Simulation device and computer-readable storage medium

Abstract

A simulation device according to the present disclosure acquires the position of a machining point in a simulation of non-contact machining, acquires an energy value input to the machining point in the simulation, calculates a cumulative value of the energy value input to a certain position in the simulation, and determines a threshold of the energy value for each predetermined position on the basis of the cumulative value of the energy value.

Description

Simulation device and computer-readable storage medium

[0001] The present disclosure relates to a simulation device and a computer-readable storage medium.

[0002] Non-contact processing machines include laser processing, plasma processing, gas processing, water jet processing, etc. In non-contact processing, energy is applied to the workpiece through media such as light, plasma, gas, water, etc. Some conventional non-contact processing machines monitor the output power and manage the output power. For example, Patent Document 1.

[0003] Japanese Patent Application Laid-Open No. 2020-46390

[0004] In non-contact processing, when a medium contacts an object, the energy of the medium is applied to the object. Excessive energy input or unexpected contact between the medium and the object may lead to damage to the object.

[0005] In the field of non-contact processing, it is desired to avoid unexpected breakage and damage.

[0006] The simulation device according to the present disclosure includes a position acquisition unit that acquires the position of a processing point in a non-contact processing simulation, an energy acquisition unit that acquires an energy value input to the processing point in the simulation, an input energy calculation unit that calculates a cumulative value of the energy value input to a certain position in the simulation, and a threshold output unit that determines a threshold value of the energy value for each predetermined position based on the cumulative value of the energy value.

[0007] It is a block diagram of a simulation device. It is a diagram showing an example of a grid. It is a diagram explaining a method of calculating a cumulative value. It is a diagram visually expressing the cumulative energy value for each grid. It is a diagram visually expressing the cumulative energy value per unit length at a certain position. It is a diagram explaining the passage of time. It is a diagram visually expressing the threshold value for each grid. It is a diagram visually showing the threshold value at a point on the trajectory. It is a block diagram of the simulation device of the second embodiment. It is a hardware configuration diagram of the simulation device.

[0008] Embodiments of this disclosure will be described below with reference to the drawings. In the following description, components having the same or similar functions will be denoted by the same reference numerals. Duplication of these components may be omitted.

[0009] In this application, "based on XX" means "based on at least XX," and includes cases where it is based on another element in addition to XX. Furthermore, "based on XX" is not limited to cases where XX is used directly, but also includes cases where it is based on something that has been calculated or processed. "XX" is any element (for example, any information).

[0010] [First Embodiment] Figure 1 is a block diagram of the simulation device 100. The simulation device 100 includes a position acquisition unit 11, an energy acquisition unit 12, an input energy calculation unit 13, a workpiece shape acquisition unit 14, a material acquisition unit 15, and a threshold output unit 16.

[0011] The position acquisition unit 11 acquires the positions of the machining points to be performed in the simulation. The analysis unit (not shown) calculates the trajectory and position of the machining points. The analysis unit analyzes the machining program and NC data, calculates the trajectory of the machining points, and generates commands. Since the simulation of non-contact machining is an existing technology, the explanation is omitted.

[0012] There are various types of trajectories, including program trajectories, command trajectories, and actual trajectories. A program trajectory is the trajectory specified by the machining program. A command trajectory is an interpolated trajectory based on commanded positions and machine configuration information. An actual trajectory is a trajectory generated by connecting actual coordinates, for example, with straight lines. There are no particular limitations on the type of trajectory, but a trajectory that is closer to the actual movement, taking into account the machine's mechanism, is desirable.

[0013] The energy acquisition unit 12 acquires the output energy value of the non-cutting process at the machining point or the input energy value input to the workpiece. The output energy value or input energy value is calculated by simulation.

[0014] In calculating output and input energy values, the processing conditions for non-contact machining are taken into consideration. For example, in laser machining, processing conditions such as laser power, pulse frequency, and pulse duty cycle affect the energy input to the workpiece.

[0015] The input energy calculation unit 13 calculates the cumulative value of the energy input at a certain location. Two methods for calculating the energy value are shown below.

[0016] [First Energy Value Calculation Method] The first energy value calculation method defines a predetermined range on the surface used as a reference for non-contact machining (for example, the machining surface) and calculates the cumulative value of the energy input into that range. In this embodiment, the machining surface is divided into a grid, and the cumulative value of the energy input into each grid is calculated. An example of a grid is shown in Figure 2. The star-shaped solid lines represent the machining pattern. The grid shape in Figure 2 is square. The size and shape of the grid are not particularly limited, but the grid size is preferably an integer multiple of the minimum movement unit of the acquisition cycle for acquiring the position of the machining point. Making it an integer multiple of the minimum movement unit reduces the processing load. Note that while a larger number of grids improves accuracy, it also increases the processing load. The size and number of grids may be set by default, set by the user, or calculated automatically.

