Waveform display device

Abstract

A waveform display device is provided that allows for easy specification of the analysis object range simply by selecting the desired analysis position for the tool path. The waveform display device includes: a position information acquisition unit that acquires motor position information of the machine tool's drive axis during workpiece machining from a control device controlling the machine tool; an axis information setting unit that sets axis information representing the axis structure of the machine tool's drive axis; a tool path display unit that calculates the trajectory of the tool tip point mounted on the machine tool during workpiece machining based on the motor position information and axis information, and displays the trajectory as a waveform; an analysis object setting unit that sets the analysis object position related to the tool tip point trajectory; an analysis object range generation unit that generates and displays an analysis object range composed of geometric shapes, including the set analysis object position; and a measurement point selection unit that selects and displays measurement points from the tool tip point trajectory that are included within the analysis object range generated by the analysis object range generation unit.

Description

Technical Field

[0001] This invention relates to a waveform display device. Background Technology

[0002] The machine tool moves the cutting tool and performs cutting operations on the workpiece according to instructions from a numerical control device based on a machining program. During cutting, the trajectory traced by the cutting tool tip on the machined surface of the workpiece directly affects the machining quality. Therefore, techniques are known to generate machining trajectory data based on a machining program and display it on a screen, allowing for visual confirmation of whether the designed machining action can be achieved (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 8-328630 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] When analyzing the impact of tool movement on the machined surface of a workpiece, it is necessary to specify the range containing the measurement points that are the object of analysis from multiple measurement points along the trajectory of the tool tip. However, on the machined surface of the workpiece, the range containing the measurement points that are the object of analysis is discontinuous in time, making it difficult to specify the range through simple operations.

[0008] Therefore, it is desirable to be able to simply specify the range of the object to be analyzed by selecting the location to be analyzed for the toolpath.

[0009] Solutions for solving problems

[0010] One aspect of this disclosure is a waveform display device comprising: a position information acquisition unit that acquires motor position information of a drive axis of a machine tool from a control device controlling the machine tool; an axis information setting unit that sets axis information representing the axis structure of the drive axis of the machine tool; a tool path display unit that calculates the trajectory of the tip point of a tool mounted on the machine tool based on the motor position information acquired by the position information acquisition unit and the axis information set by the axis information setting unit, and displays the trajectory as a waveform; an analysis object setting unit that sets an analysis object position with respect to the trajectory of the tip point displayed by the tool path display unit; an analysis object range generation unit that generates and displays an analysis object range composed of geometry, the geometry including the analysis object position set by the analysis object setting unit; and a measurement point selection unit that selects and displays measurement points from the trajectory of the tip point that are included within the analysis object range generated by the analysis object range generation unit.

[0011] The effects of the invention

[0012] According to one approach, a waveform display device can be provided that allows the range of the object to be analyzed to be easily specified simply by selecting the position to be analyzed for the toolpath. Attached Figure Description

[0013] Figure 1 This is a functional block diagram illustrating an example of the functional structure of a numerical control system according to one embodiment.

[0014] Figure 2 This is a diagram illustrating an example of the relationship between the tool tip point and the reference plane.

[0015] Figure 3 This is a diagram schematically illustrating an example of the scope of an analysis object consisting of geometry that includes the position of the analysis object in relation to the trajectory of the tool tip point.

[0016] Figure 4 This is a flowchart illustrating the display process of a waveform display device.

[0017] Figure 5 This is an example of a screen displaying the range of objects being analyzed.

[0018] Figure 6 This is an example of a screen showing the selection and display of measurement points within the range of the analysis object.

[0019] Figure 7 This is a diagram illustrating an example of the range of a curved analysis object.

[0020] Figure 8 This is a diagram illustrating an example of an analysis object whose surface is composed of an ellipsoid. Detailed Implementation

[0021] The following description uses the accompanying drawings to illustrate one embodiment of this disclosure. Figure 1 As shown, the numerical control system includes a machine tool 100, a numerical control device 200, and a waveform display device 300. These machine tool 100, numerical control device 200, and waveform display device 300 are directly connected to each other via a connection interface not shown. Alternatively, these machine tool 100, numerical control device 200, and waveform display device 300 can also be interconnected via a network not shown, such as a LAN (Local Area Network) or the Internet.

