WO2025041213A1 - Route changing device and computer-readable recording medium - Google Patents

Abstract

A route change device according to the present disclosure comprises: a program analysis unit that sequentially reads blocks from a control program and analyzes commands by the blocks; a curve formation determination unit that, when two consecutive movement commands include an arc command, detects a reference value related to curve formation in each of the movement commands, and determines, on the basis of the reference value, whether a connecting portion of the route related to the movement commands needs to be curved; and a curve formation processing unit that determines a curve formation parameter on the basis of the reference value related to the curve for the route in which curve formation is needed, and curves the route on the basis of the determined curve formation parameter, wherein the curve formation parameter determined by the curve processing unit is the same value or increases when the reference value increases.

Description

Route change device and computer-readable recording medium

The present disclosure relates to a route change device and a computer-readable recording medium.

　Machine tool machining programs are made by combining straight line commands and circular arc commands, and the connections between them are generally discontinuous. To make the commands run smoothly and achieve machining accuracy, the command path is smoothed with a filter or curved with a spline curve (for example, Patent Document 1).

JP 2015-082251 A

At connections with arcs, the normal acceleration changes at the connection, not only when the connection is discontinuous, but even when the connection is continuous. This can easily lead to shape errors at the connection, degrading machining accuracy. This makes it necessary to curve the connection. When straight lines are connected discontinuously, the connection is curved according to a specified tolerance (the maximum deviation between the original path and the curve). On the other hand, when arcs are connected to each other, the connection needs to be curved so as not to significantly damage the arc shape. In this case, it is difficult to curve with a constant tolerance. Therefore, there is a need for technology that can curve the connection between arcs with high accuracy.

The path change device disclosed herein solves the above problem by determining the curvature tolerance or curvature range for paths related to two consecutive movement commands, depending on at least one of the radius of curvature or the difference in curvature, the connection angle, and the distance between the arc center positions.

An aspect of the present disclosure is a path changing device that includes a program analysis unit that sequentially reads blocks from a control program and analyzes commands using the blocks; a curved path determination unit that detects, when two consecutive movement commands include a circular arc command, a reference value related to curving, including at least one of the difference in curvature or radius of curvature, the difference in angle between the direction of travel or the normal direction, and the distance between the center positions of the circular arc, in each of the movement commands, and determines whether or not curving is required at the connection portion of the path related to the movement command based on the reference value; and a curved path processing unit that determines, for a path that requires curving, a curved path parameter including at least one of a tolerance, which is the maximum deviation of the path before and after curving, and a range of curving, based on the reference value related to curving, and curves the path based on the determined curved path parameter, and the curved path parameter determined by the curved path processing unit is the same value or increases when the reference value increases.

1 is a schematic hardware configuration diagram of a route changing device according to a first embodiment; 1 is a block diagram showing schematic functions of a route changing device according to a first embodiment; FIG. 13 is a schematic diagram illustrating two connected arc paths; FIG. 13 is a schematic diagram showing another example of two connected arc paths; FIG. 13 is a schematic diagram showing another example of two connected arc paths. FIG. 13 is a schematic diagram showing another example of two connected arc paths. FIG. 13 is a schematic diagram showing another example of two connected arc paths. FIG. 13 is a table illustrating the relationship between differences in curvature radius and tolerance. FIG. 11 is a table illustrating the relationship between different connection angles and tolerances. 13 is a table illustrating an example of the relationship between the distance of the center position of an arc of a path and the tolerance. FIG. FIG. 13 is a table illustrating the relationship between different radii of curvature and curved ranges. FIG. 13 is a table illustrating the relationship between different connection angles and curved ranges. 13 is a table illustrating an example of the relationship between the distance of the arc center position of the path and the curved line range. FIG. 1 is a schematic diagram illustrating the relationship between the tolerance and the curvilinear range and a continuous path; 11A and 11B are schematic diagrams illustrating the process of enlarging/reducing a curved route. FIG. 11 is a block diagram showing schematic functions of a route changing device according to another embodiment.

Below, an embodiment of the present disclosure will be described with reference to the drawings. In the following description, components having the same or similar functions will be given the same reference numerals. Furthermore, duplicate descriptions of those components may be omitted.

In this application, "based on XX" means "based on at least XX," and includes cases where it is based on other elements 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 XX that has been calculated or processed. "XX" is any element (for example, any information).

