| CPC B25J 19/06 (2013.01) [B25J 9/1633 (2013.01); G01L 5/0061 (2013.01); G05B 23/0232 (2013.01)] | 18 Claims |
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1. An abnormality detection device comprising:
a sensor installed in an articulated robot having at least one joint axis, the sensor being configured to detect a torque value or an acceleration value related to the at least one joint axis,
a computer including a processor and a storage, the computer being configured to be communicably connected to a user interface and communicably connected to the sensor,
the computer being configured to
acquire a plurality of detection values from the sensor and store the plurality of detection values as time-series data,
read a portion of the time series data corresponding to a prescribed period,
detect an abnormality of the robot based on the portion of the time-series data by executing a first abnormality detection algorithm to calculate an integrated value and detecting the abnormality based on the integrated value, and
control a user interface to report the abnormality detected to a user by causing the user interface to display a warning or sound an alarm,
the first abnormality detection algorithm being configured to execute a plurality of operations with respect to the time series data at each of a plurality of specific times within the prescribed period, each of the plurality of specific times corresponding to a detection value among the plurality of detection values, the plurality of operations including:
determining whether the detection value corresponding to the specific time has increased or decreased with respect to a detection value corresponding to a prior time occurring a set period of time prior to the specific time,
assigning a first numerical value as a defined numerical value when the detection value corresponding to the specific time has increased with respect to the detection value corresponding to the prior time such that a difference between the detection value corresponding to the specific time and the detection value corresponding to the prior time is greater than a first reference value, or assigning a second numerical value as the defined numerical value when the detection value corresponding to the specific time has decreased with respect to the detection value corresponding to the prior time such that the difference is smaller than a second reference value that is equal to or smaller than the first reference value, each of the first numerical value and the second numerical value being a fixed preset value with the first numerical value being different from the second numerical value, the first numerical value being different from the first reference value, and the second numerical value being different from the second reference value, and
storing the first numerical value or the second numerical value as a defined numerical value in association with the specific time,
the first abnormality detection algorithm generating another set of time-series data made up of the defined numerical values stored for each of the plurality of specific times,
the first abnormality detection algorithm further including
calculating the integrated value by integrating the plurality of defined numerical values over a prescribed integration time and
detecting the abnormality of the device based on the integrated value.
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