JP7524698B2 - Display control device and display control method - Google Patents

Description

The present invention relates to a display control device and a display control method.

Devices that display the trajectory of a tool that processes a workpiece are known. The inspection system described in Patent Document 1 sets a predetermined range for the rotation angle to prevent the tool trajectory from overlapping for each rotation angle of the rotary table on which the workpiece is mounted.

Japanese Unexamined Patent Publication No. 60-31611

The above inspection system displays the tool trajectory when the rotation angle of the rotary table is within a specified range, so when the rotation angle of the rotary table exceeds the specified range, the tool trajectory may not be displayed.

The object of the present invention is to provide a display control device and a display control method that can properly display the trajectory of a tool that processes a workpiece even if the workpiece rotates relative to the tool.

The display control device according to the first aspect is a display control device that displays on a display unit a trajectory when a machine tool moves a tool relative to a workpiece to machine the workpiece with the tool, the machine tool is capable of moving the tool relative to the workpiece and rotating the workpiece relative to the tool around a predetermined rotation axis, and is characterized in that it includes a first acquisition unit that acquires coordinate data indicating the position of the workpiece or the tool and angle data indicating the angle of the predetermined rotation axis, a creation unit that creates drawing data for displaying the trajectory on the display unit by performing coordinate conversion on the coordinate data acquired by the first acquisition unit based on the angle data, and a display control unit that performs projection conversion on the drawing data created by the creation unit based on line-of-sight data indicating the line-of-sight direction when a user views the trajectory displayed on the display unit, and displays the trajectory on the display unit.

The display control device creates drawing data by converting the coordinate data based on the angle data. In this case, even if the workpiece rotates around the rotation axis relative to the tool, the tool trajectory displayed on the display unit can be prevented from overlapping. Therefore, the display control device can properly display the trajectory of the tool that processes the workpiece, even if the workpiece rotates around the rotation axis relative to the tool.

In the first aspect, the present invention includes a second acquisition unit that acquires the line of sight data, and a conversion unit that, when the current angle data, which is the angle data acquired this time by the first acquisition unit, differs from the previous angle data, which is the angle data acquired last time by the first acquisition unit, converts the line of sight data acquired by the second acquisition unit into coordinates based on the difference between the current angle data and the previous angle data, and the display control unit may project and convert the drawing data created by the creation unit based on the line of sight data converted by the conversion unit. When the display control device updates the angle data centered on the rotation axis, the display control device can update the line of sight direction when viewing the tool trajectory and display the tool trajectory on the display unit based on the updated line of sight direction. In this case, the display control device can display the trajectory while changing the line of sight direction in accordance with the rotation centered on the rotation axis.

In the first aspect, the display control unit may further display a workpiece image showing the workpiece on the display unit, and rotate the workpiece image displayed on the display unit according to the difference. The display control device can retain the position of the tool trajectory newly displayed on the display unit even when the angle data changes.

In the first aspect, the display control unit may further display a workpiece image showing the workpiece on the display unit, and may hold the position of the workpiece image displayed on the display unit regardless of the difference between current angle data, which is the angle data currently acquired by the first acquisition unit, and previous angle data, which is the angle data previously acquired by the first acquisition unit. The display control device can hold the position of the workpiece image displayed on the display unit even when the angle data changes.

In a first aspect, a reception unit that receives an instruction to change the line of sight direction may be provided, and the display control unit may project and convert the drawing data created by the creation unit based on the line of sight data indicating the line of sight direction changed in response to the instruction received by the reception unit, and display the trajectory on the display unit. The display control device can display on the display unit a trajectory viewed from a line of sight direction desired by the user.

In a first aspect, the machine tool includes a memory unit that stores a program having a plurality of commands including the coordinate data and the angle data, and the machine tool moves the tool relative to the workpiece and rotates the workpiece relative to the tool about the predetermined rotation axis based on the program stored in the memory unit, and the first acquisition unit may acquire the coordinate data and the angle data based on the commands of the program stored in the memory unit. The display control device can display the trajectory of the tool of the machine tool on the display unit based on a program for operating the machine tool.

In a first aspect, the command includes a first command and a second command that are executed successively by the machine tool, and the creation unit may create the drawing data by performing coordinate conversion on a plurality of coordinate data between the first coordinate data, which is the coordinate data of the first command, and the second coordinate data, which is the coordinate data of the second command, based on the angle data. The display control device can accurately draw the trajectory of a tool moving between a position indicated by the first coordinate data and a position indicated by the second coordinate data, based on the plurality of coordinate data.

In a first aspect, the predetermined rotation axis includes a first rotation axis and a second rotation axis, the machine tool is capable of moving the tool relative to the workpiece and rotating the workpiece relative to the tool about each of the first rotation axis and the second rotation axis, the first acquisition unit acquires the coordinate data, first angle data which is the angle data indicating the angle of the first rotation axis, and second angle data which is the angle data indicating the angle of the second rotation axis, and the creation unit may create the drawing data by performing coordinate conversion on the coordinate data acquired by the first acquisition unit based on the first angle data and the second angle data. The display control device can appropriately display the trajectory of the tool that processes the workpiece even when the workpiece rotates relative to the tool about the first rotation axis and the second rotation axis.

The display control method according to the second aspect of the present invention is a display control method for displaying on a display unit a trajectory when a machine tool moves a tool relative to a workpiece to machine the workpiece with the tool, the machine tool being capable of moving the tool relative to the workpiece and rotating the workpiece relative to the tool around a predetermined rotation axis, and is characterized by comprising a first acquisition step of acquiring coordinate data indicating the position of the workpiece or the tool and angle data indicating the angle of the predetermined rotation axis, a creation step of creating drawing data for displaying the trajectory on the display unit by performing coordinate conversion on the coordinate data acquired in the first acquisition step based on the angle data, and a display control step of projecting and converting the drawing data created in the creation step based on line-of-sight data indicating the line-of-sight direction when a user views the trajectory displayed on the display unit, and displaying the trajectory on the display unit. According to the second aspect, it is possible to achieve the same effect as the first aspect.

