JP2022041159A - Numerical control system and interference check method - Google Patents

Abstract

To provide a numerical control system for supporting interference check computing in a numerical control device so as to allow efficient detection of interference between machine elements, and an interference check support method.SOLUTION: A numerical control device 3 includes: a pulse generation unit 34 which allows a plurality of machine elements of a machine tool 2 to move along a plurality of control axes on the basis of movement pulses for the machine tool 2; an interference checking unit 36 which performs interference check computing to a plurality of check object sets in an order determined according to a prescribed priority; and an interference check support device 5 which supports the interference check computing. The interference check support device 5 includes a first storage unit 51 which stores machine element-control axis association information, and a priority calculation unit 54b which calculates priority for the plurality of check object sets on the basis of the movement pulses and the machine element-control axis association information.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a numerical control system and an interference check method.

The numerical control device moves a plurality of machine elements (tools, tables, jigs for holding a workpiece, etc.) constituting a machine tool along a plurality of control axes based on a numerical control program created in advance. Process the work. Further, the numerical control device has an interference check function for performing an interference check operation in parallel during machining by the machine tool to confirm whether the machine elements of the machine tool interfere with each other (for example, Patent Document 1). reference).

Patent No. 6066041

By the way, in the conventional numerical control device, whether or not two machine elements constituting a predetermined set to be checked do not interfere with each other is determined by shape information regarding the shape of each machine element, position information regarding the position of each machine element, and each. Judgment is made by performing an interference check calculation using attitude information regarding the attitude of the machine element. Further, in the conventional numerical control device, since it is necessary to perform such an interference check operation for a plurality of check target sets, it may take time.

Therefore, if the number of sets to be checked increases, it may not be possible to complete the interference check calculation for all the sets to be checked within the control cycle of the machine tool by the numerical control device. For this reason, there is a possibility that interference between machine elements cannot be detected at an appropriate timing.

This disclosure has been made in view of the above problems, and even if it is not possible to perform the interference check calculation for all the check target sets within a limited time, the machine elements can be efficiently used with each other. Provided are a numerical control system and an interference check support method that support an interference check operation in a numerical control device so that interference can be detected.

In one aspect of the present disclosure, a plurality of machine elements of a machine tool are moved along a plurality of axes based on a movement command, and an interference check calculation between the two machine elements is performed with a predetermined priority for a plurality of sets to be checked. It is provided with a numerical control device performed in the order determined by the above and an interference check support device for supporting the interference check calculation, and the interference check support device includes each axis in the machine tool and the plurality of machines. A first storage unit that stores first information associated with a machine element that moves along the axis among the elements, and the priority for the plurality of check target sets based on the movement command and the first information. It is a numerical control system including a priority calculation unit for calculation.

In one aspect of the present disclosure, a plurality of machine elements of a machine tool are moved along a plurality of axes based on a movement command, and an interference check calculation between the two machine elements is performed with a predetermined priority for a plurality of sets to be checked. It is a method of supporting the interference check calculation in the numerical control device performed in the order determined by the above, and is a machine that moves along the axis among the movement command, each axis in the machine tool, and the plurality of machine elements. It is an interference check support method that acquires the first information associated with an element and calculates the priority for the plurality of check target sets based on the movement command and the first information.

According to one aspect of the present disclosure, the priority calculator is based on a movement command and first information associating each axis of the machine tool with a plurality of machine elements that move along this axis. Then, the priority for a plurality of check target sets is calculated. Thereby, for a plurality of check target sets, for example, it is possible to raise the priority of the check target set of the combination of machine elements that are likely to cause interference. In addition, the numerical control device moves a plurality of machine elements along a plurality of axes based on a movement command, and interferes with a plurality of check target sets in the order determined by the priority calculated by the priority calculation unit. Perform a check operation. According to one aspect of the present disclosure, in the numerical control device, the interference check calculation is performed for all the check target sets within a limited time by performing the interference check calculation in order from the check target set having the highest priority. Even if it is not possible, it is possible to efficiently detect interference between machine elements.

It is a schematic diagram of the numerical control system which concerns on 1st Embodiment of this disclosure. It is a figure which shows an example of a machine tool. It is a figure which shows the display example by the machine composition tree of the machine element-control axis association information and each axis dependency information. It is a figure which shows an example of the machine element-control axis association information and each axis dependency information. FIG. 4 is a diagram showing a case where the first to fourth machine elements are classified into a dependent machine element group and a stationary machine element group under the machine element-control axis association information and each axis dependency information exemplified in FIG. 4A. It is a flowchart which shows the specific procedure of the check target group extraction process. It is a figure for demonstrating the procedure of calculating a priority by the 1st priority calculation algorithm. It is a figure for demonstrating the procedure of calculating a priority by the 2nd priority calculation algorithm. It is a figure for demonstrating the procedure of calculating a priority by a 3rd priority calculation algorithm. It is a figure which shows an example of the interference check support information generated by the interference check support device. It is a schematic diagram of the numerical control system which concerns on 2nd Embodiment of this disclosure.

<First Embodiment>
Hereinafter, the numerical control system according to the first embodiment of the present disclosure will be described with reference to the drawings.

FIG. 1 is a schematic diagram of a numerical control system 1 according to the present embodiment.

The numerical control system 1 includes a machine tool 2 and a numerical control device (CNC) 3 for controlling the machine tool 2.

The machine tool 2 has a plurality of machine elements having a predetermined three-dimensional shape such as a tool, a table, a support for supporting the tool, and a jig for holding a work, and each machine element is moved along a plurality of control axes. A plurality of servomotors 2a, 2b, ..., 2n and the like are provided. The machine tool 2 drives a plurality of servomotors 2a, ..., 2n based on a moving pulse transmitted from the numerical control device 3, and moves a plurality of machine elements along a plurality of control axes to move a work (not shown). To process. Here, the machine tool 2 is, for example, a lathe, a drilling machine, a milling machine, a grinding machine, a laser processing machine, an injection molding machine, and the like, but is not limited thereto.

In the numerical control device 3, arithmetic processing means such as a CPU (Central Processing Unit), auxiliary storage means such as an HDD (Hard Disk Drive) and SSD (Solid State Drive) storing various programs, and arithmetic processing means execute programs. Main storage means such as RAM (Random Access Memory) for storing data temporarily required above, operation means such as a keyboard on which the operator performs various operations, display means such as a display for displaying various information to the operator, etc. It is a computer composed of the hardware of.

