Program restart assist device

Abstract

The present invention provides a program restart assistance device that acquires time-series data of physical quantities detected during machining, detects a change point at which the machining state of the machining changes based on the acquired data, and records the change point of the machining state as a restartable point. Further, a restart execution point is selected from the recorded restartable points. As a result, an appropriate restartable point can be easily selected.

Description

Technical Field

[0001] The present invention relates to a program restart assist device, and more particularly to a program restart assist device that stores a change point in a machining state as a restart point. Background Art

[0002] A numerical control device that controls a machine tool performs numerical control processing according to a machining program, controls the machine tool based on the processing result, and machines a workpiece according to an instruction.

[0003] When machining a workpiece using a numerical control device, machining is sometimes interrupted due to an abnormality such as tool breakage. In such a case, after the operator replaces the broken tool, as Figure 4 illustrated, the machining program is executed from the program block at the interruption point of machining (the program block where machining has been interrupted such as the alarm generation position, the abnormal point where an abnormality has been detected), the program block that can restart the machining before it (the immediately preceding G0 instruction, auxiliary function, call, etc. program block) to restart machining. Conventionally, the numerical control device stores the interruption point and the program block that can restart machining as restart points, and the operator selects an appropriate restart point from the stored restart points as the restart execution point to perform program restart. If such a technique is used, machining can be stopped immediately after detecting an abnormal point, preventing a major problem (preventive maintenance). On the other hand, in the case of false detection of an abnormal point, a stop occurs unnecessarily and the cycle time is prolonged. For example, an abnormal point is detected and machining is stopped during rough machining. However, for example, in the case of rough machining, sometimes some machining errors due to vibration or the like are acceptable, so sometimes the detection of abnormalities is not overly strict, but the inspection objects (temperature, vibration, etc.) are strictly selected and the threshold for abnormality detection is loosely determined. In addition, as an existing technique for restarting machining, for example, refer to Japanese Patent Laid-Open No. 07-152416.

[0004] When the alarm stops due to tool breakage or the like, machining defects sometimes occur at an earlier stage. For example, as Figure 5As shown, in the case where the damage is slight and machining can continue for some time, sometimes the tool breakage is not detected as an abnormality at the moment of tool breakage, and after machining for some time, the tool breakage is detected at the moment when the state becomes more serious and the alarm is stopped. In such a case, the point to restart machining is not the breakpoint, but the position where machining defects are expected to start. That is, as an operator, there is a requirement to set the point where a change occurs in the machining state as the point to restart machining. However, when using the general machining restart function, specific start points such as the breakpoint (abnormal point), G0, auxiliary functions, and called program blocks are stored as restartable points. Therefore, there is a problem that the current restartable points may not necessarily coincide with the points where restart is desired. It is also possible to consider a solution of strictly setting the detection conditions for abnormal points to detect the points where changes occur in the machining state. However, in this case, even if there is a change that does not require stopping originally, machining may be interrupted, and an undesirable result may occur in terms of cycle time.

[0005] In order to restart machining from a point other than the machining breakpoint, it is necessary to store, as a restartable point, the program block that can restart the machining near the breakpoint in the memory as described above. However, in this method, the points that are more suitable for restarting machining are not discriminated, and a large number of restartable points are stored in such a way that they can store the vicinity of the point where restart is desired. Therefore, there is also a problem that the storage capacity of the software increases.

[0006] Moreover, in the case where machining can be restarted from the vicinity of the point where restart is desired by storing a large number of restartable points, the operator needs to judge which of the large number of restartable points is the vicinity point of the point where restart is desired. Such a judgment can be made without problems by a skilled operator. However, in other cases, it takes time to judge from which restartable point it is better to restart, and there are differences in working time depending on the operator. Summary of the Invention

[0007] Therefore, a technique that can easily select an appropriate restartable point is desired.

[0008] The present invention solves the above problems by providing a function that detects changes in the machining state and presents the state change points as restartable points.

[0009] The program restart assist device of the present invention assists in selecting a restart execution point, which represents a position within a machining program for restarting machining after interruption in a control device that controls an industrial machine for machining a workpiece according to the machining program. The program restart assist device includes: a data acquisition unit that acquires time series data of a physical quantity detected during the continuation of the machining; a machining state change point detection unit that detects a change point at which the machining state of the machining changes based on the data acquired by the data acquisition unit; a restartable point recording unit that records the change point of the machining state detected by the machining state change point detection unit as a restartable point; and a restart execution point selection unit that selects a restart execution point from the restartable points recorded by the restartable point recording unit.

[0010] The change point of the machining state may also be a change point in the frequency distribution of torque data, vibration data, and sound data of the motor detected from the industrial machine.

[0011] The change point of the machining state may also be a change point in the rate of change of temperature data of the motor detected from the industrial machine.

[0012] The change point of the machining state may also be a change point in the torque data of the motor detected from the industrial machine.

[0013] The change point of the machining state can be detected from the chip amount and the image of the chip shape during machining.

[0014] The change point of the machining state may also be a change point in the laser output during laser machining.

[0015] The program restart assist device may further include: a restart execution point analysis unit that calculates an evaluation value used by the machining state change point detection unit to detect the change point based on the time series data acquired when machining was interrupted and restarted in the past.

[0016] By having the above structure, the program restart assist device of the present invention can present only more appropriate restartable points based on changes in the machining state to the operator. In addition, since only the restartable points with a high possibility of being designated as the restart position are stored, the storage capacity as software can be reduced. Furthermore, in the case of stopping due to an alarm or the like, only the points with a high possibility related to the cause are used as restartable points, so it is easy for the operator to select an appropriate restart execution point without relying on rules of thumb. Description of the Drawings

[0017] Figure 1 It is a schematic hardware structure diagram of a program restart assist device according to an embodiment.

[0018] Figure 2 is a schematic functional block diagram of the program restart assistance device based on the first embodiment.

[0019] Figure 3 is a schematic functional block diagram of the program restart assistance device based on the second embodiment.

[0020] Figure 4 is a diagram for explaining the restart points of the processing based on the prior art.

[0021] Figure 5 is a diagram for explaining the problems of the restart points of the processing based on the prior art. Detailed Embodiment

[0022] Figure 1 is a schematic hardware structure diagram of the main part of the program restart assistance device according to an embodiment of the present invention.

[0023] The program restart assistance device 1 of the present invention can be installed, for example, as a control device for controlling industrial machinery. In addition, the program restart assistance device 1 of the present invention can be installed on a personal computer arranged in parallel with the control device for controlling industrial machinery, a personal computer connected to the control device via a wired / wireless network, a unit computer, a fog computer, or a cloud server. In the present embodiment, an example of installing the program restart assistance device 1 on a personal computer connected to the control device for controlling industrial machinery via a network is shown.

[0024] The CPU 11 included in the program restart assistance device 1 of the present embodiment is a processor that integrally controls the program restart assistance device 1. The CPU 11 reads out the system program stored in the ROM 12 via the bus 22 and controls the entire program restart assistance device 1 according to the system program. Temporary calculation data, display data, and various data input from the outside are temporarily stored in the RAM 13.

[0025] The non-volatile memory 14 is composed of, for example, a memory backed up by a battery (not shown) and an SSD (Solid State Drive), and maintains the storage state even when the power of the program restart assistance device 1 is turned off. The data read in from the external device 72 via the interface 15, the data input via the input device 71, and the data obtained from the control device 3 via the interface 20 are stored in the non-volatile memory 14. The data stored in the non-volatile memory 14 can also be expanded in the RAM 13 during execution or use. In addition, various system programs such as a known analysis program are pre-written in the ROM 12.

[0026] The interface 15 is an interface for connecting the CPU 11 of the program restart assist device 1 to an external device 72 such as a USB device. Data such as data acquired by other industrial machines or the like can be read in from the external device 72 side. In addition, data processed within the program restart assist device 1 can be stored in an external storage unit via the external device 72.

[0027] The interface 20 is an interface for connecting the CPU 11 of the program restart assist device 1 to a wired or wireless network 5. The network 5 is connected to the control device 3, fog computer, cloud server, etc., and data is exchanged with the program restart assist device 1.

[0028] In the display device 70, each data read into the memory, data obtained as a result of executing a program, etc. are output and displayed via the interface 17. In addition, an input device 71 composed of a keyboard, pointing device, etc. transfers instructions, data, etc. based on the operator's operations to the CPU 11 via the interface 18.

[0029] Figure 2 The functions of the program restart assist device 1 according to the first embodiment of the present invention are shown as a schematic block diagram.

[0030] By Figure 1 The CPU 11 of the program restart assist device 1 shown executes a system program and controls the operations of each part of the program restart assist device 1 to implement each function of the program restart assist device 1 of the present embodiment.

[0031] The program restart assist device 1 of the present embodiment includes: a data acquisition unit 100, a processing state change point detection unit 110, a restartable point recording unit 120, a restart execution point selection unit 130, and a restart execution point instruction unit 140. In addition, in the RAM 13 or non-volatile memory 14 of the program restart assist device 1, a acquired data storage unit 200 as an area for storing data acquired from the control device 3 etc. and a restartable point storage unit 210 as an area for storing restartable points are prepared in advance.

[0032] Figure 1The CPU 11 included in the program restart assist device 1 shown executes the system program read from the ROM 12, mainly performs arithmetic processing using the RAM 13 and the non-volatile memory 14 based on the CPU 11, and input control processing based on the interface 20, thereby implementing the data acquisition unit 100. The data acquisition unit 100 acquires time series data detected when the industrial machine 4 operates, data representing changes in signals at a predetermined time, etc. The data representing changes in the signal at the predetermined time can be processed as time series data by representing the changes in the signal on the time axis. The data acquisition unit 100 acquires position data, speed data, acceleration data, torque data, temperature data of the motor of the industrial machine 4, information related to the execution of each program block of the machining program in the industrial machine 4 (type of program block, start point and end point of the program block, etc.), vibration data, sound data, image data detected by the sensor 6 installed in the industrial machine 4, various data stored in the control device 3 that controls the industrial machine 4, etc.

[0033] The sensor 6 can also be used for components other than the industrial machine 4. For example, a phonocardiograph, sphygmomanometer, thermometer, etc. used by the operator who processes with the industrial machine 4, a vibration sensor, an optical sensor, a camera sensor, etc. installed near the location where the industrial machine 4 is installed can also be used. As long as the sensor 6 is a sensor that can directly or indirectly detect changes in processing, any sensor can be used. The data acquisition unit 100 can also directly acquire data related to the industrial machine 4 from the control device 3 via the network 5. The data acquired by the data acquisition unit 100 is stored in the acquired data storage unit 200.

[0034] Figure 1 The CPU 11 included in the program restart assist device 1 shown executes the system program read from the ROM 12, mainly performs arithmetic processing using the RAM 13 and the non-volatile memory 14 based on the CPU 11, thereby implementing the machining state change point detection unit 110. The machining state change point detection unit 110 analyzes the time series data related to the machining state of the industrial machine 4 acquired by the data acquisition unit 100, and detects the points at which the machining state has changed during the continuation of the machining of the workpiece. The machining state change point detection unit 110, for example, identifies the section where the type of program block is a cutting feed command and the torque of the motor of the industrial machine 4 continues in a state above a predetermined threshold as the section during the continuation of the machining of the workpiece. Moreover, the machining state change point detection unit 110 can also perform frequency analysis on the torque data, vibration data, and sound data detected in a predetermined machining section during the machining of the workpiece, and detect the moment when a predetermined difference appears in the frequency components (for example, the sum of the squares of the amplitude differences of each frequency component is above a predetermined threshold, etc.) as the point at which the machining state has changed.

[0035] The machining state change point detection unit 110 can, for example, also detect the moment when the rate of change of the motor temperature detected in a predetermined machining section during the machining of the workpiece changes to a value equal to or greater than a predetermined threshold value determined in advance as the point where the machining state has changed. The machining state change point detection unit 110 can, for example, also detect the moment when the amount, shape, and color of the chips change to a value equal to or greater than a predetermined threshold value determined in advance based on the image data detected in a predetermined machining section during the machining of the workpiece as the point where the machining state has changed. The machining state change point detection unit 110 can, for example, also detect the moment when the laser output detected in a predetermined machining section during the laser machining of the workpiece changes to a value equal to or greater than a predetermined threshold value determined in advance as the point where the machining state has changed. If configured more simply, a threshold value sufficiently smaller than the threshold value of the impact value (change value of torque) used when the industrial machine 4 issues an alarm (for example, a threshold value that is half of the threshold value used when the industrial machine 4 issues an alarm) can also be set, and the machining state change point detection unit 110 detects the moment when an impact value greater than this smaller threshold value is detected during the machining of the workpiece as the point where the machining state has changed.

[0036] Moreover, the machining state change point detection unit 110 can, for example, also indirectly detect the point where the machining state has changed by detecting changes in the biological information of the operator who performs the machining using the industrial machine 4. When the operator perceives a change in the machining state, subtle changes sometimes occur in the heart sound, blood pressure, body temperature, sweating state, etc. The machining state change point detection unit 110 can determine the point where the past state has changed based on such changes in the biological information of the operator.

[0037] In addition, the machining state change point detection unit 110 can also detect the point where the machining state has changed by combining the above-mentioned various methods. For example, the machining state change point detection unit 110 can also detect the moment when the frequency components of the torque data, vibration data, and sound data show a significant difference before and after the moment when an impact value greater than the above-mentioned smaller threshold value is detected during the machining of the workpiece, and determine this moment as the point where the machining state has changed. In this way, the machining state change point detection unit 110 extracts not only the interruption points of the machining but also the points where the machining state has changed before that. The change points of the machining state detected by the machining state change point detection unit 110 are not at the level of the industrial machine 4 issuing an alarm, but include the points where a significant difference in the machining state is confirmed before and after. In addition, regarding the acquired data stored in the acquired data storage unit 200, the time width required for the machining state change point detection unit 110 to analyze the change points of the machining state can also be reserved and then deleted. Thereby, it is possible to prevent the acquired data storage unit 200 from occupying a large amount of memory area.

[0038] Figure 1The CPU 11 included in the program restart assist device 1 shown executes the system program read from the ROM 12, mainly performs arithmetic processing using the RAM 13 and the non-volatile memory 14 based on the CPU 11, thereby implementing the restart point recording unit 120. The restart point recording unit 120 adds and records the point where the machining state changes detected by the machining state change point detection unit 110 as a restart point into the restart point storage unit 210. The restart point recording unit 120 may also record, as a restart point, a block of the machining program including the point where the machining state has changed and a group of the time from the start of the block to the point where the machining state changes into the restart point storage unit 210. The restart point storage unit 210 can store multiple restart points.

[0039] Figure 1 The CPU 11 included in the program restart assist device 1 shown executes the system program read from the ROM 12, mainly performs arithmetic processing using the RAM 13 and the non-volatile memory 14 based on the CPU 11 and input / output processing using the interfaces 17 and 18, thereby implementing the restart execution point selection unit 130. The restart execution point selection unit 130 displays the restart points stored in the restart point storage unit 210 on the display device 70. Moreover, by operating the input device 71, a restart execution point as the point to restart machining is selected from the displayed restart points. The selected restart execution point is output to the restart execution point instruction unit 140.

[0040] The restart execution point selection unit 130 may also display the restart points in association with the blocks of the machining program when the machining program is displayed on the display device 70. In addition, the restart execution point selection unit 130 may perform machining simulation based on the machining program, and display the restart points in association with the display of the machining path and the workpiece shape as a result thereof. The restart execution point selection unit 130 can enable the operator to operate a keyboard or a pointing device to select a restart execution point from the restart points displayed on the display device 70.

