Collision prevention device, processing system, collision prevention method, and collision prevention program

Abstract

The collision prevention device (100) includes a machine information extraction unit (12) that extracts information related to the state of the machine tool (200) as machine information from a numerical control device (201) that numerically controls the machine tool (200) in accordance with a machining program, a machine information storage unit (13) that stores the machine information, a machine state change estimation unit (14) that estimates a change in the state of the machine tool (200) based on the machine information stored in the machine information storage unit (13), a machining resumption confirmation unit (15) that presents the estimation result of the machine state change estimation unit (14) to a user and confirms with the user whether or not execution of the machining program can be resumed, and a machining resumption processing unit (16) that causes the numerical control device (201) to resume execution of the machining program based on the confirmation result of the machining resumption confirmation unit (15).

Description

[Technical Field]

[0001] The present disclosure relates to a collision prevention device, a machining system, a collision prevention method, and a collision prevention program that prevent collisions between structures within a machine tool. [Background technology]

[0002] Conventionally, machine tools that machine workpieces according to a machining program have been known. The machine tool includes, for example, a table or turning spindle to which the workpiece is fixed using a jig, a tool spindle to which a tool is attached, a drive mechanism that moves the table or turning spindle and the tool spindle relative to each other, and a numerical control device that numerically controls the drive mechanism according to the machining program. During operation, unexpected movement of structures such as tools, workpieces, and jigs within the machine tool can result in collisions between the structures. To prevent such collisions between the structures, machine tools use collision prevention devices.

[0003] In machine tools, the execution of a machining program may be paused for various reasons during the machining process. For example, if a user changes a tool or fine-tunes the position of a workpiece during the pause, the structure may be changed by a user operation, which may result in an unexpected collision when the program is resumed. Therefore, when the execution of a machining program is resumed after a pause, the machine tool may not always be able to perform the machining process properly. For example, Patent Document 1 discloses a numerical control device that executes an NC (Numerical Control) program composed of multiple blocks containing NC code to numerically control the motion mechanism of the machine tool. This numerical control device is configured to perform the machining process properly by checking whether the blocks of the NC program are resumable when resuming the execution of the NC program after the NC program has been paused. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-108254 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology of Patent Document 1 does not have a configuration that allows for confirmation of changes in the state of the machine tool, such as changes to the structure caused by a user operation, between the time when the execution of the NC program is paused and the time when the execution of the NC program is resumed. In other words, the technology of Patent Document 1 does not guarantee that the state of the machine tool before the NC program is paused will match the state of the machine tool when the NC program is resumed. Therefore, with the technology of Patent Document 1, there is a risk that the execution of the NC program will be paused and then resumed with the state of the machine tool still changed, which could result in collisions between structures.

[0006] The present disclosure has been made in consideration of the above, and aims to provide a collision prevention device that can prevent structures from colliding with each other even if the state of a machine tool is changed by user operation. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the collision prevention device according to the present disclosure comprises: A collision prevention device that prevents collisions between structures inside a machine tool, From a numerical control device that numerically controls machine tools according to a machining program When receiving information to suspend the execution of the machining program, the numerical control device Information related to the status of machine tools The machine A machine information extraction unit extracts machine information, a machine information storage unit stores machine information, and based on the machine information stored in the machine information storage unit, The difference between the state of the machine tool just before the execution of the machining program is paused and the actual state of the machine tool when the execution of the machining program is resumed is calculated. Changes in machine tool conditions asa machining restart confirmation unit that presents the estimation result of the machine state change estimation unit to the user and confirms with the user whether or not execution of the machining program can be resumed; and a machining restart processing unit that causes the numerical control device to resume execution of the machining program based on the confirmation result of the machining restart confirmation unit. [Effects of the Invention]

[0008] The collision prevention device according to the present disclosure has the effect of preventing structures from colliding with each other even if the state of the machine tool is changed by user operation. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing a processing system according to a first embodiment. [Figure 2] FIG. 1 is a perspective view schematically illustrating an example of a machine tool constituting a machining system according to a first embodiment; [Figure 3] FIG. 1 is a block diagram showing a collision prevention device according to a first embodiment; [Figure 4] FIG. 10 is an explanatory diagram illustrating an example of a state estimation performed by a machine state change estimation unit included in the collision prevention device according to the first embodiment; [Figure 5] FIG. 1 is an explanatory diagram schematically illustrating an example of an output device of a processing system according to a first embodiment; [Figure 6] FIG. 10 is an explanatory diagram illustrating an example of an output device of the machining system according to the first embodiment, which is a schematic diagram illustrating a state in which a warning is issued for a workpiece. [Figure 7] FIG. 10 is an explanatory diagram illustrating an example of an output device of the machining system according to the first embodiment, which is a schematic diagram illustrating a state in which a jig warning is issued. [Figure 8] FIG. 10 is an explanatory diagram illustrating an example of an output device of the machining system according to the first embodiment, which is a schematic diagram illustrating a state in which a warning is issued for a tool. [Figure 9] FIG. 10 is an explanatory diagram illustrating an example of an output device of the processing system according to the first embodiment, which is a schematic diagram illustrating a state in which a warning is issued for a plurality of structures; [Figure 10]FIG. 10 is an explanatory diagram schematically illustrating an example of a case where a change in the setting of a machine tool is presented to a user in the machining system according to the first embodiment; [Figure 11] 1 is a flowchart showing an operation procedure of a collision prevention device according to a first embodiment. [Figure 12] FIG. 1 is a block diagram illustrating a modification of the collision prevention device according to the first embodiment. [Figure 13] FIG. 10 is a block diagram showing a collision prevention device according to a second embodiment. [Figure 14] FIG. 10 is a block diagram showing a collision prevention device according to a third embodiment. [Figure 15] 10 is a flowchart showing an operation procedure of a collision prevention device according to a third embodiment. [Figure 16] FIG. 1 is an explanatory diagram showing an example of the configuration of a computer system that realizes a collision prevention device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a collision prevention device, a processing system, a collision prevention method, and a collision prevention program according to embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0011] Embodiment 1 Fig. 1 is a block diagram showing a machining system according to the first embodiment. As shown in Fig. 1, the machining system 500 according to the first embodiment includes a machine tool 200, a collision prevention device 100, an output unit 300, and an input unit 400. In the machine tool 200, structures within the machine tool 200 are controlled in accordance with a machining program created by, for example, a CAM (Computer Aided Manufacturing) system, and the machine tool 200 machines a workpiece.