[First embodiment]
1 is a schematic hardware configuration diagram showing a main part of a path changing device according to an embodiment of the present disclosure. The functions of the path changing device 1 of the present disclosure can be implemented on a control device that controls an industrial machine such as a machine tool or a robot equipped with a moving object that moves when driven by a motor. In addition, the functions can be implemented on a computer such as a personal computer attached to the control device, a personal computer connected to the control device via a wired/wireless network, a cell computer, a fog computer 6, or a cloud server 7. In this embodiment, the path changing device 1 in which each function is implemented on a control device that controls a machine tool that processes a workpiece by controlling the relative position between a tool and a workpiece will be described as an example.

The CPU 11 provided in the route changing device 1 of the present disclosure is a processor that controls the route changing device 1 as a whole. The CPU 11 reads the system program stored in the ROM 12 via the bus 22, and controls the route changing device 1 as a whole in accordance with the system program. The RAM 13 temporarily stores temporary calculation data, display data, various data input from outside, etc.

The non-volatile memory 14 is composed of, for example, a memory backed up by a battery (not shown) or an SSD (Solid State Drive), and retains its memory state even when the power to the route change device 1 is turned off. The non-volatile memory 14 stores control programs and data read from the external device 72 via the interface 15, data and control programs input via the input device 71, and various data acquired from the industrial machine 3. The control programs and data stored in the non-volatile memory 14 may be expanded in the RAM 13 when executed/used. In addition, various system programs such as well-known analysis programs are written in advance in the ROM 12.

The interface 15 is an interface for connecting the CPU 11 of the path change device 1 to an external device 72 such as a USB memory, a compact flash (registered trademark), or an SD card. For example, control programs and various data used to control the industrial machine 3 can be read from the external device 72. In addition, the control programs and various data edited in the path change device 1 can be stored in the external device 72. The PLC (Programmable Logic Controller) 16 outputs signals to the industrial machine 3 and its peripheral devices (for example, tool changers, actuators such as robots, sensors attached to the industrial machine 3, etc.) via the I/O unit 17 and controls them using a sequence program built into the path change device 1. The PLC 16 also receives signals from various switches on an operation panel installed on the main body of the industrial machine 3 and from peripheral devices, etc., and passes them to the CPU 11 after performing the necessary signal processing.

Display device 70 displays various data loaded into memory, data obtained as a result of executing control programs and system programs, etc., output via interface 18. In addition, input device 71, which is composed of a keyboard, pointing device, etc., passes commands and data based on operations by the operator to CPU 11 via interface 19.

The interface 20 is an interface for connecting the CPU 11 of the path change device 1 to a wired or wireless network 5. The network 5 may communicate using technologies such as serial communication such as RS-485, Ethernet (registered trademark), optical communication, wireless LAN, Wi-Fi (registered trademark), Bluetooth (registered trademark), etc. The network 5 is connected to other industrial machines 4, fog computers 6, cloud servers 7, etc., and exchanges data with the path change device 1.

The axis control circuit 30 for controlling the drive axis of the industrial machine 3 receives a drive axis position command from the CPU 11 and outputs a command for the drive axis to the servo amplifier 40. The servo amplifier 40 receives this command and drives the servo motor 50, which is the drive axis, to move each part of the industrial machine 3 along each axis. Each servo motor 50 has a built-in position detector, and feeds back a position feedback signal from this position detector to the axis control circuit 30. The axis control circuit 30 performs feedback control of the servo motor 50 based on this position feedback signal. Note that in the hardware configuration diagram of FIG. 1, only one axis control circuit 30, servo amplifier 40, and servo motor 50 are shown, but in reality, there are as many as the number of axes of the industrial machine 3 to be controlled. For example, when controlling a general machine tool with three linear axes, three sets of axis control circuits 30, servo amplifiers 40, and servo motors 50 are prepared to relatively move the spindle to which the tool is attached and the workpiece in the directions of the three linear axes (X-axis, Y-axis, and Z-axis).

The spindle control circuit 60 receives a spindle rotation command and outputs a spindle speed signal to the spindle amplifier 61. The spindle amplifier 61 receives this spindle speed signal and rotates the spindle motor 62 of the industrial machine 3 at the commanded rotation speed to drive the spindle. A position coder 63 is connected to the spindle motor 62. The position coder 63 outputs a feedback pulse in synchronization with the rotation of the spindle, and the feedback pulse is read by the CPU 11.

FIG. 2 is a schematic block diagram showing the functions of the route changing device 1 according to the first embodiment of the present disclosure. Each function of the route changing device 1 according to this embodiment is realized by the CPU 11 of the route changing device 1 shown in FIG. 1 executing a system program and controlling the operation of each part of the route changing device 1.