FIG. FIG. FIG. 2 is an electrical block diagram showing the electrical configuration of the numerical control device 40 and the machine tool 1. FIG. 4 is a perspective view of a workpiece line drawing 70 (workpiece 70A). A diagram showing cutting patterns 81A to 85A. FIG. 13 is a diagram showing movement trajectories 81 to 85 displayed on the display unit 19 using a first method. FIG. 13 is a diagram showing movement trajectories 81 to 85 displayed on the display unit 19 using a second method. 1 is a flow chart of a first main process. 1 is a flowchart of a drawing process. 11 is a flowchart of a first gaze update process. 13 is a flowchart of a second gaze update process. 4 is an explanatory diagram of line-of-sight vectors 91 and 93 and a display scale 96. 13 is a flow chart of the second main process. FIG. 11 is an explanatory diagram of a movement trajectory in the second embodiment.

An embodiment of the present invention will be described with reference to the drawings. In the following description, left/right, front/back, and up/down directions will be used as indicated by arrows in the drawings. The left/right, front/back, and up/down directions of the machine tool 1 are the X-axis, Y-axis, and Z-axis directions of the machine tool 1, respectively. The rightward, forward, and upward directions are positive directions, while the leftward, backward, and downward directions are negative directions. The machine tool 1 shown in Figure 1 is a multi-function machine that can perform cutting and turning of a workpiece (not shown) using a tool.

<Structure of machine tool 1>
The structure of the machine tool 1 will be described with reference to FIG. 1. The machine tool 1 includes a base 2, a Y-axis moving mechanism (not shown), an X-axis moving mechanism (not shown), a Z-axis moving mechanism (not shown), a moving body 15, a pillar 5, a spindle head 6, a spindle (not shown), a workpiece support device 8, a tool changer 9, a control box (not shown), a numerical control device 40 (see FIG. 3), and the like. The base 2 includes a stand 11, a spindle base 12, a right stand 13, a left stand 14, and the like. The stand 11 is a substantially rectangular parallelepiped structure that is elongated in the front-rear direction. The spindle base 12 is formed in a substantially rectangular parallelepiped shape that is elongated in the front-rear direction, and is provided on the rear of the upper surface of the stand 11. The right stand 13 is provided on the right front of the upper surface of the stand 11. The left stand 14 is provided on the left front of the upper surface of the stand 11. The right stand 13 and the left stand 14 each support the workpiece support device 8 on their upper surfaces.

The Y-axis movement mechanism is provided on the upper surface of the spindle base 12 and includes a Y-axis motor 62 (see FIG. 3). The Y-axis movement mechanism moves the approximately flat plate-shaped moving body 15 in the Y-axis direction by driving the Y-axis motor 62. The X-axis movement mechanism is provided on the upper surface of the moving body 15 and includes an X-axis motor 61 (see FIG. 3). The X-axis movement mechanism moves the vertical pillar 5 in the X-axis direction by driving the X-axis motor 61. The vertical pillar 5 can be moved in the X-axis and Y-axis directions on the base 2 by the Y-axis movement mechanism, the moving body 15, and the X-axis movement mechanism. The Z-axis movement mechanism is provided on the front surface of the vertical pillar 5 and includes a Z-axis motor 63 (see FIG. 3). The Z-axis movement mechanism moves the spindle head 6 in the Z-axis direction by driving the Z-axis motor 63. The spindle (not shown) is provided inside the spindle head 6 and includes a tool mounting hole (not shown) at the bottom of the spindle. A tool is mounted in the tool mounting hole. Therefore, the X-axis movement mechanism, Y-axis movement mechanism, and Z-axis movement mechanism can respectively move the tool attached to the spindle in the X-axis, Y-axis, and Z-axis directions relative to the workpiece. Hereinafter, the movement of the tool relative to the workpiece in the X-axis, Y-axis, and Z-axis directions by the X-axis movement mechanism, Y-axis movement mechanism, and Z-axis movement mechanism will be rephrased as "moving the tool in the X-axis, Y-axis, and Z-axis directions relative to the workpiece." The spindle is rotated by a spindle motor 66 (see Figure 3) provided on the top of the spindle head 6. At that time, the tool provided on the spindle rotates relative to the workpiece.

The tool changer 9 is in the shape of a substantially circular ring that surrounds the upright 5 and the spindle head 6. The tool changer 9 changes the tool currently attached to the spindle while the spindle head 6 is raised and lowered. The control box is attached to the outer wall of a cover (not shown) that covers the machine tool 1. The numerical control device 40 (see Figure 3) is stored inside the control box. The numerical control device 40 controls the operation of the machine tool 1 based on an NC program. The cover that covers the machine tool 1 is provided with an operation panel 10 (see Figure 3) on the outer wall surface. The operation panel 10 is provided with an operation unit 18 and a display unit 19. The operation unit 18 performs various settings for the numerical control device 40. The display unit 19 displays various screens, messages, alarms, the trajectory when the tool is moved relative to the workpiece, etc.

The workpiece support device 8 is fixed to the upper surfaces of the right base 13 and the left base 14. As shown in FIG. 2, the workpiece support device 8 includes an A-axis table 20, a left support table 27, a drive mechanism 28, a C-axis table 29, a C-axis drive unit 30, and the like. The A-axis table 20 includes a table section 21, a right connecting section 22, and a left connecting section 23. The table section 21 is a plate-shaped section that is approximately rectangular in plan view, with the A-axis table 20 having an inclination angle of 0 degrees and an upper surface that is a horizontal plane. The right connecting section 22 extends diagonally upward to the right from the right end of the table section 21 and is rotatably connected to the drive mechanism section 28. The left connecting section 23 extends diagonally upward to the left from the left end of the table section 21 and is rotatably connected to the left support table 27 described later. The left connecting section 23 has an approximately cylindrical support shaft 31 that protrudes leftward from its left end face. The left support table 27 rotatably supports the support shaft 31. The bottom of the left support stand 27 is fixed to the top surface of the left base stand 14 (see Figure 1).

