TOOL MACHINE CONTROL

Abstract

Control (100) for a machine tool, which includes: a sensor (170) that retrieves measurements containing information on the voltage, current, frequency, speed and acceleration of a power supply (120) of a peripheral device (120, 160) from the machine tool; an anomaly detection unit (180) that detects an anomaly in relation to the operating state of the machine tool and / or the peripheral device (120, 160) and outputs a signal indicating the anomaly and sensor measurements in which the detection of the anomaly was determined; and a diagnostic unit (195) that automatically selects measurements relating to the anomaly from among the sensor measurements and estimates and automatically diagnoses the multiple factors of the anomaly.

Description

BACKGROUND OF THE INVENTION Area of ​​the invention

[0001] The present invention relates to a control system for a machine tool. Related technology

[0002] A conventional control system is known that issues a warning when a malfunction occurs during the operation of a machine tool. If an anomaly occurs in a power supply or motor drive device used for a machine tool, the control system issues a warning and stores data acquired when the anomaly occurs. Based on the stored data, a machine tool operator determines whether the anomaly is related to the power supply or the motor drive device (see patent specification 1).

[0003] A machine tool comprising an anomaly diagnostic device is known as a configuration for identifying a more precise anomaly factor (see patents 2 and 3). In a configuration according to patent 2, the anomaly diagnostic device is provided separately from the machine tool. The anomaly diagnostic device analyzes the symptoms of an anomaly entered by an operator and estimates the anomaly factor. In a configuration according to patent 3, a machine tool is proposed that displays the details of the anomaly factor. Patent specification 1: Unexamined Japanese patent application, publication no. 2011-205740 Patent specification 2: Unexamined Japanese patent application, publication no. H03-088034 Patent specification 3: Unexamined Japanese patent application, Publication No. S60-179899

[0004] DE 10 2017 002 484 A1 describes a machine tool comprising a drive unit that drives a tool for machining a workpiece and a control unit that controls the drive unit. The machine tool further comprises an abnormality detection unit that determines, based on operating information from the drive unit, whether machining can continue, and a power failure detection unit that switches the control unit's power source from a normal power supply to an emergency power supply when a power failure is detected and switches the power source back from the emergency power supply to the normal power supply when a power supply restoration is detected after the power failure.The control unit stops the operation of the drive unit when a power failure is detected, and afterwards, when a restoration of the power supply is detected and the abnormality detection unit determines that the machining can be continued, the control unit drives the drive unit, thereby automatically resuming the machining.

[0005] DE 10 2016 102 328 A1 describes an anomaly diagnostic system which includes a component for obtaining a current value, which receives a value of an alternating current that is supplied to or supplied by a device under test.

[0006] US 2015 / 0051728A1 describes a method for detecting an abnormality in a machine tool operation. SUMMARY OF THE INVENTION

[0007] However, although the configuration according to patent specification 1 determines whether the anomaly factor is related to the power supply or the motor drive device, an operator must check the respective locations to identify the anomaly factor. For example, if an anomaly occurs in a peripheral device of a machine tool, an operator selects anomalous values ​​from stored data and checks the locations that serve as factors for the anomalous values. Therefore, a considerable amount of time is spent by the operator identifying the factors for a warning.

[0008] Although the configuration according to patent specification 2 analyzes the factors contributing to an anomaly using an anomaly diagnostic device, it requires time and effort from the operator to input the anomaly symptoms into the device. Although the configuration according to patent specification 3 displays the details of an anomaly, it does not include a function for automatically analyzing the factors contributing to the anomaly.

[0009] It is an object of the present invention to provide a machine tool control suitable for the simple identification of warning factors. This object is achieved by a control for a machine tool having the features disclosed in claim 1. Preferred embodiments are defined in the dependent claims. (1) A control unit for a machine tool (for example, a control unit 100 described later) comprises: a sensor (for example, a power supply monitoring unit 170 described later) that retrieves measurements indicating an operating state of the machine tool and / or a peripheral device of the machine tool (for example, an AC power supply 120 or a motor 160, which will be described later); an anomaly detection unit (for example, a power supply anomaly detection unit 180 described later) that detects an anomaly in the operating state of the machine tool and / or the peripheral device and outputs a signal indicating the anomaly and the measurements obtained when the anomaly was detected;and an anomaly diagnostic unit (for example, an anomaly diagnostic unit 195 described later) that automatically selects measurements relating to the anomaly from among the measurements and automatically diagnoses factors of the anomaly. (2) The control system of the machine tool according to claim 1 further comprises: a control unit (for example, a control unit 190 described later), a display unit (for example, a display unit 300 described later) and a storage unit (for example, a storage unit 197 described later), wherein a name of the anomaly, factors of the anomaly and a measurement relating to the anomaly are displayed on a display screen of the display unit and the name of the anomaly, the factors of the anomaly and the measurement relating to the anomaly are stored in the storage unit. (3) When controlling the machine tool according to (2), the anomaly detection unit sends a signal to the control unit indicating that no anomaly is present, and the control unit switches the display screen to a screen for normal operation, restarts operation of the machine tool and / or peripheral device, and refers to the memory unit to display an occurrence of the anomaly on the display screen as a preliminary history when it is determined that the factors of the anomaly have been resolved and normal operation is possible. (4) When controlling the machine tool according to (2), the anomaly detection unit sends a signal to the control unit indicating that no anomaly is present, and the control unit displays a preview on the display screen indicating the occurrence of the anomaly when it is determined that the factors causing the anomaly have been resolved and the anomaly can be rectified.

