WO2024142215A1

WO2024142215A1 - Numerical control device and computer-readable storage medium

Info

Publication number: WO2024142215A1
Application number: PCT/JP2022/048112
Authority: WO
Inventors: 拓馬宝田
Original assignee: ファナック株式会社
Priority date: 2022-12-27
Filing date: 2022-12-27
Publication date: 2024-07-04

Abstract

This numerical control device acquires a cutting trajectory of a processing head of a machine tool for processing a board material, acquires a positioning path of the processing head, determines that avoidance on the positioning path is necessary when the cutting trajectory and the positioning path intersect, and adds a retreat movement and a return movement of the processing head in the height direction to the positioning path.

Description

Numerical control device and computer-readable storage medium

This disclosure relates to a numerical control device and a computer-readable storage medium.

　Conventionally, there are machine tools for processing sheet metal, such as laser processing machines, plasma processing machines, and gas processing machines. These machine tools emit energy from laser, plasma, gas, etc., from the processing head. When cutting sheet metal into a closed shape, the cut part may not fall but may become caught on something, causing it to tilt and protrude from the sheet metal. If the processing head interferes with this protruding part, it can cause the processing head to break down.

A conventional technique for avoiding this interference is to automatically move the processing head in the opposite direction to the plate material by a preset amount when positioning it. For example, see Patent Document 1.

Japanese Utility Model Application Publication No. 03-101380

Generally, when avoiding interference, the tool is moved away a fixed distance. However, any excess movement away from the tool results in wasted machining time and energy. There is a demand for technology that can determine an efficient movement away distance for interference avoidance operations.

The numerical control device according to one aspect of the present disclosure includes a trajectory acquisition unit that acquires the cutting trajectory of the machining head of a machine tool that processes sheet metal, a path acquisition unit that acquires the positioning path of the machining head, and an avoidance unit that, when the cutting trajectory and the positioning path intersect, determines that avoidance is necessary in the positioning path and adds a vertical retraction and return operation of the machining head to the positioning path.

1 is a block diagram of a numerical control device according to a first embodiment; FIG. 4 is a schematic diagram showing an example of a cut portion. FIG. 2 is a schematic diagram showing an example of a closed shape. FIG. 13 is a schematic diagram showing a method for calculating a retraction amount. FIG. 13 is a schematic diagram showing a method for calculating a retraction amount. FIG. 11 is a schematic diagram illustrating a method for determining the necessity of avoidance. FIG. 13 is a schematic diagram illustrating an example of dividing a circular arc into straight lines. 4 is a flowchart illustrating an operation of the numerical control device. FIG. 4 is a schematic diagram showing an example of a path of a machining head. FIG. 4 is a screen display diagram showing an example of a machining program. FIG. 11 is a block diagram of a numerical control device according to a second embodiment. FIG. 2 is a hardware configuration diagram of a numerical control device.

The numerical control device 100 described below controls a machine tool that processes plate materials. Machine tools that process plate materials include laser processing machines, gas cutters, plasma cutters, etc. In the following embodiment, a laser processing machine will be described as an example.
The components of the numerical control device 100 are classified according to their functions, and do not necessarily have to be clearly distinguished in terms of physical configuration and program configuration.

First Embodiment
A numerical control device 100 according to a first embodiment will be described below. Fig. 1 is a block diagram of the numerical control device 100. The numerical control device 100 includes a trajectory acquisition unit 11, a trajectory storage unit 12, a path acquisition unit 13, a closed shape detection unit 14, a closed shape storage unit 15, a retraction amount calculation unit 16, a retraction range storage unit 17, an avoidance unit 18, a machining program analysis unit 19, and a machining program execution unit 20.

The trajectory acquisition unit 11 acquires the cutting trajectory of the processing head of the laser processing machine. The processing path of the laser processing machine is commanded by the processing program. The processing path includes a cutting trajectory that cuts the plate material and a positioning path that moves to the next processing start point.

Cutting trajectories are classified as linear or circular interpolation depending on how the machining path is specified. With linear interpolation, the cutting path moves in a straight line from the starting point to the end point specified in the machining program. With circular interpolation, the cutting path moves in an arc from the starting point. In an NC program, the shape of the circle is set using information on two or more of the end point of the circle, the center of the arc, and the rotation angle.

The path acquisition unit 13 acquires a positioning path. Unlike the cutting path, the positioning path does not involve laser output. In positioning, the processing head is moved from the end point of the previous cutting path to the start point of the next cutting path. When positioning the processing head, there is a risk of interference between the tilted cutting portion and the processing head (see Figure 2).

The closed shape detection unit 14 detects a closed shape based on the cutting trajectory and stores it in the closed shape storage unit 15. The closed shape may be a closed shape made up of a combination of straight lines, a closed shape made up of arcs, a closed shape made up of a combination of straight lines and arcs, etc. An arc can be regarded as a combination of straight lines.
Detection of a closed shape made up of straight lines will be described with reference to Fig. 3. In the example of Fig. 3, five cutting trajectories (I) to (V) form a closed shape. The cutting trajectory acquired by the trajectory acquisition unit 11 holds information on the intersections between the current trajectory and other trajectories.

The intersection information is stored, for example, by an ID. When one cut trajectory intersects with a certain cut trajectory, one ID is associated with this cut trajectory. When two cut trajectories intersect with a certain cut trajectory, two IDs are associated with this cut trajectory. A cut trajectory that intersects with two or more cut trajectories, i.e., a cut trajectory associated with two or more IDs, is searched for. When a cut trajectory intersects with multiple cut trajectories, one of the multiple cut trajectories is selected.
If the selected cutting trajectory intersects with another cutting trajectory, the cutting trajectory is selected. If the selected cutting trajectory intersects with another cutting trajectory, the cutting trajectory is selected. This process is repeated, and if there is a cutting trajectory that has a previously selected intersection, it is determined that a closed shape will be formed by cutting.

The closed shape detection will be specifically described with reference to the example of FIG.
1. Select cutting trajectory (I) as the first cutting trajectory.
2. The cutting trajectory (I) has two intersections, intersection A and intersection B. Of the two intersections, intersection B is selected.
3. Cutting trajectory (II) shares an intersection point B with cutting trajectory (I). Cutting trajectory (II) has another intersection point C.
4. Cutting trajectory (III) shares an intersection point C with cutting trajectory (II). Cutting trajectory (III) has another intersection point D.
5. Cutting trajectory (IV) shares an intersection point D with cutting trajectory (III). Cutting trajectory (IV) has another intersection point E.
6. The cutting trajectory (V) shares an intersection point E with the cutting trajectory (IV). The cutting trajectory (V) shares an intersection point A with the cutting trajectory (I).
Since the cutting trajectory (V) shares the intersection point A with the previously selected cutting trajectory (I), it can be seen that the cutting trajectory (I) to the cutting trajectory (V) form a closed shape.

The retraction amount calculation unit 16 calculates the retraction amount of the processing head based on the closed shape and stores it in the closed shape storage unit 15. The retraction amount of the processing head is the retraction amount in the height direction. The retraction amount calculation unit 16 calculates a sufficient height so that the processing head does not interfere with the cutting part when positioning the processing head.

Two methods for calculating the amount of retraction will be described.
The first method is to detect two points in the cut portion that are farthest apart, and use the distance between the two points as the retraction amount. Fig. 4 is a plan view of the cut portion. In Fig. 4, the distance between two points A and B is the farthest apart in the cut portion. The retraction amount calculation unit 16 calculates the length of line segment AB as the retraction amount. This calculation method was devised because when the cut portion is tilted and protrudes from the plate material, the height direction distance of the protruding portion is always shorter than the length of line segment AB. Note that existing technology is used to calculate the farthest distance in the cut portion.

