Line tracking method and line tracking system

Abstract

Provided is a line tracking method in which a sub-drive device (12) for driving a tool (17) in a direction parallel to a machining surface of a workpiece (W) and a main drive device (11) for driving the sub-drive device in three-axis directions (XYZ) that are orthogonal to each other are used, while the main drive device drives the sub-drive device along a basic trajectory (BT). In the route tracking method, when the position of the tool (17) driven by the sub-drive device (12) is included in a limit region of a movable range of the tool in one of the X-axis direction and the Y-axis direction, the tool (17) is driven by the sub-drive device (12) along a target trajectory (TT) while the tool (17) is driven by the sub-drive device (12) along the target trajectory (TT), and when the position of the tool (17) driven by the sub-drive device (12) is included in the limit region of the movable range of the tool in one of the X-axis direction and the Y-axis direction. When the drive direction of the tool driven by the sub-drive device faces the limit of the limit region, a drive command value to the sub-drive device with respect to the X-axis direction or the Y-axis direction is reduced.

Description

Technical Field

[0001] This invention relates to a line tracking method and a line tracking system, for example, to a line tracking method and a line tracking system preferably used to move tools such as machining tools or adhesive application nozzles relative to a target track set on the main surface of a workpiece. Background Technology

[0002] As a conventional path tracing method, a method for creating an NC program for successive forming is known (Patent Document 1). This method extracts successive forming parts from the three-dimensional CAD data of the product, determines the processing conditions for the extracted successive forming parts, decomposes the extracted successive forming parts into unit shapes, and calculates the movement trajectory of the successive forming tool corresponding to each unit shape based on the processing conditions.

[0003] Patent Document 1: Japanese Patent Application Publication No. 11-327619 Summary of the Invention

[0004] However, the aforementioned prior art involves creating NC programs for sequential forming, using CNC machining centers such as multi-joint robots to move the tool along the trajectory of the created NC program. Furthermore, the NC machining center repeatedly performs these actions, decelerating, accelerating, or temporarily stopping the tool to ensure it accurately follows the trajectory. Therefore, the aforementioned prior art suffers from the problem that it cannot address situations where there are setup errors in the machining center or the workpiece.

[0005] The problem this invention aims to solve is to provide a line tracking method and system that can cope with errors even if there are settings errors in the processing machine or workpiece.

[0006] The present invention solves the above-mentioned problem by means of the following: when the position of the tool driven by the auxiliary drive device is contained in the limit region of the movable range of the tool in one of the X-axis direction or the Y-axis direction, and the driving direction of the tool driven by the auxiliary drive device is toward the limit of the limit region, the driving command value to the auxiliary drive device relative to the X-axis direction or the Y-axis direction is reduced.

[0007] The effects of the invention

[0008] According to the present invention, even if there are setting errors in the processing machine or workpiece, it is possible to cope with them. Attached Figure Description

[0009] Figure 1A This is a front view showing the line tracing system according to an embodiment of the present invention.

[0010] Figure 1B yes Figure 1A The right-side view.

[0011] Figure 1C yes Figure 1A A bottom view.

[0012] Figure 1D yes Figure 1B A bottom view.

[0013] Figure 2 This is a perspective view showing an example of a track setting device according to an embodiment of the present invention.

[0014] Figure 3 This is a diagram illustrating a method for detecting a target track using a first track detection device and a second track detection device, and a method for driving a tool using the results, according to an embodiment of the present invention (a top view of the machined surface of the workpiece).

[0015] Figure 4 This is a top view showing the target track, the movable range of the auxiliary drive device, and the basic track involved in the embodiments of the present invention.

[0016] Figure 5 This is a top view illustrating the driving of a tool on a basic track according to an embodiment of the present invention.

[0017] Figure 6 This is a top view showing the auxiliary drive unit and tool used to illustrate defects in the boundary area of ​​the movable range.

[0018] Figure 7 This is a top view showing the operation of the tool performed by the line tracing system and line tracing method according to embodiments of the present invention.

[0019] Figure 8 This is a flowchart illustrating the process performed by the control device according to an embodiment of the present invention.