The path change device 1 of this embodiment includes a program analysis unit 100, a curve formation determination unit 110, a curve formation processing unit 120, an interpolation unit 130, an acceleration/deceleration unit 140, and a servo control unit 150. In addition, the RAM 13 to the non-volatile memory 14 of the path change device 1 store a control program 200 for controlling the industrial machine 3.

The program analysis unit 100 sequentially reads out blocks of the control program 200 and analyzes the read out blocks. Then, based on the analysis results, it creates a movement command related to a path for moving the drive unit equipped in the industrial machine 3. This path is, for example, a connection of multiple straight paths and multiple curved paths that take into account offset values such as tool diameter compensation. The program analysis unit 100 outputs the created movement command to the curved line determination unit 110.

The curved line determination unit 110 determines whether to curve the paths related to two consecutive movement commands created by the program analysis unit 100. When at least one of the two consecutive movement commands is a command for a circular arc path, the curved line determination unit 110 detects at least one of the following as a reference value for curving: the difference in the curvature or radius of curvature of the path before and after the connection point of the paths related to each movement command, the difference in the angle of the path's progression direction or normal direction, and the distance to the center position of the circular arc of the path. Then, based on the reference value for curving, it determines whether or not to curve the paths at the connection point. The curved line determination unit 110 outputs the detected reference value and the determination result of whether or not to curve to the curved line processing unit 120.

FIG. 3 is a schematic diagram illustrating two connected arc paths. In the example of FIG. 3, an arc path C _i connecting points P _i and P _i+1 and an arc path C i+1 connecting points P _i+1 and P _i+2 are connected with point P _{i+1 as} a connection point. The radius of curvature R _i of the arc path C _i is the same as the radius of curvature R i _{+1 of the arc path C i +1} . In addition, the direction of travel of the arc path C _i just before point P _{i+1 ,} which is the connection point, is the same as the direction of travel of the arc path C _{i +1} just after point P i+1 (connection angle θ _i is 0°). Furthermore, the distance between the center position of the arc path C _{i and the center position of the arc path C i+1} is 0. This indicates that the arc path C _i and the arc path C _i+1 are smoothly connected and no sudden change in curvature occurs. In this way, when all the reference values related to curving are 0, the curving judgment unit 110 may determine that curving is not necessary for the connection portion of point P _i+1 . Alternatively, the curving judgment unit 110 may determine that curving processing is to be performed using predetermined curving parameters.

FIG. 4 is a schematic diagram showing another example of two connected arc paths. In the example of FIG. 4, an arc path C _i connecting points P _i and P _i+1 and an arc path C i ₊ 1 connecting points P _i+1 and P _i+2 are connected with point P _i+1 as a connection part. The radius of curvature R _i of the arc path C _i is smaller than the radius of curvature R _{i +1 of the arc path C i} +1. In addition, the direction of travel of the arc path C _i just before point P _{i+1 ,} which is the connection part, is the same as the direction of travel of the arc path C _i+1 just after point P _i+1 (connection angle θ _i is 0°). Furthermore, the distance d _i between the center position of the arc path C _i and the center position of the arc path C i+1 is greater than 0. This indicates that although the arc path C _i and the arc path C _i+1 are smoothly connected, a sudden change in curvature occurs. In such a case, the curved line forming determination unit 110 determines that the connection part of point P _i+1 needs to be curved.

FIG. 5 is a schematic diagram showing another example of two connected arc paths. In the example of FIG. 5, an arc path C _i connecting points P _i and P _i+1 and an arc path C i ₊ 1 connecting points P _i+1 and P _i+2 are connected with point P _i+1 as a connection part. The radius of curvature R _i of the arc path C _i is the same as the radius of curvature R _{i +1 of the arc path C i+} 1. In addition, the direction of travel of the arc path C _i just before point P _i+1 , which is the connection part, is different from the direction of travel of the arc path C _{i +1} just after point P i+1 (the connection angle θ _i is 0° or more). Furthermore, the distance d _i between the center position of the arc path C _i and the center position of the arc path C i ₊₁ is greater than 0. This indicates that although there is no sudden change in curvature between the arc path C _i and the arc path C _i+1 , they are not smoothly connected at the connection point. In such a case, the curved line determination unit 110 determines that the connection part of point P _i+1 needs to be curved.