[0012] FIG. 2 is a perspective view schematically illustrating an example of a machine tool constituting the machining system according to the first embodiment. As shown in FIGS. 1 and 2, the machine tool 200 includes, as an example of a structure, a bed 20, a column 21, a table 22 on which a workpiece W is placed, a jig 23 for fixing the workpiece W, a tool 24 for cutting the workpiece W, a tool holder 25 to which the tool 24 is attached, a drive mechanism for moving the table 22 and the tool holder 25 relative to each other, and a numerical control device 201 for numerically controlling the drive mechanism in accordance with a machining program for the workpiece W. The drive mechanism includes a Y-axis movement mechanism 26 for moving the table 22 in the Y-axis direction, an X-axis movement mechanism 27 for moving the tool holder 25 in the X-axis direction, and a Z-axis movement mechanism 28 for moving the tool holder 25 in the Z-axis direction. The Y-axis movement mechanism 26 is provided on the upper surface of the bed 20. The X-axis movement mechanism 27 and the Z-axis movement mechanism 28 are attached to the column 21. It should be noted that numerical control device 201 does not necessarily have to be a part of the components of machine tool 200, and may be configured as a separate member from machine tool 200.

[0013] In cutting processing by machine tool 200, tool 24 attached to tool holder 25 and workpiece W fixed to table 22 are moved relative to each other by the drive mechanism. Then, tool holder 25 rotates, causing tool 24 to rotate, and tool 24 comes into contact with workpiece W, cutting away a portion of workpiece W. At this time, machine tool 200 processes workpiece W while determining whether or not a collision has occurred between structures based on shape models of the structures. If a collision between shape models of the structures is confirmed prior to cutting processing of workpiece W, machine tool 200 stops the movement of the drive mechanism.

[0014] It should be noted that machine tool 200 is not limited to the configuration shown in the figure and may have other configurations. For example, machine tool 200 may have a configuration including a turning spindle that can hold and rotate workpiece W. In this case, the turning spindle is a structure within machine tool 200.

[0015] Collision prevention device 100 according to the first embodiment is a device for preventing structures from colliding with each other even when the state of machine tool 200 is changed by a user operation while execution of a machining program is paused and before execution of the machining program is resumed. Collision prevention device 100 may be realized by a device external to machine tool 200, or may be a device connectable to numerical control device 201 via a network. Collision prevention device 100 may also be a device present on a cloud server.

[0016] Fig. 3 is a block diagram showing the collision prevention device according to the first embodiment. As shown in Fig. 3, the collision prevention device 100 includes a machine state model update processing unit 10, a machine state model storage unit 11, a machine information extraction unit 12, a machine information storage unit 13, a machine state change estimation unit 14, a machining resumption confirmation unit 15, and a machining resumption processing unit 16.

[0017] The machine state model update processing unit 10 acquires virtual operations of structures within the machine tool 200 from the numerical control device 201 based on information from the numerical control device 201, and updates a machine state model that represents the state of the machine tool 200. Examples of structures within the machine tool 200 include workpiece W, jig 23, and tool 24, the shapes and positional relationships of which are likely to change with each machining operation. The machine state model is a model that virtually represents the state of the machine tool 200, including the structures within the machine tool 200. The information from the numerical control device 201 is information from the numerical control device 201 that represents changes in the structures. For example, the machine state model update processing unit 10 can update, from time to time, the positions of parts in the machine state model that represent the structures within the machine tool 200 that are activated by a position command of a certain command axis created by the numerical control device 201, and virtually represent the movement of the structures within the machine tool 200 during machining.

[0018] The machine state model storage unit 11 stores the machine state model updated by the machine state model update processing unit 10.

[0019] When machine information extraction unit 12 receives information to temporarily suspend execution of the machining program from numerical control device 201, it extracts information relating to the state of machine tool 200 from numerical control device 201 as machine information from the time the pause information is received. The information relating to the state of machine tool 200 is information relating to changes in structures within machine tool 200 and information relating to changes in settings of machine tool 200.

[0020] Information related to changes in structures within machine tool 200 includes information that directly represents changes in structures within machine tool 200, and information related to operations that may cause changes in structures within machine tool 200.

[0021] Information that directly represents a change in a structure within machine tool 200 is, for example, information that a user has manually operated a handle to drive a drive mechanism. Driving the drive mechanism moves structures such as table 22, workpiece W, jig 23, or tool 24. In this case, the distance by which a command axis has moved is transmitted from numerical control device 201 to machine information extraction unit 12.