The numerical control device 3 has a machining program memory 31, a command analysis unit 32, an interpolation unit 33, a pulse generation unit 34, a position / orientation calculation unit 35, an interference check unit 36, a shape storage unit 37, and an interference check, depending on the hardware configuration. Various functions such as the support device 5 are realized.

The machining program memory 31 stores a numerical control program including a command for moving each machine element of the machine tool 2 along each control axis (including translational movement and rotational movement). The numerical control program is written in a predetermined programming language (for example, G code).

The command analysis unit 32 reads out the numerical control program stored in the machining program memory 31 for each block, analyzes it, and generates movement command data for commanding the movement of each control axis of the machine tool 2 based on the analysis result. The command analysis unit 32 transmits the generated movement command data to the interpolation unit 33.

The interpolation unit 33 generates interpolation data obtained by interpolating and calculating points on the command path in a predetermined interpolation cycle based on the movement command data transmitted from the command analysis unit 32. The interpolation unit 33 transmits the generated interpolation data to the pulse generation unit 34.

The pulse generation unit 34 generates a movement command for the machine tool 2, that is, a movement pulse for each of the servomotors 2a, ..., 2n of the machine tool 2 for each interpolation cycle based on the interpolation data transmitted from the interpolation unit 33. .. By inputting the moving pulse generated as described above to the servomotors 2a, ..., 2n, the pulse generation unit 34 moves a plurality of machine elements of the machine tool 2 along a plurality of control axes. When it is determined that any of the plurality of machine elements interferes with each other based on the interference check calculation described later in the interference check unit 36, the pulse generation unit 34 generates and operates a moving pulse in order to prevent this interference. Stop the input to the machine 2.

Further, the pulse generation unit 34 generates a moving pulse for each interpolation cycle based on the interpolation data as described above, and inputs the moving pulse to be input to the machine tool 2 in the current interpolation cycle to the machine tool 2. It is transmitted to the position / orientation calculation unit 35 before.

The position / orientation calculation unit 35 is based on the movement pulse transmitted from the pulse generation unit 34 in each interpolation cycle, and when each control axis is moved based on the movement pulse, the position / orientation calculation unit 35 per unit time of each control axis (for example, interpolation). The axis movement amount vector related to the axis movement amount (per cycle), the pre-movement position vector related to the position of each machine element before moving each control axis based on the movement pulse, and each control axis moved based on the movement pulse. The post-movement position vector regarding the position of each machine element after the movement and the post-movement posture information regarding the posture of each machine element after moving each control axis based on the movement pulse are calculated. The position / orientation calculation unit 35 transmits the calculated axis movement amount vector for each control axis and the pre-movement position vector for each machine element to the interference check support device 5. Further, the position / attitude calculation unit 35 transmits the calculated post-movement position vector and post-movement attitude information for each machine element to the interference check unit 36.

The direction and norm of the axis movement amount vector calculated by the position / orientation calculation unit 35 are defined as follows. If the control axis is a straight axis that translates the machine element along its axis, the orientation of the axis movement vector is parallel to the control axis and the norm of the axis movement vector is the unit time along the axis of the control axis. Equal to the hit travel distance [mm]. When the control axis is a rotation axis that rotates and moves the machine element around its axis, the angular velocity vector of the control axis is used as the axis movement amount vector. That is, when the control axis is the rotation axis, the direction of the axis movement amount vector is parallel to the control axis, and the norm of the axis movement amount vector is equal to the rotation angle [rad] per unit time of the control axis. In the following, the norm of the axis movement amount vector is also simply referred to as “axis movement amount”.

The shape storage unit 37 stores shape information regarding the shape of each of the plurality of machine elements constituting the machine tool 2. When a moving pulse having the same interpolation cycle as the moving pulse input from the pulse generation unit 34 to the machine tool 2 is input to the position / orientation calculation unit 35 as described above, the interference check calculation by the interference check unit 36 is performed within the interpolation cycle. It is preferable to add a small margin to the shape information stored in the shape storage unit 37 so that interference does not occur immediately even if the above cannot be completed. That is, it is preferable that the shape information stored in the shape storage unit 37 is created based on a machine element slightly larger than the actual machine element.

The interference check unit 36 determines whether or not interference occurs between a plurality of machine elements constituting the machine tool 2 when the moving pulse generated by the pulse generation unit 34 is continuously input to the machine tool 2 as described above. The interference check operation for determination is performed on a plurality of check target sets. Here, the check target set is configured by combining two of the plurality of machine elements constituting the machine tool 2. Therefore, when the total number of machine elements constituting the machine tool 2 is N, the total number of check target sets is N (N-1) / 2.

More specifically, the interference check unit 36 receives the post-movement position vector and the post-movement attitude information transmitted from the position / orientation calculation unit 35 for each interpolation cycle, and the interference check support device 5 for each interpolation cycle according to the procedure described later. Based on the generated interference check support information and the shape information stored in the shape storage unit 37, an interference check calculation based on a known interference check algorithm (for example, a separation axis method) is performed, and the pulse generation unit 34 performs an interference check calculation. When the generated moving pulse is continuously input to the machine tool 2, it is determined whether or not the plurality of machine elements constituting the machine tool 2 interfere with each other. When the interference check unit 36 determines that interference is caused by the interference check calculation, it notifies the pulse generation unit 34 to that effect, and stops the generation of the moving pulse and the input to the machine tool 2 before the interference occurs.

The interference check support device 5 includes a first storage unit 51, a second storage unit 52, a third storage unit 53, and a check support information generation unit 54, and by using these, interference in the interference check unit 36 Interference check support information, which is information for supporting the check operation, is generated.

In the first storage unit 51, a machine element-control shaft string that associates each control axis in the machine tool 2 with a machine element that moves along the control axis related to the movement when each control axis is moved. The attached information is stored in an arbitrary format such as a machine configuration tree or a table. In this embodiment, a case where the machine element-control axis association information is stored in the first storage unit 51 in a machine configuration tree format as illustrated in FIG. 3 described later will be described.

In the second storage unit 52, each axis dependency information that defines the dependency between each control axis in the machine tool 2 is stored in an arbitrary format such as a machine component tree or a table. In this embodiment, a case where each axis dependency information is stored in the second storage unit 52 in a machine configuration tree format as illustrated in FIG. 3 described later will be described.