FIG. 6 is a schematic diagram showing another example of two connected arc paths. In the example of FIG. 6, an arc path C _i connecting points P _i and P _i+1 and an arc path C i ₊ 1 connecting points P _i+1 and P _i+2 are connected with point P _i+1 as a connection part. The radius of curvature R _i of the arc path C _i is smaller than the radius of curvature R _{i +1 of the arc path C i} +1. In addition, the direction of travel of the arc path C _i just before point P _{i+1 ,} which is the connection part, is different from the direction of travel of the arc path C _i+1 just after point P i+1 (the connection angle θ _i is 0° or more). Furthermore, the distance d _i between the center position of the arc path C _i and the center position of the arc path C _i+1 is greater than 0. This indicates that the arc path C _i and the arc path C _i+1 are not smoothly connected and that a sudden change in curvature also occurs. In such a case, the curved line forming determination unit 110 determines that the connection part of point P _i+1 needs to be curved.

FIG. 7 is a schematic diagram showing another example of two connected arc paths. In the example of FIG. 7, an arc path C _i connecting points P _i and P _i+1 and an arc path C i+1 connecting points P i _{+ 1} and P _i+2 are connected with point P _i+1 as a connection part. In addition, the center position of the arc path C _i and the center position of the arc path C _i+1 are located on opposite sides of the path. In such a case, the distance d _i between the arc center positions of the path becomes a very large value and cannot be used as a reference value for curving with the same criterion. Therefore, the curved path determining unit 110 may determine that curving is to be performed without imposing a limit on the tolerance. Note that, when one of the paths related to two consecutive movement commands is a straight path, the difference in the curvature or curvature radius of the path cannot be used as a reference value for curving with the same criterion. In such a case, the curve formation judgment unit 110 may regard the straight line as a circular arc with an infinite radius of curvature, and may treat the radius of curvature R _i =∞ or d _i =∞ as a special reference value for curve formation to judge whether or not curve formation is necessary.

The curved line processing unit 120 performs a curved line processing on two consecutive paths that require curved line processing. The curved line processing may use known techniques such as a smoothing filter or a spline curve. The curved line processing unit 120 determines curved line parameters including at least one of the tolerance when curved line processing (maximum deviation between the path before curved line processing and the path after curved line processing) and the range of curved line processing, depending on reference values including at least one of the difference in the curvature or radius of curvature of the paths, the difference in the angle of the path's progression direction or normal direction, and the distance to the center position of the arc of the paths. Then, the curved line processing unit 120 curves the paths related to the two consecutive movement commands based on the determined curved line parameters. The curved line processing unit 120 outputs the curved movement command to the interpolation unit 130.

The curve forming processing unit 120 may determine the tolerance T of the curve forming using a table or a formula that defines the relationship between the reference value and the tolerance T of the curve forming. FIG. 8 is a table diagram illustrating the relationship between the difference in the radius of curvature and the tolerance T. Moreover, the following formula 1 shows an example of a formula that defines the relationship between the difference in the radius of curvature and the tolerance T. In FIG. 8 and formula 1, the smaller radius of curvature of the radii of curvature R _i and R _i+1 of two consecutive curved paths is indicated as R _s and the larger radius of curvature is indicated as R _l . As illustrated in FIG. 8 and formula 1, it is desirable to increase the value of the tolerance T as the difference between the radius of curvature R _i of the previous arc path C _i and the radius of curvature R _{i+ 1 of the subsequent arc path C i} +1 increases. With regard to this relationship, an appropriate relationship between the difference in the radius of curvature and the tolerance T may be obtained in advance by an experiment or the like.

FIG. 9 is a table illustrating the relationship between the difference in connection angle and the tolerance T. The following formula 2 shows an example of a formula that defines the relationship between the difference in connection angle and the tolerance T. In FIG. 9 and formula 2, the smaller radius of curvature of the two consecutive curved paths, R _i and R _i+1 , is indicated as R _s . As illustrated in FIG. 9 and formula 2, it is desirable to increase the value of the tolerance T as the connection angle θ _i between the previous arc path C _i and the subsequent arc path C _i+1 increases. With regard to this relationship, it is sufficient to obtain an appropriate relationship between the difference in connection angle and the tolerance T in advance by an experiment or the like.