[0022] Machine tool 100 has drive axes (not shown) including one or more servo motors that are operated by numerical control via numerical control unit 200. Machine tool 100 feeds back information indicating the operation state to numerical control unit 200 based on the operation commands from numerical control unit 200. The information indicating the operation state includes position information of the servo motors indicating the position of the drive axis (hereinafter referred to as motor position information). Specifically, the motor position information includes information about the motor command position output from numerical control unit 200 to the servo motor and information about the actual position of the motor when the servo motor is driven according to the motor command position.

[0023] The numerical control device 200 controls the operation of the machine tool 100. The numerical control device 200 is a control device known to those skilled in the art.

[0024] The waveform display device 300 includes a position information acquisition unit 301, an axis information setting unit 302, a tool path display unit 303, an analysis object setting unit 304, an analysis object range generation unit 305, and a measurement point selection unit 306.

[0025] In addition, the waveform display device 300 is designed to achieve... Figure 1 The operation of the function blocks includes an arithmetic processing unit (not shown) such as a CPU (Central Processing Unit). Furthermore, the waveform display device 300 includes auxiliary storage devices (not shown) such as ROM (Read Only Memory) and HDD (Hard Disk Drive) that store various control programs, and main storage devices (not shown) such as RAM (Random Access Memory) used to temporarily store necessary data when the arithmetic processing unit executes programs.

[0026] In the waveform display device 300, the arithmetic processing unit reads the operating system and application software from the auxiliary storage device, expands the read operating system and application software into the main storage device, and performs arithmetic processing based on these operating systems and application software. The waveform display device 300 then controls various hardware components based on the processing results. This achieves the utilization of… Figure 1 The processing of functional blocks. In other words, the various functions of the waveform display device 300 are implemented through collaboration between hardware and software.

[0027] The position information acquisition unit 301 samples from the numerical control device 200 at a predetermined frequency and acquires motor position information indicating the position of the drive axis of the machine tool 100 during workpiece machining. The position information acquisition unit 301 outputs the acquired motor position information to the tool path display unit 303.

[0028] The axis information setting unit 302 sets axis information representing the axis structure of the drive axis of the machine tool 100. The axis information includes information such as the type of tool mounted on the machine tool 100, the length of the tool, and the shape of the tool. The axis information setting unit 302 outputs the axis information to the tool path display unit 303.

[0029] The tool path display unit 303 calculates the trajectory of the tool tip point based on the motor position information acquired by the position information acquisition unit 301 and the axis information acquired by the axis information setting unit 302. The trajectory of the tool tip point is the movement path depicted by the tip of the tool mounted on the machine tool 100 when the machine tool 100 performs an action based on the machining program. Specifically, the tool path display unit 303 calculates the coordinates (Xt, Yt, Zt) of each tool tip point based on the sampled motor position information and axis information. The coordinate calculation method can use well-known methods.

[0030] The tool path display unit 303 sets parameters a, b, c, and d in the following formula (1) to represent the reference surface, which is the machining surface in the workpiece that serves as the target.

[0031] ax + by + cz = d…(1)

[0032] This parameter is set, for example, by user input via an external device such as a PC or tablet connected to the waveform display device 300. Furthermore, the normal vector of the reference plane in equation (1) is set to a direction whose dot product with the tool vector is positive. The tool vector is a vector from the tip of the tool mounted on the machine tool 100 toward the base.

[0033] The tool path display unit 303 calculates the distance in the vertical direction from the tool tip point to the reference plane based on the coordinates (Xt, Yt, Zt) of the tool tip point. Specifically, the tool path display unit 303 uses the coordinates (Xt, Yt, Zt) of each of the multiple tool tip points and the following formula (2) to calculate the distance L in the vertical direction from the tool tip point to the reference plane.

[0034] L=(aXt+bYt+cZt-d) / (a 2 +b 2 +c 2 ) 1 / 2 …(2)

[0035] The distance L calculated by equation (2) has a positive polarity when the tool tip is on the side of the normal vector relative to the reference plane, and a negative polarity when the tool tip is on the side opposite to the side of the normal vector relative to the reference plane.

[0036] Figure 2 This is a diagram illustrating an example of the relationship between multiple tool tip points and a reference plane. Figure 2 The figure shows the vertical distances L1 to L4 between the four tool tip points 1 to 4 and the reference plane. The line connecting the tool tip points 1 to 4 ( Figure 2 The dashed line in the image represents the trajectory of the tool tip. The trajectory of the tool tip represents the unevenness information of the machined surface.