[0041] Figure 1 The CPU 11 included in the program restart assist device 1 shown executes the system program read from the ROM 12, mainly performs arithmetic processing using the RAM 13 and the non-volatile memory 14 based on the CPU 11 and input control processing based on the interface 20, thereby implementing the restart execution point instruction unit 140. The restart execution point instruction unit 140 outputs an instruction to the control device 3 that controls the industrial machine 4 to restart machining from the restart execution point selected by the restart execution point selection unit 130.

[0042] In the program restart assist device 1 of the present embodiment having the above structure, instead of storing conventional restart points such as machining interruption points or program blocks of G0, auxiliary functions, and calls, the time when the machining state changes before and after during workpiece machining is stored as a restart point. Therefore, it is possible to present only a more appropriate restart point based on the change in the machining state to the operator. In addition, since only restart points with a high probability of being designated as the position for restarting machining are stored, the storage capacity as software can be reduced. Furthermore, in the case of stopping due to an alarm or the like, only points highly likely to be related to the cause are used as restart points, so that the operator can easily select an appropriate restart execution point without relying on rules of thumb.

[0043] Figure 3 The functions of the program restart assist device 1 of the second embodiment of the present invention are shown as a schematic block diagram.

[0044] Each function of the program restart assist device 1 of the present embodiment is realized by Figure 1 the CPU 11 of the program restart assist device 1 shown executing a system program and controlling the operations of the respective parts of the program restart assist device 1.

[0045] The program restart assist device 1 of the present embodiment detects change points in the machining state using the following data, etc., which are time-series data detected during the operation of the industrial machine and data indicating changes in signals at a predetermined time, detected before and after points where machining was interrupted during past operation of the industrial machine and then restarted by a skilled operator. In the present embodiment, the program restart assist device 1 is connected to the fog computer 7 or the cloud server 8 via the network 5. The fog computer 7 or the cloud server 8 stores multiple sets of data, which are time-series data detected during the operation of the industrial machine and data indicating changes in signals at a predetermined time, detected before and after points where machining was interrupted during past operation of the industrial machine and then restarted by a skilled operator.

[0046] The program restart assist device 1 of the present embodiment further includes a restart execution point analysis unit 150 in addition to the functions of the program restart assist device 1 of the first embodiment.

[0047] Figure 1The CPU 11 included in the restart assist device 1 shown executes the system program read from the ROM 12, mainly performing arithmetic processing using the RAM 13 and the non-volatile memory 14 based on the CPU 11 and input control processing based on the interface 20, thereby implementing the restart execution point analysis unit 150. The restart execution point analysis unit 150 analyzes time-series data detected during the operation of the industrial machine, data on changes in signals indicating a predetermined time, etc., detected before and after the point where the processing was interrupted and restarted in the past processing stored in the fog computer 7 and the cloud server 8, and calculates an evaluation value representing the change trend before and after the point selected as the restart execution point.

[0048] For each set of multiple sets of data stored in the fog computer 7 and the cloud server 8, the restart execution point analysis unit 150, for example, performs frequency analysis on the torque data, vibration data, and sound data detected before and after the point selected as the restart execution point, respectively before and after the point, and calculates the sum of the squares of the amplitude differences of each frequency component. Moreover, a value obtained by multiplying its average value by a predetermined constant (for example, 0.8 to 0.9) can also be calculated as the evaluation value. For each set of multiple sets of data stored in the fog computer 7 and the cloud server 8, the restart execution point analysis unit 150, for example, calculates the change rate of the motor temperature detected before and after the point selected as the restart execution point. Moreover, a value obtained by multiplying its average value by a predetermined constant (for example, 0.8 to 0.9) can also be calculated as the evaluation value.

[0049] Then, the processing state change point detection unit 110 of the present embodiment uses the evaluation value analyzed by the restart execution point analysis unit 150 to detect the change point of the processing state. More specifically, the evaluation value calculated by the restart execution point analysis unit 150 is used as a threshold for detecting the change point of the processing state.