The second method is to calculate the center of gravity of the cut portion, and use the distance from the center of gravity to the farthest point as the retraction amount. Figure 5 is a plan view of the cut portion. In Figure 5, point C is the furthest from the center of gravity. The retraction amount calculation unit 16 calculates the length of the line segment WC connecting the center of gravity W and point C as the retraction amount. This calculation method is based on the fact that when the cut portion tilts, any part of the cut portion gets caught and tilts toward the center of gravity relative to the part that got caught on the center of gravity side. In this way, the longest height direction distance of the protruding part is when a part that is slightly shifted from the center of gravity W in the direction of the line segment WC gets caught, so it is sufficient to retract the part by the length of the line segment WC. Existing technology is used to calculate the center of gravity W and the point C that is the furthest from the center of gravity W.

The retraction range memory unit 17 stores the upper or lower limit value of the retraction amount. If the calculated retraction amount exceeds the range of the upper or lower limit value, the retraction amount calculation unit 16 adjusts the retraction amount so that it is within the range of the upper or lower limit value. If the retraction amount is too large, adjustment is necessary. Also, if the retraction amount is too small, there is a risk that the dross (molten metal adhering in the form of balls or icicles) in the cutting area will interfere with the processing head. Therefore, the retraction amount is adjusted using the lower limit value.

When positioning the machining head, the avoidance unit 18 determines the necessity of avoidance in the positioning path, and if avoidance is necessary, adds a retraction operation and a return operation of the machining head to the positioning path.

The necessity of avoidance is judged based on whether or not a cutting path that forms a closed shape intersects with the positioning path. One example of a method of judgment is a method using the cross product of vectors.
A method for determining whether or not the cutting trajectory AB intersects with the positioning path CD will be described with reference to Fig. 6. For the sake of explanation, the machining surface is defined as the XY plane, and the height direction from the machining surface is defined as the Z axis.
The cutting trajectory AB is one of the cutting trajectories included in the closed shape. If one of the cutting trajectories included in the closed shape intersects with the positioning path, it is determined that the cutting portion of the closed shape intersects with the positioning path.

To determine whether the cutting trajectory and positioning path intersect on the machining surface, the cutting trajectory and positioning path are projected onto the machining surface (XY plane). In the projection, a point ABCD is found, ignoring the Z-axis components of the cutting trajectory AB and positioning path CD. If the signs of the cross product of vector AB and vector AC and the cross product of vector AB and vector AD do not match, and if the signs of the cross product of vector CA and vector CB and the cross product of vector CD and vector CB do not match, it is found that the cutting trajectory and positioning path intersect. If the cutting trajectory and positioning path intersect, the avoidance unit 18 determines that avoidance is necessary.

When machining a plate material into a circular arc, the avoidance unit 18 divides the circular arc into multiple straight lines as shown in FIG. 7, and determines whether the divided lines intersect with the positioning path.

When the positioning path intersects with the closed shape, the avoidance unit 18 determines that avoidance is necessary and adds a retraction operation and a return operation of the machining head to the positioning path. The height to which the machining head is retracted is calculated by the retraction amount calculation unit 16. Usually, the retraction operation starts at the start point of the positioning path. The return operation starts when the remaining distance of the positioning path falls below a predetermined distance.
The start timing of the retraction operation and the return operation is not limited to this, and it is sufficient that the processing head passes through the cutting portion at the retracted height.
During the retraction and return operations, the movement speed in the XY axis direction does not change. In the numerical control device 100 of the present embodiment, the movement speed of the machining head in the XY axis direction during positioning is not changed, and the machining head moves in a straight line on the XY plane, so that positioning can be performed more quickly than by detouring the cutting portion.

In the intersection determination, the avoidance unit 18 determines whether the positioning path for one block intersects with the cutting trajectory of the block executed before the block in question. Note that a block means one line of the machining program.
When a positioning block (for example, a block including the command "G00") exists in the machining program, the avoidance unit 18 determines whether or not the cutting trajectory before this block intersects with the positioning path of this block.