Next, specific examples of the machine element-control axis association information and each axis dependency information stored in the storage units 51 and 52 will be described with reference to FIGS. 2 and 3.

FIG. 2 is a diagram showing an example of the machine tool 2. The machine tool 2 illustrated in FIG. 2 can move six machine elements 21, 22, 23, 24, 25, 26 along five control axes X, Y, Z, A, and C. ing. The fifth machine element 25 is a jig that supports a work (not shown), and the sixth machine element 26 is a table that supports the fifth machine element 25. The fifth machine element 25 and the sixth machine element 26 can be rotationally moved around a control axis C extending along a vertical direction, for example. The fourth machine element 24 is a tool for machining a work supported by the fifth machine element 25. The third machine element 23 is a support that supports the fourth machine element 24 at its tip. The second machine element 22 is a support that rotatably supports the base end portion of the third machine element 23 around a control shaft A extending along a horizontal plane. The first mechanical element 21 is a support that movably supports the second mechanical element 22 along a control axis Z along the vertical direction, and a control axis X and a control axis Y orthogonal to each other in a horizontal plane. That is, in the example of FIG. 2, the control axes X, Y, and Z are straight axes, and the control axes A and C are rotation axes.

That is, in the machine tool 2 illustrated in FIG. 2, the fifth machine element 25 and the sixth machine element 26 are integrally rotated along the control axis C. Further, the first machine element 21, the second machine element 22, the third machine element 23, and the fourth machine element 24 are integrally rotated along the control axes X, Y, and Z, and the third machine element 23 and The fourth machine element 24 is integrally rotated along the control axis A.

FIG. 3 is a diagram showing an example of displaying the machine element-control axis association information and each axis dependency information in the machine tool 2 exemplified in FIG. 2 by a machine configuration tree. In the machine tool 2 illustrated in FIG. 2, the control axis C and the control axes X, Y, Z, and A can be moved independently. Therefore, as shown in the machine configuration tree of FIG. 3, the control axis C and the control axes X, Y, Z, and A are independently dependent on the route R. Further, in the machine tool 2 illustrated in FIG. 2, when the control axes X, Y, Z are moved, the control axis A also moves, but even if the control axis A is moved, the control axes X, Y, Z do not move. That is, the control axis A is lower than the control axes X, Y, and Z. Therefore, as shown in the machine configuration tree of FIG. 3, the control axis A is dependent on the control axes X, Y, and Z.

Further, since the fifth machine element 25 and the sixth machine element 26 are integrally rotated along the control axis C, these machine elements 25 and 26 are connected to the control axis C as shown in the machine configuration tree of FIG. Be associated. Further, since the third machine element 23 and the fourth machine element 24 are integrally rotated along the control axis A lower than the control axes X, Y, Z, these machines are shown in the machine configuration tree of FIG. Elements 23 and 24 are associated with control axis A. Further, since the first machine element 21 and the second machine element 22 are integrally rotated along the control axes X, Y, Z, these machine elements 21 and 22 are controlled as shown in the machine configuration tree of FIG. It is associated with the lowest control axis Z among the axes X, Y, and Z.

Returning to FIG. 1, the check support information generation unit 54 includes a check target set extraction unit 54a that extracts one or more check target sets from all combinations of the plurality of machine elements of the machine tool 2, and a plurality of check targets. It includes a set, more specifically, a priority calculation unit 54b for calculating a priority for a plurality of check target sets extracted by the check target set extraction unit 54a. Here, the priority for the plurality of check target sets is an integer value that determines the order when the interference check unit 36 sequentially performs the interference check operation on the plurality of check target sets. In the following, it is assumed that the priority is lowered in ascending order from the smallest value.

The third storage unit 53 combines information on the check target group extracted by the check target group extraction unit 54a and information on the priority determined for each check target group by the priority calculation unit 54b. The configured interference check support information is stored.

The check target set extraction unit 54a includes the axis movement amount of each control axis transmitted from the position / orientation calculation unit 35 for each interpolation cycle, the machine element-control axis association information stored in the first storage unit 51, and the first. 2 One or more sets of check targets by excluding combinations that do not need to execute an interference check calculation from all combinations of a plurality of machine elements based on each axis dependency information stored in the storage unit 52. Extract pairs.

First, the check target group extraction unit 54a specifies a control axis to be moved by a movement pulse from among a plurality of control axes as a movement control axis based on the axis movement amount of each control axis transmitted from the position / orientation calculation unit 35. do. More specifically, the check target set extraction unit 54a specifies a control axis in which the axis movement amount (norm of the axis movement amount vector) is not 0 as the movement control axis.

After that, the check target set extraction unit 54a converts a plurality of machine elements constituting the machine tool 2 into a dependent machine element group and a stationary machine element group based on the machine element-control axis association information and each axis dependency information. Classify. The dependent machine element group is a group to which the machine element that moves together with the movement control axis belongs, and the stationary machine element group is a group to which the machine element that does not move even if the movement control axis is moved belongs. More specifically, the check target set extraction unit 54a classifies the machine elements associated with the movement control axis and the control axis lower than the movement control axis into the dependent machine element group, and the dependent machine among all the machine elements. Machine elements that do not belong to the element group are classified into the stationary machine element group.

Here, all the machine elements belonging to the dependent machine element group move together with the movement control axis. Therefore, it is clear that the combination of machine elements belonging to the dependent machine element group does not interfere even if the interference check operation is not executed, so that the combination is excluded from the check target set. Moreover, all the machine elements belonging to the stationary machine element group do not move even if the movement control axis is moved. Therefore, it is clear that the combination of machine elements belonging to the stationary machine element group does not interfere even if the interference check operation is not executed, so that the combination is excluded from the check target set. Therefore, the check target set extraction unit 54a extracts the combination of each machine element belonging to the dependent machine element group and each machine element belonging to the stationary machine element group as the check target set. In other words, the check target set extraction unit 54a excludes the combination of the machine elements belonging to the dependent machine element group and the combination of the machine elements belonging to the stationary machine element group from all the combinations of the plurality of machine elements. The combined combination is extracted as the check target group. The check target group extraction unit 54a stores the list of check target groups extracted by the above procedure (hereinafter referred to as “check target group list”) in the third storage unit 53.