[0022] Operations that may cause changes to structures within the machine tool 200 include, for example, opening and closing a door (not shown) equipped on the machine tool 200, opening and closing a chuck, or unclamping within a tool magazine (not shown).

[0023] Information related to the opening and closing of the door of machine tool 200 does not directly represent changes in the structures moved by the command axes. However, there is a possibility that workpiece W, jig 23, or tool 24 may be removed or changed while the door of machine tool 200 is open. Therefore, information related to the opening and closing of the door of machine tool 200 represents an operation that may cause a change in the structures within machine tool 200, and is treated as machine information. Information related to the opening and closing of the chuck, like information related to the opening and closing of the door of machine tool 200, represents a possibility that workpiece W may be removed or changed while the chuck is open. Therefore, information related to the opening and closing of the chuck represents an operation that may cause a change in the structures within machine tool 200, and is treated as machine information. Information related to the occurrence of unclamping in the tool magazine represents a possibility that tool 24 or tool holder 25 installed in the tool magazine may be removed or changed. Therefore, information related to the occurrence of unclamping in the tool magazine represents an operation that may cause a change in the structures within machine tool 200, and is treated as machine information.

[0024] Information related to changes in the settings of the machine tool 200 includes, for example, information such as an update of parameter values ​​of the numerical control device 201, a change in parts of the machine state model of the numerical control device 201, or a change in the mode of the numerical control device 201, caused by a user operation. An example of an update of a parameter value is a change in override settings. Override settings are settings related to machining conditions related to the movement of command axes. Therefore, information related to changes in override settings is treated as machine information.

[0025] An example of a change in a part of the machine state model is the replacement of a tool model. A tool model virtually represents one of the structures of the machine state model. When a tool model is replaced, for example, changing the length or size of the tool model, the machine state model changes. Therefore, information related to the replacement of a tool model is treated as machine information. An example of a change in mode is when automatic operation is changed to manual operation. Note that information related to changes in settings of the machine tool 200 is not limited to the above configuration, and may be other changes in settings.

[0026] The machine information storage unit 13 stores the machine information extracted by the machine information extraction unit 12. The machine information storage unit 13 stores the machine information in chronological order of when it was generated.

[0027] The machine state change estimation unit 14 estimates a change in the state of the machine tool 200 based on the machine state model stored in the machine state model storage unit 11 and the machine information stored in the machine information storage unit 13. Specifically, the machine state change estimation unit 14 estimates the difference between the state of the machine tool 200 represented by the machine state model updated immediately before the suspension of the execution of the machining program and the actual state of the machine tool 200 at the time when the execution of the machining program is resumed. Note that the machine state change estimation unit 14 may estimate the change in the state of the machine tool 200 based only on the machine information stored in the machine information storage unit 13. In this case, the machine state change estimation unit 14 estimates the difference between the actual state of the machine tool 200 at the time when the execution of the machining program is paused and the actual state of the machine tool 200 at the time when the execution of the machining program is resumed, from all operations that may change the state of the machine tool 200 from the time when the execution of the machining program is paused to the time when the execution of the machining program is resumed.

[0028] A change in the state of machine tool 200 is a change in the state of a structure within machine tool 200 or a change related to the settings of machine tool 200. The state of a structure within machine tool 200 includes the shape of the structure, the position of the structure, the material of the structure, etc. The settings of machine tool 200 include settings related to machining, settings related to a machine state model, etc.

[0029] FIG. 4 is an explanatory diagram illustrating an example of the state of estimation performed by the machine state change estimation unit constituting the collision prevention device according to the first embodiment. The “NC information” in FIG. 4 refers to information extracted from the numerical control device 201 by the machine information extraction unit 12. As shown in FIG. 4, the machine information storage unit 13 sequentially records four pieces of machine information—“pause of machining program,” “door open,” “door closed,” and “machining program execution instruction”—as machine information data extracted from the numerical control device 201 by the machine information extraction unit 12. All of this machine information is generated by user operations. In this case, the estimation target period estimated by the machine state change estimation unit 14 is from the time when the “machining program pause” information is generated to the time when the “machining program execution instruction” information is generated. If the machine information extraction unit 12 extracts the “door open” and “door closed” machine information within the estimation target period, the machine state change estimation unit 14 determines that a change may have occurred to the structure within the machine tool 200. The machine state model at the time when the machining program is paused includes structure models of the workpiece W, the jig 23, and the tool 24. Based on the updated machine state model and the extracted machine information, it is possible that multiple machine state changes have occurred. For example, for workpiece W, machine state changes such as "workpiece W has been removed," "workpiece W has been moved," and "workpiece W has been replaced" are estimated. Furthermore, for jig 23, machine state changes such as "jig 23 has been removed," "jig 23 has been moved," and "jig 23 has been replaced" are estimated. Furthermore, for tool 24, machine state changes such as "tool 24 has been removed," "tool 24 has been moved," and "tool 24 has been replaced" are estimated. Additionally, a user may have brought a tool, part, protective equipment, or the like into the machining area of ​​machine tool 200 while the door was open. In this case, a machine state change such as "something has been placed in the machining area" can be estimated. Note that the state changes of machine tool 200 are not limited to these, and other changes may also be possible.

