Control system of a machine tool

Abstract

A control system (100) of a machine tool that processes a workpiece (W), wherein the control system (100) comprises: a control device (17) that controls a drive axis of the machine tool (10) on the basis of chronological control data; a device (20) for measuring a machined surface, which measures a machined surface of the workpiece (W); and a data processing device (30), wherein the data processing device (30) is set up: to retrieve the chronological control data from the control device (17) during the machining of the workpiece (W); to retrieve spatial measurement data for a machined surface measured by the device (20) after the workpiece (W) has been machined; and to assign the retrieved chronological control data to the retrieved spatial measurement data for a machined surface, wherein the chronological control data are position information of the drive axis of the machine tool (10), and the data processing device (30): A first image of the shape of a workpiece is generated based on the chronological position information; A second image of the shape of a workpiece is generated based on the spatial measurement data of a machined surface; where the matching process involves superimposing the first image of the shape of a workpiece and the second image of the shape of a workpiece, wherein the data processing device (30) further: a defect on the machined surface of the workpiece (W) and its position are detected based on the retrieved spatial measurement data of a machined surface, and Based on the superimposed first and second images, chronological control data relating to the position of the defect was identified.

Description

BACKGROUND OF THE INVENTION Area of ​​the invention

[0001] The present invention relates to the control system of a machine tool that processes a workpiece. Related technology

[0002] A machine tool processes a workpiece by moving either the workpiece (the object to be machined) or a tool along predetermined drive axes. In other words, the machine tool processes the workpiece by changing the relative position of the workpiece and the tool.

[0003] When the workpiece is machined by the machine tool described above, a striped pattern (a defect) may appear on the machined surface of the workpiece due to vibration, etc. In other words, streaks or lines may appear at predetermined intervals.

[0004] Therefore, for example, patent specifications 1 and 2 disclose technologies according to which a stripe pattern (a defect) on the machined surface of the workpiece is detected based on the movement of the front end of a tool during the machining of a workpiece. Patent specification 1: Unexamined Japanese patent application, Publication No. JP 2016-57843A Patent specification 2: Unexamined Japanese patent application, Publication No. JP 2017-13178A

[0005] Further state of the art: US 2014 / 0 157 610 A1 SUMMARY OF THE INVENTION

[0006] The inventors of the present application have attempted an approach to detecting a defect on the machined surface of a workpiece that differs from the technologies disclosed in patent specifications 1 and 2. Specifically, as a further method for detecting the defect on the machined surface of the workpiece after machining, an optical sensor or the like is used to capture an image of the machined surface. Image processing is then performed on the data from the captured image, thereby detecting the defect on the machined surface and its position.The inventors of the present application then carried out thorough investigations to determine that it is useful for analyzing the cause of the defect and investigating measures against it if control data that control drive axes can be identified when the defect occurs on the machined surface.