Here, a specific procedure for extracting the check target set by the check target set extraction unit 54a as described above will be described with reference to the specific examples of FIGS. 4A and 4B.

FIG. 4A is a diagram showing an example of machine element-control axis association information and each axis dependency information. In the example shown in FIG. 4A, the machine tool has the first machine element, the second machine element, the third machine element, and the fourth machine element as the first control axis, the second control axis, the third control axis, and the fourth. It is possible to move along the control axis, the fifth control axis, and the sixth control axis. Further, in the example of each axis dependency information illustrated in FIG. 4A, the first to fourth control axes and the fifth to sixth control axes can be moved independently of each other. The fifth control axis is lower than the sixth control axis, the second to fourth control axes are lower than the first control axis, and the third control axis and the fourth control axis are the first control axis and the second control axis, respectively. It is lower than the control axis, and the second control axis is lower than the first control axis. Further, in the example of the machine element-control axis association information exemplified in FIG. 4A, the first machine element is associated with the first control axis, the second machine element is associated with the fourth control axis, and the fourth machine element is the first. The 6th control axis is associated and the 3rd machine element is associated with the 5th control axis.

FIG. 4B shows a case where the first to fourth machine elements are classified into a dependent machine element group and a stationary machine element group under the machine element-control axis association information and each axis dependency information exemplified in FIG. 4A. It is a figure. In the example of FIG. 4B, the first control axis among the first to sixth control axes is used as the movement control axis. As shown in FIG. 4B, the first control axis, which is a movement control axis, and the first and second machine elements associated with the second, third, and fourth control axes below the first control axis are dependent. The third and fourth machine elements, which are classified into the machine element group and do not belong to the dependent machine element group among all the machine elements, are classified into the stationary machine element group. Therefore, in the example shown in FIG. 4B, all combinations of the first to fourth machine elements (first and second machine elements, first and third machine elements, first and fourth machine elements, second and third machines). Of the six combinations of elements, second and fourth mechanical elements, and third and fourth mechanical elements), the first and third mechanical elements, the first and fourth mechanical elements, and the second and third mechanical elements. , And a total of four combinations of the second and fourth machine elements are extracted as the set to be checked.

Returning to FIG. 1, when a plurality of movement control axes exist, the check target set extraction unit 54a extracts the union of the check target sets extracted according to the above procedure under each movement control axis as the check target set.

FIG. 5 is a flowchart showing a specific procedure of the check target set extraction process in the check target set extraction unit 54a. In the process shown in FIG. 5, the total number of control axes is N (N is an arbitrary integer of 2 or more). The check target group extraction unit 54a executes the check target group extraction process shown in FIG. 5 in response to receiving a new axis movement amount from the position / orientation calculation unit 35.

First, in S1, the check target set extraction unit 54a sets the value of the control axis counter C to 1, and moves to S2. In S2, the check target set extraction unit 54a determines whether or not the axis movement amount of the Cth control axis associated with the counter C is not 0 based on the axis movement amount for each control axis transmitted from the position / orientation calculation unit 35. Is determined. The check target group extraction unit 54a moves to S3 when the determination result of S2 is YES, and moves to S5 when the determination result of S2 is NO.

In S3, the check target set extraction unit 54a classifies a plurality of machine elements into a dependent machine element group and a stationary machine element group according to the above procedure by using the Cth control axis as the movement control axis, and moves to S4. .. In S4, the check target set extraction unit 54a sets all combinations of each machine element belonging to the dependent machine element group and each machine element belonging to the stationary machine group as the check target set, and the check target set in the third storage unit 53. Add to the list and move to S5.

In S5, the check target set extraction unit 54a determines whether or not the value of the control axis counter C is equal to the total number N of the control axes. If the determination result of S5 is NO, the check target set extraction unit 54a moves to S6, counts up only one control axis counter C, and then returns to S2. If the determination result of S5 is YES, the check target set extraction unit 54a ends the check target set extraction process shown in FIG.

According to the check target set extraction process as described above, when there are a plurality of movement control axes, it is obtained by classifying the plurality of machine elements into a dependent machine element group and a stationary machine element group under each movement control axis. The union of a plurality of combinations to be checked is extracted as a set to be checked.

Returning to FIG. 1, the priority calculation unit 54b sends the position / orientation calculation unit 35 to the axis movement amount vector of each control axis, the pre-movement position vector of each machine element, and the first storage unit 51, which are transmitted for each interpolation cycle. Based on the stored machine element-control axis association information, the priority is calculated in descending order from the one with the highest possibility of interference to the plurality of check target sets extracted by the check target set extraction unit 54a. .. The priority calculation unit 54b calculates the priority for a plurality of check target sets based on one of the first, second, and third priority calculation algorithms described below or a priority calculation algorithm that combines them. It is possible to do.

<First priority calculation algorithm>
Under the first priority calculation algorithm, the priority calculation unit 54b calculates the priority for a plurality of check target sets based on the axis movement amount of each control axis transmitted from the position / orientation calculation unit 35. More specifically, the priority calculation unit 54b calculates the machine element order for each machine element associated with each control axis by the machine element-control axis association information in descending order from the control axis having the largest axis movement amount. Next, the priority calculation unit 54b calculates the priority for the check target set including each machine element in descending order from the machine element having the highest calculated machine element order. That is, under the first priority calculation algorithm, the priority calculation unit 54b is likely to interfere in the check target set including the machine element associated with the control axis having a large amount of axis movement per unit time. Judgment is made, and the priority of the check target group including such a machine element is increased.

By the way, the dimension of the axis movement amount differs depending on whether the control axis is a straight axis or a rotation axis. More specifically, when the control axis is a straight axis, the axis movement amount is a movement distance, and when the control axis is a rotation axis, the axis movement amount is a rotation angle. Therefore, it is not possible to directly compare the magnitude of the axis movement amount with respect to the straight axis and the axis movement amount with respect to the rotation axis. Therefore, under the first priority calculation algorithm, a check target set including a rotary machine element, which is a machine element associated with the rotation axis and a machine element-control axis association information, and a check target not including this rotation machine element. The priority for each check target group is calculated separately for each group. More specifically, since the rotating axis is less likely to notice interference than the straight axis, under the first priority calculation algorithm, the priority for the set to be checked including the rotating machine element is set to the rotating machine element. Set higher than the priority for the set to be checked that is not included.

