| CPC G01M 13/021 (2013.01) [B25J 19/0095 (2013.01)] | 13 Claims |
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1. A failure diagnosis system comprising:
a mechanical apparatus including:
a motor;
a reduction gear driven by the motor, the reduction gear being configured to slow down rotation power of the motor and transmit the rotation power to an operating part of the mechanical apparatus;
an encoder configured to detect a rotational position of the motor; and
a sensor configured to detect a motor current supplied to the motor, the motor current being one of load current of the motor and a current value having a correlation with the load current;
a processor programmed to:
acquire rotation speed data of the motor based on a signal from the encoder;
identify an acceleration/deceleration period during which operation of the mechanical apparatus accelerates and/or decelerates based on the acquired rotation speed data based on the signal from the encoder;
generate a group of time series rotation speed data by sequentially sampling the portion of the acquired rotation speed data from the identified acceleration/deceleration period acquired based on the signal from the encoder;
acquire a signal indicating the motor current from the sensor;
generate a group of time series motor current data by sequentially sampling the portion of the acquired signal indicating the motor current from the sensor from the identified acceleration/deceleration period;
make the group of time series motor current data correspond to the group of time series rotation speed data, conduct a frequency analysis of the group of time series motor current data, and generate frequency spectra of the group of motor current data corresponding to the group of time series rotation speed data;
extract a peak value of a current amplitude of the motor current within a particular frequency range corresponding to a specific frequency of the reduction gear, from the frequency spectra of the group of motor current data; and
make a determination of whether the reduction gear indicates a sign of failure induced by abrasion based on a comparison between a given amplitude threshold and the extracted peak value in a change in frequency spectrum of the motor current with respect to a change in a rotation speed of the motor during the acceleration/deceleration period; and
an outputter that outputs a result of the determination of whether the reduction gear indicates the sign of failure.
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