[0030] In these cases, the state of machine tool 200 at the time of "instruction to execute the machining program" may differ from the machine state model at the time of "pausing the machining program." Therefore, as a result of estimation by machine state change estimation unit 14, it is considered possible that the machine state model at the time of "instruction to execute the machining program" does not correctly represent the actual state of machine tool 200. In this case, if machining is continued without modifying the structures within machine tool 200 or changing the machine state model, there is a possibility that collisions between structures may occur.

[0031] Furthermore, when the machine information extraction unit 12 extracts machine information of "chuck opening and closing" within the estimation target period, the machine state change estimation unit 14 estimates a change in the machine state, for example, for the workpiece W, such as "the workpiece W has been removed," "the workpiece W has been moved," or "the workpiece W has been replaced." Furthermore, when the machine information extraction unit 12 extracts machine information of "occurrence of unclamping in the tool magazine" within the estimation target period, the machine state change estimation unit 14 estimates a change in the machine state, such as "the tool 24 has been removed," "the tool 24 has been moved," or "the tool 24 has been replaced."

[0032] In this way, machine state change estimation unit 14 estimates changes in the shape, position, and material of a structure within machine tool 200, based on the machine state model stored in machine state model storage unit 11 and the machine information stored in machine information storage unit 13. In other words, by estimating operations that are not directly visible to the user from information from numerical control device 201, the range of collision prevention can be expanded and the risk of collision between structures can be reduced.

[0033] The machining resumption confirmation unit 15 presents the estimation result of the machine condition change estimation unit 14 to the user, who is the decision-maker, and confirms with the user whether or not execution of the machining program can be resumed. The machining resumption confirmation unit 15 displays the estimation result of the machine condition change estimation unit 14 and the possible occurrence of a collision on the output device 300 for presentation to the user, and receives from the user via the input device 400 whether or not execution of the paused machining program can be resumed. The confirmation by the machining resumption confirmation unit 15 may include two operations: presenting the estimation result of the machine condition change estimation unit 14 to the user, and, after the presentation, obtaining from the user a decision on whether or not execution of the machining program can be resumed. In the confirmation by the machining resumption confirmation unit 15, it does not matter how the user used the estimation result of the machine condition change estimation unit 14 as a basis for their decision, or whether or not they referred to the estimation result.

[0034] Based on a command from the machining resumption confirmation unit 15, the output unit 300 outputs the estimation result of the machine state change estimation unit 14 and the possible occurrence of a collision, and presents them to the user. The output unit 300, for example, displays a text warning or a colored machine state model on the display screen of a display unit, or outputs an alarm or sound from an audio unit. The input unit 400 receives from the user whether or not to resume execution of the machining program, and transmits this to the machining resumption confirmation unit 15. Examples of the input unit 400 include a keyboard, a touch screen, or a microphone. The user inputs whether or not to resume execution of the machining program into the input unit 400. The input information received from the user is confirmed by the machining resumption confirmation unit 15. Note that the output unit 300 and the input unit 400 do not necessarily have to be separate entities, and may be configured as an integrated unit.

[0035] The user may be any person who determines whether or not execution of the machining program can be resumed. Furthermore, the user is not limited to, for example, a person who directly operates machine tool 200 or a person who is near machine tool 200. For example, the user may be in a location away from machine tool 200 and determine whether or not execution of the machining program can be resumed based on the estimation result of machine state change estimation unit 14 presented on the display screen of a mobile terminal or a computer, for example.

[0036] 5 is an explanatory diagram schematically illustrating an example of an output device of the machining system according to the first embodiment. When the machining resumption confirmation unit 15 determines that the machine state of the machine tool 200 has changed based on the estimation result of the machine state change estimation unit 14, the output device 300 presents the estimation result to the user. The output device 300 shown in FIG. 5 is, for example, a display screen of a display device such as a monitor, which displays a colored machine state model and presents it to the user. The output device 300 shown in FIG. 5 displays the workpiece W, table 22, jig 23, tool 24, and tool holder 25 as the machine state model.

[0037] 6 is an explanatory diagram showing an example of an output device of the machining system according to the first embodiment, which diagrammatically illustrates a state in which a warning is issued for the workpiece. As shown in FIG. 6, when the estimation result of the machine state change estimation unit 14 estimates that a problem has occurred in the workpiece W, the workpiece W is displayed in color in the machine state model. This allows the user to determine that the structure that may be subject to change is the workpiece W.

[0038] 7 is an explanatory diagram showing an example of an output device of the machining system according to the first embodiment, which diagrammatically illustrates a state in which a jig warning is issued. As shown in FIG. 7, when the machine state change estimation unit 14 estimates that a problem has occurred in the jig 23, the jig 23 is displayed in color in the machine state model. This allows the user to determine that the jig 23 is a structure that may be subject to change.

[0039] 8 is an explanatory diagram showing an example of an output device of the machining system according to the first embodiment, and is a schematic diagram showing a state in which a warning is issued for a tool. As shown in FIG. 8, when the estimation result of the machine state change estimation unit 14 estimates that a problem has occurred in the tool 24, the tool 24 is displayed in color in the machine state model. This allows the user to determine that the structure that may be subject to change is the tool 24.

[0040] 9 is an explanatory diagram showing an example of an output device of the machining system according to the first embodiment, and is a schematic diagram showing a state in which a warning is issued for a plurality of structures. As shown in FIG. 9, when the estimation result of the machine state change estimation unit 14 estimates that a problem has occurred in the workpiece W, the jig 23, and the tool 24, the workpiece W, the jig 23, and the tool 24 in the machine state model are displayed in a color different from that of the other structures. This allows the user to determine that the structures that may be subject to change are the workpiece W, the jig 23, and the tool 24.