Here, a specific procedure for calculating the priority by the first priority calculation algorithm as described above will be described with reference to the specific example of FIG.

FIG. 6 is a diagram for explaining a procedure for calculating the priority by the first priority calculation algorithm. The left side of FIG. 6 shows an example of machine element-control axis association information and each axis dependency information, and the right side of FIG. 6 shows various parameters calculated by the priority calculation unit 54b under such a configuration. It is a figure which shows.

In the example shown on the left side of FIG. 6, the machine tool has the first machine element, the second machine element, the third machine element, and the fourth machine element as the first control axis, the second control axis, and the third control axis. It is possible to move along the fourth control axis and the fifth control axis. In the example on the left side of FIG. 6, it is assumed that the first control axis, the third control axis, and the fourth control axis are straight axes, and the second control axis and the fifth control axis are rotation axes. In the example of each axis dependency relationship illustrated on the left side of FIG. 6, the first to second control axes and the third to fifth control axes can be moved independently of each other. The second control axis is lower than the first control axis, the fourth control axis and the fifth control axis are lower than the third control axis, and the fifth control axis is lower than the fourth control axis. Further, in the example of the machine element-control axis association information exemplified on the left side of FIG. 6, the first machine element is associated with the first control axis, the second machine element is associated with the second control axis, and the third machine element is associated with the third machine element. Is associated with the 4th control axis and the 4th machine element is associated with the 5th control axis. Further, in FIG. 6, the axis movement amount of the first control axis is 4, the axis movement amount of the second control axis is 2, the axis movement amount of the third control axis is 3, and the fourth control axis has an axis movement amount of 3. An example is shown in the case where the axis movement amount is 1 and the axis movement amount of the 5th control axis is 3. That is, in the example of FIG. 6, the amount of axial movement of the straight axis increases in the order of the fourth control axis, the third control axis, and the first control axis, and the amount of axial movement of the rotary axis increases with respect to the second control axis and the second control axis. It increases in the order of the fifth control axis.

As shown in FIG. 6, the first mechanical element is associated with the first control axis, which is the linear axis, the second mechanical element is associated with the second control axis, which is the rotary axis, and the third mechanical element is the linear axis. It is associated with a fourth control axis, and the fourth mechanical element is associated with a fifth control axis, which is the axis of rotation. That is, the second machine element and the fourth machine element are rotary machine elements associated with the rotary axis, and the first mechanical element and the third mechanical element are straight machine elements associated with the straight axis. Therefore, when the machine element order for each machine element associated with each control axis is calculated in descending order from the control axis in which the rotating machine element is higher than the straight machine element and the amount of shaft movement is large, the fourth machine element becomes the first place. The second machine element is in second place, the first machine element is in third place, and the third machine element is in fourth place. Further, when the priority is calculated for each check target set including each machine element in descending order from the machine element having the highest machine element order, the combination of the second and fourth machine elements becomes the first place, and the first and fourth machine elements The combination is in 2nd place, the combination of 3rd and 4th machine elements is in 3rd place, the combination of 1st and 2nd machine elements is in 4th place, the combination of 2nd and 3rd machine elements is in 5th place, and the 1st place. And the combination of the third machine element is the 6th place.

<Second priority calculation algorithm>
Under the second priority calculation algorithm, the priority calculation unit 54b calculates the priority for a plurality of check target sets based on the axis movement amount vector of each control axis transmitted from the position / orientation calculation unit 35. More specifically, the priority calculation unit 54b uses the axis movement amount vector calculated for each control axis, so that the relative axis movement amount with respect to the axis pair configured by combining two of the plurality of control axes. Calculate the vector. Here, when the total number of control axes is M, the total number of axis pairs is M (M-1) / 2. Further, for example, when the axis movement amount vector of the nth control axis is vn and the axis movement amount vector of the mth control axis is vm, the relative axis movement amount with respect to the axis pair composed of the nth control axis and the mth control axis. The vector dnm is vn-vm.

Next, the priority calculation unit 54b calculates the relative axis movement amount (that is, the norm of the relative axis movement amount vector) for all the axis pairs. Next, the priority calculation unit 54b gives priority to each check target group including the combination of each axis pair and the machine element associated with the machine element-control axis association information in descending order from the axis pair having the largest calculated relative axis movement amount. Calculate the degree. That is, under the second priority calculation algorithm, the priority calculation unit 54b may interfere in a set to be checked including a combination of machine elements associated with an axis pair having a large relative axis movement amount per unit time. Is judged to be high, and the priority of the set to be checked including such a combination of machine elements is increased.

As described above, the dimension of the axis movement amount differs depending on whether the control axis is a straight axis or a rotation axis. Therefore, the relative axis movement amount vector dnm obtained by subtracting the axis movement amount vector vm from the axis movement amount vector vn is physically obtained when at least one of the nth control axis and the mth control axis is the rotation axis. It loses its meaning. Therefore, when the rotation axis is included in all the control axes, the priority is calculated under the above-mentioned first priority calculation algorithm for the check target set including the rotation machine element associated with this rotation axis. Then, the priority is calculated under the second priority calculation algorithm only for the check target set including only the straight-ahead machine element.

Here, a specific procedure for calculating the priority by the second priority calculation algorithm as described above will be described with reference to the specific example of FIG. 7.

FIG. 7 is a diagram for explaining a procedure for calculating the priority by the second priority calculation algorithm. The left side of FIG. 7 shows an example of machine element-control axis association information and each axis dependency information, and the right side of FIG. 7 shows various parameters calculated by the priority calculation unit 54b under such a configuration. It is a figure which shows.

In the example shown on the left side of FIG. 7, the machine tool has the first machine element, the second machine element, and the third machine element as the first control axis, the second control axis, the third control axis, and the fourth control axis. It is possible to move along. In the example on the left side of FIG. 7, it is assumed that the first control axis, the second control axis, the third control axis, and the fourth control axis are all linear axes. In the example of each axis dependency relationship illustrated on the left side of FIG. 7, the first to second control axes and the third to fourth control axes can be moved independently of each other. The second control axis is lower than the first control axis, and the fourth control axis is lower than the third control axis. Further, in the example of the machine element-control axis association information exemplified on the left side of FIG. 7, the first machine element is associated with the first control axis, the second machine element is associated with the second control axis, and the third machine element is associated with the third machine element. Is associated with the 4th control axis.