The machining program analysis unit 19 calculates the cutting path and positioning path of the machining head based on the machining program.

The machining program execution unit 20 controls the movement of the machining head, the output of the laser, etc., according to the analysis results of the machining program analysis unit 19. The avoidance unit 18 outputs the start position of the retraction operation, the start position of the return operation, the retraction amount, etc. to the machining program execution unit 20. The machining program execution unit 20 adds the retraction operation and the return operation to the positioning operation of the machining head.

The operation of the numerical control device 100 will be described with reference to FIG.
The numerical control device 100 analyzes the machining program (step S1). The numerical control device 100 judges whether the program path of the block is a cutting path or a positioning path. If the path is a cutting path (step S2; cutting), the numerical control device 100 judges whether the cutting path forms a closed shape. If the cutting path does not form a closed shape (step S3; No), the numerical control device 100 proceeds to step S8.
If the cutting path forms a closed shape (step S3; Yes), the numerical controller 100 calculates the retraction amount of the machining head based on the closed shape (step S4). The numerical controller 100 stores the closed shape and the retraction amount (step S5) and proceeds to step S8.

If the program path is a positioning path (step S2; positioning), the numerical control device 100 reads out the already stored cutting trajectory of the closed shape and determines whether the positioning path and the cutting trajectory of the closed shape intersect. If the cutting trajectory of the closed shape and the positioning path intersect (step S6; Yes), the numerical control device 100 adds a retreat operation and a return operation to the positioning operation of the machining head, and prevents interference between the cutting part and the machining head (step S7).

The numerical control device 100 determines whether the block that was read is the end of the machining program. If it is not the end of the machining program (step S8; No), it moves to step S1 and reads the next block. If it is the end of the machining program (step S8; Yes), it ends the operation.

As described above, the numerical control device 100 of the first embodiment detects whether or not a closed cut portion exists from the path (cutting trajectory) on which cutting has already been performed, and if a closed cut portion exists, calculates the retraction amount based on the shape of the closed shape. The numerical control device 100 executes the retraction operation and return operation with the calculated retraction amount, and avoids interference between the closed cut portion and the machining head.

The numerical control device 100 of the first embodiment determines whether or not the machining head needs to avoid the cut based on whether or not the cut portion of the closed shape intersects with the positioning path. If avoidance is not required, machining time and required energy can be saved.

In addition, the numerical control device 100 of the first embodiment determines the retraction and return operations of the machining head based on the intersection of the cut portion of the closed shape and the positioning path. Therefore, there is no need to set up an avoidance path or information for generating an avoidance path other than the machining program in advance, making it highly versatile.

In addition, since the numerical control device 100 of the first embodiment has a closed shape memory unit 15, even when multiple machining programs are executed to machine a single sheet of workpiece, it can store the closed shapes of past machining programs and determine whether the cutting trajectory and positioning path intersect across multiple machining programs.

In addition, information on the evacuation and return operations may be stored in association with the machining program. When executing the same machining program, the avoidance unit 18 can reduce the computational load by referring to information on the evacuation and return operations that have already been executed.

(Example)
The operation of the numerical control device 100 of the first embodiment will be specifically described with reference to FIG.
Fig. 9 shows the path of the machining head. Fig. 10 shows the machining program. The path of the machining head is assigned the block number of the machining program. The G code "G90" in block number "N1" specifies absolute coordinates. "E001" in block number "N2" calls the machining condition file "E001".
The G code "G00 X80.0 Y100.0" of block number "N3" is a positioning command. The machining head moves to coordinates (X, Y) = (80.0, 100.0). No closed shape has been generated in the block before the "N3" block. Therefore, avoidance is not performed.