The drive mechanism 28 is located on the right side of the A-axis table 20. The drive mechanism 28 houses the right support table (not shown), the A-axis motor 65 (see FIG. 3), etc. inside. The right connecting part 22 has a substantially cylindrical support shaft (not shown) that protrudes to the right from its right end face. The right support table rotatably supports the support shaft of the right connecting part 22. The support shaft of the right connecting part 22 and the output shaft of the A-axis motor 65 are connected to each other. When the output shaft of the A-axis motor 65 rotates, the A-axis table 20 rotates integrally with the right connecting part 22 around the support shaft 31 parallel to the X-axis direction. The rotation axis of the A-axis table 20 is the A-axis. The drive mechanism 28 can rotate the workpiece relative to the tool around the A-axis. The A-axis table 20 can tilt the workpiece in any direction relative to the tool attached to the spindle by tilting it at any angle around the A-axis. The bottom of the right support stand is fixed to the top surface of the right base stand 13 (see Figure 1).

The C-axis table 29 is rotatably mounted at approximately the center of the upper surface of the base 21. The C-axis table 29 is formed in a disk shape and is mounted at approximately the center of the upper surface of the A-axis table 20. The C-axis drive unit 30 is mounted on the lower surface of the base 21 and is connected to the C-axis table 29 through a hole (not shown) provided at approximately the center of the base 21. The C-axis drive unit 30 is equipped with a rotating shaft (not shown), a C-axis motor 64 (see FIG. 3), etc. inside. The rotating shaft extends in a direction perpendicular to the C-axis table 29. The rotating shaft is fixed to the C-axis table 29. The C-axis motor 64 is fixed to the rotating shaft. Therefore, when the C-axis motor 64 rotates the rotating shaft, the C-axis table 29 can rotate around an axis parallel to the Z-axis direction. The rotating axis of the C-axis table 29 is the C-axis. The jig 200 on the upper surface of the C-axis table 29 fixes the workpiece. The C-axis drive unit 30 can rotate the workpiece relative to the tool around the C-axis.

<Electrical configuration>
The electrical configuration of the numerical control device 40 and the machine tool 1 will be described with reference to Fig. 3. The numerical control device 40 includes a CPU 41, a ROM 42, a RAM 43, a flash memory 44, an input/output unit 45, and drive circuits 51-56. The machine tool 1 includes an X-axis motor 61, a Y-axis motor 62, a Z-axis motor 63, a C-axis motor 64, an A-axis motor 65, a spindle motor 66, and encoders 61A-66A. Hereinafter, when the drive circuits 51-56 are not distinguished from each other, they will be collectively referred to as a drive circuit 50. When the X-axis motor 61, the Y-axis motor 62, the Z-axis motor 63, the C-axis motor 64, the A-axis motor 65, and the spindle motor 66 are not distinguished from each other, they will be collectively referred to as a motor 60. When the encoders 61A-66A are not distinguished from each other, they will be collectively referred to as an encoder 60A.

The CPU 41 controls the operation of the machine tool 1. The ROM 42 stores control programs and the like for executing the first main process (see FIG. 11) and the second main process (see FIG. 21) described below. The RAM 43 stores various data generated during the execution of various processes. The flash memory 44 stores NC programs and the like. The NC program includes multiple commands that specify coordinate data indicating the position of the tool in the X-axis, Y-axis, and Z-axis directions relative to the workpiece, and angle data indicating the angle between the A-axis table 20 and the C-axis table 29. The input/output unit 45 inputs and outputs various signals between the drive circuit 50, the encoder 60A, the operation unit 18, and the display unit 19.

The drive circuit 50 outputs a pulse signal to the motor 60 based on the control signal output by the CPU 41. The encoder 60A detects the rotational position of the corresponding motor 60 and outputs the detection signal to the drive circuit 50 and the input/output unit 45. Both motors 60 are servo motors. The encoder 60A is a general absolute value encoder, and is a position sensor that detects and outputs the absolute position of the rotational position.

<How to display the tool movement trajectory>
The CPU 41 of the numerical control device 40 displays on the display unit 19 a path (referred to as a movement path) along which the machine tool 1 moves the tool to machine the workpiece with the tool. The CPU 41 calculates the movement path based on the movement of the tool based on the X-axis, Y-axis, and Z-axis, the rotation of the A-axis stage 20 about the A-axis, and the rotation of the C-axis stage 29 about the C-axis. A method of displaying the movement path will be specifically described with reference to Figs. 4 to 7. An example of a tool movement path 80 (see Figs. 6 and 7) when cutting cutting patterns 81A to 85A shown in Fig. 5 for an actual workpiece 70A shown by a line drawing pattern (referred to as a workpiece line drawing 70) in Fig. 4 is shown.

As shown in FIG. 4, the workpiece 70A is a decahedron with the upper four corners of a rectangular parallelepiped cut off. The left and right, front and back, and up and down arrows in FIG. 4 indicate the directions of the workpiece 70A fixed to the A-axis table 20 with the top surface being a horizontal plane. The workpiece 70A has vertices 7A to 7L. The vertices 7A, 7B, 7C, and 7D correspond to the four vertices of the square top surface 71A. The vertices 7A, 7B, and 7E correspond to the three vertices of the triangular inclined surface 72A. The vertices 7B, 7C, and 7F correspond to the three vertices of the triangular inclined surface 73A. The vertices 7C, 7D, and 7G correspond to the three vertices of the triangular inclined surface 74A. The vertices 7D, 7A, and 7H correspond to the three vertices of the triangular inclined surface 75A. The inclined surfaces 72A to 75A are each inclined with respect to the horizontal plane. The portions of the workpiece line drawing 70 that correspond to the top surface 71A and inclined surfaces 72A to 75A of the workpiece 70A are referred to as the top surface 71 and inclined surfaces 72 to 75.

Figure 5 (1) shows the cutting pattern 81A (diamond-shaped circular pattern) when cutting the top surface 71A. Figure 5 (2) shows the cutting pattern 82A (heart-shaped pattern) when cutting the inclined surface 72A. Figure 5 (3) shows the cutting pattern 83A (spiral pattern) when cutting the inclined surface 73A. Figure 5 (4) shows the cutting pattern 84A (reciprocating pattern) when cutting the inclined surface 74A. Figure 5 (5) shows the cutting pattern 85A (spiral staircase pattern) when cutting the inclined surface 75A.