In the example shown on the left side of FIG. 7, the machine tool includes first to fourth control axes. Therefore, by combining two of the first to fourth control axes, the first and second control axes, the first and third control axes, the first and fourth control axes, the second and third control axes, and the first A total of six axis pairs of the second and fourth control axes and the third and fourth control axes can be configured. Further, in FIG. 7, the relative axis movement amount between the first control axis and the second control axis is 4, and the relative axis movement amount between the first control axis and the third control axis is 5. The relative axis movement amount between the first control axis and the fourth control axis is 3, the relative axis movement amount between the second control axis and the third control axis is 1, and the second control axis and the second control axis. An example is shown in which the relative axis movement amount between the 4 control axes is 6 and the relative axis movement amount between the 3rd control axis and the 4th control axis is 2. That is, in the example of FIG. 7, the second and third control axes, the third and fourth control axes, the first and fourth control axes, the first and second control axes, the first and third control axes, and the first The relative axis movement amount increases in the order of the second and fourth control axes.

As shown in FIG. 7, the first and fourth control axes are associated with a combination of first and third machine elements, and the first and second control axes are associated with a combination of first and second machine elements. , 2nd and 4th control axes are associated with a combination of 2nd and 3rd machine elements. Therefore, when the priority for each check target group including the combination of each axis pair and the machine element associated with the machine element-control axis association information is calculated in descending order from the axis pair with the largest relative axis movement amount, the second and third The combination of machine elements is in first place, the combination of first and second machine elements is in second place, and the combination of first and third machine elements is in third place.

<Third priority calculation algorithm>
Under the third priority calculation algorithm, the priority calculation unit 54b performs a plurality of checks based on the axis movement amount vector of each control axis and the pre-movement position vector of each machine element transmitted from the position / orientation calculation unit 35. Calculate the priority for the target set. More specifically, the priority calculation unit 54b is a check target based on the axis movement amount vector of each control axis, the pre-movement position vector of each machine element, and the machine element-control axis association information. A reduction rate parameter proportional to the reduction rate of the distance between the two machine elements constituting the set is calculated, and the priority for each check target set is calculated based on these reduction rate parameters.

The procedure for calculating the reduction rate parameter for each check target group will be described below. First, the priority calculation unit 54b acquires the axis movement amount vector of each control axis transmitted from the position / orientation calculation unit 35, and based on these axis movement amount vectors, each control axis is based on the machine element-control axis association information. Calculate the speed vector of the machine element associated with. Here, for the straight-moving machine element associated with the straight-moving axis, the axis movement amount vector is used as it is as the velocity vector. For the rotating machine element associated with the rotating axis, the outer product of the axis movement amount vector and the predetermined moving diameter vector is used as the velocity vector. Here, the radius vector used is predetermined for each rotation axis. More specifically, the direction of the radial vector is the radial direction orthogonal to the axis of rotation, and the norm of the radial vector is the distance along the radial direction from the axis of rotation to the machine element.

Next, the priority calculation unit 54b acquires the pre-movement position vector of each machine element transmitted from the position / attitude calculation unit 35, and based on these pre-movement position vectors, the two machine elements constituting each check target set. Calculate the normalized relative position vector for. Here, when the pre-movement position vector of the n-th machine element is rn and the pre-movement position vector of the m-th machine element is rm, the normalized relative position vector for the combination of the n-th machine element and the m-th machine element is , (Rn-rm) / | rn-rm |.

Next, the priority calculation unit 54b calculates the relative velocity vector for the two machine elements constituting each check target set based on the velocity vector for each machine element calculated earlier. Here, when the velocity vector of the nth machine element is vn and the velocity vector of the mth machine element is vm, the relative velocity vector for the combination of the nth machine element and the m machine element is vn-vm.

Next, the priority calculation unit 54b calculates the reduction rate parameter for each check target set by multiplying the inner product of the previously calculated relative velocity vector and relative position vector by a negative sign. Here, when the set to be checked is composed of the nth machine element and the mth machine element, the reduction rate parameters are − (vn-vm) · (rn-rm) / | rn-rm |. The reduction rate parameter calculated by the above procedure is proportional to the reduction rate of the distance between the two machine elements per unit time. That is, if the distance between the two machine elements does not change, the reduction rate parameter becomes 0, and if the distance between the two machine elements changes in the direction of increasing, the reduction rate parameter becomes negative and the two machine elements If the distance between them changes in the direction of becoming closer, the reduction rate parameter becomes positive.

Next, the priority calculation unit 54b calculates the priority in descending order from the check target group including the combination of the machine elements having the large reduction rate parameter calculated by the above procedure. That is, under the third priority calculation algorithm, the priority calculation unit 54b determines that there is a high possibility of interference in the check target set in which the reduction rate of the distance between the two components is large, and such a machine. Increase the priority of the set to be checked including the combination of elements.

Here, a specific procedure for calculating the priority by the above-mentioned third priority calculation algorithm will be described with reference to the specific example of FIG.

FIG. 8 is a diagram for explaining a procedure for calculating the priority by the third priority calculation algorithm. The left side of FIG. 8 shows an example of machine element-control axis association information and each axis dependency information, and the right side of FIG. 8 shows various parameters calculated by the priority calculation unit 54b under such a configuration. It is a figure which shows. Since the machine tool configuration shown on the left side of FIG. 8 is the same as that shown on the left side of FIG. 7, detailed description thereof will be omitted.

In the example of FIG. 8, the velocity vector of the first machine element associated with the first control axis is v1, the velocity vector of the second machine element associated with the second control axis is v2, and the fourth is associated with the fourth control axis. 3 The speed vector of the machine element is v3, the pre-movement position vector of the first machine element is r1, the pre-movement position vector of the second machine element is r2, and the pre-movement position vector of the third machine element is r3. Further, in the example of FIG. 8, the relative velocity vector v1-v2 for the combination of the first and second machine elements is (0,0,1), and the relative velocity vector v1-v3 for the combination of the first and third machine elements is. (0,2,0) and the relative velocity vector v2-v3 for the combination of the second and third machine elements is (1,0,0) and normalized relative to the combination of the first and second machine elements. The position vector r1-r2 is (0,0, -1) and the normalized relative position vector r1-r3 for the combination of the first and third machine elements is (0,0,1), the second and second. 3 The normalized relative position vector r2-r3 for the combination of machine elements is (1,0,0).

