2004 年 70 巻 691 号 p. 664-670
Acoustic diagnosis system with condenser microphone has some attractive characters what is more cheaper for cost of devices of sensor, is not keeping contact with machinery components and is wide band range on frequency compared with piezoelectric accelerometers. This paper proposes a method to do condition diagnosis about strong non stationary signal generated by operating rotating machineries which are rolling bearings. Especially, a signal processing technique in order to eliminate non stationary noises including operating sound is described by adopting locally stationary AR model a kind of system identification. Further, the optimum order of locally stationary AR model is determined from presumption of division terms. The effectiveness of this method has been identified by experiment based on a rotary simulator device on rolling bearings.