용FFT여부리협역변환(Inverse fast Fourier transform, IFFT)처리륜속신호적신방법。장채집적륜속신호진행FFT변환，재빈역리보지신호적능량불변，용곡선의합적방법장조성적능량진일보강저。경여차빈역“려파”후，재통과IFFT역변환획득시역적진실신호。경과차FFT/IFFT처리후적륜속신호적신조비(Signal-to-noise ratio, S/N)현저제고。재간접식륜태기압감측계통(Tire pressure monitoring system, TPMS)적실차도로시험중，분별대륜속신호진행전로려파、잡이만려파여FFT/IFFT려파효과진행비교，FFT/IFFT처리륜속신호능유효소제조성，효과최호。
When a car is running at high speeds, the signal-to-noise ratio from the wheel speed sensors is reduced, and the data calculated by the wheel speed signal are emanative, which is the problem for the safety and effective control of a car. The wheel speed sensor signals are transformed into the frequency domain using fast Fourier transform(FFT), and the characteristics of the waveforms of the true signal and noise are studied in the frequency domain. The frequency range of true signals is very narrow and its energy is very strong, but the noise spectral range is very width and its energy is very weak. According to this difference, a new method is given to process wheel speed signals using FFT and IFFT. Wheel speed sensor signals are transformed into frequency domain with inverse fast Fourier transform(FFT). In frequency domain the energy of signals keeps unchanged, and that of noise is reduced with the method of polynomial fitting. After so“filtering”processing, the curve of spectrum wave is transformed back into time domain with IFFT to obtain real signals. The S/N of signals is significantly improved with this FFT/IFFT processing. In tire pressure monitoring system(TPMS)test in road, the effects of three filtering methods are compared which are electronic current filter, Karman filter and FFT/IFFT filter. The test indicates that the method of FFT/IFFT filter can get rid of noise efficiently, and its effect is best.