Therefore, when the reduction rate parameter for each combination of machine elements is calculated according to the above procedure, the reduction rate parameter for the combination of the first and second machine elements is 1, and the reduction rate parameter for the combination of the first and third machine elements is 0. Therefore, the reduction rate parameter for the combination of the second and third machine elements is -1. Therefore, when the priority is calculated in descending order from the check target group including the combination of machine elements with a large reduction rate parameter, the combination of the first and second machine elements is ranked first, and the combination of the first and third machine elements is ranked second. Therefore, the combination of the second and third machine elements is ranked third.

Returning to FIG. 1, the priority calculation unit 54b has the first to third priority calculation algorithms as described above for the plurality of check target groups extracted by the check target group extraction process in the check target group extraction unit 54a. The priority is calculated based on the priority calculation algorithm of any of the above or a combination thereof, and the calculated priority is added to the check target group list in the third storage unit 53. As a result, priority is given to the plurality of check target sets extracted by the check target set extraction unit 54a.

As described above, the interference check support device 5 extracts the set to be checked from all the combinations of the plurality of machine elements based on the axis movement amount vector and the pre-movement position vector transmitted from the position / orientation calculation unit 35. Further, priorities are given to these plurality of check target groups, and the check target group list to which the priorities are given is stored in the third storage unit 53 as interference check support information (see, for example, FIG. 9).

The interference check unit 36 acquires the post-movement position vector and the post-movement posture information transmitted from the position / attitude calculation unit 35 for each interpolation cycle, and the interference check support information stored in the third storage unit 53. Further, the interference check unit 36 performs an interference check operation for a plurality of check target sets defined by the acquired interference check support information, in order from the check target set having the highest priority.

According to this embodiment, the following effects are achieved.
The priority calculation unit 54b associates a moving pulse with respect to the machine tool 2 with each control axis in the machine tool 2 and a machine element moving along the control axis among a plurality of machine elements-control axis association information. And, based on, the priority for a plurality of check target sets is calculated. Thereby, for a plurality of check target sets, for example, it is possible to raise the priority of the check target set of the combination of machine elements that are likely to cause interference. Further, the numerical control device 3 moves a plurality of machine elements along a plurality of control axes based on a numerical control program, and is determined by the priority calculated by the priority calculation unit 54b for a plurality of check target sets. Interference check operations are performed in the order shown. According to the present embodiment, the numerical control device 3 cannot perform the interference check calculation for all the check target sets within a limited time by performing the interference check calculation in order from the check target set having the highest priority. Even in such a case, it is possible to efficiently detect interference between machine elements.

The priority calculation unit 54b calculates the priority for a plurality of check target sets based on the axis movement amount vector of each control axis and the machine element-control axis association information calculated based on the movement pulse. As a result, it is possible to specify a combination of machine elements that are likely to cause interference according to the length and direction of the axis movement amount vector, and to raise the priority of this check target set.

The priority calculation unit 54b raises the priority for the check target group including the rotating machine element associated with the rotary axis higher than the priority for the check target group including only the straight machine element associated with the straight axis. As a result, the priority for the check target set including the rotary machine element associated with the rotary axis, which is less likely to notice the interference than the straight axis, can be higher than the priority for the check target set not including the rotary machine element.

Under the first priority calculation algorithm, the priority calculation unit 54b is a machine element for each machine element associated with each control axis by the machine element-control axis association information in descending order from the control axis having the largest axis movement amount. The order is calculated, and the priority for each check target group including each machine element is calculated in descending order from the machine element having the highest machine element order. As a result, it is determined that there is a high possibility that the axis movement amount per unit time will interfere with the check target group including the machine element associated with the large control axis, and the priority of the check target group including such a machine element is determined. Can be raised. Further, according to such a first priority calculation algorithm, the priority can be calculated by a simple calculation, so that the calculation load in the numerical control device 3 can be reduced.

Under the second priority calculation algorithm, the priority calculation unit 54b calculates the relative axis movement amount for a plurality of sets of axis movements based on the axis movement amount, and in descending order from the axis pair with the largest relative axis movement amount. Calculate the priority for each check target set including the combination of each axis pair and the machine element-machine element associated with the control axis association information. As a result, it is judged that there is a high possibility of interference in the set to be checked including the combination of machine elements associated with the axis pair having a large relative axis movement amount per unit time, and the check including such a combination of machine elements is determined. The priority of the target group can be increased.

Under the third priority calculation algorithm, the priority calculation unit 54b constitutes two check target sets based on the axis movement amount vector, the pre-movement position vector, and the machine element-control axis association information. The reduction rate parameters are calculated according to the reduction rate of the distance between the machine elements, and the priority for each check target set is calculated based on these reduction rate parameters. As a result, it is determined that there is a high possibility of interference in the check target set in which the reduction rate of the distance between the machine elements is large, and the priority of the check target set including such a combination of machine elements can be increased.

The priority calculation unit 54b stores information on the priority for a plurality of check target sets in the third storage unit 53 as interference check support information, and the interference check unit 36 stores the interference check support stored in the third storage unit 53. Refer to the information and perform the interference check operation. As a result, the priority calculation unit 54b can perform an operation of calculating the priority of the check target set at a free timing independent of the interference check operation in the interference check unit 36.

The check target set extraction unit 54a is selected from all combinations of a plurality of machine elements based on the axis movement amount calculated based on the movement pulse, the machine element-control axis association information, and each axis dependency information. Extract one or more sets to be checked. Further, the priority calculation unit 54b calculates the priority for a plurality of check target sets extracted by the check target set extraction unit 54a. As a result, the priority calculation unit 54b does not necessarily have to calculate the priority for all the check target groups, and can calculate the priority only for the check target groups narrowed down by the check target group extraction unit 54a. Therefore, the calculation load on the numerical control device 3 can be reduced.

Further, in the present embodiment, the interference check support device 5 having a function of generating interference check support information is incorporated into the numerical control device 3 that controls the machine tool 2 and performs the interference check calculation, and the interference check support device 5 has a numerical value. Interference check support information is generated based on the moving pulse transmitted from the pulse generation unit 34 of the control device 3. As a result, although the calculation load on the numerical control device 3 becomes large, it is possible to generate interference check support information in real time while controlling the machine tool 2 by the numerical control device 3. Therefore, for example, even when the machine tool 2 is manually operated by an operator, appropriate interference check support information can be generated.