FIG. 10 is a table illustrating the relationship between the distance d _i of the arc center position of the path and the tolerance T. Moreover, the following formula 3 shows an example of a formula that defines the relationship between the distance of the arc center position of the path and the tolerance T. In FIG. 10 and formula 3, the smaller radius of curvature of the radii of curvature R _i and R _i+1 of two consecutive curved paths is indicated as R _s . As illustrated in FIG. 10 and formula 3, it is desirable that the value of the tolerance T increases as the distance d _i of the arc center position of the path increases. With regard to this relationship, it is sufficient to obtain an appropriate relationship between the difference in connection angle and the tolerance T in advance by experiments or the like.

A table or formula may be prepared that defines the relationship between the combination of multiple reference values and the tolerance T for curved line formation. Even in such a case, the relationship between the appropriate multiple reference values and the tolerance T can be determined in advance through experiments or the like and then defined.

The curved line processing unit 120 may determine the curved line range L using a table or a formula that defines the relationship between the reference value and the curved line range L. FIG. 11 is a table diagram illustrating the relationship between the difference in the curvature radius and the curved line range L. Moreover, the following formula 4 shows an example of a formula that defines the relationship between the difference in the curvature radius and the curved line range L. In addition, in FIG. 11 and formula 4, the smaller curvature radius of the two consecutive curved paths, R _i and R _i+1 , is indicated as R _s and the larger curvature radius is indicated as R _l . As illustrated in FIG. 11 and formula 4, it is desirable to increase the value of the curved line range L as the difference between the curvature radius R _i of the previous arc path C _i and the curvature radius R _i+1 of the subsequent arc path C _i+1 increases. With regard to this relationship, it is sufficient to obtain an appropriate relationship between the difference in the curvature radius and the curved line range L by an experiment or the like in advance.

FIG. 12 is a table illustrating the relationship between the difference in connection angle and the range L of curvature. The following formula 5 shows an example of a formula that defines the relationship between the difference in connection angle and the range L of curvature. In FIG. 12 and formula 5, the smaller radius of curvature of the two consecutive curved paths, R _i and R _i+1 , is indicated as R _s . As illustrated in FIG. 12 and formula 4, it is desirable that the larger the connection angle θ _i between the previous arc path C _i and the subsequent arc path C _i+1 , the larger the value of the range L of curvature. With regard to this relationship, it is sufficient to obtain an appropriate relationship between the difference in connection angle and the range L of curvature in advance by experiments or the like.

Fig. 13 is a table diagram illustrating an example of the relationship between the distance d _i of the arc center position of the path and the curved line range L. Moreover, the following formula 6 shows an example of a formula that defines the relationship between the distance of the arc center position of the path and the curved line range L. As illustrated in Fig. 13 and formula 6, it is desirable that the value of the curved line range L increases as the distance d _i of the arc center position of the path increases. Regarding this relationship, an appropriate relationship between the distance of the arc center position and the curved line range L can be obtained in advance by experiments or the like.

A table or formula may be prepared that defines the relationship between the combination of multiple reference values and the range L of the curve. Even in such a case, the relationship between the appropriate multiple reference values and the range L of the curve can be determined and defined in advance through experiments, etc.

Fig. 14 is a schematic diagram illustrating the relationship between the tolerance T, the curved range L, and a continuous path. In Fig. 14, the solid lines indicate two continuous paths C _i and C _i+1 instructed by a block of the control program 200. The dotted lines indicate a path S _i generated by curved processing. As shown in Fig. 14, curved processing is performed over a curved range L from C _i L/(C _i +C _i+1 ) before the connection point of the two continuous paths C _i and C i ₊ 1 to C _i+1 L/(C _i +C _i+1 ) after the connection point. At this time, the curved processing may be performed with the tolerance T set as the maximum deviation from the original path.

The interpolation unit 130 performs an interpolation process to calculate the amount of movement for each axis of the industrial machine 3 per interpolation cycle. Then, it creates movement command data indicating the amount of movement for each axis per interpolation cycle. The interpolation unit 130 outputs the created movement command data for each interpolation cycle to the acceleration/deceleration unit 140.

The acceleration/deceleration unit 140 performs post-interpolation acceleration/deceleration processing to adjust the amount of movement for each interpolation cycle for the movement command data for each interpolation cycle created by the interpolation unit 130. The post-interpolation acceleration/deceleration processing performed by the acceleration/deceleration unit 140 suppresses the magnitude of the first-order differential value in the movement of the drive unit along a specified axis based on the movement command data by, for example, applying an average filter to the movement command data for each interpolation cycle. The acceleration/deceleration unit 140 outputs the movement command data for each interpolation cycle that has been subjected to acceleration/deceleration processing to the servo control unit 150.