[0037] The tool path display unit 303 displays the calculated tool tip point trajectory as a waveform on a display device such as an LCD monitor (not shown). The tool tip point is constructed based on sampled motor position information. Figure 3 Multiple measurement points 310 are shown. However, during workpiece machining, the tip of the tool moves relative to the machining surface, changing position according to the movement of the machine tool 100. Therefore, the trajectory of the tool tip point is as follows: Figure 3 As shown, multiple waveform lines 320 are displayed side by side on the screen of a display device (not shown).

[0038] The display device (not shown) can be configured on either the waveform display device 300 or the numerical control device 200. Alternatively, the display device (not shown) can also be configured on an external device such as a PC (Personal Computer) or tablet terminal that is connected to the numerical control device 200 or the waveform display device 300 via wired or wireless connection.

[0039] The analysis object setting unit 304 sets the analysis object position related to the trajectory of the tool tip point displayed by the tool path display unit 303. The analysis object position is position information used to specify the generation position of the analysis object range generated by the analysis object range generation unit 305 (described later), and is set by user input. The analysis object position related to the trajectory of the tool tip point is not limited to the position of any measurement point 310 on the trajectory, but can also be the position between adjacent measurement points 310, 310 or between adjacent waveform lines 320, 320.

[0040] As a specific method for setting the position of the analysis object, one method is to set the position of the point as the analysis object position when one or more points are selected on the screen displaying the trajectory of the tool tip using a pointing device such as a mouse, touch panel or digitizer operated by the user. Figure 3 This illustration shows a scenario where the user selects one of multiple measurement points 310 on the trajectory of the tool tip point, namely measurement point 310a, and sets that measurement point 310a as the analysis object position 330. Alternatively, when the user selects a line segment connecting multiple points related to the trajectory of the tool tip point, the analysis object position 330 is set based on the position of that line segment. The analysis object setting unit 304 sets the position selected by the user as the analysis object position 330 in this way.

[0041] The analysis object range generation unit 305 generates an analysis object range 340 including the analysis object position 330 on the trajectory of the tool tip point based on the analysis object position 330 set by the analysis object setting unit 304, and displays it via a display device (not shown). The trajectory of the tool tip point represents the concavity / convexity information of the workpiece's machining surface; therefore, the analysis object range 340 needs to be a shape capable of encompassing the concavity / convexity of the machining surface. Therefore, the analysis object range 340 is composed of a geometric body including the analysis object position 330 and a plurality of measurement points 310 around it. In the analysis object range 340 composed of the geometric body, the length is along the direction of the tool's forward direction vector. The width is perpendicular to both the tool's forward direction vector and the tool's tool vector. The height is perpendicular to the surface formed by the length and width.

[0042] Figure 3 An example of an analysis object range 340, comprising a cuboid including the analysis object position 330, is shown. Multiple measurement points 310b within this analysis object range 340 are measurement points of the analysis object. The orientation of the analysis object range 340, comprising the cuboid, i.e., the direction of its long side, is arranged along the tool's forward direction vector V1. Therefore, the state of the workpiece's machined surface can be accurately analyzed along the tool's forward direction.

[0043] Figure 3The analysis object range 340 shown has a size of nine measurement points, including a measurement point 310a selected by the user as the analysis object position 330 and eight surrounding measurement points 310b. However, the length × width × height of the analysis object range 340 is not limited as long as it can include multiple measurement points 310b, including the analysis object position 330, within the analysis object range 340. Information related to the size of the analysis object range 340 is preset in a storage unit (not shown) provided in the analysis object range generation unit 305 or the waveform display device 300. The size of the analysis object range 340 set in the storage unit is not limited to one type and can be multiple types corresponding to the shape of the workpiece's machined surface.

[0044] The measurement point selection unit 306 selects measurement points from the trajectory of the tool tip point on the waveform line 320 within the analysis object range 340 generated by the analysis object range generation unit 305, and displays them via a display device (not shown). That is, within the analysis object range generation unit 305, as shown... Figure 3 When the analysis object range 340 is generated as shown, the measurement point selection unit 306 magnifies and displays the analysis object range 340 on the screen of the display device (not shown). Thus, the user can easily visually confirm the condition of the machined surface of the workpiece within the analysis object range 340 and perform analysis.

[0045] Next, use Figure 4 The following flowchart illustrates the specific display processing actions in the waveform display device 300. Before the workpiece is actually processed by the machine tool 100, the display actions of the waveform display device 300 shown in the flowchart below are executed based on instructions from the user.