[0020] Figure 9 This is a top view showing the operation of the tool performed by the line tracing system and line tracing method according to embodiments of the present invention. Detailed Implementation

[0021] Hereinafter, examples of embodiments for carrying out the present invention will be described with reference to the accompanying drawings. Figure 1A This is a front view showing one implementation of a line tracing system. Figure 1B yes Figure 1A The right-side view, Figure 1C yes Figure 1A The bottom view, Figure 1D yes Figure 1BThe image shows a bottom view. Furthermore, the driving direction of the tool 17 driven by the secondary drive unit 12 of the line tracking system 1 according to this embodiment is represented using the X-axis and Y-axis, and the driving direction of the secondary drive unit 12 driven by the primary drive unit 11 is represented using a three-dimensional space with a Z-axis added to the aforementioned X-axis and Y-axis. In this specification, "drive" means to provide power and cause movement, and "move" means to cause displacement or to cause a displacement; for example, it is expressed as "the secondary drive unit 12 drives the tool 17 according to the drive command value from the control unit 16, thereby moving the tool 17 along the X-axis direction." Depending on the situation, the same meaning may also be used.

[0022] The line tracking system 1 of this embodiment can be applied, for example, to a successive forming process in which a machining tool is moved relative to a metal sheet serving as a workpiece to perform plastic forming on the metal sheet, or to a coating process in which a nozzle is moved relative to a workpiece to apply an adhesive or sealant to the workpiece. Hereinafter, embodiments of the line tracking system of the present invention will be described in the context of a process in which a metal sheet serving as a workpiece is successively formed into a predetermined product shape.

[0023] The track tracking system 1 involved in this embodiment includes a main drive device 11, a secondary drive device 12, a track setting device 13, a first track detection device 14, a second track detection device 15, and a control device 16.

[0024] The main drive unit 11 in this embodiment is a drive unit that drives the auxiliary drive unit 12 along three orthogonal axes, and can be used with CNC machining centers such as articulated industrial robots or NC machine tools. For example, when using an industrial robot as the main drive unit 11, the auxiliary drive unit 12 is mounted on the robot's manipulator 111. Thus, the auxiliary drive unit 12 can be driven along three orthogonal axes (X-axis, Y-axis, and Z-axis directions). The main drive unit 11 may also be configured to rotate the auxiliary drive unit 12 about three orthogonal axes.

[0025] In this embodiment, the secondary drive device 12 is a secondary drive device that drives the tool 17 in a direction parallel to the workpiece W. For example... Figure 1A Front view, Figure 1B Right side view Figure 1C and Figure 1DAs shown in the bottom view, the secondary drive device 12 of this embodiment includes: a rectangular frame 121; a beam 122 held by the frame 121 and configured to reciprocate relative to the frame 121 along the X-axis; and a slider 123 held by the beam 122 and configured to reciprocate relative to the beam 122 along the Y-axis, with a tool 17 fixed to the slider 123. That is, the frame 121, beam 122, and slider 123 form an XY worktable between the main drive device 11 and the tool 17.

[0026] Between the frame 121 and beam 122 constituting the X-axis drive mechanism of the XY stage, a linear guide (not shown) is provided to allow the beam 122 to reciprocate freely relative to the frame 121 along the X-axis, and an X-axis actuator 124 is provided to allow the beam 122 to reciprocate relative to the frame 121 along the X-axis by a predetermined distance. Similarly, between the beam 122 and slider 123 constituting the Y-axis drive mechanism of the XY stage, a linear guide (not shown) is provided to allow the slider 123 to reciprocate freely relative to the beam 122 along the Y-axis, and a Y-axis actuator 125 is provided to allow the slider 123 to reciprocate freely relative to the beam 122 along the Y-axis by a predetermined distance. Thus, the tool 17, fixed to the slider 123, can be driven relative to the main drive unit 11, which is fixed to the frame 121, along two axes (X-axis and Y-axis) horizontally to the machining surface of the workpiece W.

[0027] In addition, such as only Figure 1A As shown, the workpiece W, made of a metal plate such as steel or aluminum, is horizontally positioned below the auxiliary drive unit 12, restrained by the clamp 2. Furthermore, a rod-shaped tool 17 with a suitably shaped front end is held in place by the auxiliary drive unit 12 with its front end facing downwards.

[0028] The track setting device 13 of this embodiment is a device that sets the target track TT of the tool 17 on the machining surface of the workpiece W in a detectable manner. Examples include a device that directly draws the target track TT on the workpiece W, a device that displays the target track TT by scanning with a laser, and a device that projects the target track TT onto the workpiece W. Figure 2 This is a perspective view showing an example of the track setting device 13 of this embodiment. The track setting device 13 shown is a projection device that projects a target track TT corresponding to the shape of the forming part onto the machining surface of the workpiece W by laser scanning. Furthermore, the track setting device 13 of this embodiment is not a necessary structure for the line tracking system 1, and can be appropriately omitted when the target track TT is set in the previous process, etc.

