Patent ID: 8997472
Filing Date: 2015-04-07
Classification: E02F,F04B,G05B

Abstract:
1. An abnormality detecting device for a construction machine equipped with a plurality of sensor means placed at a plurality of parts of the construction machine, the sensor means detecting a plurality of related physical states and outputting a plurality of pieces of sensor information, comprising: correlation coefficient calculation means which receives the plurality of pieces of sensor information outputted from the plurality of sensor means, generates time-series physical state information in a predetermined period on each of the plurality of pieces of sensor information corresponding to the plurality of sensor means, and calculates a plurality of correlation coefficients between separated pieces of time-series physical state information on each of the plurality of pieces of sensor information; correlation coefficient comparison means which compares the correlation coefficients calculated by the correlation coefficient calculation means and calculates the degree of difference of each correlation coefficient from other correlation coefficients; and abnormality judgment means which judges that when the degree of difference calculated by the correlation coefficient comparison means exceeds a preset value, an abnormality has occurred to a part related to the corresponding sensor means, wherein assuming that Xi and Xj (i,j=1, . . . , n) (n: the number of the sensor means supplying the plurality of pieces of sensor information) represent two pieces of time-series physical state information arbitrarily selected from the time-series physical state information generated by the correlation coefficient calculation means, Xi(t) and Xj(t) represent the measurement values of Xi and Xj at time t and ρ(i, j) represents the correlation coefficient between the input values Xi and Xj between time t=0 and time t=Δt(T−1) (Δt: the time between measurements, T: the number of measurements), the correlation coefficien ρ(i, j) is calculated using averages μi and μj and standard deviations σi and σj according to the following equation: