JP7734091B2 - Laser processing machine, laser processing machine control method, and program - Google Patents

Description

The present invention relates to a laser processing machine, a control method for a laser processing machine, and a program.

For example, Patent Document 1 discloses a processing machine that processes workpieces. When the processing machine described in Patent Document 1 detects a processing defect while processing a workpiece, it identifies the part (product) that is currently being processed. The processing machine skips processing the identified part and then resumes processing the remaining parts that have not yet been processed.

A workpiece is assigned multiple parts. By skipping the processing of the part where a problem has occurred, processing of the remaining parts can continue. This enables automatic operation of the laser processing machine in situations where there are no workers, such as at night, thereby reducing the burden on workers and improving productivity.

JP 2010-120071 A

Some machined parts cut out from a workpiece may stand upright, tilting relative to the workpiece surface. As a result, when machining unmachined parts, the machining head may collide with the upright parts. While the skip function shown in Patent Document 1 enables automatic operation of the laser processing machine, this function still has room for improvement.

One aspect of the present invention is a laser processing machine that includes a laser processing machine main body that processes a workpiece by moving a processing head that irradiates a laser beam relative to the workpiece, and a control device that controls the laser processing machine main body based on a processing program for cutting out multiple parts assigned to the workpiece in order from the workpiece. The control device determines whether a collision of the processing head has occurred, and if it determines that a collision of the processing head has occurred, identifies the obstructing part that the processing head has collided with from among the multiple machined parts cut out from the workpiece, and searches for an interfering part from among unmachined parts that has not been machined, which will interfere with the obstructing part when the unmachined part is machined.

With a laser processing machine according to one aspect of the present invention, by identifying the obstructing part, it is possible to search for an interfering part that will cause the processing head to interfere with the obstructing part when processing the unprocessed part. This makes it possible to predict in advance a situation in which the processing head will collide with the obstructing part again when processing of the unprocessed part is resumed.

One aspect of the present invention makes it possible to take measures against faulty parts, thereby improving the automatic operation function of laser processing machines.

FIG. 1 is a diagram showing a schematic configuration of a laser processing machine according to this embodiment. FIG. 2 is a block diagram showing the functions of the control device. FIG. 3 is an explanatory diagram showing the state of machining a workpiece. FIG. 4 is a flowchart showing a method for controlling a laser processing machine. FIG. 5 is a diagram illustrating an outline of the process for identifying a faulty part. FIG. 6 is a diagram illustrating an outline of the process of setting the second determination area and the process of searching for an interfering part. FIG. 7 is a diagram illustrating an outline of the process of setting the second determination area and the process of searching for an interfering part.

The laser processing machine, the control method for the laser processing machine, and the program will be explained below with reference to the drawings.

Figure 1 is a diagram showing the general configuration of a laser processing machine according to this embodiment. The laser processing machine according to this embodiment includes a laser processing machine main body 10 that processes the workpiece W by moving a processing head 30 that irradiates a laser beam relative to the workpiece W, and a control device 60 that controls the laser processing machine main body 10 based on a processing program for sequentially cutting out from the workpiece W multiple parts assigned to the workpiece W. The control device 60 determines whether a collision of the processing head 30 has occurred, and if it determines that a collision of the processing head 30 has occurred, it identifies the obstructing part that the processing head 30 has collided with from among the multiple machined parts cut out from the workpiece W, and searches for an interfering part from among unmachined parts that has not been machined, which will interfere with the obstructing part when the processing head 30 processes the unmachined part.

The detailed configuration of the laser processing machine is described below. The laser processing machine is a processing machine that processes (cuts) a workpiece W using a laser beam. The workpiece W to be processed is a sheet-like material, such as sheet metal. The laser processing machine comprises a laser processing machine main body 10 and a control device 60.

The laser processing machine body 10 is mainly composed of a table 15, a head drive mechanism 20, a processing head 30, and a laser oscillator 40.

The table 15 is a base for supporting the workpiece W to be machined. The table 15 is equipped with a frame member, which is a rectangular frame. Multiple workpiece supports, each made of a plate-shaped member, are arranged at predetermined intervals on the frame member. The workpiece W on the table 15 is supported by the multiple workpiece supports so that it lies along a horizontal plane (the surface of the workpiece W) defined by the mutually perpendicular X-axis and Y-axis. There are gaps between the individual workpiece supports, and scrap generated during machining falls downward through these gaps.