[0007] Therefore, it is an object of the present invention to provide the control system of a machine tool that assigns chronological data for controlling the drive axes during the machining of a workpiece to spatial measurement data on the machined surface of a workpiece after the machining of the workpiece. (1) A control system (for example, a numerical control system 100 of a machine tool, which will be described later) of a machine tool according to the present invention, which machines a workpiece (W), comprises: a control device (for example, a numerical control device 17, which will be described later) that controls the drive axis of the machine tool (for example, a machine tool 10, which will be described later) according to control data; a device for measuring a machined surface (for example, a device 20 for measuring a machined surface, which will be described later) that measures the machined surface of the workpiece;and a data processing device (for example, a data processing device 30, which will be described later), wherein the data processing device comprises: a first retrieval section (for example, a section 31 for retrieving control data for the drive axes, which will be described later) that retrieves the chronological control data from the control device during the machining of the workpiece; a second retrieval section (for example, a section 32 for retrieving measurement data for a machined surface, which will be described later) that retrieves spatial measurement data for a machined surface measured by the device for measuring a machined surface after the machining of the workpiece;and a data mapping processing section (for example, a data mapping processing section 34, which will be described later) that maps the chronological control data retrieved by the first retrieval section to the spatial measurement data retrieved by the second retrieval section to a processed surface. (2) In the control system of the machine tool according to (1), the control data can be position information about the drive axis of the machine tool, and the processing section for assigning data can generate a first image of the shape of a workpiece based on the chronological position information, generate a second image of the shape of a workpiece based on the spatial measurement data about a machined surface, and assign the chronological position information to the spatial measurement data about a machined surface in order to overlay the first image of the shape of a workpiece and the second image of the shape of a workpiece. (3) In the control system of the machine tool according to (2), the chronological position information may be machine coordinate information, and the spatial measurement data relating to a machined surface may be machine coordinate information calculated from machine coordinates of the device for measuring a machined surface. (4) In the control system of the machine tool according to (1), the control data can be torque information for the drive axis of the machine tool, and the processing section for assigning data can, based on a change in the chronological torque information, detect a start position of the machining and a finish position of the machining as the edge position of the workpiece in order to generate a first image of the shape of a workpiece, detect an edge position of the workpiece based on the spatial measurement data of a machined surface in order to generate a second image of the shape of a workpiece, and assign the chronological torque information to the spatial measurement data of a machined surface in order to superimpose the edge position of the first image of the shape of a workpiece and the edge position of the second image of the shape of a workpiece. (5) In the control system of the machine tool according to (1), the control data can be torque information for the drive axis of the machine tool, and the processing section for assigning data can, based on a change in chronological load information determined by subtracting a torque component for acceleration / deceleration from the chronological torque information, determine a starting position of the machining and a finishing position of the machining as the edge position of the workpiece in order to generate a first image of the shape of a workpiece, determine an edge position of the workpiece based on the spatial measurement data of a machined surface in order to generate a second image of the shape of a workpiece, and assign the chronological torque information to the spatial measurement data of a machined surface.to superimpose the edge position of the first image of the shape of a workpiece and the edge position of the second image of the shape of a workpiece. (6) In the control system of the machine tool according to any of points (1) to (5), the data processing device may further comprise: a section for detecting a defect of a machined surface (for example, a section 35 for detecting a defect of a machined surface, which will be described later), which detects a defect on the machined surface of the workpiece and its position on the basis of the spatial measurement data of a machined surface retrieved by the second retrieval section;and an identification section (for example, a section 36 for identifying the control data for the position of a defect, which will be described later) which, based on the control data and measurement data assigned to the processed surface by the processing section for assigning data to the processing surface, identifies corresponding control data for the position of the defect of the processed surface to the measurement data acquired by the section for detecting a defect of a processed surface. (7) In the control system of the machine tool according to (6), the identification section can use the chronological control data to assign information about the defect on the machined surface of the workpiece to a machining direction. (8) In the control system of the machine tool according to (6), the defect on the machined surface of the workpiece may be a streak or a stripe. (9) In the control system of the machine tool according to (7), the defect on the machined surface of the workpiece may be a streak or a stripe, and the information about the defect may be a direction of the streak or stripe. (10) In the control system of the machine tool according to (1), the control data may be a command value or a feedback value; the command value may be a position command value, a velocity command value or a torque command value; and the feedback value may be a position feedback value, a velocity feedback value or a current feedback value.

[0008] The present invention makes it possible to provide the control system of a machine tool that assigns chronological data for controlling the drive axes during the machining of a workpiece to spatial measurement data on the machined surface of a workpiece after the machining of the workpiece. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view showing an example of the configuration of a machine tool according to the present embodiment of the present invention. Fig. Figure 2 is a diagram showing the configuration of a numerical control system of the machine tool according to the embodiment of the present invention. Fig. Figure 3 is a flowchart showing data processing performed by the data processing device of the numerical control system of the machine tool according to the embodiment of the present invention. Fig. Figure 4 is a diagram that schematically shows the processing for assigning data. Fig. Figure 5 is a diagram that schematically shows the identification processing of the control data to determine the location of a defect. Fig. Figure 6 is a diagram that schematically shows the processing for capturing the edge position of the workpiece using torque information. DETAILED DESCRIPTION OF THE INVENTION

[0009] Examples of the embodiment of the present invention are described below with reference to the accompanying drawings. In the drawings, corresponding or identical sections are designated by the same reference numerals. (Machine tool)

[0010] First, an example of a machine tool in a numerical control system according to the embodiment of the present invention is described. Fig. Figure 1 is a perspective view showing an example of the machine tool configuration according to the present embodiment of the present invention. This machine tool 10 is a machine tool that performs a machining operation (material removal). The machine tool in the numerical control system according to the present invention is not limited to this machine tool and can be any industrial machine.