The servo control unit 150 controls each servo motor 50 so that the drive unit of the industrial machine 3 moves along each axis based on the movement command data for each interpolation period input from the acceleration/deceleration unit 140.

The path change device 1 according to this embodiment, which is configured as described above, can select appropriate curved line parameters for each continuous path commanded by a block of the control program 200 that includes an arc, and perform the curved line processing. This reduces the change in acceleration that occurs at the connection of the blocks, and is expected to improve the machining accuracy.

[Second embodiment]
The following describes the route changing device 1 according to the second embodiment. The route changing device 1 according to the present embodiment determines a reference radius _R0 when making two consecutive routes into a curve, and makes the route into a curve based on this reference radius _R0 .

The path changing device 1 according to the second embodiment of the present disclosure, like the path changing device 1 according to the first embodiment, includes a program analysis unit 100, a curve forming determination unit 110, a curve forming processing unit 120, an interpolation unit 130, an acceleration/deceleration unit 140, and a servo control unit 150. In addition, the RAM 13 to the non-volatile memory 14 of the path changing device 1 store a control program 200 for controlling the industrial machine 3.

The program analysis unit 100, curved line determination unit 110, interpolation unit 130, acceleration/deceleration unit 140, and servo control unit 150 of this embodiment have the same functions as the program analysis unit 100, curved line determination unit 110, interpolation unit 130, acceleration/deceleration unit 140, and servo control unit 150 of the first embodiment.

When performing curved line processing between paths related to two consecutive movement commands, the curved line processing unit 120 according to this embodiment enlarges or reduces the curved line having a smaller radius of curvature among the paths so that the radius of curvature is the same as that of a circle having a predetermined reference radius _R0 . The reference radius _R0 is set to an appropriate value (e.g., 10 mm) according to the parameter value used in the curved line processing. The other path is also enlarged or reduced at the same ratio before the curved line processing is performed. After the curved line processing, each path is reduced or enlarged at the opposite ratio.

FIG. 15 is a schematic diagram for explaining the enlargement/reduction process of a curved path. In the example of FIG. 15, an arc path C _i connecting points P _i and P _i+1 and an arc path C i ₊₁ connecting points P _i+1 and P _i+2 are connected with point P _i+1 as a connection part. The radius of curvature R _i of the arc path C _i is smaller than the radius of curvature R i _{+1 of the arc path C i +1} . Hereinafter, the radius of curvature R _i of the arc path C _i is represented as R _S and the radius of curvature R _i of the arc path C _i is represented as R _l . The dotted circle shown in the lower right of FIG. 15 is a circle with a predetermined reference radius R ₀ that is determined in advance. Before performing the curved path processing, the curved path processing unit 120 enlarges or reduces the arc path with the smaller radius of curvature so that the radius of curvature is the same as the reference radius R ₀ . In the example of Fig. 15, since the arc path C _i has a small radius of curvature, an arc path C _{i '} is created by multiplying (enlarging) the arc path C _i by R ₀ /R _s . Then, an arc path C _{i+1 '} is created by similarly multiplying (enlarging) the other path, the arc path C _i+1 , by R ₀ /R _s , and connected to the arc path C _i ' at the same connection angle as before the enlargement. The curve processing unit 120 performs curve processing on the two consecutive arc paths thus enlarged in the same manner as described in the first embodiment. Then, the path after the curve processing is reduced by R _s /R ₀ times.

When a route is enlarged to form a curve, the tolerance T may become larger than expected. In such a case, a tolerance limit value _Tmax is set in advance, and if the tolerance T set during the curve forming process exceeds the tolerance limit value _Tmax , the enlarged route is reduced by _Tmax /T before the curve forming process is performed.

The path changing device 1 according to the present embodiment having the above configuration performs a curved line processing on a path that has been enlarged or reduced in accordance with a circle of a predetermined reference radius _R0 , so that the ratio of the tolerance and length with respect to the radius of curvature becomes constant, and the visual balance of the arc shape is maintained. In general, as the radius of the arc becomes smaller, the feed rate also decreases, so the machining shape precision is maintained, and it can be expected that more appropriate curved line processing can be performed.

[Third embodiment]
The following describes a route changing device 1 according to a third embodiment. The route changing device 1 according to the present embodiment adjusts the speed at a curved portion when two consecutive routes are curved.