A gate-shaped frame (not shown) that can move along the X-axis direction is provided on the table 15. A carriage (not shown) that can move along the Y-axis direction is provided on this gate-shaped frame. A machining head 30 is attached to the carriage.

The head drive mechanism 20 moves the processing head 30 along the X and Y axes, and raises and lowers the processing head 30 along the Z axis, which is the vertical direction. Specifically, the head drive mechanism 20 includes an X-axis drive unit 21 that moves the gate-shaped frame in the X-axis direction, a Y-axis drive unit 22 that moves the carriage in the Y-axis direction, and a Z-axis drive unit 23 that moves the processing head 30 in the Z-axis direction. By driving the X-axis drive unit 21 and the Y-axis drive unit 22 to move the gate-shaped frame and carriage, the processing head 30 can be moved horizontally. Furthermore, by driving the Z-axis drive unit 23, the processing head 30 can be moved vertically.

Instead of being configured to move the processing head 30 relative to the workpiece W, the laser processing machine body 10 may be configured to move the workpiece W while keeping the position of the processing head 30 fixed. It is sufficient for the laser processing machine body 10 to be configured to move the processing head 30 relative to the workpiece W.

The processing head 30 irradiates a laser beam from above the workpiece W to cut out parts from the workpiece W. A laser beam emitted from a laser oscillator 40 is transmitted to the processing head 30. A nozzle 31 that emits the laser beam is detachably attached to the tip of the processing head 30. A circular opening is provided at the tip of the nozzle 31, and the laser beam is irradiated onto the workpiece W from the opening at the tip of the nozzle 31.

By moving the machining head 30 in the X-axis and Y-axis directions, the machining head 30 can be moved two-dimensionally on the surface of the workpiece W. At this time, by moving the machining head 30 in the Z-axis direction as needed, the machining head 30 can be moved to follow the surface of the workpiece W. This allows the machining head 30 to move so as to follow the surface of the workpiece W while maintaining a constant distance between the workpiece W and the machining head 30.

The laser oscillator 40 generates a laser beam and supplies the laser beam to the processing head 30. The laser oscillator 40 is connected to the processing head 30 via a process fiber.

The control device 60 controls the operation of the laser processing machine. The control device 60 is composed of a computer having a hardware processor such as a CPU (Central Processing Unit), memory, and various interfaces. The memory and various interfaces are connected to the hardware processor via a bus. The hardware processor executes programs stored in the memory, allowing the control device 60 to perform various functions to control the laser processing machine. The control device 60 also includes functions such as an NC (Numerical Control) device.

The control device 60 receives a sensor signal output from the sensor unit 35 mounted on the machining head 30. The sensor unit 35 detects when the machining head 30 (nozzle 31) collides with an obstacle. For example, the sensor unit 35 detects that the nozzle 31, which has collided with an obstacle, has changed position from its standard mounting position, thereby detecting a collision with an obstacle.

An operation and display unit 70 is connected to the control device 60. The operation and display unit 70 includes an operation unit that the operator operates to input information into the control device 60, and a display unit that displays information output from the laser processing machine main body 10 and the control device 60. For example, the operation and display unit 70 is mainly composed of a display and a touch panel that allows input operations to be performed in accordance with the information displayed on the display. By operating the operation and display unit 70, the worker can input various information into the control device 60. The worker can also recognize various information related to the laser processing machine main body 10 from the information displayed on the operation and display unit 70.

Figure 2 is a block diagram showing the functions of the control device. Figure 3 is an explanatory diagram showing the machining state of the workpiece. In this embodiment, an example is shown in which 11 parts (products) P1 to P11 are assigned to the workpiece W. The 11 parts P1 to P11 are cut out in the order of the numbers appended after the letter "P." Parts P1 to P6 shown in solid lines represent machined parts that have already been machined and cut out from the workpiece W, while parts P8 to P11 shown in dashed lines represent unmachined parts that have not yet been machined. Part P7 shown in dashed lines represents the part that was being machined when the machining head 30 collided.

The control device 60 includes a machining program memory unit 61, a machining control unit 62, a fault processing unit 63, a fault part determination unit 64, an interfering part determination unit 65, and a program processing unit 66.