[0050] The program restart assist device 1 of the present embodiment having the above structure can analyze the change in the processing state before and after the point selected by a skilled person in the past as the restart position of the processing, and utilize the analysis result when newly detecting the change point of the processing state.

[0051] As a modification example of the program restart assist device 1 of the present embodiment, it may also be configured to use a machine learning device as the restart implementation point analysis unit 150. In such a case, for example, during the training period of the machine learning device, the processing state (motor load, motor temperature, chip amount / shape, impact, laser output, etc.) and the distribution of the executed program blocks and processing elapsed time may be sampled, and unsupervised learning using the sampled data may be performed. During the operation period, if there is no data from the training period within a certain vicinity during processing, it is determined that the processing state has changed. When using a machine learning device, the restart implementation point analysis unit 150 creates a group of data separated before and after the restart implementation point for the data detected before and after the point where the processing was interrupted and restarted in the past, stored in the fog computer 7 and the cloud server 8. After that, the correct data label is assigned to the group of data, and machine learning is performed using this as teacher data to generate a learning model. Then, the processing state change point detection unit 110 uses the generated learning model to execute the detection process of the change point with the data acquired by the data acquisition unit 100 as the input. As the machine learning device, for example, a neural network, SVM, etc. can be used.

[0052] As described above, one embodiment of the present invention has been described, but the present invention is not limited to the above-described example of the embodiment and can be implemented in various ways by making appropriate changes.

Claims

1. A program restart assistance device that assists in selecting a restart execution point, which represents a position within a machining program where machining is restarted after interruption in a control device that controls an industrial machine for machining a workpiece according to the machining program, characterized in that the program restart assistance device includes: a data acquisition unit that acquires time series data of a physical quantity associated with the machining of the workpiece detected during the continuation of the machining; a machining state change point detection unit that detects a change point at which the machining state of the machining changes based on the data acquired by the data acquisition unit; a restartable point recording unit that records the change point of the machining state detected by the machining state change point detection unit as a restartable point; and a restart execution point selection unit that selects a restart execution point from the restartable points recorded by the restartable point recording unit, the physical quantity includes: torque data, vibration data, or sound data; motor temperature; chip amount, shape, or color; laser output; and at least one of the biological information of the operator, the machining state change point detection unit detects a change point at which the machining state of the machining changes based on the data acquired by the data acquisition unit through at least one of the following: performing frequency analysis on torque data, vibration data, or sound data detected in a predetermined machining section during the machining of the workpiece, and the moment when a predetermined difference appears in the frequency components; the moment when the change rate of the motor temperature detected in a predetermined machining section during the machining of the workpiece changes to a predetermined threshold value or more determined in advance; the moment when the chip amount, shape, or color changes to a predetermined threshold value or more determined in advance according to image data detected in a predetermined machining section during the machining of the workpiece; the moment when the laser output detected in a predetermined machining section during the laser machining of the workpiece changes to a predetermined threshold value or more determined in advance; and changes in the biological information of the operator who performs machining using the industrial machine.

2. The program restart assistance device according to claim 1, characterized in that the change point of the machining state is a change point in the frequency distribution of torque data, vibration data, and sound data of the motor detected from the industrial machine.

3. The program restart assistance device according to claim 1, characterized in that the change point of the machining state is a change point in the change rate of the temperature data of the motor detected from the industrial machine.

4. The program restart assistance device according to claim 1, characterized in that the change point of the machining state is a change point in the torque data of the motor detected from the industrial machine.

5. The program restart assistance device according to claim 1, characterized in that detecting the change point of the machining state from the chip amount and the image of the chip shape during machining.

6. The program restart assistance device according to claim 1, characterized in that the change point of the machining state is a change point in the laser output during laser machining.

7. The program restart assist device according to claim 1, wherein the program restart assist device further includes: a restart execution point analysis unit that calculates an evaluation value for the process state change point detection unit to detect the change point based on time series data obtained when processing was interrupted and restarted in the past.

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