[0011] The in Fig. The machine tool 10 shown in Figure 1 comprises a head 2, a holding element 3 that movably supports the head 2, a holding stand 4 that movably supports the holding element 3, a base 5 that supports the holding stand 4, and a table 6. A tool T, such as an end mill, is attached to the head 2, and a workpiece W is mounted on the table 6. The machine tool 10 includes a drive device (not shown) and a numerical control device (not shown).

[0012] The drive unit comprises servo motors, which will be described later. The drive unit moves the base 5 in the direction of an X-axis (an arrow X), the table 6 in the direction of a Y-axis (an arrow Y), and the holding element 3 in the direction of a Z-axis (an arrow Z). Furthermore, the drive unit rotates the tool T relative to the head 2 in the direction of an A-axis (an arrow A) and the head 2 relative to the holding element 3 in the direction of a B-axis (an arrow B).

[0013] The numerical control device controls the drive device by controlling the drive axes formed by the three directly moving axes (the X-axis, the Y-axis, and the Z-axis) and the two rotary axes (the A-axis and the B-axis), thereby controlling the relative position of the tool T with respect to the workpiece W and its orientation. In this way, the machine tool 10 machines the workpiece W, changing the relative position of the tool T with respect to the workpiece W and its orientation. (Numerical control system of the machine tool)

[0014] Next, the numerical control system of the machine tool according to the embodiment of the present invention will be described. Fig. Figure 2 is a diagram showing the configuration of the numerical control system in the machine tool according to the embodiment of the present invention. The diagram in Fig. The numerical control system 100 of the machine tool shown in Figure 2 comprises the machine tool 10 described above, a device 20 for measuring a machined surface and a data processing device 30.

[0015] The machine tool 10 comprises several servomotors M1 to M5 in the drive device described above, measuring encoders (position / speed detectors) 11 to 15, each provided in the servomotors M1 to M5, current detectors CT1 to CT5, a measuring scale (a position detector) 16 and the numerical control device (CNC) 17. Fig. Figure 2 shows only the configuration of the machine tool 10 which relates to the features of the present invention, and the presentation of further configurations is omitted.

[0016] The servomotors M1 to M5 drive the drive axes described above (the X-axis, the Y-axis, the Z-axis, the A-axis, and the B-axis) via the control of the numerical control device 17. The encoders 11 to 15 each detect the rotational positions of the servomotors M1 to M5 and send the detected rotational positions as position feedback values ​​to the numerical control device 17. The encoders 11 to 15 each detect the rotational speeds of the servomotors M1 to M5 and send the detected rotational speeds as speed feedback values ​​to the numerical control device 17.

[0017] The current detectors CT1 to CT5 each detect the drive current values ​​of the servomotors M1 to M5 and send the detected drive current values ​​as current feedback values ​​(actual current values ​​and actual torque values) to the numerical control device 17.

[0018] A measuring scale 16 is provided, for example, in the table 6 on which the workpiece W described above is clamped. The measuring scale 16 detects the position of the workpiece and sends the detected position as position feedback to the numerical control device 17.

[0019] The numerical control device 17 generates torque command values ​​(current command values) for the drive axes based on position command values ​​(motion command values) for the drive axes, the position feedback value from the measuring scale 16 or the position feedback values ​​from the encoders 11 to 15, the speed feedback values ​​from the encoders 11 to 15 and the current feedback values ​​from the current detectors CT1 to CT5, and drives the servomotors M1 to M5 by means of these torque command values.

[0020] More precisely, the numerical control device 17 comprises a section for generating position commands, a section for generating velocity commands, and a section for generating torque commands. The section for generating position commands generates the position command values ​​(the motion command values) for the drive axes according to the machining program stored in a memory section. The section for generating velocity commands generates velocity command values ​​for the drive axes based on differences between the position command values ​​and the position feedback values. The section for generating torque commands generates the torque command values ​​(the current command values) for the drive axes based on differences between the velocity command values ​​and the velocity feedback values.The numerical control device 17 generates the drive currents for the drive axes based on differences between the torque command values ​​(the current command values) and the current feedback values.