[0046] First, the waveform display device 300 samples and acquires motor position information, representing the position of the drive axis of the machine tool 100 during workpiece machining, from the numerical control device 200 via the position information acquisition unit 301. The waveform display device 300 then outputs this motor position information and axis information, representing the axis structure of the drive axis of the machine tool 100 set by the axis information setting unit 302, to the tool path display unit 303 (step S1).

[0047] Next, the waveform display device 300 calculates the trajectory of the tool tip point based on the motor position information and shaft information in the tool trajectory display unit 303 (step S2), and displays the calculated trajectory of the tool tip point on the screen of the display device (not shown) (step S3).

[0048] After displaying the trajectory of the tool tip point on the display device (not shown) in step S3, the waveform display device 300 determines whether the user has selected the position of the analysis object (step S4).

[0049] Figure 5 A screen SC shows the state where the user has selected the analysis object position 330 on multiple waveform lines 320 representing the trajectory of the tool tip point. In this screen SC, the analysis object position 330 is represented by a line segment connecting the two points selected by the user. The waveform lines 320 representing the trajectory of the tool tip point show the machined surface of the workpiece, which is composed of polygons.

[0050] In this case, if the user selects the analysis object position 330 in step S4 (step S4; "Yes"), after the waveform display device 300 sets the position selected by the user as the analysis object position 330 in the analysis object setting unit 304, the analysis object range generation unit 305 generates an analysis object range 340 based on the analysis object position 330 and displays it on the screen SC (step S5). Figure 5 As shown, the analysis object range 340 is superimposed on multiple waveform lines 320 representing the trajectory of the tool tip point. Furthermore, if the user does not specify the analysis object position 330 in step S4 (step S4: "No"), the process repeats step S4 and waits for the user to specify the analysis object position 330.

[0051] After the analysis object range 340 is generated in step S5, the waveform display device 300 selects multiple measurement points included in the analysis object range 340 displayed on the screen SC in the measurement point selection unit 306, and enlarges the display on the screen SC (step S6).

[0052] Figure 6 This example shows a screen SC that selects and displays measurement points within the analysis object range 340. Multiple measurement points within the analysis object range 340 are represented on the screen SC as multiple waveform lines 350 showing the trajectory of the tool tip point. These multiple waveform lines 350 are... Figure 5 The waveform display is obtained by magnifying the trajectory of the tool tip point within the analysis object range 340. Therefore, the user can easily visually confirm the unevenness of the machined surface of the workpiece by observing the trajectory of the tool tip point composed of multiple waveform lines 350 displayed on the screen SC. After selecting and displaying the measurement points in this way, the waveform display device 300 ends the display processing operation.

[0053] Furthermore, in the measurement point selection unit 306, the measurement points (multiple waveform lines 350) displayed on the screen SC are color-coded with a gradient corresponding to the degree of unevenness relative to the reference surface. This allows the user to more easily visually confirm the unevenness of the machined surface of the workpiece.

[0054] As described above, the waveform display device 300 of this embodiment includes: a position information acquisition unit 301, which acquires motor position information of the drive axis of the machine tool 100 from the numerical control device 200 controlling the machine tool 100; an axis information setting unit 302, which sets axis information representing the axis structure of the drive axis of the machine tool 100; and a tool trajectory display unit 303, which calculates the trajectory of the tip point of the tool mounted on the machine tool 100 based on the motor position information acquired by the position information acquisition unit 301 and the axis information set by the axis information setting unit 302, and displays the trajectory as a waveform. The analysis object setting unit 304 sets the analysis object position 330 related to the trajectory of the tool tip point displayed by the tool path display unit 303; the analysis object range generation unit 305 generates and displays an analysis object range 340 composed of geometry, which includes the analysis object position 330 set by the analysis object setting unit 304; and the measurement point selection unit 306 selects and displays measurement points from the trajectory of the tool tip point that are included within the analysis object range 340 generated by the analysis object range generation unit 305. Therefore, by simply selecting the desired analysis position for the tool path, the range of measurement points including the analysis object can be easily specified. This greatly simplifies the user's analysis work on the machined surface of the workpiece.

[0055] In this embodiment, the analysis object setting unit 304 sets the analysis object position 330 using one or more points. Therefore, the user can easily perform analysis of a specified range of machining surfaces simply by selecting the desired analysis position on the screen using one or more points.

[0056] Furthermore, in this embodiment, the analysis object setting unit 304 can also set the analysis object position 330 by using a line segment connecting multiple points. Therefore, the user can easily perform analysis of a specified range of processing surfaces simply by selecting the desired analysis position on the screen using a line segment.

