Abstract: The object is to aim at the reduction in the influence of noises in an output of an AE sensor in a working machine. In a working system comprising a working device for working a work W by causing a tool 14 to come into contact work W, an AE sensor 21, and an AE signal processing section 22 for processing an AE signal output from the AE sensor, AE signal processing section 22 comprises an A/D converter 33 for converting an AE signal into a digital signal, a frequency analysis section 34 for calculating the frequency characteristics of a digital AE signal, storage sections 35, 37 for storing the frequency characteristics when the tool is not in contact with the work or tool dresser as non-contact frequency characteristics, and a difference calculation section 35 for calculating a difference between the frequency characteristics of the detected digital AE signal and the non-contact frequency characteristics.

Abstract: The object is to aim at the reduction in the influence of noises in an output of an AE sensor in a working machine. In a working system comprising a working device for working a work W by causing a tool 14 to come into contact work W, an AE sensor 21, and an AE signal processing section 22 for processing an AE signal output from the AE sensor, AE signal processing section 22 comprises an A/D converter 33 for converting an AE signal into a digital signal, a frequency analysis section 34 for calculating the frequency characteristics of a digital AE signal, storage sections 35, 37 for storing the frequency characteristics when the tool is not in contact with the work or tool dresser as non-contact frequency characteristics, and a difference calculation section 35 for calculating a difference between the frequency characteristics of the detected digital AE signal and the non-contact frequency characteristics.

Abstract: The object is to make it possible to check the operating state such as degradation in sensitivity of an AE sensor when it is used actually. There are provided an AE conversion element 41, a pulse signal transmitter 42 for applying a pulse signal to the AE conversion element through the output passage of an AE signal from AE conversion element 41, a receiver/processor 43 for converting the AE signal into a digital signal and calculating the frequency characteristics by processing the digital signal, a reference frequency characteristic storage section 44 for storing the frequency characteristics of the AE signal of the AE conversion element in the reference state as reference frequency characteristics, and a comparator 45 for comparing the frequency characteristics of the AE signal calculated in response to an operation check request signal with the reference frequency characteristics.