The operation of the machine tool 1 when it actually cuts the cutting patterns 81A to 85A into the workpiece 70A will be described. The machine tool 1 drives the A-axis motor 65 to rotate the A-axis table 20 so that the top surface 71A of the workpiece 70A is horizontal. The machine tool 1 also drives the C-axis motor 64 to rotate the C-axis table 29 so that cutting of the cutting pattern 81A can be started. In this state, the machine tool 1 drives the X-axis movement mechanism, the Y-axis movement mechanism, the Z-axis movement mechanism, and the spindle motor 66 to cut the cutting pattern 81A into the top surface 71A. Next, the machine tool 1 drives the A-axis motor 65 to rotate the A-axis table 20 so that the inclined surface 72A of the workpiece 70A is horizontal. The machine tool 1 also drives the C-axis motor 64 to rotate the C-axis table 29 so that cutting of the cutting pattern 82A can be started. In this state, the machine tool 1 drives the X-axis movement mechanism, the Y-axis movement mechanism, the Z-axis movement mechanism, and the spindle motor 66 to cut the cutting pattern 82A into the inclined surface 72A. Thereafter, in a similar manner, the machine tool 1 cuts the cutting patterns 83A, 84A, and 85A in order into the inclined surfaces 73A, 74A, and 75A of the workpiece 70A.

The CPU 41 can display the workpiece line drawing 70 and the movement trajectory 80 on the display unit 19 by one of the following two methods. In the first method, the workpiece line drawing 70 and the movement trajectory 80 already displayed on the display unit 19 are rotated in accordance with the rotation of the A-axis table 20 and the C-axis table 29. At that time, the virtual arrangement of the tool on the display screen of the display unit 19 does not change even if the A-axis table 20 and the C-axis table 29 rotate. FIG. 6 shows the display screen displayed on the display unit 19 by the CPU 41 by the first method. On the other hand, in the second method, the virtual arrangement of the tool on the display screen of the display unit 19 is rotated in accordance with the rotation of the A-axis table 20 and the C-axis table 29. At that time, the workpiece line drawing 70 and the movement trajectory 80 already displayed on the display unit 19 do not change even if the A-axis table 20 and the C-axis table 29 rotate. FIG. 7 shows a display screen displayed on the display unit 19 by the CPU 41 using the second method. (1) to (5) in each of FIG. 6 and FIG. 7 show in sequence how cutting patterns 81A to 85A are cut into the upper surface 71A and inclined surfaces 72A to 75A of the workpiece 70A. Hereinafter, the movement trajectory 80 of the tool for cutting the cutting patterns 81A to 85A will be referred to as movement trajectories 81 to 85, respectively.

In the first method shown in FIG. 6, for example, after the machine tool 1 cuts the cutting pattern 81A (FIG. 6(1)), before cutting the next cutting pattern 82A, the A-axis table 20 and the C-axis table 29 rotate to rotate the workpiece 70A, as shown in FIG. 6(2), the workpiece line drawing 70 and the movement trajectory 81 already displayed in FIG. 6(1) rotate following the rotation of the A-axis table 20 and the C-axis table 29. Similarly, for example, after the machine tool 1 cuts the cutting pattern 82A (FIG. 6(2)), before cutting the next cutting pattern 83A, the workpiece line drawing 70 and the movement trajectories 81, 82 already displayed in FIG. 6(2) rotate following the rotation of the A-axis table 20 and the C-axis table 29. The same is true when cutting patterns 84A to 85A (see Figures 6 (4) and (5)). Note that the virtual placement of the tools on the display screen is always on the front side of Figure 6, and does not change even if the A-axis table 20 and C-axis table 29 rotate.

In the second method shown in Figure 7, for example, after the machine tool 1 cuts cutting pattern 81A (Figure 7 (1)), before cutting the next cutting pattern 82A, when the A-axis table 20 and C-axis table 29 are rotated to rotate the workpiece 70A, as shown in Figure 7 (2), the workpiece line drawing 70 and movement trajectory 81 already displayed in Figure 7 (1) do not rotate, unlike Figure 6 (2). On the other hand, the virtual position of the tool on the display screen follows the rotation of the A-axis table 20 and C-axis table 29, and rotates and moves from vertically above the top surface 71 to vertically above the inclined surface 72. Similarly, for example, after the machine tool 1 cuts the cutting pattern 82A (FIG. 7(2)), before cutting the next cutting pattern 83A, when the A-axis table 20 and the C-axis table 29 rotate to rotate the workpiece 70A, as shown in FIG. 7(3), the workpiece line drawing 70 and movement trajectories 81, 82 already displayed in FIG. 7(2) do not rotate but are fixed, unlike FIG. 6(3). Meanwhile, the virtual position of the tool on the display screen follows the rotation of the A-axis table 20 and the C-axis table 29, and rotates and moves from vertically above the inclined surface 72 to vertically above the inclined surface 73.

When the movement trajectory 80 is calculated and displayed based only on the movement of the tool relative to the X-axis, Y-axis, and Z-axis as in the conventional method, the movement trajectories 81 to 85 overlap with each other, making it difficult for the user to distinguish between them. On the other hand, when the movement trajectory 80 is calculated using the first method (see FIG. 6) and the second method (see FIG. 7), the movement trajectories 81 to 85 do not overlap with each other. Therefore, the user can distinguish between the movement trajectories 81 to 85.

<First embodiment>
The first main process according to the first embodiment will be described with reference to Figures 8 to 11. The CPU 41 repeatedly executes the first main process at a predetermined cycle based on a program stored in the flash memory 44. The flash memory 44 stores in advance initial values of line-of-sight data, first angle data, second angle data, projection surface information, display scale information, and workpiece information, which will be described later.