[0021] The numerical control device 17 is, for example, formed by a computing processor such as a DSP (a digital signal processor) or an FPGA (a field-programmable gate array). The various types of functions of the numerical control device 17 are implemented by executing predefined software (programs and applications) stored in the (not shown) memory section. The various types of functions of the numerical control device 17 can be implemented through the interaction of hardware and software or solely through hardware (an electronic circuit).

[0022] The device 20 for measuring a machined surface is a device that measures the workpiece W in such a way as to measure the machined surface of the workpiece W. Specific examples of the device 20 for measuring a machined surface include an optical sensor, an optical microscope, a laser microscope, or a three-dimensional coordinate measuring machine. The device 20 for measuring a machined surface transmits the measured image data or position data of the workpiece W to the data processing device 30. The device 20 for measuring a machined surface is, for example, provided in a measuring platform, a clamping platform, or an end effector of a robot outside the machine tool 10. The device 20 for measuring a machined surface can also be integrated into the machine tool 10.

[0023] The data processing device 30 is a device that processes the data retrieved by the numerical control device 17 and the device 20 for measuring a machined surface. The data processing device 30 comprises a section 31 for retrieving control data for the drive axes (a first retrieval section), a section 32 for retrieving measurement data for the machined surface (a second retrieval section), the storage section 33, a processing section 34 for assigning data, a section 35 for detecting a defect in a machined surface, and a section 36 for identifying the control data for the location of a defect.

[0024] Section 31, for retrieving control data for the drive axes, retrieves the chronological data for controlling the drive axes during the machining of workpiece W from the numerical control device 17. More precisely, Section 31 retrieves the position feedback values ​​(the position information (machine information) for the drive axes) of workpiece W, as recorded by the measuring scale 16, as control data for the drive axes. Section 31 can retrieve the position feedback values ​​(position information (machine information) for the drive axes) of the servomotors M1 to M5, as recorded by the encoders 11 to 15, or it can retrieve the position command values ​​(position information (machine information) for the drive axes).

[0025] Section 32, for retrieving measurement data for a machined surface, retrieves the spatial measurement data for a machined surface measured by the device 20 after the workpiece W has been machined. More precisely, Section 32 retrieves three-dimensional image data or position data (coordinate data) as measurement data for the machined surface. Section 32 can also retrieve two-dimensional image data as measurement data for the machined surface.

[0026] Memory section 33 stores the chronological data for controlling the drive axes, retrieved by section 31 for control data, and the spatial measurement data for a machined surface, measured by device 20 for measuring a machined surface. Memory section 33 is, for example, a rewritable memory such as an EEPROM.

[0027] Data assignment processing section 34 assigns the chronological data for controlling the drive axes to the spatial measurement data stored in memory section 33 for a processed surface. The details of the data assignment processing are described later.

[0028] Section 35 for detecting a defect of a machined surface uses the spatial measurement data stored in memory section 33 to detect a defect (a streak or a stripe) on the machined surface of the workpiece W and its position.

[0029] Section 36, for identifying control data for the position of a defect, uses the control data for the drive axes and the measurement data of the machined surface, which were assigned to each other by processing section 34 for assigning data, to identify control data for the position of the defect on the machined surface that correspond to the measurement data for the position of the defect on the machined surface, which were acquired by section 35 for detecting a defect on a machined surface. Section 36 for identifying control data for the position of a defect also assigns the direction of a defect (a streak or a striation) on the machined surface to the direction of machining, based on the chronological control data for the position of the defect.

[0030] The data processing device 30 is, for example, formed by a computing processor such as a DSP (a digital signal processor) or an FPGA (a field-programmable gate array). The various types of functions of the data processing device 30 are realized by executing predefined software (programs and applications) stored in the (not shown) memory section. The various types of functions of the data processing device 30 can be realized through the interaction of hardware and software or solely by hardware (an electronic circuit).

[0031] The various types of functions of the data processing device 30 can be implemented within the numerical control device 17 of the machine tool 10.

[0032] Next, with reference to the Fig. 3, Fig. 4 to Fig. 5 describes the data processing carried out by the data processing device 30 of the numerical control system 100 of the machine tool according to the present embodiment. Fig. Figure 3 is a flowchart showing the data processing performed by the data processing device 30 of the numerical control system 100 of the machine tool according to the present embodiment. Fig. Figure 4 is a diagram that schematically shows the processing for assigning data. Fig. Figure 5 is a diagram that schematically shows the identification processing of the control data to determine the location of the defect.

