A numerical control device of a machine tool recognizes a failure of a vibration detection unit in a relatively short time to minimize damage to functions achieved using the vibration detection unit. A program interpreting unit interprets an automatic tool exchange operation, and a storage unit is instructed to store vibration information V(x) from the vibration detection unit. After the automatic tool exchange operation is finished, the storage unit is instructed to stop storage. When none of the vibration information V(x) stored in the storage unit exceeds a prescribed vibration level, a vibration information analysis unit determines abnormality of the vibration detection unit.

A management system including a network, plural manufacturing cells connected to the network, and a management device that is connected to the network and manages the plurality of manufacturing cells, in which the manufacturing cell includes: a machine tool; and a control device that controls the machine tool, analyzes a vibration state of a spindle positioning shaft of the machine tool, and sends an analysis result via the network; in which the management device includes: a communication unit that receives the analysis result sent by the control device; and a detection unit that compares the analysis results thus received, and compares vibration states of the machine tool of each of the manufacturing cells, so as to detect spindle failure of any of the machine tools; and in which the communication unit, in a case of the detection unit detecting the spindle failure, sends a failure signal via the network.

The present disclosure is directed toward a diagnostic method for a spindle arm of a machine. The method includes rotating the spindle arm of the machine at a first rotational speed, and acquiring, from an accelerometer, data indicative of a vibrational response of the spindle arm operating at the first rotational speed. The accelerometer is disposed along the spindle arm. The method further includes converting the vibrational response to a frequency based response to obtain a first frequency response, determining whether an amplitude of the first frequency response exceeds a diagnostic threshold, and performing a designated correction on the machine in response to the frequency response exceeding the diagnostic threshold.

Compensation for an external disturbance can be applied without requiring a model of the external disturbance, and, particularly, the amount of control can be accurately predicted even when the amplitude of a waveform representing changes in a predicted error with respect to time is not constant with respect to time in a case in which the predicted error that is an error between an actually-measured value of the amount of control of a control target and a predicted value periodically changes. A controller compensates a predicted value of the current amount of control using a predicted error of a previous period by taking changes in the amplitude of a waveform representing a predicted error that is an error between an actually-measured value of the amount of control and a predicted value into account.

A method to control a power tool including the method steps: specifying the rotational speed of the drive at a first value, measuring a first amplitude of a signal, filtering the signal within a frequency range, measuring a second amplitude of the filtered signal, reducing the rotational speed of the drive to a second value if the first amplitude exceeds a first quantity and if the second amplitude exceeds a second quantity, and incrementally increasing the rotational speed of the drive to the first value, whereby each incremental increase of the rotational speed only takes place once the first amplitude remains below the first quantity for a time interval, and the second amplitude remains below the second quantity. A power tool that uses this method, includes: a drive, an acceleration sensor a filter, and a control unit.

A method for designing cutting conditions for cutting a workpiece with a cutting tool uses design parameters, including a feed speed, an axial direction cutting amount, a radial direction cutting amount, and a cutting speed of/by the cutting tool. A deflection amount of the cutting tool is calculated from the design parameters. Then a chattering vibration occurs or not in the cutting tool is determined. Depending on the determination result, a maximum cutting thickness of the workpiece is calculated. Then a cutting temperature of the cutting tool is calculated. Then whether a tool life of the cutting tool is satisfied or not is determined. Depending on the determination result, a cutting efficiency of the cutting tool is calculated and compared with data of a cutting efficiency stored in advance. When the calculated cutting efficiency is a maximum value among the data, the design parameters are used as the cutting conditions.

A management system including a network, plural manufacturing cells connected to the network, and a management device that is connected to the network and manages the plurality of manufacturing cells, in which the manufacturing cell includes: a machine tool; and a control device that controls the machine tool, analyzes a vibration state of a spindle positioning shaft of the machine tool, and sends an analysis result via the network; in which the management device includes: a communication unit that receives the analysis result sent by the control device; and a detection unit that compares the analysis results thus received, and compares vibration states of the machine tool of each of the manufacturing cells, so as to detect spindle failure of any of the machine tools; and in which the communication unit, in a case of the detection unit detecting the spindle failure, sends a failure signal via the network.

Method for machining articles by means of a numerical-control machine tool (1) with at least one tool (2) mounted on a rotating spindle (4) and movement means (6), comprising a step i) of carrying out test machining operations on test articles using predetermined operating conditions, a step ii) of detecting at least first values relating to operating parameters of the tool (2) and/or spindle (4) and/or movement means (6) and at least second values relating to the amplitude and the frequency of the vibrations and/or the loads acting on the machine (1), a step iii) of analysing and processing the operating conditions of the first and second values to obtain optimized reference values of the operating parameters, and a step iv) of carrying out one or more machining operations on an article based on the optimized reference values. The step iii) of analysing and processing the operating conditions and the first and second values is performed by means of a process for training a software based on at least one artificial intelligence algorithm. The present invention also relates to a machine tool (1) for machining the articles.

A determination device includes an interface configured to acquire a vibration signal generated when a position of an object is switched, and a controller configured to determine a state of the object using the vibration signal.