An abnormality diagnostic method executes causing the feed axis to perform an axis operation in a predetermined diagnosis condition to obtain servo information according to a control of the servomotor, performing a frequency analysis on the obtained servo information, obtaining a damage frequency generated while the feed axis whose bearing is damaged performs the axis operation, from a result of the frequency analysis, and comparing the obtained damage frequency with a predetermined threshold to determine a presence/absence of an abnormality. In the determining, before the damage frequency is compared with the threshold, a determination whether a vibration frequency of the bearing interferes with a vibration frequency generated while a rolling element passes through a nut of the ball screw or not is performed, and the comparison is performed by setting the respective thresholds that are different in a case of the interference and a case of no interference.

In a machine tool, when machining is in a steady zone, a rotation phase of a main spindle at the time of measurement in the N-th sampling is calculated, and the calculated rotation phase and the measurement value are recorded in a recording section so as to be associated with each other. The measurement and calculation of the rotation phase of the main spindle at the time of each measurement are continued for plural times of rotations of the main spindle, and thus the measurement values are obtained at various rotation phases, whereby change in drive force during one rotation of the main spindle is finally calculated.

Information is collected from a management target device having a drive unit such as a machine tool, and this collected information is more practically used. An information collection device includes a collection unit that collects, from management target devices having a drive unit, operating state information which is information indicating an operating state of the management target device while operating accompanying movement of the drive unit; and a comparison unit that extracts a plurality of sets of information matching in a predetermined condition from the operating state information thus collected, and outputs a comparison result of the plurality of sets of information thus extracted.

A device, system, method, business method, and process of monitoring at least one machine tool including: determining a target signal of a component of the machine tool when performing a work step on the basis of at least one pre-definable or predefined reference number; detecting a current signal of the component of the machine tool when performing the work step; detecting a deviation of the target signal from the current signal; and generating a deviation signal. The deviation signal includes a piece of information about the component, the machine tool, and/or the deviation. The device, system, method, business method, and process of monitoring at least one machine tool further includes transferring the deviation signal as a new data set to an externally accessible storage unit that is separate or separable from the machine tool.

A method for anomaly detection in a cutting machine with a spindle that is driven by an electric motor, wherein the method includes determining an electric power consumption of the motor during a working cycle of the machine, dividing the working cycle into time windows, determining, for each time window, whether the spindle was cutting and/or idling based on associated electric power values, determining median and expected deviation of electric power values for cutting and idling operation over the sequence of time windows, and determining an anomaly if electric power values during cutting or idling exceed a predetermined relationship to the corresponding median and expected deviation values.

In a machine tool, when machining is in a steady zone, a rotation phase of a main spindle at the time of measurement in the N-th sampling is calculated, and the calculated rotation phase and the measurement value are recorded in a recording section so as to be associated with each other. The measurement and calculation of the rotation phase of the main spindle at the time of each measurement are continued for plural times of rotations of the main spindle, and thus the measurement values are obtained at various rotation phases, whereby change in drive force during one rotation of the main spindle is finally calculated.

A method for determining a dynamic response of a machine having at least one axis, including performing a measurement run for each axis of the machine over an entire work area of each respective axis, capturing and recording data associated with each measurement run, determining a time-frequency representation of recorded data using a data processing unit, and analyzing the time-frequency representation or a related representation using an image processing algorithm.