[0033] When the workpiece W is machined by the machine tool 10, the numerical control device 17 controls the drive axes on the basis of the position command values, the speed command values ​​and the torque command values ​​(the current command values) for the drive axes, the position feedback values ​​from the measuring scale 16 (or the position feedback values ​​from the encoders 11 to 15), the speed feedback values ​​from the encoders 11 to 15 and the current feedback values ​​(the actual current values ​​and the actual torque values) from the current detectors CT1 to CT5 and thereby controls the relative position of the tool T with respect to the workpiece W and its position.

[0034] During the machining of workpiece W, section 31, responsible for retrieving control data for the drive axes, retrieves the chronological data for controlling the drive axes from the numerical control device 17 in step S11 and stores it in memory section 33. More precisely, section 31 retrieves the position feedback values ​​(the position information (machine information) for the drive axes) from the measuring scale 16 as control data for the drive axes. Section 31 can retrieve the position feedback values ​​(the position information (machine information) for the drive axes) from the encoders 11 to 15, or it can retrieve the position command values ​​(the position information (machine information) for the drive axes).

[0035] Once the machining of workpiece W is complete, the device 20 for measuring a machined surface measures the machined surface of workpiece W. In step S12, section 32 for retrieving measurement data for a machined surface retrieves the spatial measurement data for a machined surface from the device 20 for measuring a machined surface and stores it in memory section 33. More precisely, section 32 for retrieving measurement data for a machined surface retrieves three-dimensional image data or position data (coordinate data) as measurement data for the machined surface.

[0036] Then, in step S13, processing section 34 assigns the chronological data for controlling the drive axes to the spatial measurement data for a machined surface stored in memory section 33. Here, after machining the workpiece, the data for an image captured by an optical sensor are, for example, three-dimensional data, whereas the control data for the drive axes determined by the numerical control device 17 during the machining of workpiece W are chronological data, making it difficult to assign these types of data to each other. The inventors of the present application use the following method for assigning these types of data to each other.

[0037] In particular, the data mapping processing section 34 first converts the measurement data of the machined surface into machine coordinate data. If the device 20 for measuring a machined surface is an optical sensor, the measurement data of the machined surface is, for example, image data. In this case, the data mapping processing section 34 uses image processing technology to determine the coordinate data of the workpiece W from the image data. Then, the data mapping processing section 34 converts the coordinate data of the workpiece W into machine coordinate data based on the distance between the device 20 for measuring a machined surface and the workpiece W, as well as the position (machine coordinates) and angle (viewing angle) of the device 20 for measuring a machined surface.If, on the other hand, the device 20 for measuring a machined surface is an optical microscope, a laser microscope, or a three-dimensional coordinate measuring machine, the measurement data for the machined surface are position data (coordinate data). In this case, the data mapping processing section 34 converts the position data (the coordinate data) of the workpiece W into machine coordinate data based on the distance between the device 20 for measuring a machined surface and the workpiece W, and the position (machine coordinates) and angle (viewing angle) of the device 20 for measuring a machined surface.

[0038] Then, processing section 34 assigns the position feedback values ​​(the machine coordinates), which are the chronological data for controlling the drive axes during the machining of workpiece W, to the spatial position data (the machine coordinates) of the machined surface after the machining of workpiece W. For example, in Fig. As shown in Figure 4, processing section 34, which assigns data based on the position feedback values ​​(the machine coordinates), which are the chronological data for controlling the drive axes during the machining of workpiece W, generates a first image W1 of the workpiece shape. Similarly, processing section 34, which assigns data based on the spatial position data (the machine coordinates) of the machined surface, generates a second image W2 of the workpiece shape after the machining of workpiece W. Then, processing section 34 assigns the chronological position feedback values ​​to the spatial position data of the machined surface in order to overlay the first image W1 and the second image W2 of the workpiece shape.