The machining program storage unit 61 stores machining programs and the like. Machining programs are created by a computer such as a CAM (Computer-Aided Manufacturing) system. The CAM creates machining programs consisting of code (G-code) that defines the operation of the laser processing machine main body 10 based on shape data indicating the shape of the parts and cutting data in which multiple parts P1 to P11 are allocated to the workpiece W. In this embodiment, as shown in Figure 3, the machining program is created to cut out multiple parts P1 to P11 in order from the workpiece W based on the cutting data in which multiple parts P1 to P11 are allocated to the workpiece W.

The processing control unit 62 executes the processing program and controls the laser processing machine main body 10 in accordance with the processing program.

The fault processing unit 63 determines whether the machining head 30 has collided with one of the machined parts P1 to P6 based on the detection results of the sensor unit 35. If the fault processing unit 63 determines that the machining head 30 has collided, it stops the operation of the machining head 30. The fault processing unit 63 then determines whether the machining head 30 can be automatically restored by performing a recovery operation to recover from the failure.

The obstacle part determination unit 64 identifies the obstacle part that the machining head 30 collided with from among the multiple machined parts P1 to P6 cut out from the workpiece W.

The interfering part determination unit 65 searches for interfering parts from among the multiple unmachined parts P8 to P11 that will cause the machining head 30 to interfere with the obstacle part when machining the unmachined parts P8 to P11.

The program processing unit 66 has the function of editing and creating machining programs.

A method for controlling a laser processing machine will be described with reference to Figures 3 and 4. Figure 4 is a flowchart showing the method for controlling a laser processing machine. When the control device 60 operates the laser processing machine (laser processing machine main body 10) according to the processing program, it executes the processing shown in the flowchart of Figure 4.

First, in step S10, the control device 60 determines whether a collision of the machining head 30 has occurred. The machined parts P1 to P6 cut out from the workpiece W are supported by multiple plate-shaped workpiece support members. Depending on the shape of the cut-out parts, the position of the allocated parts, etc., the machined parts P1 to P6 may stand up at an angle relative to the plane of the workpiece W. When the machining head 30 moves during machining, it may collide with the upright machined parts P1 to P6.

The control device 60 determines whether a collision has occurred based on the detection result of the sensor unit 35. If it determines that a collision has not occurred (S10: No), the control device 60 performs the process of step S10 again. On the other hand, if it determines that a collision has occurred (S10: Yes), the control device 60 performs the process of stopping the movement of the machining head 30 and the process of stopping the output of the laser beam, and then performs the process of step S11. For example, it is assumed that it has been determined that a collision of the machining head 30 has occurred while machining part P7.

In step S11, the control device 60 determines whether recovery is possible. If a collision occurs with the machining head 30, various problems may occur, such as the optical axis of the laser beam being misaligned from the center of the nozzle 31 opening. Therefore, the control device 60 determines whether automatic recovery of the machining head 30 is possible by utilizing a function that automatically recovers from a failure (automatic recovery function), such as an automatic centering function.

If recovery is not possible (S11: No), the process proceeds to step S12. On the other hand, if recovery is possible (S11: Yes), the control device 60 performs the processes from step S13 onwards.

In step S12, the control device 60 issues an alarm stop to stop the operation of the laser processing machine main body 10, and then ends this process.

In step S13, the control device 60 identifies the obstructing part that the machining head 30 collided with from among the multiple machined parts P1 to P6 cut out from the workpiece W.

Figure 5 is a diagram outlining the process for identifying obstructing parts. The control device 60 references the cutting data in which multiple parts P1 to P11 are assigned to the workpiece W, and sets a first determination area 110 centered on the position where the machining head 30 stopped moving, i.e., the collision position 100 where the machining head 30 collided. The first determination area 110 indicates the range within which the machining head 30 exists, and is, for example, a circular area corresponding to the diameter of the machining head 30. However, the first determination area 110 may be set by adding a certain margin to the diameter of the machining head 30, or may be set in a shape that conforms to the shape of the machining head 30. In other words, the first determination area 110 only needs to have an area (predetermined area) large enough to identify obstructing parts.

The control device 60 compares the cutting path for cutting the machined parts P1-P6, i.e., the outlines of the machined parts P1-P6, with the first judgment area 110. The control device 60 then identifies the machined parts P1-P6 whose outlines fall within the first judgment area 110 as obstructive parts. In the example shown in Figure 5, the machined part P5 is included in the first judgment area 110, so the control device 60 identifies the machined part P5 as an obstructive part.