[0057] The analysis object range 340 is composed of a geometry with a length along the direction of the tool's forward direction vector, a width perpendicular to both the forward direction vector and the tool's tool vector, and a height perpendicular to the surface formed by the length and width. Based on this, the unevenness of the workpiece's machined surface can be reliably analyzed.

[0058] In this embodiment, the analysis object range 340 is a cuboid shape. The cuboid-shaped analysis object range 340 can be easily generated by setting its length, width, and height. However, the analysis object range 340 can have various shapes depending on the shape of the workpiece's machined surface and is not limited to a cuboid shape.

[0059] For example, when the machined surface of a workpiece is curved, such as the blades of an impeller, the surface of the analysis object range 340 can also be analyzed as follows: Figure 7 The surface shown corresponds to the shape of the machined surface of the workpiece. Figure 7 In the analysis object range 340, which is composed of geometric objects, the two surfaces facing the Z-axis are respectively composed of curved surfaces 340a and 340b. That is, the analysis object range 340 is defined as the range enclosed by curved surfaces 340a and 340b.

[0060] Surface 340a is represented by the following equation (3). Surface 340b is represented by the following equation (4).

[0061] z = a0x 2 +a1y 2 +a2xy+a3x+a4y+a5···(3)

[0062] z = b0x 2 +b1y 2 +b2xy+b3x+b4y+b5···(4)

[0063] Here, x min <x<x max ,y min <y<y max .

[0064] Figure 7 The analysis object range 340 shown is curved along the Y-axis direction but not in the X-axis direction. Additionally, surfaces 340a and 340b are convex in the same direction along the Z-axis. However, the surface of the analysis object range 340, composed of curved surfaces, could also be a spherical surface that is curved along the X and Y axes and convex in the opposite direction along the Z-axis, corresponding to the shape of the workpiece's machined surface. Figure 8 The analysis object range 340 is shown, whose surface is composed of an ellipsoid. The ellipsoid is represented by the following equation (5).

[0065] ax 2 +by 2 +cz 2 =d···(5)

[0066] Furthermore, although not illustrated, the surface of the analysis object range 340, which is composed of curved surfaces, can be curved in a concave shape along the Z-axis direction, or it can be curved in a convex or concave shape only in one direction along the Z-axis direction.

[0067] Explanation of reference numerals in the attached figures

[0068] 100: Machine tool; 200: Numerical control device; 300: Waveform display device; 301: Position information acquisition unit; 302: Axis information setting unit; 303: Tool path display unit; 304: Analytical object setting unit; 305: Analytical object range generation unit; 306: Measurement point selection unit; 330: Analytical object position; 340: Analytical object range.

Claims

1. A waveform display device, comprising: The position information acquisition unit acquires the motor position information of the drive axis of the machine tool from the control device that controls the machine tool; Axis information setting unit, which sets axis information representing the axis structure of the drive axis of the machine tool; The tool path display unit, based on the motor position information obtained by the position information acquisition unit and the axis information set by the axis information setting unit, calculates the distance in the vertical direction of the tool tip point relative to the workpiece machining surface, i.e., the reference surface, according to the coordinates of multiple tool tip points along the forward direction of the tool mounted on the machine tool. It then calculates the trajectory of the tool tip point using a line connecting each tool tip point and displays the trajectory as multiple parallel waveform lines representing the concavity and convexity information of the machining surface. The analysis object setting unit sets the position of the analysis object related to the trajectory of the tool tip point displayed by the tool path display unit for the multiple parallel waveform lines, using one or more points or a line segment connecting the multiple points. An analysis object range generation unit generates and displays an analysis object range composed of geometric shapes, wherein the geometric shapes include the analysis object positions set by the analysis object setting unit; and The measurement point selection unit selects measurement points from the trajectory of the tool tip point that are within the analysis object range generated by the analysis object range generation unit and displays them in a magnified manner.

2. The waveform display device according to claim 1, wherein, The scope of the analysis object is a geometric body with length along the direction of the tool's forward direction vector, width in a direction perpendicular to the forward direction vector and the tool's tool vector, and height in a direction perpendicular to the surface formed by the length and the width.

3. The waveform display device according to claim 2, wherein, The scope of the analysis object is a cuboid shape.

4. The waveform display device according to claim 2, wherein, The surface of the area being analyzed is curved.

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