[0029] like Figures 1A to 1DAs shown, in this embodiment, the first track detection device 14 is fixed to the slider 123 on which the tool 17 is fixed, with its line of sight facing the Y-axis direction. It moves together with the tool 17 to detect the target track TT in the X-axis direction relative to the workpiece W, and outputs the detection result to the control device 16. Based on the detection result of the first track detection device 14, the control device 16 controls the X-axis actuator 124 to drive the tool 17 along the X-axis direction. The first track detection device 14 in this embodiment can be configured with a CCD camera or the like, and can capture images of a certain area including the front end of the tool 17 and the machined surface of the workpiece W.

[0030] In addition, such as Figure 1A and Figure 1B As shown, in this embodiment, the second track detection device 15 is fixed to the slider 123 on which the tool 17 is fixed, with its line of sight facing the X-axis direction. It moves together with the tool 17 to detect the target track TT in the Y-axis direction relative to the workpiece W, and outputs the detection result to the control device 16. Based on the detection result of the second track detection device 15, the control device 16 controls the Y-axis actuator 125 to drive the tool 17 along the Y-axis direction. The second track detection device 15 in this embodiment can be configured with a CCD camera or the like, and can capture images of a certain area including the front end of the tool 17 and the machined surface of the workpiece W.

[0031] Figure 3 This diagram illustrates the method for detecting the target trajectory TT using the first trajectory detection device 14 and the second trajectory detection device 15, and the method for driving the tool 17 using the results, in this embodiment. It is a top-view diagram of the machined surface of the workpiece W. In the trajectory tracking system 1 of this embodiment, the two first trajectory detection devices 14 and the second trajectory detection device 15 are configured to capture images of the tool 17 and the target trajectory TT from mutually orthogonal directions.

[0032] In this graph, if the horizontal axis is set as the X-axis and the vertical axis as the Y-axis, then as follows: Figure 3 As shown in the upper left figure, a first track detection device 14 detects the target track TT within a detection area R1 containing the tool 17. Furthermore, as... Figure 3 As shown in the lower left figure, at least two locations around the tool 17 in the X-axis direction of the workpiece W, and more preferably two locations before and after the movement direction of the tool 17, are set to the front detection area A1 and the rear detection area A2 through which the target track TT passes.

[0033] In contrast, such as Figure 3 As shown in the upper left figure, another second track detection device 15 detects the target track TT within the detection area R2 containing tool 17. Furthermore, as... Figure 3As shown in the upper right figure, at least two locations around the tool 17 in the Y-axis direction of the workpiece W, and more preferably two locations before and after the movement direction of the tool 17, are set to the front detection area A1 and the rear detection area A2 through which the target track TT passes.

[0034] The track tracking system 1 of this embodiment determines the target position Pt of the tool 17 based on the positions P1 and P2 of the target track TT detected by the first track detection device 14 and the second track detection device 15 in their respective detection areas A1 and A2. The target position Pt at this time can be, for example, the midpoint of the straight line connecting the two positions P1 and P2.

[0035] And, as Figure 3 As shown in the lower right figure, a drive command value corresponding to the X-axis movement L1 of tool 17 determined based on data from the first track detection device 14 is output to the X-axis actuator 124, driving beam 122 along the X-axis. Simultaneously, a drive command value corresponding to the Y-axis movement L2 of tool 17 determined based on data from the second track detection device 15 is output to the Y-axis actuator 125, driving slider 123 along the Y-axis. Thus, by simultaneously driving beam 122 and slider 123 along the X-axis and Y-axis respectively, their combined vector becomes the actual movement Lt of tool 17, which moves along the target track TT. Specifically, by decomposing the movement of tool 17 into movement along the X-axis and Y-axis, and controlling each actuator using the XY stage, X-axis actuator 124, and Y-axis actuator 125, the control content is significantly simplified, and the control responsiveness is improved.

[0036] return Figure 1A The control device 16 in this embodiment is composed of a computer including a ROM storing software, RAM as a temporary storage device, and a CPU. Based on the detection results of the first track detection device 14 and the second track detection device 15, it controls the main drive device 11 and the sub-drive device 12. In addition to sharing the structure mounted on the main drive device 11, the control device 16 in this embodiment can also be configured to independently control the main drive device 11 and the sub-drive device 12.