The gaze data is data of a vector (called a gaze vector) indicating the gaze direction when the user looks at the movement trajectory 80 displayed on the display unit 19. For example, in the first method, the gaze data when looking at the movement trajectory 81 of the upper surface 71 shown in FIG. 6 (1) is data of the gaze vector 91 shown in FIG. 12. The gaze vector 91 extends perpendicular to the upper surface 71 toward the center of the workpiece line drawing 70. For example, in the first method, the gaze data when looking at the movement trajectory 83 of the inclined surface 73 shown in FIG. 6 (3) is data of the gaze vector 93 shown in FIG. 12. The gaze vector 93 extends perpendicular to the inclined surface 73 toward the center of the workpiece line drawing 70. Although not shown, the gaze vector data when looking at the movement trajectories 82, 84, and 85 in the first method is also the same. On the other hand, in the second method, the gaze data when looking at the movement trajectories 81 to 85 is common, and is data of the gaze vector 90 shown in FIG. 12. In other words, in the first method, the line of sight vectors when viewing the movement trajectories 81 to 85 are different, whereas in the second method, the line of sight vectors when viewing the movement trajectories 81 to 85 are the same. The initial value of the line of sight data stored in the flash memory 44 is the data of the line of sight vector 90 when the user views the movement trajectory 80 displayed in the second method.

The first angle data indicates the angle of the A-axis table 20 centered on the A-axis. The second angle data indicates the angle of the C-axis table 29 centered on the C-axis. The projection plane information indicates the projection plane when the workpiece line drawing 70 and the movement trajectory 80 defined in a three-dimensional space are projected onto a two-dimensional plane and displayed on the display unit 19. The display scale information indicates the position and size of the workpiece line drawing 70 and the movement trajectory 80 when projected onto the projection plane. For example, when the workpiece line drawing 70 and the movement trajectory 80 are displayed on the display unit 19 in the range surrounded by dotted lines 96A, 96B, 96C, and 96D from the line of sight direction indicated by the line of sight vector 93 shown in FIG. 12, the display scale information indicates the rectangular display scale 96 formed on the projection plane 97. The workpiece information is line drawing information necessary to define the workpiece line drawing 70 in a three-dimensional space.

但し、（ｘ_ｐ，ｙ_ｐ，ｚ_ｐ）はＡ軸の中心座標データである。（ｘ_ｑ，ｙ_ｑ，ｚ_ｑ）はＣ軸の中心座標データである。Ｐ（－ｐ_ｍ）はＡ軸周りにｐ_ｍ度回転する逆回転行列であり、式（２）で示せる。

Ｘ（－ｐ_ｍ）、Ｙ（－ｐ_ｍ）、Ｚ（－ｐ_ｍ）は夫々、Ａ軸がＸ軸、Ｙ軸、Ｚ軸の各々の周りを回転する時の角度を示し、式（３）（４）（５）で示せる。尚、式（３）～（５）にて－ｐ_ｍをθで示す。

Ｑ（－ｑ_ｍ）はＣ軸周りにｑ_ｍ度回転する逆回転行列であり、Ｐ（－ｐ_ｍ）の場合と同様の式で表せる。 8, the CPU 41 acquires coordinate data ( _xm , _ym , _zm ) indicating the tool position in each of the X-axis, Y-axis, and Z-axis directions, first angle data ( _pm ), and second angle data ( _qm ) based on the signal output by the encoder 60A (S11). The CPU 41 performs coordinate conversion processing by substituting the acquired coordinate data ( _xm , _ym , _zm ), first angle data ( _pm ), and second angle data ( _qm ) into equation (1), and creates coordinate data (referred to as drawing data ( _xt , _yt , _zt )) for displaying the movement trajectory 80 on the display unit 19 (S13).

Here, ( _xp , _yp , _zp ) is the center coordinate data of the A axis, ( _xq , _yq , _zq ) is the center coordinate data of the C axis, and P( _-pm ) is an inverse rotation matrix for rotating _pm around the A axis, and can be expressed by equation (2).

X(-p _m ), Y(-p _m ), and Z(-p _m ) respectively indicate the angles when the A-axis rotates around the X-axis, Y-axis, and Z-axis, and can be expressed by equations (3), (4), and (5). Note that in equations (3) to (5), -p _m is represented by θ.

Q(-q _m ) is an inverse rotation matrix for rotating q _m degrees around the C axis, and can be expressed by the same formula as in the case of P(-p _m ).

The CPU 41 stores the created drawing data ( _xt , _yt , _zt ) in the flash memory 44 (S15). Since the CPU 41 periodically and repeatedly executes the first main process, the flash memory 44 stores a plurality of drawing data ( _xt , _yt , _zt ). A line segment connecting positions indicated by the plurality of drawing data ( _xt , _yt , _zt ) stored in the flash memory 44 corresponds to a movement trajectory 80 to be displayed on the display unit 19. The CPU 41 executes a drawing process (see FIG. 9) to display the movement trajectory 80 on the display unit 19 based on the plurality of drawing data ( _xt , _yt , _zt ) stored in the flash memory 44 (S17).

The drawing process will be described with reference to FIG. 9. The CPU 41 accepts an operation via the operation unit 18 to specify whether the display method of the movement trajectory 80 on the display unit 19 is to be the first method or the second method. If the CPU 41 accepts an instruction to use the first method (S21: YES), it executes a first gaze update process (see FIG. 10) to update the gaze data to display the movement trajectory 80 using the first method (S23). After the first gaze update process ends, the CPU 41 advances the process to S25. If the CPU 41 accepts an instruction to use the second method (S21: NO), it advances the process to S25 because the initial value of the gaze data stored in the flash memory 44 can be used as is.

The first gaze update process will be described with reference to FIG. 10. The CPU 41 acquires the gaze data stored in the flash memory 44 (S31). The CPU 41 acquires the first angle data and the second angle data based on the signal output by the encoder 60A (S31). The CPU 41 acquires the coordinate data indicating the A axis and the coordinate data indicating the C axis (S31).

The CPU 41 calculates the difference (Δp _m ) between the first angle data (p _m ) acquired by the processing of S31 and the first angle data (p _m ) stored in the flash memory 44 (S33). The CPU 41 calculates the difference (Δq _m ) between the second angle data (q _m ) acquired by the processing of S31 and the second angle data (q _m ) stored in the flash memory 44 (S33). If the calculated difference (Δp _m ) is 0, the CPU 41 determines that the A-axis stand 20 has not rotated around the A-axis after the first main processing was last executed. If the calculated difference (Δq _m ) is 0, the CPU 41 determines that the C-axis stand 29 has not rotated around the C-axis after the first main processing was last executed. If the CPU 41 determines that neither the A-axis stand 20 nor the C-axis stand 29 has rotated (S35: NO), the CPU 41 advances the processing to S39.