A closed shape is formed from block numbers "N4" to "N7." The coordinates of the vertices of the closed shape are (X, Y) = (80.0, 100.0), (130.0, 100.0), (130.0, 70.0), and (80.0, 70.0).
The closed shape detection unit 14 determines that the cutting trajectories from "N4" to "N7" form a closed shape. That is, the cutting trajectory of "N4" has an intersection with the cutting trajectory of "N5", the cutting trajectory of "N5" has an intersection with the cutting trajectory of "N6", and the cutting trajectory of "N6" has an intersection with "N7". The cutting trajectory of "N7" has an intersection with the cutting trajectory of "N4". Since the cutting trajectory of "N4" has an intersection selected in the past, it can be determined that it forms a closed shape.

The retraction amount calculation unit 16 calculates the retraction amount based on the vertices of the closed shape. The retraction amount is the longest distance between the vertices of the closed shape. The retraction amount of the closed shape formed by "N4" to "N7" is "58.3".

The G code for block number "N8" "G00 X20.0 Y50.0" is a positioning command. The machining head moves from the end point of "N7" (80.0, 70.0) to the command destination of "N8" (20.0, 50.0). Here, the cutting path of blocks "N4" to "N7", which form a closed shape, and the positioning path of "N8" do not intersect. It is determined that the path of "N8" does not pass over the closed shape formed by "N4" to "N8".

A closed shape is formed from block numbers "N9" to "N12". The coordinates of the vertices of the closed shape are (X,Y) = (20.0,50.0), (50.0,50.0), (50.0,30.0), (20.0,30.0).

The retraction amount calculation unit 16 calculates the retraction amount based on the coordinates of the vertices of the closed shape. The retraction amount is the longest distance between the vertices of the closed shape. The retraction amount of the closed shape formed by block numbers "N9" to "N12" is "36.1".

The G code "G00 X200.0 Y120.0" of block number "N13" is a positioning command. The machining head moves from the end point (20.0, 50.0) of "N12" to the command destination (200.0, 120.0) of "N13".
The avoidance unit 18 determines that the positioning path of "N13" intersects with the cut portion from "N4" to "N7." Since the longest distance of the closed shape formed by block numbers "N4" to "N7" is "58.3", the retraction amount is set to "58.3", and the retraction and return operations of the machining head are added to "G00 (positioning operation)" of "N13."

Second Embodiment
FIG. 11 is a block diagram of a numerical control device 100 according to the second embodiment.
The numerical control device 100 of the second embodiment includes a pre-analysis unit 21 .
The pre-analysis unit 21 analyzes the machining program in advance. The trajectory storage unit 12 stores the machining paths calculated by the pre-analysis unit 21. The machining paths calculated by the pre-analysis unit 21 include a cutting path and a positioning path.

When the laser processing machine is operating, the trajectory acquisition unit 11 acquires execution data from the processing program execution unit 20. The trajectory acquisition unit 11 adds execution information to the cutting path calculated in advance based on the execution data from the processing program execution unit 20. When the execution information is added, the cutting path becomes a cutting trajectory.

For example, the values of the start and end points of the path are used to associate the execution data with the cutting path. When the trajectory acquisition unit 11 acquires the execution data, it searches for a cutting path having the same start and end points as the execution data. The trajectory acquisition unit 11 adds execution completion information to the cutting path having the same start and end points as the execution data.
The execution data and the cutting path may be associated with each other by adding a line number of the machining program to each of the execution data and the cutting path.

The numerical control device 100 of the second embodiment calculates the machining path in advance, which reduces the computational load when machining is performed. In addition, it is possible to predict whether there is another obstacle ahead of the avoided obstacle. Furthermore, before machining begins, the retraction amount and machining path calculated in advance can be displayed on the display unit 70, and user settings (e.g., retraction amount, whether or not to execute the retraction process) can be accepted via the input unit 30.

Below, the hardware configuration of the numerical control device 100 to which this disclosure is applied will be described. FIG. 12 is a hardware configuration diagram of the numerical control device 100. As shown in FIG. 12, the numerical control device 100 comprises a CPU 111 that controls the numerical control device 100 as a whole, a ROM 112 that records programs and data, and a RAM 113 for temporarily expanding data, and the CPU 111 reads out the system program recorded in the ROM 112 via the bus and executes a workaround in accordance with the system program.