Note that if the parts included in the first determination area 110 are unmachined parts P8 to P11, the control device 60 does not identify those parts as obstructive parts. That is, the control device 60 identifies the obstructive part from among the machined parts P1 to P6. Furthermore, if there are multiple machined parts P1 to P6 included in the first determination area 110, the control device 60 preferably refers to the cutting path of part P7 and identifies the machined parts P1 to P6 located upstream of the cutting path as obstructive parts.

On the other hand, if there are no machined parts P1-P6 in the first judgment area 110, it is possible that the machining head 30 has collided with an obstacle other than the machined parts P1-P6. In this case, it is preferable for the control device 60 to issue an alarm stop and terminate this process.

As shown in FIG. 4, in step S14, the control device 60 sets a second judgment area. Then, in step S15, the control device 60 searches for interfering parts based on the second judgment area.

Figures 6 and 7 are diagrams outlining the process of setting the second judgment area and the process of searching for interfering parts. Figure 6 illustrates machined part P5 as an example of the obstructing part, and Figure 7 illustrates machined part P6 as an example of the obstructing part. The control device 60 sets the second judgment area 120 based on the machined parts P5 and P6, which are the obstructing parts. Specifically, the control device 60 calculates an area obtained by expanding the machining path used to cut and machine the machined parts P5 and P6 in a direction perpendicular to the machining path by a width D equivalent to the diameter of the machining head 30. The control device 60 sets this calculated area as the second judgment area 120.

An interfering part is a part of the unmachined parts P8-P11 that will interfere with the machining head 30 when cutting the unmachined parts P8-P11. The control device 60 compares the cutting path for cutting the unmachined parts P8-P11, i.e., the outlines of the unmachined parts P8-P11, with the second judgment area 120, and searches for unmachined parts P8-P11 whose outlines fall within the second judgment area 120. In the example shown in Figure 6, none of the unmachined parts P8-P11 (not shown) are included in the second judgment area 120, so the search does not identify any interfering parts. On the other hand, in the example shown in Figure 7, the unmachined part P10 is included in the second judgment area 120, so the search identifies the unmachined part P10 as an interfering part.

As shown in Figures 3 and 4, in step S16, the control device 60 determines whether or not there are any interfering parts. If there are no interfering parts (S16: No), the control device 60 performs the process of step S17. On the other hand, if there are interfering parts (S16: Yes), the control device 60 performs the process of step S18.

In step S17, the control device 60 skips the processing of part P7, which is currently being processed, and resumes processing of unprocessed parts P8 to P11.

In step S18, the control device 60 edits the machining program. Specifically, the control device 60 creates and saves a machining program for remachining the unmachined parts P8, P9, and P11 by deleting the G-code for machining the interfering unmachined part P10 from the G-code for machining the unmachined parts P8 to P11.

In step S19, the control device 60 extracts the G-code related to machining the interfering unmachined part P10. Then, based on the extracted G-code, the control device 60 creates and saves a machining program for remachining the interfering unmachined part P10.

In step S20, the control device 60 skips the processing of part P7, which is currently being processed, and resumes processing of unmachined parts P8 to P11. At this time, the control device 60 resumes processing based on the processing program for remachining unmachined parts P8, P9, and P11 created in step S18.

The control device 60 resumes machining based on a new machining program for re-machining, but machining may also be resumed using the original machining program. In this case, once the control device 60 recognizes the machining start command for the interfering unmachined part P10 in the G-code, it will operate to skip the G-code until the machining start command for the next unmachined part P11.

In step S21, the control device 60 ends machining based on the machining end G-code specified in the machining program.

Once the worker removes the obstructing machined part P6, the worker instructs the start of machining the interfering part, unmachined part P10. In step S22, the control device 60 reads the machining program created in step S19 for remachining the interfering part, unmachined part P10. The control device 60 machines the interfering part, unmachined part P10, based on the read machining program.

In step S23, the control device 60 ends the machining based on the machining end G-code specified in the machining program.

After going through this series of steps, the control of the laser processing machine is complete.

According to this embodiment, by identifying the obstructing part, it is possible to search for interfering parts that will interfere with the obstructing part when machining the unmachined part. This makes it possible to predict in advance a situation in which the machining head 30 will collide with the obstructing part again when machining of the unmachined part is resumed. This makes it possible to take measures against the obstructing part, thereby improving the automatic operation function of the laser machining machine.