[0037] In order to perform the following line tracking method, the control device 16 of this embodiment has the following functions: setting a target track TT corresponding to the shape of the forming part in the workpiece W; setting the movable range of the tool 17 implemented by the sub-drive device 12 with the target track TT as a reference; setting the basic track BT of the sub-drive device 12 implemented by the main drive device 11 within the movable range; and driving the sub-drive device 12 along the basic track BT by the main drive device 11 while driving the tool 17 along the target track TT by the sub-drive device 12.

[0038] Figure 4 This is a top view showing the target track TT, the movable range of the auxiliary drive device 12, and the basic track BT. In the line tracking method of this embodiment, as... Figure 4 As shown, a target track TT is set that corresponds to the shape of the forming part in workpiece W. The forming part shown is the outer hood panel of a car, with the upper side representing the front of the car body. The target track TT shown is a track along the contour of the forming part, i.e., the outer hood panel.

[0039] Next, in the path tracing method of this embodiment, the target trajectory TT is used as a reference, and the full range of motion (the area shaded in gray) E of the tool T, realized by the sub-drive device 12, is set. In this case, the range of motion of the tool 17 at the sub-drive device 12 is as follows: Figure 4 The four parts shown are the ranges in the X-axis and Y-axis directions parallel to the workpiece W. Therefore, the entire movable range E with the target track TT as the reference is the overall area when the center of the auxiliary drive device 12 moves along the target track TT, and has a certain width on both sides of the target track TT.

[0040] Next, in the line tracking method of this embodiment, a basic track BT of the auxiliary drive device 12, implemented by the main drive device 11, is set within the entire movable range E. The basic track BT can be simplified in shape arbitrarily compared to the target track TT, which may have a complex shape. In the illustrated example, the basic track BT is a rectangle with curvature (curves) at its corners. Furthermore, the shape of the basic track BT is not limited to the illustrated example; simple shapes such as circles or ellipses are more preferred.

[0041] When a basic track BT is set, for the main drive unit 11, in order for the center of the auxiliary drive unit 12 to move along the basic track BT, setpoints (coordinates) PP that should be passed through are set on the basic track BT. However, as described above, the basic track BT in this embodiment has a simple shape, so the number of setpoints PP can be significantly reduced. In the illustrated example, two setpoints PP are provided at each of the four corners of the basic track BT, for a total of eight setpoints, and these setpoints PP are input to the control device 16 of the main drive unit 11.

[0042] Furthermore, in the line tracking method of this embodiment, the tool 17 is pressed against the workpiece W, and while the main drive device 11 moves the secondary drive device 12 along a basic track BT of a simple shape, the secondary drive device 12 is positioned such that... Figure 5 As shown, tool 17 is driven in the direction of the arrow according to the difference and direction between the basic track BT and the target track TT. Figure 5 This is a top view showing the movement of tool 17 on the basic track BT, with arrows indicating the driving distance and direction of tool 17. At this time, the line tracking system 1 of this embodiment moves the auxiliary drive device 12 while maintaining a certain orientation through the main drive device 11, and drives tool 17 along the X-axis and Y-axis directions through the XY worktable of the auxiliary drive device 12.

[0043] Thus, while in contact with the workpiece W, the tool 17 moves along the target track TT, and then, by moving in a contour-lined circular motion, it plastically shapes a concave portion by slowly pressing down towards the bottom. Furthermore, both the target track TT and the basic track BT decrease in size with each circle of the tool 17, but the control of the tool 17's movement based on the difference between the two remains the same.

[0044] In the successive forming method using the line tracking method according to this embodiment, the number of setpoints PP on the basic track BT is significantly reduced, and consequently, the moving speed of the sub-drive device 12, implemented by the main drive device 11, can be increased accordingly. Furthermore, compared to the main drive device 11, the sub-drive device 12 has a smaller mass and higher responsiveness, thus enabling high-speed driving of the tool 17 along the target track TT while moving at high speed. Therefore, even if the forming portion of the workpiece W has a complex shape, the forming time can be shortened.

[0045] Furthermore, the successive forming method using the line tracking method described in this embodiment employs a rectangle with curvature at the corners as the shape of the basic track BT. Therefore, the control of the main drive device 11 is easy, and the forming can be performed continuously without temporarily stopping the auxiliary drive device 12 at the corners, which can contribute to further shortening the forming time.

