Research of acoustic emission signal enhancement based on Discrete Fractional cosine Transform

The new method for discrete fractional cosine transform is proposed, and it was introduced in acoustic emission signal enhancement. According to the characteristic of rub-impact acoustic emission (AE) signal from rotating machinery, two constructions are proposed to enhance AE signal, which based on three cycles discrete fractional cosine transform (FDCT3), and modified transform (MFDCT3). The experiment date was rub impact AE signals sampled from rotating test stand, Gaussian white noise and non-stationary noise were added to simulate the real AE signal which polluted seriously by noise. Then, FDCT3 and MFDCT3 were used into de-noising and AE recognition.The result shown that FDCT3 and MFDCT3 are effective at the de-noising, and those performance is better than DCT.