On the other hand, if the calculated difference (Δp _m ) is not 0, the CPU 41 determines that the A-axis mount 20 has rotated around the A-axis after the first main process was last executed. If the calculated difference (Δq _m ) is not 0, the CPU 41 determines that the C-axis mount 29 has rotated around the C-axis after the first main process was last executed. If the CPU 41 determines that at least one of the A-axis mount 20 and the C-axis mount 29 has rotated (S35: YES), the CPU 41 advances the process to S37 in order to update the line of sight data stored in the flash memory 44.

The CPU 41 performs coordinate conversion processing by substituting the gaze data ( _xv , _yv , _zv ), the coordinate data ( _xp , _yp , _zp ) indicating the A axis, the coordinate data ( _xq , _yq , _zq ) indicating the C axis, and the difference ( _Δpm , _qm ) acquired from the flash memory 44 in S31 into equation (6), and updates the gaze data ( _xv , _yv , _zv ) (S37). Note that (xv _' , _yv ', _zv ') indicates the updated gaze data.

The CPU 41 rewrites and updates the first angle data and the second angle data stored in the flash memory 44 with the first angle data and the second angle data acquired based on the signal output by the encoder 60A in S31 (S39). When the CPU 41 executes the process of S37, it rewrites and updates the line of sight data ( _xv , _yv , _zv ) stored in the flash memory 44 with the line of sight data ( _xv ', _yv ', _zv ') calculated in S37 (S39). The CPU 41 ends the first line of sight update process and returns the process to the drawing process (see FIG. 9). As shown in FIG. 9, after the first line of sight update process ends, the CPU 41 advances the process to S25.

As shown in FIG. 9, in S25, the CPU 41 determines whether an operation to change the line of sight direction or the display scale has been detected via the operation unit 18 (S25). If the CPU 41 does not detect an operation (S25: NO), the process proceeds to S29. If the CPU 41 detects an operation to change the line of sight direction (S25: YES), the CPU 41 executes a second line of sight update process to update the line of sight data in response to the operation (S27).

The second gaze update process will be described with reference to FIG. 11. The CPU 41 acquires the gaze data and display scale information stored in the flash memory 44 (S41). The CPU 41 further acquires the movement amount (referred to as the vector movement amount) and the rotation amount (referred to as the vector rotation amount) of the gaze vector corresponding to the operation detected by the process of S25 (S41). The CPU 41 adds the vector movement amount to the gaze vector indicated by the gaze data, and updates the gaze data (S43). The CPU 41 further rotates the gaze vector indicated by the gaze data by the vector rotation amount, and updates the gaze data (S45). The CPU 41 rewrites and updates the display scale information stored in the flash memory 44 with the acquired display scale information (S47). The CPU 41 ends the second gaze update process, and returns the process to the drawing process (see FIG. 9). As shown in FIG. 9, the CPU 41 advances the process to S29 after the second gaze update process ends.

9, the CPU 41 defines the workpiece line drawing 70 in a three-dimensional space based on the workpiece information stored in the flash memory 44. The CPU 41 defines the movement trajectory 80 in the three-dimensional space based on the multiple drawing data stored in the flash memory 44. In detail, the CPU 41 defines the movement trajectory 80 in the three-dimensional space by connecting the positions indicated by each drawing data with a straight line. The CPU 41 projects the workpiece line drawing 70 and the movement trajectory 80 defined in the three-dimensional space onto the projection plane 97 (see FIG. 14) based on the line-of-sight data and the projection plane information stored in the flash memory 44, and performs projection conversion to a two-dimensional image (S29). The CPU 41 cuts out the projection-converted two-dimensional image using the display scale 96 (see FIG. 14) based on the display scale information stored in the flash memory 44. Note that the projection conversion to the two-dimensional image and the cutout using the display scale 96 can be performed using various well-known methods as appropriate. The CPU 41 displays the cut-out two-dimensional image on the display unit 19 and updates the display content (S29, see Figures 6 and 7). The CPU 41 ends the drawing process and returns the process to the first main process (see Figure 8). As shown in Figure 8, the CPU 41 ends the first main process after the drawing process (see S17) ends.

<Functions and Effects of the First Embodiment>
The numerical control device 40 performs coordinate conversion processing by substituting the coordinate data indicating the position of the tool in each of the X-axis, Y-axis, and Z-axis directions, the first angle data, and the second angle data into formula (1) to create drawing data (S13). In this case, even if the workpiece rotates around the A-axis and C-axis relative to the tool, the movement trajectories 81 to 85 displayed on the display unit 19 can be prevented from overlapping. Therefore, the numerical control device 40 can appropriately display the movement trajectories 81 to 85 even if the workpiece rotates around the A-axis and C-axis relative to the tool.

When the workpiece rotates around at least one of the A-axis and C-axis relative to the tool (S35: YES), the numerical control device 40 performs a coordinate conversion process by substituting the gaze data, the coordinate data indicating the A-axis and C-axis, and the difference between the first angle data and the second angle data into equation (6) to update the gaze data (S37). The numerical control device 40 can display the movement trajectory 80 on the display unit 19 based on the updated gaze data. In this case, even when the workpiece rotates around the A-axis and C-axis, the numerical control device 40 can display the movement trajectory 80 on the display unit 19 while changing the gaze direction in accordance with the rotation.

When the numerical control device 40 receives an instruction to change the display method to the first method (S21: YES), it displays the workpiece line drawing 70 and the movement trajectory 80 on the display unit 19 using the first method. In this case, the workpiece line drawing 70 and the movement trajectory 80 already displayed on the display screen of the display unit 19 rotate following the rotation of the A-axis table 20 and the C-axis table 29 (see FIG. 6). The numerical control device 40 can maintain the virtual arrangement of the tool relative to the display screen and the position of the movement trajectory 80 to be newly displayed on the display screen at a fixed position even when the A-axis table 20 and the C-axis table 29 rotate.

When the numerical control device 40 receives an instruction to change the display method to the second method (S21: NO), it displays the workpiece line drawing 70 and movement trajectory 80 on the display unit 19 using the second method. In this case, the workpiece line drawing 70 and movement trajectory 80 already displayed on the display screen of the display unit 19 do not move even if the A-axis table 20 and the C-axis table 29 rotate. The numerical control device 40 can maintain the positions of the workpiece line drawing 70 and movement trajectory 80 displayed on the display unit 19 even when the A-axis table 20 and the C-axis table 29 rotate.