[0039] Then, in step S14, section 35, for detecting a defect on a machined surface, uses the spatial measurement data stored in memory section 33 to detect a defect (a streak or a stripe) on the machined surface of the workpiece W and its position. More precisely, the measurement data for the machined surface are image data if the device 20 for measuring a machined surface is an optical sensor. In this case, section 35 detects the defect on the machined surface and its position based on the characteristic amount of streaks and stripes on the machined surface in the image data.If, on the other hand, the device 20 for measuring a machined surface is an optical microscope, a laser microscope, or a three-dimensional coordinate measuring machine, the measurement data for the machined surface are position data (coordinate data). In this case, section 35 for detecting a defect on a machined surface detects the defect on the machined surface and its position based on a slight change (such as a vibration) in the position of the machined surface in the position data (coordinate data).

[0040] Then, section 36 identifies the control data for the location of a defect in step S15, as shown in Fig. 5 shown, using the control data for the drive axes (of the first image W1 of the shape of a workpiece) and the measurement data for the machined surface (of the second image W2 of the shape of a workpiece), which were assigned to each other by the processing section 34 for the assignment of data, the control data to a position D1 of a defect, which correspond to the measurement data of the machined surface to a position D2 of a defect, which were acquired by the section 35 for the detection of a defect of a machined surface.

[0041] Section 36, which identifies the control data for the position of a defect, also assigns the direction of a defect (a streak or a stripe) on the machined surface to the direction of the machining based on the chronological control data for the position of the defect.

[0042] As described above, the processing section 34 for assigning data of the data processing device 30 in the numerical control system 100 of the machine tool according to the present embodiment can assign the chronological data for controlling the drive axes during the machining of the workpiece to the spatial measurement data for the machined surface of a workpiece after the machining of the workpiece.

[0043] In the numerical control system 100 of the machine tool according to the present embodiment, section 36 identifies control data for the position of a defect in the chronological data for controlling the drive axes during workpiece machining when a defect occurs on the machined surface of the workpiece W. This makes it possible, for example, to analyze the cause of the defect and to investigate countermeasures (such as adjusting the gain of a control circuit of the numerical control device).

[0044] In the numerical control system 100 of the machine tool according to the present embodiment, section 36 assigns the direction of a defect (a streak or a stripe) on the machined surface to the data processing device 30 for the identification of the control data for the position of a defect based on the chronological control data for the position of a defect and the direction of machining. In this way, it is possible to determine whether the defect (a streak or a stripe) is a defect that intersects the direction of machining or a defect (a streak or a stripe) that is parallel to the direction of machining, thus making it possible to use this information for analyzing the cause of the defect and for investigating countermeasures. (Second embodiment)

[0045] In the first embodiment, the position information (the machine coordinates) (the position command values, the position feedback values) is retrieved from the numerical control device 17 as control data for the drive axes, and therefore the control data for the position information is identified when a defect occurs on the machined surface. According to a second embodiment, torque information (torque command values ​​(current command values), current feedback values ​​(actual current values, actual torque values)) is retrieved as control data for the drive axes, and thus the control data for the torque information is identified when a defect occurs on the machined surface.

[0046] The configuration of the numerical control system 100 of the machine tool according to the second embodiment corresponds to that described in the Fig. 1 and Fig. The configuration of the numerical control system 100 of the machine tool according to the first embodiment is the same as shown in Figure 2. In the numerical control system 100 of the machine tool according to the second embodiment, the functions and operations of section 31 for retrieving control data for the drive axes and of processing section 34 for assigning data to the data processing device 30 differ from those of section 31 for retrieving control data for the drive axes and of processing section 34 for assigning data to the data processing device 30 according to the first embodiment.

[0047] Section 31 for retrieving control data for the drive axes retrieves the torque command values ​​(the torque information for the drive axes) as chronological data for controlling the drive axes during the machining of the workpiece W from the numerical control device 17 and stores them in memory section 33 (according to Fig. Step 3 S11). Section 31 for retrieving control data for the drive axes can retrieve the current feedback values ​​(the actual current values, i.e., the actual torque values) (the torque information for the drive axes) captured by the current detectors CT1 to CT5 as control data for the drive axes.

[0048] Here, for example, the machine tool processes the entire workpiece W, with the tool T moving back and forth relative to the workpiece W. When the tool T comes into contact with the workpiece W and when it moves away from the workpiece W, the torque command values ​​and the current feedback values ​​change. In this way, the point of change in the torque command values ​​or the point of change in the current feedback values ​​is detected, and therefore it is possible to determine the edge position of the workpiece W, i.e., the outline of the workpiece W.