In this embodiment, the control device 60 sets a first judgment area 110 with a predetermined area centered on the collision position 100 where the machining head 30 collided, based on the cutting data in which multiple parts P1 to P11 are assigned to the workpiece W, and identifies the machined part P5 included in the first judgment area 110 as the obstructing part.

This configuration makes it possible to easily search for faulty parts without using detection means such as sensors.

In this embodiment, the control device 60 sets a second judgment area 120 by widening the machining path used to machine the obstructing part (machined part P5) by a certain width based on the cutting data, and identifies the unmachined part P10 included in the second judgment area 120 as an interfering part.

This configuration makes it possible to easily search for interfering parts without using detection means such as sensors.

In addition to setting a second judgment area 120 on the obstructing part, another method for searching for interfering parts is to set a second judgment area 120 on each of the unmachined parts P8 to P11 and compare each of the second judgment areas 120 with the obstructing part. However, when setting a second judgment area 120 on the unmachined parts P8 to P11, it is necessary to set a second judgment area 120 on all of the unmachined parts P8 to P11, which increases the computational load when there are a large number of unmachined parts. On the other hand, when setting a second judgment area 120 on the obstructing part, it is only necessary to set a second judgment area 120 on at least the obstructing part, thereby reducing the computational load. This allows for searching for interfering parts with simple calculations.

In this embodiment, if an interfering part is identified as a result of the search, the control device 60 skips machining of the interfering part (unmachined part P10) when resuming machining of unmachined parts P8 to P11.

This configuration prevents the machining head 30 from colliding with interfering parts after machining resumes. This prevents machining from being stopped again when machining unmachined parts P8 to P11, thereby improving the reliability of the laser machining machine's automatic operation function.

In this embodiment, the control device 60 extracts the program for machining the interfering part and saves the machining program for remachining the interfering part.

With this configuration, a machining program for remachining the interfering part is saved, allowing the worker to smoothly machine the interfering part after removing the obstructing part.

In this embodiment, when the control device 60 determines that a collision has occurred with the machining head 30, it determines whether automatic recovery of the machining head 30 is possible, and if it determines that automatic recovery of the machining head 30 is possible, it performs processing to identify the faulty part.

With this configuration, the process of identifying faulty parts is performed within the scope of automatic recovery of the laser processing machine. This prevents unnecessary processing in situations where the laser processing machine cannot automatically recover and an alarm shutdown occurs.

In this embodiment, the processing program for processing unmachined parts is automatically edited, assuming automatic operation of the laser processing machine. However, the laser processing machine may also be restarted manually by the operator. In this case, the operator edits the processing program or starts reprocessing using the normal sheet reprocessing function. At this time, if an interfering part that interferes with the obstructing part is detected, the control device 60 may display information about the interfering part. Alternatively, the control device 60 may permit the start of reprocessing only if no interfering part is detected. This prevents the processing head 30 from colliding with the obstructing part again when processing unmachined parts P8 to P11.

Furthermore, machining of part P7, which was interrupted due to a collision with an obstructing part, did not end normally. Therefore, the control device 60 may extract the program related to machining part P7 and save it as a machining program for remachining part P7.

One aspect of this embodiment includes a method for controlling a laser processing machine that processes a workpiece W by moving a processing head 30 that irradiates a laser beam relative to the workpiece W. The method for controlling a laser processing machine operates the laser processing machine in accordance with a processing program for sequentially cutting out from the workpiece W multiple parts P1 to P11 assigned to the workpiece W, determines whether a collision of the processing head 30 has occurred, and, if it is determined that a collision of the processing head 30 has occurred, identifies an obstructing part that the processing head has collided with from among the multiple processed parts P1 to P6 cut out from the workpiece W, and searches for an interfering part from among unprocessed parts P8 to P11 that will interfere with the obstructing part when the processing head 30 processes the unprocessed parts P8 to P11.

Another aspect of this embodiment includes a program for controlling a laser processing machine that processes a workpiece W while moving a processing head 30 that irradiates a laser beam relative to the workpiece W. This program causes a computer to operate the laser processing machine in accordance with a processing program for sequentially cutting out from the workpiece W multiple parts P1 to P11 assigned to the workpiece W, determine whether a collision of the processing head 30 has occurred, and, if it is determined that a collision of the processing head 30 has occurred, identify an obstructing part that the processing head 30 has collided with from among the multiple machined parts P1 to P6 cut out from the workpiece W, and search for an interfering part from among the unmachined parts P8 to P11 that has not yet been machined, that will interfere with the obstructing part when the processing head 30 processes the unmachined parts P8 to P11.