[0041] FIG. 10 is an explanatory diagram schematically illustrating an example of a case where a change in the settings of the machine tool is presented to the user in the machining system according to the first embodiment. If the machine state change estimation unit 14 determines that the settings of the machine tool 200 have been changed based on the estimation result, the output unit 300 warns the user. The warning content shown in FIG. 10 displays, as an example, a message indicating that the override setting value has been changed, along with the setting values ​​before and after the change. The warning message can also be read aloud. The user can input whether or not to resume execution of the machining program by touching the “OK” button or the “Cancel” button on the input unit 400 with their finger or pressing it with a mouse. When the user selects the “OK” button, the machining resumption confirmation unit 15 determines that the user has confirmed the change in the machine tool 200 and has permitted the resumption of execution of the machining program in the changed state.

[0042] The presentation of the estimation result by the output device 300 is not limited to the above configuration, and any means may be used as long as the information is presented in a form that the user can obtain. For example, the presentation of the estimation result by the output device 300 may be a signal that makes the user aware that input by the input device 400 is required. This signal may be in any form as long as it is a signal that the user can notice using their five senses. Furthermore, the user's decision on whether or not to proceed may be in any form as long as it is transmitted to the collision prevention device 100.

[0043] The machining restart processing unit 16 instructs the numerical control device 201 to restart or terminate execution of the machining program based on the confirmation result of the machining restart confirmation unit 15. Specifically, the machining restart processing unit 16 instructs the numerical control device 201 to resume execution of the machining program when the machining restart confirmation unit 15 obtains permission from the user to resume execution of the machining program. The numerical control device 201 resumes execution of the machining program from the state of the machine tool 200 at the time when the restart instruction was obtained. On the other hand, when the machining restart confirmation unit 15 does not obtain permission from the user to resume execution of the machining program, the machining restart processing unit 16 instructs the numerical control device 201 to terminate execution of the machining program.

[0044] 11 is a flowchart showing the operation procedure of the collision prevention device according to the first embodiment. First, when the operation of the collision prevention device 100 starts, the machine state model update processing unit 10 determines whether or not execution of a machining program has started in the numerical control device 201 (step S101). When the machine state model update processing unit 10 determines that execution of the machining program has started (step S101: Yes), it acquires a machine state model from the numerical control device 201 and stores it in the machine state model storage unit 11, and updates the machine state model stored in the machine state model storage unit 11 as machining progresses (step S102). On the other hand, when the machine state model update processing unit 10 determines that execution of the machining program has not started (step S101: No), the operation of the collision prevention device 100 ends.

[0045] Next, the machine information extraction unit 12 determines whether the currently executing machining program has been paused (step S103). The machine information extraction unit 12 determines that the machining program is in a paused state by receiving machine information from the numerical control device 201 that the currently executing machining program has been paused. If the machine information extraction unit 12 determines that the currently executing machining program has been paused (step S103: Yes), it extracts machine information from the numerical control device 201 (step S104) and stores the extracted machine information in the machine information storage unit 13. On the other hand, if the machine information extraction unit 12 determines that the currently executing machining program has not been paused (step S103: No), the process proceeds to step S110.

[0046] Next, the machine state change estimation unit 14 estimates a change in the state of the machine tool 200 based on the machine state model stored in the machine state model storage unit 11 and the machine information stored in the machine information storage unit 13 (step S105). The machining restart confirmation unit 15 causes the output device 300 to output the estimation result by the machine state change estimation unit 14 and present it to the user (step S106), and confirms with the user whether or not execution of the paused machining program can be resumed (step S107). If the machining restart confirmation unit 15 determines that the user has given permission to resume execution of the machining program (step S108: Yes), the machining restart processing unit 16 instructs the numerical control device 201 to resume execution of the machining program (step S109). On the other hand, if the machining restart confirmation unit 15 determines that the user has not given permission to resume execution of the machining program (step S108: No), the machining restart processing unit 16 instructs the numerical control device 201 to terminate the machining program, and then the operation of the collision prevention device 100 terminates.

[0047] After the machining restart processing unit 16 instructs the numerical control device 201 to restart the execution of the machining program (step S109), the machine information extraction unit 12 determines whether the currently executing machining program has ended (step S110). If the machine information extraction unit 12 determines that the currently executing machining program has ended (step S110: Yes), the operation of the collision prevention device 100 ends. On the other hand, if the machine information extraction unit 12 determines that the currently executing machining program has not ended (step S110: No), the process returns to step S102, and the process is repeated until the machining program ends.

[0048] As described above, the collision prevention device 100 according to the first embodiment includes a machine state model update processing unit 10 that acquires virtual operations of structures within the machine tool 200 from the numerical control device 201 and updates a machine state model that represents the state of the machine tool 200 based on the virtual operations; a machine information extraction unit 12 that extracts information related to the state of the machine tool 200 as machine information from the numerical control device 201 that numerically controls the machine tool 200 according to a machining program; a machine information storage unit 13 that stores the machine information; a machine state change estimation unit 14 that estimates changes in the state of the machine tool 200 based on the machine information stored in the machine information storage unit 13; a machining resume confirmation unit 15 that presents the estimation result of the machine state change estimation unit 14 to the user and confirms with the user whether or not execution of the machining program can be resumed; and a machining resume processing unit 16 that causes the numerical control device 201 to resume execution of the machining program based on the confirmation result of the machining resume confirmation unit 15. Therefore, even if the state of machine tool 200 is changed by a user operation while execution of a machining program is paused and before the execution of the machining program is resumed, collision prevention device 100 according to the first embodiment estimates the change in the state of machine tool 200, presents it to the user, and asks the user whether or not execution of the machining program can be resumed, thereby preventing a situation in which structures collide with each other. Furthermore, because collision prevention device 100 according to the first embodiment can prevent a situation in which structures collide with each other, it can reduce the number of times machine tool 200 is stopped due to such collisions. This reduces the user's effort required for machining, and also reduces the machining time.