When the numerical control device 40 detects an operation to change the line of sight direction (S25: YES), it performs projection conversion of the drawing data based on the line of sight data indicating the changed line of sight direction, and displays it as a trajectory on the display unit 19. Therefore, the numerical control device 40 can display on the display unit 19 the movement trajectory 80 as seen from the line of sight direction desired by the user.

Second Example
The second main processing according to the second embodiment will be described with reference to Figures 13 and 14. The same processes as those in the first main processing are given the same reference numerals and will not be described. The CPU 41 executes the second main processing each time it selects one command from the multiple commands in the NC program stored in the flash memory 44 in order.

The CPU 41 acquires the coordinate data, first angle data, and second angle data specified by the command (referred to as the second command) selected from the NC program (S51). The CPU 41 acquires the coordinate data, first angle data, and second angle data specified by the command (referred to as the first command) selected from the NC program in the previous second main process (S53). The first command and second command are two consecutive commands among the multiple commands of the NC program. The first command corresponds to the command before the second command among the multiple commands of the NC program.

The CPU 41 calculates the difference (Δp _m ) between the first angle data and the difference (Δq m ) between the second angle data based on the first angle data (p _m ) and the second angle data (q _{m )} of the first command and the second command. The CPU 41 determines whether at least one of the A-axis stand 20 and the C-axis stand 29 has rotated when the machine tool 1 executes the second command following the first command based on the calculated difference (Δp _m , Δq _m ) (S55). When the CPU 41 determines that neither the A-axis stand 20 nor the C-axis stand 29 has rotated (S55: NO), the process proceeds to S13.

On the other hand, if the CPU 41 determines that at least one of the A-axis table 20 and the C-axis table 29 has rotated (S55: YES), it divides the movement path of the tool that moves between the first position indicated by the coordinate data of the first command (referred to as the first coordinate data) and the second position indicated by the coordinate data of the second command (referred to as the second coordinate data) into N (S57). The CPU 41 stores in the flash memory 44 N-1 pieces of coordinate data (referred to as divided coordinate data) that indicate the positions of both ends of each of the N divided movement paths.

The following will be described with reference to a specific example shown in FIG. 14. The workpiece 100 moves in the X-axis direction relative to the tool 40A based on a first command (see arrow Y11, FIG. 14 (2)), and then rotates around the C-axis relative to the tool 40A based on a second command (see arrow Y12, FIG. 14 (3)). Coordinate data indicating the first position P1, which is the position after the tool 40A moves based on the first command, corresponds to the first coordinate data. Coordinate data indicating the second position P2 after the tool 40A moves based on the second command corresponds to the second coordinate data. At that time, the CPU 41 divides the movement path 87A of the tool 40A moving between the first position P1 and the second position P2 into N equal parts. The CPU 41 calculates divided coordinate data indicating each of the N-1 positions Pn(1), Pn(2) ... Pn(N-1) corresponding to the positions of the N equally divided movement path. The CPU 41 calculates angle data (referred to as divided first angle data) indicating the rotation angle about the A axis when the tool moves along a movement path divided into N equal parts. The CPU 41 further calculates angle data (referred to as divided second angle data) indicating the rotation angle about the C axis when the tool moves along a movement path divided into N equal parts. The CPU 41 stores the calculated divided coordinate data in the flash memory 44.

As shown in Fig. 13, the CPU 41 performs a coordinate conversion process by substituting the coordinate data ( _xm , _ym , _zm ), the first angle data ( _pm ), and the second angle data ( _qm ) acquired by the process of S51 into formula (1) to create drawing data (S13). When the CPU 41 calculates N-1 pieces of divided coordinate data by the process of S57, the CPU 41 performs a coordinate conversion process by substituting each of the N-1 pieces of divided coordinate data, the first divided angle data, and the second divided angle data into formula (1) to create drawing data (S13). The CPU 41 stores the created drawing data in the flash memory 44 (S15). The CPU 41 executes a drawing process (see Fig. 9) to display a movement trajectory 80 on the display unit 19 based on the multiple drawing data stored in the flash memory 44 (S17).

In the processing of S29 of the drawing process shown in FIG. 9, the CPU 41 defines a movement trajectory 80 by connecting the positions indicated by each of the multiple drawing data stored in the flash memory 44 with straight lines. At this time, as shown in FIG. 14 (3), for example, the movement trajectory between the first position P1 indicated by the first coordinate data of the first command and the second position P2 indicated by the second coordinate data of the second command is defined by straight lines connecting each of the N-1 positions Pn(1), Pn(2) ... Pn(N-1) indicated by the multiple divided coordinate data. After the projection transformation and display scale processing, the CPU 41 displays the movement trajectory 80 on the display unit 19 (S29).

<Functions and Effects of the Second Embodiment>
The numerical control device 40 can display the movement trajectory 80 of the tool of the machine tool 1 on the display unit 19 based on the NC program for operating the machine tool 1. In this case, the numerical control device 40 can display the movement trajectory 80 of the tool on the display unit 19 without actually operating the machine tool 1.

When multiple division coordinate data, division first angle data, and division second angle data are not created, the numerical control device 40 displays a movement trajectory indicating a movement path 87B that connects the first position P1 and the second position P2 with a straight line on the display unit 19, as shown in FIG. 14 (4). However, the actual movement path at that time is not preferable because it has an arc shape caused by the rotation of the workpiece 100 about the C axis. In response to this, the CPU 41 defines the movement trajectory as a straight line connecting each of the N-1 positions Pn(1), Pn(2) ... Pn(N-1) indicated by the multiple division coordinate data, as shown in FIG. 14 (3). This allows the numerical control device 40 to accurately draw the movement trajectory of the tool moving between the first position P1 and the second position P2.