[0017] The input energy calculation unit 13 calculates the cumulative value of the energy (referred to as the cumulative energy value). This energy value is a predicted value predicted to be input to the grid based on simulations. The input energy calculation unit 13 calculates the cumulative value of the predicted value. The method for calculating the cumulative value will be explained with reference to Figure 3. In Figure 3, the vertical axis represents the energy value of non-contact processing, and the horizontal axis represents time. The input energy calculation unit 13 determines the grid that the processing point passes through and calculates the product of the time the processing point stays in the grid and the energy value input to the processing point. This product is the cumulative energy value. For example, in grid A in Figure 2, the processing point reaches grid A at a certain time T1 and passes through grid A for a period of 4 cycles of the position acquisition cycle. After that, the processing point leaves grid A and moves to another grid, and at time T2 re-enters grid A and passes through grid A for a period of 6 cycles of the position acquisition cycle. If the energy value in each position acquisition cycle is Pi (1 ≤ i ≤ N) [W], the number of position acquisition cycles included in the period during which the machining point stays on the grid is N, and the time of the position acquisition cycle is T [s], then the cumulative energy value E [J] at each grid is expressed as follows. Note that either the output energy value or the input energy value may be used to calculate the cumulative energy value. As mentioned above, the output energy value represents the amount of energy output from the energy source, and the input energy value represents the amount of energy input to the workpiece. Both energy values ​​are calculated by simulation.

[0018]

[0019] Figure 4 is a visual representation of the cumulative energy values ​​for each grid. The cumulative energy values ​​for P1 to P31 are calculated for each grid that the processing point passes through. The cumulative energy values ​​for each grid are used as a reference for calculating the threshold in the threshold output unit 16.

[0020] [Second Energy Calculation Method] The second energy value calculation method is a method for calculating the cumulative energy value per unit length at a certain position. To calculate the energy per unit time, the speed of the processing point is used. The speed of the processing point can be calculated from the position information and the acquisition period. The input energy calculation unit 13 divides the output energy value at a certain position by the speed of the processing point at that position to calculate the cumulative energy value per unit length at that point.

[0021] Figure 5 visually represents the energy value per unit length at a certain location. Cumulative energy values ​​P1 to P17 per unit length are calculated at multiple locations. The cumulative energy value per unit length at each location is used as a reference for calculating the threshold in the threshold output unit 16.

[0022] [Exclusion of energy values ​​after a predetermined time has elapsed] In the calculation of the first and second cumulative energy values ​​described above, energy values ​​may be excluded or gradually reduced according to the time elapsed since energy input. An example of the passage of time will be explained with reference to Figure 6. Consider the trajectory of the machining point, starting from point B, moving in direction a, and then arriving back at point B from direction b. When the machining point moves along such a trajectory, a long time may have elapsed between the time the machining point leaves point B and the time it returns to point B. In that case, the energy at the time the machining point departs from point B has disappeared or decreased by the time the machining point returns to point B. The input energy calculation unit 13 stores the time the machining point has passed and excludes or gradually reduces the energy at the position after a predetermined time has elapsed since energy input.

[0023] [Calculation of Threshold] The workpiece shape acquisition unit 14 acquires the shape of the workpiece. The workpiece shape includes at least the thickness of the workpiece. The material acquisition unit 15 acquires the material of the workpiece. Information such as the shape and material of the workpiece is either stored in the simulation device 100 in advance or acquired by the simulation device 100 from an external storage device including the cloud.

[0024] The threshold output unit 16 outputs a threshold value for detecting an excess of energy input, based on the energy value input at a certain position. There are two threshold values: a cumulative energy value threshold (first threshold) and an energy value threshold per unit length (second threshold), but the calculation method for both is the same.

[0025] The energy values ​​calculated in the simulation are predicted values ​​based on the machining program and NC data. These predicted values ​​represent the energy values ​​when machining is performed without problems. The cumulative energy value, or energy value per unit length, calculated from these values ​​is assumed to be an ideal value and will not cause accidents or damage.