[0010] According to the present invention, it is possible to provide a machine tool control system suitable for easily identifying the factors that may trigger a warning. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a functional block diagram of a control system according to an embodiment of the present invention. Fig. Figure 2 is a flowchart that illustrates a sequence for identifying the cause of an anomaly according to an embodiment of the present invention. Fig. Figure 3 is a diagram representing a display screen of a display unit according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present invention is described below with reference to the drawings. Fig. Figure 1 is a functional block diagram of a controller 100. A rectifier 130 converts alternating current (AC) from an AC power supply 120 into direct current (DC). An inverter 140 converts the DC from the rectifier 130 into AC and supplies the AC to a motor 160. A smoothing capacitor 150 is provided between the rectifier 130 and the inverter 140 for noise reduction.

[0012] A power supply monitoring unit 170 acquires measurements (i.e., voltage, current, frequency, and the voltage of the smoothing capacitor 150) that are input to the rectifier 130. The acquired measurements are fed to a power supply anomaly detection unit 180 and a control unit 190. The measurements supplied by the power supply monitoring unit 170 are continuously recorded in a memory (not shown) provided in the control unit 190. For example, a memory unit 197 provided in the control unit 190 has non-volatile memory and stores an anomalous condition acquired by the power supply anomaly detection unit 180 and the measurements obtained during the acquisition of an anomaly. The control unit 190 comprises an anomaly diagnostic unit 195, which diagnoses an anomaly, and a display unit 300, which will be described in detail later.

[0013] Fig. Figure 2 is a flowchart illustrating the sequence for identifying the cause of an anomaly according to one embodiment of the present invention. The diagram shown in Fig. The processes shown in step 2 are executed by the power supply anomaly detection unit 180 and the control unit 190. In the processes of steps S210 to S246, the presence of an anomaly during the operation of the machine tool is determined based on various measurements, and the necessity of switching a display screen is determined according to the result of the determination.

[0014] In step S210, the values ​​from the power supply monitoring unit 170 (see Fig. 1) Retrieved recorded measurements. The measurements are information on the voltage and / or current of a peripheral device of the machine tool, which controls the voltage, current and frequency of the AC power supply 120 (see Fig. 1) include the voltage of the capacitor 150 and the speed and acceleration of the motor 160.

[0015] Once the measurements have been retrieved, step S214 determines whether the measurements are within a normal range. The normal range is a range of values ​​within which the controller 100 (see Fig. 1) is working normally. If the measurements are within the normal range, step S218 determines that no anomaly is present.

[0016] If step S214 determines that the measurements are not within the normal range, the process continues with step S222. If step S222 determines that an anomaly is present, the power supply anomaly detection unit sends 180 (see Fig. 1) a signal indicating an anomaly to the anomaly diagnostic unit 195 (see Fig. 1).

[0017] Upon receiving a signal indicating an anomaly, the anomaly diagnostic unit 195 performs a repeated process in step S226 to identify the cause of the anomaly. In an anomaly cause identification loop, it is determined whether m (m is a positive integer) measurements are sufficient to identify an anomaly cause (meaning that the measurements are within the normal range). The value of m is determined by the number of measurement types acquired by the power supply monitoring unit 170.

[0018] If it is determined that the anomaly factor is satisfied, the anomaly factor is sent to control unit 190 in step S234 (see Fig. 1) sent. When the anomaly factor is sent to control unit 190, control unit 190 sets the display screen to a warning screen like the one in Fig. 3 shown.

[0019] If the anomaly factor identification loop process ends in step S226, step S238 determines whether the anomaly factor was sent to control unit 190. If step S238 determines that the anomaly factor was not sent, the process is executed in step S242.

[0020] In step S242, a signal indicating that no anomaly factor has been identified is sent to control unit 190 (see Fig. 1) sent. In step S246, the control unit 190 switches the display screen of the display unit 300 to a warning screen and indicates that no anomaly factor could be identified.

[0021] Fig. Figure 3 is a diagram representing the display screen of display unit 300. Display unit 300 comprises a warning area 310, a value display area 320, and a graph display area 330.