[0049] FIG. 12 is a block diagram showing a modification of the collision prevention device according to the first embodiment. The collision prevention device 100A of the modification shown in FIG. 12 is configured such that the machine state model update processing unit 10 and the machine state model storage unit 11 are omitted compared to the collision prevention device 100 shown in FIG. 3 . That is, the collision prevention device 100A includes a machine information extraction unit 12, a machine information storage unit 13, a machine state change estimation unit 14, a machining restart confirmation unit 15, and a machining restart processing unit 16. In this case, the machine state change estimation unit 14 estimates a change in the state of the machine tool 200 based only on the machine information stored in the machine information storage unit 13. Specifically, the machine state change estimation unit 14 estimates a difference between the actual state of the machine tool 200 at the time execution of the machining program is paused and the actual state of the machine tool 200 at the time execution of the machining program is resumed, based on all operations that may change the state of the machine tool 200 from the time execution of the machining program is paused to the time execution of the machining program is resumed.

[0050] Embodiment 2 Next, a collision prevention device 101 according to a second embodiment will be described. Note that the same components as those in the first embodiment will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate. FIG. 13 is a block diagram showing a collision prevention device according to the second embodiment. As shown in FIG. 13, the collision prevention device 101 according to the second embodiment includes an operation information extraction unit 17 in addition to the configuration described in the first embodiment.

[0051] The operation information extraction unit 17 extracts operation information performed by the user from the information related to the state of the machine tool 200 extracted by the machine information extraction unit 12. The information related to the state of the machine tool 200 extracted by the machine information extraction unit 12 includes various pieces of machine information. Of the various pieces of machine information extracted by the machine information extraction unit 12, information related to operations performed by the user is particularly important machine information. The operation information performed by the user is machine information that leads to a change in the state of the machine tool 200 due to the user's operation. Examples of user operations include the user pressing a button on the machine tool 200, turning a handle, and manually moving a structure inside the machine tool 200. Note that user operations are not limited to these operations and may include other operations. For example, information related to the opening and closing of the door of the machine tool 200 is machine information that is generated when the user presses the "door open" and "door close" buttons. Therefore, the operation information extraction unit 17 can extract operation information that "the door open / close button was pressed by the user" from the machine information of "door open" and "door close." The operation information extracted by the operation information extraction unit 17 is stored in the machine information storage unit 13 as machine information.

[0052] Collision prevention device 101 according to the second embodiment can also achieve the same effects as collision prevention device 100 according to the first embodiment. Furthermore, collision prevention device 101 according to the second embodiment can extract operation information performed by the user from machine information extraction unit 12, and therefore can improve the accuracy of estimating changes in the state of machine tool 200.

[0053] Embodiment 3 Next, a collision prevention device 102 according to a third embodiment will be described. Note that the same components as those in the first and second embodiments are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate. FIG. 14 is a block diagram showing a collision prevention device according to the third embodiment. As shown in FIG. 14, the collision prevention device 102 according to the third embodiment includes a machine state model correction unit 18 in addition to the configuration described in the first embodiment.

[0054] The machine state model correction unit 18 corrects the machine state model stored in the machine state model storage unit 11 based on the estimation result by the machine state change estimation unit 14 and the confirmation result from the user by the machining restart confirmation unit 15. Correction of the machine state model means correcting the position and shape of the model of the structure included in the machine state model in order to match the machine state model to the position and shape of the structure within the machine tool 200. That is, the collision prevention device 102 according to the third embodiment corrects the machining program of the numerical control device 201 in accordance with a user's instruction in accordance with a change in the state of the structure within the machine tool 200. On the other hand, in the collision prevention devices 100 and 100A according to the first embodiment and the collision prevention device 101 according to the second embodiment, when there is a change in the state of the structure within the machine tool 200, the user corrects the state of the structure of the machine tool 200 in accordance with the machining program of the numerical control device 201.

[0055] Fig. 15 is a flowchart showing the operation procedure of the collision prevention device according to the embodiment 3. In steps S101 to S110 shown in Fig. 15, the same processes as those in steps S101 to S110 shown in Fig. 11 will not be described again.

[0056] The machining restart confirmation unit 15 outputs the estimation result by the machine state change estimation unit 14 to the output device 300 and presents it to the user (step S106), and confirms with the user whether or not execution of the paused machining program can be resumed (step S107). If the machining restart confirmation unit 15 determines that the user has given permission to resume execution of the machining program (step S108: Yes), the machining restart processing unit 16 instructs the numerical control device 201 to resume execution of the machining program (step S109). Then, the machine information extraction unit 12 determines whether the currently executing machining program has ended (step S110). If the machine information extraction unit 12 determines that the currently executing machining program has ended (step S110: Yes), the operation of the collision prevention device 102 ends. On the other hand, if the machine information extraction unit 12 determines that the currently executing machining program has not ended (step S110: No), the process returns to step S102 and repeats the process until the machining program ends.