[0026] The threshold output unit 16 determines the threshold based on the cumulative energy value obtained from the simulation. The method for determining the threshold is not particularly limited, but several examples are given. One method is to use the energy value obtained from the simulation (cumulative energy value or energy value per unit length) as a reference value and determine the threshold by adding percentages such as "add 10% of the reference value" or "add 50% of the reference value". A second method is to add a pre-prepared fixed value to the reference value. A third method is to determine the threshold by considering the output energy value, workpiece material, workpiece size, processing type, etc. Since the order of magnitude of the output differs depending on the workpiece material, thickness, and processing type (cutting, marking, welding, surface modification, etc.), the threshold is determined based on these conditions.

[0027] Figure 7 is a visual representation of the threshold values ​​for each grid. Threshold values ​​Th1 to Th31 are calculated for each grid that the trajectory passes through. These threshold values ​​are compared with the energy values ​​input to each grid during actual processing and are used to detect excess energy.

[0028] Figure 8 is a visual representation of the thresholds at points along the trajectory. Thresholds Th1 to Th17 are the threshold values ​​for the energy value per unit length at each point. The threshold output unit 16 outputs the determined thresholds to a numerical control device, external storage device, etc. During actual non-contact processing, these thresholds are compared with the actual cumulative energy value at each point and used to detect excess energy.

[0029] [Second Embodiment] The simulation device 100 of the second embodiment will be described. The simulation device 100 of the second embodiment is substantially the same as that of the first embodiment, so only the differences will be described. Figure 9 is a block diagram of the simulation device 100 of the second embodiment. The simulation device 100 of the second embodiment does not include a workpiece shape acquisition unit 14 and a material acquisition unit 15. The input energy calculation unit 13 of the simulation device 100 of the second embodiment calculates the cumulative energy value or the energy value per unit length without considering the processing conditions. The position information of the processing point and the energy value are obtained from the processing program or NC data. The method for calculating the cumulative energy value and the energy value per unit length is the same as in the first embodiment. The cumulative energy value calculated in this way has lower accuracy than the cumulative energy value calculated by simulation, but it can be easily calculated even by a device that does not have a simulation function.

[0030] As described above, the simulation device 100 of this embodiment simulates non-contact processing and determines a threshold for detecting excessive energy input based on the position of the processing point and the cumulative value of the energy input obtained from the simulation.

[0031] Excessive energy accumulation can occur, for example, due to unexpected machine stoppages or reductions in feed rate. When a machine stops or the feed rate decreases, energy continues to be supplied to a specific area. Excessive energy accumulation can also occur at the end of machining. If energy continues to be supplied even after machining has ended due to a machine failure, energy continues to be supplied to the end point of machining.

[0032] Areas where energy is being injected experience concentrated heat, which can lead to accidents such as fires or machine damage. Because the laser from a laser processing machine is invisible, operators may come into contact with it unknowingly. If the energy penetrates the workpiece, the medium can pass through the hole, potentially causing unexpected damage.

[0033] The energy values ​​calculated in the simulation are predicted values ​​based on the machining program and NC data. These predicted values ​​represent the energy values ​​when machining is performed without problems. The cumulative energy value, or the energy value per unit length, calculated from these energy values ​​is assumed to be an ideal value and will not cause accidents or damage. Then, a threshold is determined based on the ideal value obtained from the simulation.

[0034] The hardware configuration of the simulation device 100 to which this disclosure is applied will be described below. Figure 10 is a hardware configuration diagram of the simulation device 100. As shown in Figure 10, the simulation device 100 includes a CPU 111 that controls the simulation device 100 as a whole, a ROM 112 that records programs and data, and a RAM 113 for temporarily expanding data. The CPU 111 reads the system program recorded in the ROM 112 via a bus.

[0035] The non-volatile memory 114 is backed up, for example, by a battery (not shown), so that its stored state is maintained even when the simulation device 100 is powered off. The non-volatile memory 114 stores various data, such as programs read from the external device 120 via interfaces 115, 118, and 119, and operation inputs entered via the input device 20. The non-volatile memory 114 may also store programs and data for running the simulation device 100 of this embodiment.

[0036] Interface 115 is an interface for connecting the simulation device 100 to an external device 120 such as an adapter. Programs and various parameters are read from the external device 120. Interface 118 is an interface for connecting the simulation device 100 to a display device 30 such as a liquid crystal display. The display device 30 displays data read into memory, data obtained as a result of executing programs, etc. Interface 119 is an interface for connecting the simulation device 100 to an input device 20 such as a keyboard or pointing device. The input device 20 passes commands, data, etc. based on operator operations to the CPU 111 via interface 119.