[0022] The name of an anomaly, an estimated anomaly factor, and instructions are displayed in alert area 310. The anomaly name briefly describes the phenomenon, such as "X-axis: SV input power anomaly." The estimated anomaly factor indicates several values ​​from the anomaly diagnostic unit 195 (see Fig. 1) Estimated anomaly factors such as "1. SV, VSp or VSt fault", "2. Input power anomaly" and "3. MCC or line fault". The guidance message is intended to initiate more specific countermeasures such as "No power is being supplied" and "There is a fault in the power cable, voltage sensing cable or input power".

[0023] The measurements obtained when an anomaly occurs are displayed in the value display range 320. As described above, these measurements include, for example, the voltage, current, and frequency of the power supply 120 (see...). Fig. 1) In addition, a graph based on the measurements displayed in the value display area 320 is shown in graph display area 330. An operator can compare the graph with the estimated anomaly factors to identify the location of the anomaly. Furthermore, the operator can track changes in the measurements against the historical data stored in a (not shown) memory of the control unit 190 (see Fig. 1) Refer to recorded measurements.

[0024] If the operator eliminates the anomaly factor according to the instructions on the display unit 300, the readings from the power supply monitoring unit 170 (see Fig. 1) The recorded measurements return to normal values. Upon detecting that the measurements are returning to normal values, the power supply anomaly detection unit 180 (see Fig. 1) a signal indicating that no anomaly is present, to control unit 190.

[0025] Upon receiving a signal indicating that no anomaly is present, the control unit 190 determines that the anomaly can be rectified and switches the display screen of the display unit 300 to a normal operating screen. For example, upon receiving a signal indicating that no anomaly is present, the control unit 190 clears the warning indicator and displays a history of a previously occurring anomaly in a predefined area of ​​the display unit 300. In this case, depending on the type of anomaly, the control unit 190 may automatically restart the operation of the machine tool and / or peripheral device instead of clearing the warning indicator. For example, if the anomaly is a minor one that does not require manual maintenance such as replacing parts, the machine tool and / or peripheral device may restart automatically.

[0026] The configuration according to the present embodiment offers the following advantages. The controller 100 automatically diagnoses the factors of an anomaly by automatically selecting a measurement related to the anomaly from m types of measurements. This means that when an anomaly occurs during the operation of a machine tool, the controller 100 identifies the factors of the anomaly by automatically determining them with respect to m types of values ​​in the anomaly factor identification loop. Since the operator does not have to manually identify the anomaly factor in this way, maintenance characteristics are improved.

[0027] Although in the present embodiment the power supply monitoring unit 170 records the measurements of the AC power supply 120 and the capacitor 150, the measurements of the voltage and / or current of the peripheral device of the machine tool, which include the speed and acceleration of the motor 160, can also be recorded. EXPLANATION OF THE REFERENCE SYMBOLS 100 Control 120 AC power supply (peripheral device) 160 Motor (peripheral device) 170 Power supply monitoring unit (sensor) 180 Power supply anomaly detection unit (detector) 190 control unit 195 Anomaly Diagnostic Unit 197 storage units 300 display units

Claims

[1] Control (100) for a machine tool, comprising: a sensor (170) that retrieves measurements containing information on the voltage, current, frequency, speed and acceleration of a power supply (120) of a peripheral device (120, 160) from the machine tool; an anomaly detection unit (180) that detects an anomaly in relation to the operating state of the machine tool and / or the peripheral device (120, 160) and outputs a signal indicating the anomaly and sensor measurements in which the detection of the anomaly was determined; and a diagnostic unit (195) that automatically selects measurements relating to the anomaly from among the sensor measurements and estimates and automatically diagnoses the multiple factors of the anomaly. [2] Control (100) of the machine tool according to claim 1, further comprising: a control unit (190), a display unit (300), and a storage unit (197), wherein a name of the anomaly, factors of the anomaly and a measurement relating to the anomaly are displayed on a display screen of the display unit (300) and the name of the anomaly, the factors of the anomaly and the measurement relating to the anomaly are stored in the memory unit (197). [3] Control (100) of the machine tool according to claim 2, wherein the anomaly detection unit (180) outputs a signal to the control unit (190) indicating that no anomaly is present when it is determined that the factors of the anomaly have been rectified and normal operation is possible, and the control unit (190) switches the display screen to a screen for normal operation, restarts operation of the machine tool and / or the peripheral device (120, 160) and refers to the storage unit (197) to display an occurrence of the anomaly on the display screen as a history. [4] Control (100) for the machine tool according to claim 2, wherein the anomaly detection unit (180) outputs a signal to the control unit (190) indicating that no anomaly is present when it is determined that the factors of the anomaly have been rectified and the anomaly can be rectified, and the control unit (190) displays a pre-history indicating an occurrence of the anomaly on the display screen.

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