[0049] Since the torque command values ​​and current feedback values ​​also change according to acceleration / deceleration, the present embodiment uses a value (load information) determined by subtracting a torque value for acceleration / deceleration from the torque command values ​​and current feedback values. This prevents a reversal point during a back-and-forth movement of the tool T relative to the workpiece W from being mistakenly interpreted as the edge position of the workpiece W. If the tool T is not moved back-and-forth relative to the workpiece W, the torque command values ​​and current feedback values ​​can be used without processing.

[0050] More precisely, processing section 34, which deals with the allocation of data, describes how in Fig. Figure 6 shows that, based on point t1, a change in the chronological load information determined by subtracting a torque for acceleration / deceleration from the chronological torque command values ​​is used as the boundary position P1 of the workpiece W, representing a starting position and a finishing position of the machining process, and thereby generating the first image W1 of the shape (outline) of a workpiece, as shown in Fig. 4 shown. Processing section 34 for assigning data also captures the edge position of the workpiece based on the spatial position data (the machine coordinates) of the machined surface after machining the workpiece W and thereby generates the second image W2 of the shape (outline) of a workpiece, as shown in Fig. 4 shown. Then, the data mapping processing section 34 assigns the chronological torque command values ​​to the spatial position data of the machined surface in order to superimpose the first image W1 of the shape of a workpiece and the second image W2 of the shape of a workpiece (according to Fig. 3 Step S13).

[0051] With the numerical control system 100 of the machine tool according to the present embodiment, it is also possible to achieve the same advantages as with the numerical control system 100 according to the first embodiment.

[0052] The numerical control system 100 of the machine tool according to the present embodiment uses the edge position of the workpiece without using the machine coordinate data to assign the types of data to each other and is therefore suitable for a case in which the position of the device 20 for measuring a machined surface is not fixed and in which the coordinate information for the device 20 for measuring a machined surface is not determined (for example, in which a user makes recordings while carrying an optical sensor that serves as the device 20 for measuring the machined surface).

[0053] When the tool T comes into contact with the workpiece W and when the tool T is removed from the workpiece W, the speed command values ​​and the speed feedback values ​​also change. Therefore, in the second embodiment, speed information (speed command values, speed feedback values) can be retrieved from the numerical control device 17 as control data for the drive axes, so that the control data for the speed information can be identified by a change in the speed information when a defect occurs on the machined surface.

[0054] Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above. The results described in connection with the present embodiments are merely those that result from a list of the most preferred results obtained by the present invention, and therefore the results of the present invention are not limited to those described in connection with the present embodiments.

[0055] Although, in the embodiments described above, the data processing device 30 automatically detects a defect on the machined surface and its position based on the image data or position data (coordinate data) of the workpiece W (the machined surface) from the device 20 for measuring a machined surface, this data can also be captured manually. The measurement result (three-dimensional image data or position data) of the device 20 for measuring a machined surface can, for example, be displayed on a monitor or the like, a defect and its position can be captured by the user, and the captured position of the defect can then be manually entered into the data processing device 30. EXPLANATION OF THE REFERENCE SYMBOLS 2 heads 3 retaining element 4 support stands 5 sockets 6 Table 10 machine tool 11 to 15 measuring sensors 16 measuring scale 17 numerical control device (control device) 20 Device for measuring a machined surface 30 Data processing device Section 31 for retrieving control data for the drive axles (first retrieval section) Section 32 for retrieving measurement data for the processed surface (second retrieval section) 33 Storage section 34 Processing section for data allocation Section 35 on the detection of a defect on a machined surface Section 36 on the identification of control data for the location of a defect 100 numerical control system (tax system) CT1 to CT5 current detector M1 to M5 servo motor T tool W workpiece

