“…Likewise, an exponential Wiener process is used to predict the RUL [112]. BPF [67,71], OMA [51,101,100] Preload loss -Vibration [52,102,103], force [104], Hall sensor [52] EMA [102,103], OMA [52], analytic [104] Backlash Rotary encoder [76,83,[105][106][107], linear encoder [76,108,109,105,106], NC data [105,110] -Error [83,108,109,105], EMA [110], algorithm [107], analytic [76,105], adaptive estimation [106]…”