[0057] On the other hand, if the machining restart confirmation unit 15 determines that the user has not given permission to resume execution of the machining program (step S108: No), it displays a proposal for modifying the machine state model on the output device 300 based on the estimation result of the machine state change estimation unit 14, and asks the user whether the modification is possible (step S201). A possible modification is, for example, a simple model modification such as changing the movement of the workpiece W or the length of the tool 24. The machining restart confirmation unit 15 receives confirmation from the user via the input device 400. If the machining restart confirmation unit 15 determines that the user can modify the machine state model (step S202: Yes), the machine state model modification unit 18 executes a process for modifying the machine state model (step S203). Specifically, the machine state model modification unit 18 modifies the machine state model stored in the machine state model storage unit 11, and when the modification of the machine state model is completed, it causes the machining restart confirmation unit 15 to display the modified machine state model on the output device 300 and present it to the user. Then, the machining restart confirmation unit 15 confirms again with the user whether or not the execution of the machining program that is in the paused state can be restarted (step S107). On the other hand, if the machining restart confirmation unit 15 determines that the user cannot modify the machine state model (step S202: No), the machining restart processing unit 16 instructs the numerical control device 201 to end the machining program, and then the operation of the collision prevention device 102 ends.

[0058] The collision prevention device 102 according to the third embodiment may further include the operation information extraction unit 17 described in the second embodiment.

[0059] As described above, the collision prevention device 102 according to the third embodiment includes the machine state model correction unit 18 that corrects the machine state model stored in the machine state model storage unit 11 based on the estimation result of the machine state change estimation unit 14 and the confirmation result of the machining restart confirmation unit 15. Therefore, even if the state of the machine tool 200 is changed by a user operation between the time when execution of the machining program is paused and the time when execution of the machining program is resumed, the collision prevention device 102 according to the third embodiment corrects the machine state model stored in the machine state model storage unit 11 based on the estimation result of the machine state change estimation unit 14 and the confirmation result of the machining restart confirmation unit 15, and confirms with the user whether execution of the machining program can be resumed. This makes it possible to prevent collisions between structures. Furthermore, the collision prevention device 102 according to the third embodiment can virtually reproduce changes in the structure within the machine tool 200 in the machine state model by correcting the machine state model. This eliminates the need to execute the machining program from the beginning, and allows the machining program to be resumed from the point of suspension.

[0060] 16 is an explanatory diagram showing an example of the configuration of a computer system that realizes the collision prevention device according to this embodiment. In the collision prevention devices 100, 100A, 101, and 102 according to this embodiment, a computer program describing the processing in the collision prevention devices 100, 100A, 101, and 102 is executed on the computer system, so that the computer system functions as the collision prevention devices 100, 100A, 101, and 102. As shown in FIG. 16, this computer system includes, for example, a processor 600, a memory 601, a storage 602, and a communication device 603, which are connected via a system bus 604.

[0061] The processor 600, memory 601, storage 602, and communication device 603 can transmit and receive information to and from each other via a system bus 604. The processor 600 is an example of a processing circuit and includes one or more of a CPU (Central Processing Unit), a DSP (Digital Signal Processor), and a system LSI (Large Scale Integration). The memory 601 includes one or more of a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable Read Only Memory), and an EEPROM (Electrically Erasable Programmable Read Only Memory). The memory 601 also includes a recording medium on which a computer-readable program is recorded. Such a recording medium includes one or more of a nonvolatile or volatile semiconductor memory, a magnetic disk, a flexible memory, an optical disk, a compact disk, and a DVD (Digital Versatile Disc). The memory 601 stores programs to be executed by the processor 600, necessary data obtained during processing, and the like. The memory 601 is also used as a temporary storage area for programs. The communication device 603 is a receiver and a transmitter that perform communication processing. Note that the computer system is not limited to the configuration shown in Fig. 16 and may include other components.

[0062] Here, an example of the operation of the computer system until the program of this embodiment is ready to be executed will be described. In the computer system having the above configuration, a computer program is installed in storage 602 from a medium such as a CD-ROM or DVD-ROM inserted in a CD (Compact Disc)-ROM drive or DVD-ROM drive (not shown). When the program is executed, the program read from storage 602 is stored in the main storage area of ​​memory 601. In this state, processor 600 executes the processing of collision prevention devices 100, 100A, 101, and 102 according to this embodiment in accordance with the program stored in memory 601.

[0063] In the above explanation, a program describing the processing in the collision prevention devices 100, 100A, 101, and 102 is provided using a CD-ROM or DVD-ROM as a recording medium, but this is not limiting, and depending on the configuration of the computer system, the capacity of the program to be provided, etc., it is also possible to use a program provided via a transmission medium such as the Internet via the communication device 603.

[0064] The collision prevention program in this embodiment causes a computer system to execute the following steps: extracting information relating to the state of machine tool 200 as machine information from numerical control device 201, which numerically controls machine tool 200 in accordance with a machining program; storing the machine information; estimating changes in the state of machine tool 200 based on the stored machine information; presenting the estimation results to a user and confirming with the user whether or not execution of the machining program can be resumed; and causing numerical control device 201 to resume execution of the machining program based on the confirmation results.