<Second Embodiment>
Next, the numerical control system according to the second embodiment of the present disclosure will be described. In the following description, the same reference numerals are given to the same configurations as those of the numerical control system according to the first embodiment, and detailed description thereof will be omitted.

FIG. 10 is a schematic diagram of the numerical control system 1A according to the present embodiment. As described above, in the first embodiment, the case where the interference check support device 5 is incorporated in the numerical control device 3 has been described. On the other hand, the numerical control system 1A according to the present embodiment relates to the first embodiment in that it includes a numerical control device 3A and an interference check support device 5A configured separately from the numerical control device 3A. It is different from the numerical control system 1A.

The interference check support device 5A includes a first storage unit 51, a second storage unit 52, a check support information generation unit 54, and a movement amount position calculation unit 55A.

The movement amount position calculation unit 55A reads out the numerical control program stored in the machining program memory 31, and performs calculations in the command analysis unit 32, the interpolation unit 33, the pulse generation unit 34, and the position / attitude calculation unit 35 of the numerical control device 3. By the same procedure, the axis movement amount vector of each control axis and the pre-movement position vector of each machine element are generated in the same cycle as the interpolation cycle in the numerical control device 3. The movement amount position calculation unit 55A transmits the generated axis movement amount vector and the pre-movement position vector to the check support information generation unit 54. The procedure for generating interference check support information in the check support information generation unit 54 based on the axis movement amount vector and the pre-movement position vector transmitted from the movement amount position calculation unit 55A is the same as that in the first embodiment. The explanation is omitted.

In the present embodiment, the interference check support device 5A that generates interference check support information based on the numerical control program stored in the machining program memory 31 is configured separately from the numerical control device 3A. Thereby, before starting the control of the machine tool 2 by the numerical control device 3A, more specifically, at the stage where the numerical control program is created, the interference check support information can be generated based on this numerical control program. .. Therefore, according to the numerical control system 1 according to the present embodiment, it is possible to reduce the calculation load of the numerical control device 3A when controlling the machine tool 2 as compared with the numerical control system 1 according to the first embodiment. can.

The present disclosure is not limited to the above embodiment, and various modifications and modifications are possible. For example, in the first embodiment, the check support information generation unit 54 stores the generated check support information in the third storage unit 53, and the interference check unit 36 reads the check support information stored in the third storage unit 53. The case where the interference check calculation is performed has been described above, but the present invention is not limited to this. The check support information generated by the check support information generation unit 54 may be transmitted to the interference check unit 36 without going through the third storage unit 53.

1,1A ... Numerical control system 2 ... Machine tool 3,3A ... Numerical control device 31 ... Machining program memory 32 ... Command analysis unit 33 ... Interpretation unit 34 ... Pulse generation unit 35 ... Position and orientation calculation unit 36 ... Interference check unit 37 ... Shape storage unit 5,5A ... Interference check support device 51 ... 1st storage unit 52 ... 2nd storage unit 53 ... 3rd storage unit 54 ... Check support information generation unit 54a ... Check target group extraction unit 54b ... Priority calculation unit 55A … Movement amount position calculation unit

Claims (9)

A plurality of machine elements of a machine tool are moved along a plurality of axes based on a movement command, and an interference check calculation between the two machine elements is performed for a plurality of check target sets in an order determined by a predetermined priority. Numerical control device and
A numerical control system including an interference check support device that supports the interference check calculation.
The interference check support device is
A first storage unit that stores first information that associates each axis of the machine tool with a machine element that moves along the axis among the plurality of machine elements.
A numerical control system including a priority calculation unit for calculating the priority for the plurality of check target sets based on the movement command and the first information. The numerical value according to claim 1, wherein the priority calculation unit calculates the priority for the plurality of check target sets based on the axis movement amount of each axis calculated based on the movement command and the first information. Control system. The plurality of axes are divided into a straight axis that translates the machine element along an axis and a rotation axis that rotates the machine element around the axis.
The priority calculation unit sets the priority for the check target set including the rotary machine element, which is a machine element associated with the rotary axis by the first information, and the priority for the check target set not including the rotary machine element. The numerical control system according to claim 2, which is higher than the above. The priority calculation unit
The machine element order for each axis and each machine element associated with the first information is calculated in descending order from the axis having the largest amount of axis movement.
The numerical control system according to claim 2 or 3, wherein the priority is calculated for each check target set including each machine element in descending order from the machine element having the highest machine element order. The priority calculation unit
Based on the axis movement amount, the relative axis movement amount for a plurality of sets of axis pairs is calculated.
The second or third aspect of the present invention, wherein the priority is calculated for each check target set including the combination of each axis pair and the machine element associated with the first information in descending order from the axis pair having the largest relative axis movement amount. Numerical control system. The priority calculation unit calculates a reduction rate parameter according to the reduction rate of the distance between the two machine elements constituting each check target set based on the axis movement amount and the first information, and the reduction rate parameter is calculated. The numerical control system according to claim 2, wherein the priority is calculated for each set to be checked based on the rate parameter. Further, a third storage unit for storing information regarding the priority calculated by the priority calculation unit is provided.
The numerical control system according to any one of claims 1 to 6, wherein the numerical control device refers to the information regarding the priority stored in the third storage unit and performs the interference check calculation for each check target set. .. The interference check support device is based on a second storage unit that stores second information that defines a dependency relationship between axes in the machine tool, a movement command, the first information, and the second information. Further, a check target set extraction unit for extracting one or more sets of check target sets from all combinations of the plurality of machine elements is further provided.
The numerical control system according to any one of claims 1 to 7, wherein the priority calculation unit calculates the priority for a plurality of check target sets extracted by the check target set extraction unit. A plurality of machine elements of a machine tool are moved along a plurality of axes based on a movement command, and an interference check operation between the two machine elements is performed for a plurality of check target sets in an order determined by a predetermined priority. It is an interference check support method that supports the interference check operation in a numerical control device.
The movement command and the first information associating each axis in the machine tool with the machine element moving along the axis among the plurality of machine elements are acquired.
An interference check support method for calculating the priority for the plurality of check target sets based on the movement command and the first information.

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