[0037] While embodiments of this disclosure have been described in detail above, this disclosure is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the spirit of the invention or from the idea and intent of this disclosure derived from the claims and their equivalents. For example, the order of operations and processes in the embodiments described above are shown as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments described above.

[0038] The following are annotations relating to embodiments of the present disclosure. (Annotation 1) A simulation apparatus (100) according to one aspect of the present disclosure includes: a position acquisition unit (11) that acquires the position of a processing point in a simulation of non-contact processing; an energy acquisition unit (12) that acquires the energy value input to the processing point in the simulation; an input energy calculation unit (13) that calculates the cumulative value of the energy value input to a certain position in the simulation; and a threshold output unit (16) that determines a threshold energy value for each predetermined position based on the cumulative energy value. (Annotation 2) The input energy calculation unit (13) defines a predetermined range on a surface used as a reference for the non-contact processing and calculates the cumulative value of the energy value input to the range, and the threshold output unit (16) determines a threshold energy value for each range. (Annotation 3) The predetermined range is a grid. (Annotation 4) The predetermined range is determined based on the minimum movement unit of the processing point. (Annotation 5) The input energy calculation unit (13) calculates the cumulative energy value per unit length at a certain position. (Note 6) The input energy calculation unit (13) calculates the cumulative energy value per unit length by dividing the output energy at a certain position by the speed of the processing point at that position. (Note 7) The input energy calculation unit (13) excludes energy values ​​from the accumulation target or gradually reduces the accumulated energy value according to the elapsed time after energy input. (Note 8) The threshold output unit (16) determines the cumulative value as a percentage of the reference value. (Note 9) The threshold output unit (16) determines the threshold by considering at least one condition of the workpiece size, workpiece shape, and processing type. (Note 10) A computer-readable storage medium (112, 113, 114) according to one aspect of the present disclosure records a program that causes a computer (111) to operate as: a position acquisition unit (11) that acquires the position of a processing point in a simulation of non-contact processing; an energy acquisition unit (12) that acquires the energy value to be input to the processing point in the simulation; an input energy calculation unit (13) that calculates the cumulative value of the energy value to be input to a certain position in the simulation; and a threshold output unit (16) that determines a threshold value of the energy value for each predetermined position based on the cumulative value of the energy value.

[0039] 100 Simulation device 11 Position acquisition unit 12 Energy acquisition unit 13 Input energy calculation unit 14 Workpiece shape acquisition unit 15 Material acquisition unit 16 Threshold output unit 111 CPU 112 ROM 113 RAM 114 Non-volatile memory

Claims

1. A simulation device comprising: a position acquisition unit that acquires the position of a processing point in a simulation of non-contact processing; an energy acquisition unit that acquires the energy value applied to the processing point in the simulation; an input energy calculation unit that calculates the cumulative value of the energy value applied to a certain position in the simulation; and a threshold output unit that determines a threshold energy value for each predetermined position based on the cumulative value of the energy value.

2. The simulation apparatus according to claim 1, wherein the input energy calculation unit defines a predetermined range on the surface to be used as a reference for the non-contact processing, calculates the cumulative value of the energy input into the range, and the threshold output unit determines a threshold value for the energy value for each range.

3. The simulation apparatus according to claim 2, wherein the predetermined range is a grid.

4. The simulation apparatus according to claim 2, wherein the predetermined range is determined based on the minimum movement unit of the processing point.

5. The simulation apparatus according to claim 1, wherein the input energy calculation unit calculates the cumulative energy value per unit length at a certain position.

6. The simulation apparatus according to claim 5, wherein the input energy calculation unit divides the output energy at a certain position by the speed of the processing point at that position to calculate the cumulative energy value per unit length.

7. The simulation apparatus according to claim 1, wherein the input energy calculation unit excludes energy values ​​from the accumulation target or gradually reduces the accumulated energy values ​​according to the elapsed time after energy input.

8. The simulation apparatus according to claim 1, wherein the threshold output unit determines the cumulative value as a percentage of the reference value.

9. The simulation apparatus according to claim 1, wherein the threshold output unit determines a threshold considering at least one of the following conditions: workpiece size, workpiece shape, and processing type.

10. A computer-readable storage medium containing a program that causes the computer to operate as: a position acquisition unit for acquiring the position of a machining point in a non-contact machining simulation; an energy acquisition unit for acquiring the energy value applied to the machining point in the simulation; an input energy calculation unit for calculating the cumulative value of the energy value applied to a certain position in the simulation; and a threshold output unit for determining a threshold energy value for each predetermined position based on the cumulative energy value.

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