The path changing device 1 according to the third embodiment of the present disclosure, like the path changing device 1 according to the first embodiment, includes a program analysis unit 100, a curve forming determination unit 110, a curve forming processing unit 120, an interpolation unit 130, an acceleration/deceleration unit 140, and a servo control unit 150. In addition, the RAM 13 to the non-volatile memory 14 of the path changing device 1 store a control program 200 for controlling the industrial machine 3.

The program analysis unit 100, curved line determination unit 110, interpolation unit 130, acceleration/deceleration unit 140, and servo control unit 150 of this embodiment have the same functions as the program analysis unit 100, curved line determination unit 110, interpolation unit 130, acceleration/deceleration unit 140, and servo control unit 150 of the first embodiment.

When performing curved processing between paths related to two consecutive movement commands, the curved processing unit 120 according to this embodiment adjusts the feed speed before and after the connection part of the paths so that the feed speed changes monotonically from the feed speed before the connection part to the feed speed after the connection part. For example, when connecting an arc with a small radius of curvature to an arc with a large radius of curvature with a curve, the feed speed on the inserted curve continues to increase gradually without decreasing midway. In general, the feed speed of the arc part becomes smaller as the radius of curvature becomes smaller. Therefore, at the connection part of two consecutive paths with different curvatures, a sudden change in feed speed occurs. Therefore, the acceleration and deceleration are adjusted so that the feed speed changes gradually to prevent a sudden change in feed speed. This adjustment may be performed by adjusting the normal acceleration. The normal acceleration A when moving along an arc path can be expressed by the following equation 7, where the feed speed is V and the radius of curvature is R. The curved line processing unit 120 according to this embodiment may adjust the feed speed V so that, for example, in the curved line range L, the normal acceleration changes gradually from the normal acceleration before the connection to the normal acceleration after the connection.

The path changing device 1 according to this embodiment, which is configured as described above, adjusts the feed speed on a curved path so that the speed does not change suddenly before and after the connection. This is expected to suppress sudden changes in acceleration that occur at the connection of machining blocks that involve arcs, improving machining accuracy, and minimizing deterioration of the shape of the arc.

[Other embodiments]
In the above embodiment, an example is shown in which the path changing device 1 according to the present disclosure is implemented on a control device of an industrial machine. However, as illustrated in FIG. 16, the functions up to the curved line processing may be implemented on a computer. In such a configuration, the path changing device 1 reads each block of the control program 200 and creates a movement command that has been subjected to the curved line processing. The created movement command may then be passed to the control device 2 for use in controlling the industrial machine 3. At this time, the path changing device 1 may pass the curved line movement command to the control device 2 via the network 5, or may cause the control device 2 to read the curved line movement command stored in the external device 72.

Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments, without departing from the gist of the invention, or without departing from the idea and intent of the present disclosure derived from the contents described in the claims and their equivalents. For example, in the above-mentioned embodiments, the order of each operation and the order of each process are shown as examples, and are not limited to these. The same applies when numerical values or formulas are used in the explanation of the above-mentioned embodiments.

Below, notes relating to embodiments of the present disclosure are provided.
(Appendix 1)
A path changing device (1) according to one aspect of the present disclosure includes a program analysis unit (100) that sequentially reads blocks from a control program (200) and analyzes commands using the blocks; a curvature determination unit (110) that, when two consecutive movement commands include arc commands, detects reference values related to curvature, including at least one of a difference in curvature or radius of curvature, a difference in angle between the direction of travel or the normal direction, and a distance between arc center positions, in each of the movement commands, and determines whether or not curvature is required at a connection portion of the paths related to the movement commands based on the reference values; and a curvature processing unit (120) that determines curvature parameters for a path that requires curvature, including at least one of a tolerance, which is a maximum deviation of the path before and after curving, and a curvature range, based on the reference values related to curvature, and curves the path based on the determined curvature parameters, and the curvature parameters determined by the curvature processing unit (120) remain the same or increase when the reference value increases.

(Appendix 2)
The curve forming determination unit (110) provided in a route changing device (1) according to another aspect of the present disclosure determines that curve forming should be performed using a predetermined curve forming parameter when the reference value for the curve forming is 0.
(Appendix 3)
The curve forming processing unit (120) provided in a path changing device (1) according to another aspect of the present disclosure enlarges or reduces the path related to the movement command to fit a circle of a predetermined reference radius, curves the enlarged or reduced path, and then reduces or enlarges the curved path.