Claims

[1] A control system (100) of a machine tool that processes a workpiece (W), wherein the control system (100) comprises: a control device (17) that controls a drive axis of the machine tool (10) on the basis of chronological control data; a device (20) for measuring a machined surface, which measures a machined surface of the workpiece (W); and a data processing device (30), wherein the data processing device (30) is set up: to retrieve the chronological control data from the control device (17) during the machining of the workpiece (W); to retrieve spatial measurement data for a machined surface measured by the device (20) after the workpiece (W) has been machined; and to assign the retrieved chronological control data to the retrieved spatial measurement data for a machined surface, wherein the chronological control data are position information of the drive axis of the machine tool (10), and the data processing device (30): A first image of the shape of a workpiece is generated based on the chronological position information; A second image of the shape of a workpiece is generated based on the spatial measurement data of a machined surface; where the matching process involves superimposing the first image of the shape of a workpiece and the second image of the shape of a workpiece, wherein the data processing device (30) further: a defect on the machined surface of the workpiece (W) and its position are detected based on the retrieved spatial measurement data of a machined surface, and Based on the superimposed first and second images, chronological control data relating to the position of the defect was identified. [2] Control system (100) of the machine tool according to claim 1, wherein the chronological position information is machine coordinate information and the spatial measurement data for a machined surface is machine coordinate information calculated from machine coordinates of the device for measuring a machined surface. [3] A control system (100) of a machine tool that processes a workpiece (W), wherein the control system (100) comprises: a control device (17) that controls a drive axis of the machine tool (10) on the basis of chronological control data; a device (20) for measuring a machined surface, which measures a machined surface of the workpiece (W); and a data processing device (30), wherein the data processing device (30) is set up: to retrieve the chronological control data from the control device (17) during the machining of the workpiece (W), to retrieve spatial measurement data measured by the device (20) for measuring a machined surface after the machining of the workpiece (W) and to assign the retrieved chronological control data to the retrieved spatial measurement data for a machined surface, wherein the chronological control data are torque information for the drive axis of the machine tool (10) and the data processing device (30): Based on a change in the chronological torque information, a starting position of the machining and a finishing position of the machining are recorded as the edge position of the workpiece (W) in order to generate a first image of the shape of a workpiece; Based on the spatial measurement data of a machined surface, an edge position of the workpiece (W) is recorded in order to generate a second image of the shape of a workpiece, and where the matching involves superimposing the edge position of the first image of the shape of a workpiece and the edge position of the second image of the shape of a workpiece, wherein the data processing device (30) further: a defect on the machined surface of the workpiece (W) and its position are detected based on the retrieved spatial measurement data of a machined surface, and Based on the superimposed first and second images, chronological control data relating to the position of the defect was identified. [4] A control system (100) of a machine tool that processes a workpiece (W), wherein the control system (100) comprises: a control device (17) that controls a drive axis of the machine tool (10) on the basis of chronological control data; a device (20) for measuring a machined surface, which measures a machined surface of the workpiece (W); and a data processing device (30), wherein the data processing device (30) is set up: to retrieve the chronological control data from the control device (17) during the machining of the workpiece (W), to retrieve spatial measurement data measured by the device (20) for measuring a machined surface after the machining of the workpiece (W) and to assign the retrieved chronological control data to the retrieved spatial measurement data for a machined surface, wherein the chronological control data are torque information for the drive axis of the machine tool (10) and the data processing device (30): Based on a change in chronological load information determined by subtracting a torque component for acceleration / deceleration from the chronological torque information, an initial machining position and a machining termination position are recorded as the edge position of the workpiece (W) in order to generate a first image of the shape of a workpiece; based on the spatial measurement data of a machined surface, an edge position of the workpiece (W) is captured in order to generate a second image of the shape of a workpiece; and wherein the mapping comprises superimposing the edge position of the first image of the shape of a workpiece and the edge position of the second image of the shape of a workpiece, wherein the data processing device (30) further: a defect on the machined surface of the workpiece (W) and its position are detected based on the retrieved spatial measurement data of a machined surface, and Based on the superimposed first and second images, chronological control data relating to the position of the defect was identified. [5] Control system (100) of the machine tool according to one of claims 1 to 4, wherein the data processing device (30) assigns information on the defect on the machined surface of the workpiece (W) to a machining direction based on the chronological control data on the position of the defect. [6] Control system (100) of the machine tool according to one of claims 1 to 4, wherein the defect on the machined surface of the workpiece (W) is a streak or a stripe. [7] Control system (100) of the machine tool according to claim 5, wherein the defect on the machined surface of the workpiece (W) is a streak or a stripe and the information about the defect is a direction of the streak or stripe. [8] Control system (100) of the machine tool according to claim 1, wherein the chronological control data are a command value or a feedback value, the command value is a position command value, a velocity command value, or a torque command value and The feedback value is a position feedback value, a speed feedback value, or a current feedback value.

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