A weighted multi-scale morphological gradient filter for rolling element bearing fault detection

► The weighted multi-scale morphological gradient filter (WMMG) can depress the noise at large scale and preserve the impulsive shape details at small scale. ► The WMMG can extract the impulsive components from a raw vibration signal with strong background noise. ► The WMMG requires low computation cost and is very suitable for on-line condition monitoring of bearing operating states.