<Modification>
The present invention is not limited to the above embodiment, and various modifications are possible. The first main process (see FIG. 8) and the second main process (see FIG. 11) may be executed by a CPU of an external device (e.g., a PC) connected to the machine tool 1. The machine tool 1 may move the tool in the X-axis and Y-axis directions relative to the fixed workpiece. At that time, the machine tool 1 may fix the workpiece in the X-axis, Y-axis, and Z-axis directions. Furthermore, the machine tool 1 may rotate the tool with the A-axis and C-axis as the central axis relative to the fixed workpiece. The central axis when the machine tool 1 rotates the workpiece relative to the tool may be only one of the A-axis and C-axis. The central axis when the machine tool 1 rotates the workpiece relative to the tool may be three or more axes. The numerical control device 40 may display the movement trajectory 80 on the display unit 19 by only either the first method or the second method.

＜Other＞
The numerical control device 40 is an example of the "display control device" of the present invention. The A-axis and the C-axis are examples of the "rotation axis" of the present invention. The workpiece line drawing 70 is an example of the "workpiece image" of the present invention. The CPU 41 that performs the processes of S11 and S51 is an example of the "first acquisition unit" of the present invention. The CPU 41 that performs the process of S13 is an example of the "creation unit" of the present invention. The CPU 41 that performs the process of S29 is an example of the "display control unit" of the present invention. The CPU 41 that performs the process of S31 is an example of the "second acquisition unit" of the present invention. The CPU 41 that performs the process of S37 is an example of the "conversion unit" of the present invention. The CPU 41 that performs the process of S25 is an example of the "reception unit" of the present invention. The flash memory 44 that stores the NC program is an example of the "storage unit" of the present invention. The processes of S11 and S51 are an example of the "first acquisition step" of the present invention. The process of S13 is an example of the "creation step" of the present invention. The process of S29 is an example of the "display control step" of the present invention.

1: Machine tool 8: Workpiece support device 19: Display section 20: A-spindle stock 29: C-spindle stock 40: Numerical control device 40A: Tool 41: CPU
44: Flash memory 70: Line drawing of workpiece 70A, 100: Workpiece 91, 93: Line of sight vector 96: Display scale

Claims (7)

A display control device that displays on a display unit a trajectory of a tool moving relative to a workpiece in a machine tool for machining the workpiece,
The machine tool comprises:
The tool is movable relative to the workpiece, and the workpiece is rotatable relative to the tool about a predetermined rotation axis;
A first acquisition unit that acquires coordinate data indicating a position of the workpiece or the tool and angle data indicating an angle of the predetermined rotation axis;
a creating unit that creates drawing data for displaying the trajectory on the display unit by performing coordinate conversion on the coordinate data acquired by the first acquiring unit based on the angle data;
a display control unit that performs projection transformation of the drawing data created by the creation unit based on line-of-sight data indicating a line-of-sight direction when a user views the trajectory displayed on the display unit, and displays the trajectory on the display unit;
A second acquisition unit that acquires the line of sight data;
a conversion unit that converts the line of sight data acquired by the second acquisition unit into coordinates based on a difference between the current angle data, which is the angle data acquired by the first acquisition unit this time, and the previous angle data, which is the angle data acquired previously by the first acquisition unit, when the current angle data is different from the previous angle data;
Equipped with
The display control unit is
A display control device comprising: a display control unit that performs projection conversion on the drawing data created by the creation unit based on the line-of-sight data converted by the conversion unit . The display control unit is
A workpiece image showing the workpiece is further displayed on the display unit;
The display control device according to claim 1 , further comprising: rotating the image of the workpiece displayed on the display unit in accordance with the difference. a reception unit for receiving an instruction to change the line of sight,
The display control unit is
The display control device according to claim 1 or 2, characterized in that the drawing data created by the creation unit is projected and transformed based on the gaze data indicating the gaze direction changed in accordance with the instruction received by the reception unit, and displayed as the trajectory on the display unit. a storage unit that stores a program having a plurality of commands including the coordinate data and the angle data;
The machine tool comprises:
Based on the program stored in the storage unit, the tool is moved relative to the workpiece, and the workpiece is rotated relative to the tool about the predetermined rotation axis;
The first acquisition unit,
4. The display control device according to claim 1, wherein the coordinate data and the angle data are acquired based on the command of the program stored in the storage unit. the commands include a first command and a second command which are executed successively by the machine tool;
The creation unit is
The display control device according to claim 4, characterized in that the drawing data is created by performing coordinate conversion on a plurality of coordinate data between the first coordinate data, which is the coordinate data of the first command, and the second coordinate data, which is the coordinate data of the second command, based on the angle data. the predetermined rotation axis includes a first rotation axis and a second rotation axis,
The machine tool comprises:
The tool is movable relative to the workpiece, and the workpiece is rotatable relative to the tool about each of the first rotation axis and the second rotation axis;
The first acquisition unit,
acquiring the coordinate data, first angle data which is the angle data indicating an angle of the first rotation axis, and second angle data which is the angle data indicating an angle of the second rotation axis;
The creation unit is
A display control device according to any one of claims 1 to 5, characterized in that the drawing data is created by converting the coordinate data acquired by the first acquisition unit into coordinates based on the first angle data and the second angle data. A display control method for displaying on a display unit a trajectory of a tool relative to a workpiece in order for a machine tool to machine the workpiece, the method comprising:
The machine tool comprises:
The tool is movable relative to the workpiece, and the workpiece is rotatable relative to the tool about a predetermined rotation axis;
a first acquisition step of acquiring coordinate data indicating a position of the workpiece or the tool and angle data indicating an angle of the predetermined rotation axis;
a creating step of creating drawing data for displaying the trajectory on the display unit by performing coordinate conversion on the coordinate data acquired in the first acquiring step based on the angle data;
a display control step of projecting and transforming the drawing data created in the creation step based on line-of-sight data indicating a line-of-sight direction when a user views the trajectory displayed on the display unit, and displaying the trajectory on the display unit;
A second acquisition step of acquiring the line of sight data;
a conversion step of converting the line of sight data acquired in the second acquisition step into coordinates based on a difference between the current angle data, which is the angle data acquired in the first acquisition step, and the previous angle data, which is the angle data acquired last time in the first acquisition step, when the current angle data is different from the previous angle data;
Equipped with
The display control step includes:
A display control method comprising : projecting and transforming the drawing data created in the creation step based on the line-of-sight data converted in the conversion step .

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