The non-volatile memory 114 is backed up by, for example, a battery (not shown), and retains its stored state even when the power supply to the numerical control device 100 is turned off. The non-volatile memory 114 stores various data, such as programs read from the external device 120 via the

interfaces

115, 118, and 119, and user operations input via the input unit 30. The non-volatile memory 114 may also store programs and data for executing the numerical control device 100 of this embodiment. In addition, the display unit 70 displays various data, measurement results, causes of invalid data, and the like.

The interface 115 is an interface for connecting the numerical control device 100 to an external device 120 such as an adapter. Programs, various parameters, etc. are read from the external device 120.
The interface 118 is an interface for connecting the numerical control device 100 to a display unit 70 such as a liquid crystal display. The display unit 70 displays various data loaded onto the memory, data obtained as a result of execution of a program, and the like.
The interface 119 is an interface for connecting the numerical control device 100 to an input unit 30 such as a keyboard, a pointing device, etc. The input unit 30 passes instructions, data, etc. based on operations by an operator to the CPU 111 via the interface 119.

Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible to these embodiments without departing from the gist of the present disclosure, or without departing from the gist of the present disclosure derived from the contents described in the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-mentioned embodiments, the order of each operation and the order of each process are shown as examples, and are not limited to these.

The following supplementary notes are further disclosed regarding the above embodiment and modified examples.
(Appendix 1)
The numerical control device (100) includes a trajectory acquisition unit (11) that acquires a cutting trajectory of a machining head of a machine tool that processes sheet metal, a path acquisition unit (13) that acquires a positioning path of the machining head, a closed shape detection unit (14) that detects a cutting trajectory that forms a closed shape, a retraction amount calculation unit (16) that calculates a retraction amount in the height direction of the machining head based on the closed shape, and an avoidance unit (18) that, when the closed shape and the positioning path intersect, determines that avoidance on the positioning path is necessary and adds to the positioning path a retraction operation that retracts the machining head in the height direction by the retraction amount and a return operation that restores the height of the machining head.
(Appendix 2)
The retraction amount is the distance between the two points on the periphery of the closed shape that are the furthest apart.
(Appendix 3)
The retraction amount is the distance between the center of gravity and a point on the outer periphery of the closed shape that is farthest from the center of gravity of the closed shape.
(Appendix 4)
The avoidance unit (18) executes the retraction and return operations of the machining head only when it is determined that avoidance on the positioning path is necessary.
(Appendix 5)
The numerical control device (100) comprises a machining program analysis unit (19) that analyzes the numerical control machining program and calculates a machining path including a cutting path and a positioning path, and a machining program execution unit (20) that drives the machine tool based on the analysis results of the machining program, and the trajectory acquisition unit (11) acquires the machining path along which the machining program execution unit (20) executed machining as a cutting trajectory, and the path acquisition unit (13) acquires the positioning path from the machining program analysis unit (19).
(Appendix 6)
The numerical control device (100) comprises a pre-analysis unit (21) that analyzes a machining program in advance and calculates a machining path of the machining head, a machining program analysis unit (19) that analyzes the machining program and calculates the machining path of the machining head, and a machining program execution unit (20) that drives the machine tool based on the analysis results of the machining program, and the machining path includes a cutting path and a positioning path, and the trajectory acquisition unit (11) adds executed information of the machining program execution unit to the cutting path and acquires it as the cutting trajectory.
(Appendix 7)
The numerical control device (100) includes a trajectory memory unit (12) that stores cutting trajectories of a plurality of machining programs, and the avoidance unit (18) determines that avoidance is necessary in the positioning path when a closed shape formed by the plurality of machining programs intersects with the positioning path.
(Appendix 8)
The trajectory storage unit (12) stores information on the retreat motion and the return motion in association with the machining program, and refers to the information on the retreat motion and the return motion when executing the machining program.
(Appendix 9)
The storage medium (112, 113, 114) stores computer-readable instructions that cause one or more processors (111) to execute processing to acquire a cutting trajectory of a machining head of a machine tool that processes sheet metal, acquire a positioning path of the machining head, detect a cutting trajectory that forms a closed shape, calculate a heightwise retraction amount of the machining head based on the closed shape, and if the closed shape and the positioning path intersect, determine that avoidance on the positioning path is necessary, and add to the positioning path a retraction operation that retracts the machining head in the height direction by the retraction amount and a return operation that returns the height of the machining head.