According to these aspects of the present embodiment, by identifying the obstructing part, it is possible to search for interfering parts that will interfere with the obstructing part when machining the unmachined part. This makes it possible to predict in advance a situation in which the machining head 30 will collide with the obstructing part again when machining of the unmachined part is resumed. This makes it possible to take measures against the obstructing part, thereby improving the automatic operation function of the laser machining machine.

As described above, an embodiment of the present invention has been described. However, the descriptions and drawings that form part of this disclosure should not be understood as limiting this invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure.

REFERENCE SIGNS LIST 10 Laser processing machine body 15 Table 20 Head drive mechanism 21 X-axis drive unit 22 Y-axis drive unit 23 Z-axis drive unit 30 Processing head 31 Nozzle 35 Sensor unit 40 Laser oscillator 60 Control device 61 Processing program storage unit 62 Processing control unit 63 Fault processing unit 64 Fault part determination unit 65 Interfering part determination unit 66 Program processing unit 70 Operation display unit 100 Collision position 110 First determination area 120 Second determination area P1 to P5 Part (machined part)
P7 Parts (parts in the process of being processed)
P8 to P11 Parts (unprocessed parts)
D Width W Work

Claims (8)

a laser processing machine body that processes a workpiece by moving a processing head that irradiates a laser beam relative to the workpiece;
a control device that controls the laser processing machine body based on a processing program for cutting out the plurality of parts allocated to the workpiece in order from the workpiece,
The control device
determining whether a collision of the processing head has occurred;
When it is determined that the collision of the machining head has occurred, an obstacle part with which the machining head has collided is identified from among a plurality of machined parts cut out from the workpiece;
A laser processing machine that searches for an interfering part from among unmachined parts that have not been machined, which will cause the machining head to interfere with the obstructing part when machining the unmachined part. The control device
Based on the board placement data in which the plurality of parts are allocated to the workpiece, a first judgment area having a predetermined area is set around the collision position where the collision of the machining head occurs;
The laser processing machine according to claim 1 , wherein the machined part included in the first determination area is identified as the defective part. The control device
a second determination area is set by widening the machining path used to machine the obstacle part by a certain width based on the cutting data;
The laser processing machine according to claim 2 , wherein the unmachined part included in the second determination area is identified as the interfering part. The control device
4. The laser processing machine according to claim 3, wherein, if the interfering part is identified as a result of the search, processing of the interfering part is skipped when processing of the unmachined part is resumed. The control device
The laser processing machine according to claim 4, wherein the processing program for processing the interfering part is extracted, and the processing program for re-processing the interfering part is saved. The control device
When it is determined that the collision of the machining head has occurred, it is determined whether or not automatic recovery of the machining head is possible;
The laser processing machine according to claim 1 , wherein, when it is determined that the automatic recovery of the processing head is possible, a process of identifying the faulty part is performed. A method for controlling a laser processing machine that processes a workpiece by moving a processing head that irradiates a laser beam relative to the workpiece, comprising:
Operate the laser processing machine in accordance with a processing program for cutting out the plurality of parts allocated to the workpiece in order from the workpiece;
determining whether a collision of the processing head has occurred;
When it is determined that the collision of the machining head has occurred, an obstacle part with which the machining head has collided is identified from among a plurality of machined parts cut out from the workpiece;
A control method for a laser processing machine, the method comprising: searching for an interfering part from among unmachined parts that have not been machined, the interfering part causing the machining head to interfere with the obstructing part when machining the unmachined part; A program for controlling a laser processing machine that processes a workpiece while moving a processing head that irradiates a laser beam relative to the workpiece,
Operate the laser processing machine in accordance with a processing program for cutting out the plurality of parts allocated to the workpiece in order from the workpiece;
determining whether a collision of the processing head has occurred;
When it is determined that the machining head has collided with the obstacle part, the obstacle part is identified from among the plurality of machined parts cut out from the workpiece.
A program that causes a computer to execute a process of searching for an interfering part from among unmachined parts that have not been machined, which will cause the machining head to interfere with the obstructing part when machining the unmachined part.