[0065] The collision prevention program in this embodiment may further include a step of acquiring virtual operations of structures within machine tool 200 from numerical control device 201 and updating a machine state model representing the state of machine tool 200 based on the virtual operations, and a machine state model storage step of storing the updated machine state model. In this case, in the step of estimating a change in the state of machine tool 200, the change in the state of machine tool 200 is estimated based on the machine state model and machine information.

[0066] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies or may be combined with other embodiments. Furthermore, it is also possible to omit or modify part of the configurations without departing from the spirit of the invention. [Explanation of symbols]

[0067] 10 Machine state model update processing unit, 11 Machine state model memory unit, 12 Machine information extraction unit, 13 Machine information memory unit, 14 Machine state change estimation unit, 15 Machining restart confirmation unit, 16 Machining restart processing unit, 17 Operation information extraction unit, 18 Machine state model correction unit, 20 Bed, 21 Column, 22 Table, 23 Jig, 24 Tool, 25 Tool holder, 26 Y-axis movement mechanism, 27 X-axis movement mechanism, 28 Z-axis movement mechanism, 100, 100A, 101, 102 Collision prevention device, 200 Machine tool, 201 Numerical control device, 300 Output device, 400 Input device, 500 Machining system, 600 Processor, 601 Memory, 602 Storage, 603 Communication device, 604 System bus, W Work.

Claims

1. A collision prevention device that prevents collisions between structures inside a machine tool, a machine information extraction unit that, when receiving information to suspend execution of the machining program from a numerical control device that numerically controls the machine tool in accordance with the machining program, extracts information relating to the state of the machine tool from the numerical control device as machine information from the time the suspension information is received until execution of the machining program is resumed; a machine information storage unit that stores the machine information; a machine state change estimation unit that estimates, based on the machine information stored in the machine information storage unit, a difference between the state of the machine tool immediately before the suspension of execution of the machining program and the actual state of the machine tool at the time of resuming execution of the machining program as a change in the state of the machine tool; a machining restart confirmation unit that presents an estimation result of the machine state change estimation unit to a user and confirms with the user whether or not execution of the machining program can be restarted; and a machining restart processing unit that causes the numerical control device to restart execution of the machining program based on the confirmation result of the machining restart confirmation unit. A collision prevention device characterized by:

2. a machine state model update processing unit that acquires a virtual operation of a structure inside the machine tool from the numerical control device and updates a machine state model that represents a state of the machine tool based on the virtual operation; a machine state model storage unit that stores the machine state model updated by the machine state model update processing unit, the machine state change estimation unit estimates a change in the state of the machine tool based on the machine state model stored in the machine state model storage unit and the machine information stored in the machine information storage unit.

2. The collision prevention device according to claim 1.

3. a machine state model correction unit that corrects the machine state model stored in the machine state model storage unit based on the estimation result of the machine state change estimation unit and the confirmation result of the machining restart confirmation unit, the machining restart confirmation unit presents the machine state model corrected by the machine state model correction unit to the user, and confirms with the user whether or not execution of the machining program can be restarted.

3. The collision prevention device according to claim 2.

4. The machine state change estimation unit estimating changes in the shape and position of a structure inside the machine tool based on the machine state model stored in the machine state model storage unit and the machine information stored in the machine information storage unit; 4. A collision prevention device according to claim 2 or 3.

5. an operation information extraction unit that extracts operation information performed by a user from the information relating to the state of the machine tool extracted by the machine information extraction unit, The operation information extracted by the operation information extraction unit is stored as machine information in the machine information storage unit.

4. A collision prevention device according to claim 1.

6. a machine tool that processes a workpiece according to a processing program; The collision prevention device according to any one of claims 1 to 3, A processing system characterized by:

7. an output device that outputs the estimation result of the machine state change estimation unit based on a command from the machining restart confirmation unit and presents it to a user; an input device that receives from the user whether or not execution of the machining program can be resumed and transmits the information to the machining resumption confirmation unit, The processing system according to claim 6 .

8. A collision prevention method for preventing collisions between structures inside a machine tool, comprising: a step of receiving, from a numerical control device that numerically controls a machine tool in accordance with a machining program, information to suspend execution of the machining program, extracting, as machine information, information relating to the state of the machine tool from the numerical control device during the period from the time the suspension information is received until execution of the machining program is resumed; storing the machine information; a step of estimating, based on the stored machine information, a difference between a state of the machine tool immediately before the temporary suspension of execution of the machining program and an actual state of the machine tool at the time of resuming execution of the machining program as a change in the state of the machine tool; presenting the estimation result to a user and confirming with the user whether or not execution of the machining program can be resumed; and causing the numerical control device to resume execution of the machining program based on the confirmation result. A collision prevention method characterized by:

9. A collision prevention program for preventing collisions between structures inside a machine tool, comprising: a step of receiving, from a numerical control device that numerically controls a machine tool in accordance with a machining program, information to suspend execution of the machining program, extracting, as machine information, information relating to the state of the machine tool from the numerical control device during the period from the time the suspension information is received until execution of the machining program is resumed; storing the machine information; a step of estimating, based on the stored machine information, a difference between a state of the machine tool immediately before the temporary suspension of execution of the machining program and an actual state of the machine tool at the time of resuming execution of the machining program as a change in the state of the machine tool; presenting the estimation result to a user and confirming with the user whether or not execution of the machining program can be resumed; and causing the computer to execute the step of causing the numerical control device to resume execution of the machining program based on the confirmation result. A collision prevention program characterized by:

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