REFERENCE SIGNS LIST 100 Numerical control device 11 Trajectory acquisition unit 12 Trajectory storage unit 13 Path acquisition unit 14 Closed shape detection unit 15 Closed shape storage unit 16 Retraction amount calculation unit 17 Retraction range storage unit 18 Avoidance unit 19 Machining program analysis unit 20 Machining program execution unit 21 Pre-analysis unit 111 CPU
112 ROM
113 RAM
114 Non-volatile memory

Claims

a trajectory acquisition unit that acquires a cutting trajectory of a machining head of a machine tool that processes a plate material;
A path acquisition unit that acquires a positioning path of the processing head;
a closed shape detection unit that detects a cutting trajectory that forms a closed shape;
a retraction amount calculation unit that calculates a retraction amount in a height direction of the processing head based on the closed shape;
an avoidance unit that determines that avoidance is necessary on the positioning path when the closed shape and the positioning path intersect, and adds to the positioning path a retraction operation that retracts the machining head in a height direction by the retraction amount and a return operation that returns the height of the machining head;
A numerical control device comprising:
The numerical control device according to claim 1, wherein the retraction amount is the distance between the two points on the periphery of the closed shape that are the furthest apart.
The numerical control device according to claim 1, wherein the retraction amount is the distance between the center of gravity and a point on the periphery of the closed shape that is farthest from the center of gravity of the closed shape.
The numerical control device according to claim 1, wherein the avoidance unit executes the retraction and return operations of the machining head only when it is determined that avoidance is necessary on the positioning path.
A machining program analysis unit that analyzes a machining program and calculates a machining path including a cutting path and a positioning path;
a machining program execution unit that drives the machine tool based on an analysis result of the machining program,
The trajectory acquisition unit acquires a machining path along which the machining program execution unit executes machining as a cutting trajectory,
The numerical control device according to claim 1 , wherein the path acquisition unit acquires the positioning path from the machining program analysis unit.
A pre-analysis unit that analyzes a machining program in advance and calculates a machining path of the machining head;
a machining program analysis unit that analyzes the machining program and calculates a machining path of the machining head; and a machining program execution unit that drives the machine tool based on a result of the analysis of the machining program,
The processing path includes a cutting path and a positioning path,
The numerical control device according to claim 1 , wherein the trajectory acquisition unit adds execution information of the machining program execution unit to the cutting path and acquires the result as the cutting trajectory.
A trajectory storage unit is provided for storing cutting trajectories of a plurality of machining programs,
The numerical control device according to claim 1 , wherein the avoidance unit determines that avoidance on the positioning path is necessary when a closed shape formed by the plurality of machining programs intersects with the positioning path.
The numerical control device according to claim 7, wherein the trajectory memory unit stores information on the retreat and return operations in association with the machining program, and refers to the information on the retreat and return operations when executing the machining program.
One or more processors,
The cutting trajectory of the machining head of the machine tool that processes the plate material is acquired,
Obtaining a positioning path of the processing head;
Detecting a cutting path that forms a closed shape;
Calculating a retraction amount in a height direction of the processing head based on the closed shape;
When the closed shape and the positioning path intersect, it is determined that an avoidance in the positioning path is necessary, and a retraction operation for retracting the machining head in a height direction by the retraction amount and a return operation for returning the height of the machining head to the original position are added to the positioning path.
A storage medium that stores computer-readable instructions for executing a process.