(Appendix 4)
The curve forming processing unit (120) provided in a route changing device (1) according to another aspect of the present disclosure reduces the enlarged route and then curves the route so as not to exceed a predetermined tolerance limit value.
(Appendix 5)
A path change device (1) according to another aspect of the present disclosure adjusts the feed speed so that the feed speed before and after the connection part of the path changes monotonically.
,
The route changing device according to claim 1 .
(Appendix 6)
A path change device (1) according to another aspect of the present disclosure adjusts the feed speed so that the normal acceleration before and after the connection part of the path changes gradually.

(Appendix 7)
A computer-readable recording medium according to one aspect of the present disclosure causes a computer to function as: a program analysis unit (100) that sequentially reads blocks from a control program (200) and analyzes commands using the blocks; a curvature determination unit (110) that, when two consecutive movement commands include arc commands, detects reference values related to curvature, including at least one of the difference in curvature or radius of curvature, the difference in angle between the traveling direction or normal direction, and the distance between arc center positions, in each of the movement commands, and determines whether or not curvature is required at a connection portion of paths related to the movement commands based on the reference values; and a curvature processing unit (120) that determines curvature parameters for a path that requires curvature, including at least one of a tolerance, which is the maximum deviation of the path before and after curving, and a curvature range, based on the reference values related to curvature, and curves the path based on the determined curvature parameters, and the curvature parameters determined by the curvature processing unit (120) remain the same or increase when the reference value increases.

REFERENCE SIGNS LIST 1 Route change device 3 Industrial machine 4 Industrial machine 5 Network 6 Fog computer 7 Cloud server 11 CPU
12 ROM
13 RAM
14 Non-volatile memory 15, 18, 19, 20 Interface 16 PLC
17 I/O unit 22 Bus 30 Axis control circuit 40 Servo amplifier 50 Servo motor 60 Spindle control circuit 61 Spindle amplifier 62 Spindle motor 63 Position coder 70 Display device 71 Input device 72 External device 100 Program analysis section 110 Curve forming determination section 120 Curve forming processing section 130 Interpolation section 140 Acceleration/deceleration section 150 Servo control section 200 Control program

Claims (7)

a program analysis unit that sequentially reads blocks from a control program and analyzes commands based on the blocks;
a curved path determination unit which, when two successive movement commands include a circular arc command, detects a reference value relating to curved path formation, including at least one of a difference in curvature or a radius of curvature, a difference in an angle between a moving direction or a normal direction, and a distance between circular arc center positions, in each of the movement commands, and determines whether or not curved path formation is required at a connection portion of the paths related to the movement commands based on the reference value;
a curving processing unit that determines, for a route requiring curving, curvature parameters including at least one of a tolerance that is a maximum deviation amount of the route before and after curving and a range to be curved, based on the reference value related to curvature, and curves the route based on the determined curvature parameters;
Equipped with
the curve fitting parameter determined by the curve fitting processing unit is the same value or increases when the reference value increases;
Route change device. the curve forming determination unit determines that curve forming should be performed using a predetermined curve forming parameter when the reference value related to the curve forming is 0;
The route changing device according to claim 1 . the curved path processing unit enlarges or reduces the path related to the movement command in accordance with a circle having a predetermined reference radius, curves the enlarged or reduced path, and then reduces or enlarges the curved path.
The route changing device according to claim 1 . the curved path processing unit reduces the enlarged path and then curves the path so as not to exceed a predetermined tolerance limit value.
The route changing device according to claim 3 . Adjusting the feed rate so that the feed rate before and after the connection portion of the path changes monotonically.
The route changing device according to claim 1 . adjusting the feed rate so that the normal acceleration before and after the connection part of the path changes gradually;
The route changing device according to claim 1 . a program analysis unit that sequentially reads blocks from the control program and analyzes commands based on the blocks;
a curved line forming determination unit which, when two successive motion commands include a circular arc command, detects a reference value relating to curved line forming, including at least one of a difference in curvature or a radius of curvature, a difference in an angle between a moving direction or a normal direction, and a distance between a circular arc center position, in each of the two successive motion commands, and determines whether or not curved line forming is required at a connection portion of the paths related to the motion commands based on the reference value;
a curvature processing unit that determines, for a route requiring curvature, curvature parameters including at least one of a tolerance that is a maximum deviation amount of the route before and after curvature and a range to be curved, based on the reference value related to curvature, and curves the route based on the determined curvature parameters;
The computer functions as
the curve fitting parameter determined by the curve fitting processing unit is the same value or increases when the reference value increases;
A computer-readable recording medium on which a program is recorded.

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