[0046] Therefore, in the line tracing system and line tracing method of this embodiment described above, as in Figure 3 As explained earlier, by independently controlling the movement L1 in the X-axis direction and the movement L2 in the Y-axis direction, the control becomes significantly simpler and the control responsiveness is improved. However, because the movement L1 in the X-axis direction and the movement L2 in the Y-axis direction are controlled independently, malfunctions occur near the limits of mobility in each axis direction.

[0047] Figure 6 This is a top view showing the auxiliary drive unit 12 and tool 17 used to illustrate this defect. In this figure, the dashed rectangular line represents the full range of motion E of tool 17 achieved by the auxiliary drive unit 12, the reference numeral 12C indicates its movable origin, and tool 17 indicates the current position of tool 17. At the current point in time shown in the figure, if the movement L1 in the X-axis direction and the movement L2 in the Y-axis direction relative to the target track TT are calculated independently, sometimes, as shown in the figure, the movement L2 in the Y-axis direction reaches the limit of the movable range in the Y-axis direction. In this case, tool 17 is driven relative to the X-axis direction by the amount of movement L1. However, relative to the Y-axis direction, although a drive command value equivalent to the movement L2 is output to the Y-axis actuator 125, the XY table of the auxiliary drive device 12 (specifically, the slider 123 opposite to the beam 122) reaches its movable limit at both the physical and mechanical levels. Therefore, it cannot be driven by the amount of movement L2. Consequently, the actual tool 17' deviates from the target track TT, as shown in the figure. The reference numeral 17' indicates the position of the tool when its movable limit is reached.

[0048] Therefore, in the line tracking system 1 and line tracking method of this embodiment, when the position of the tool 17 driven by the auxiliary drive device 12 is contained in the limit region of the movable range of the tool 17 in either the X-axis direction or the Y-axis direction, and the driving direction of the tool 17 driven by the auxiliary drive device 12 is toward the limit of the limit region, control is performed to reduce the driving command value toward the auxiliary drive device 12 relative to either the X-axis direction or the Y-axis direction.

[0049] Here, regarding the case where the position of tool 17 is contained within the limit region of its movable range in either the X-axis or Y-axis direction, there are no particular limitations, and various margins can be set. For example, if the current position coordinate of tool 17 in the X-axis or Y-axis direction is set to P, the movable range coordinate of tool 17 in the X-axis or Y-axis direction is set to R, and the margin constant is set to a (a is a constant from 0 to 1), the position of tool 17 satisfies |P|≥|a|. In the case of R|, it can be determined that the position of the tool 17 is contained within the limit region. In this case, if the margin constant a is set to 0.9, the limit region of the movable range is the range of 10% from the movable limit.

[0050] Furthermore, the case where the driving direction of the tool 17 driven by the auxiliary drive device 12 is toward the limit of the limit region refers to the case where the tool 17 is driven further toward the limit of the limit region. And, for example, in... Figure 7In the top view representing the auxiliary drive device 12 and the tool 17, the entire movable range E of the tool 17 is represented by XY coordinates with the movable origin 12C as the origin (in the first quadrant, X and Y are both positive values; in the second quadrant, X is negative and Y is positive; in the third quadrant, X and Y are both negative values; and in the fourth quadrant, X is positive and Y is negative). With the current position coordinate of the tool 17 in the X-axis or Y-axis direction set to P, and the drive command value to the auxiliary drive device 12 set to ΔD, the tool 17's drive direction satisfies P... When ΔD≥0, it can be determined that the driving direction of tool 17 is toward the limit of the limit region.

[0051] Here, the position coordinate P of tool 17 and the drive command value ΔD are positive or negative (or 0) values ​​defined in the XY coordinate system with the aforementioned movable origin 12C as the origin. For example, if the current position coordinate P of tool 17 is in the second quadrant of the XY coordinate system (the X coordinate is negative), and it is further driven in the negative direction of the X-axis from here, ΔD becomes a negative value. Therefore, P satisfies... ΔD≥0. Therefore, in this case, the driving direction of tool 17 is toward the limit of the limit region.

[0052] The reduction control (also known as suppression control) of the drive command value in this embodiment is performed when the position of tool 17 is contained within a limit region in either the X-axis or Y-axis direction, and the drive direction of tool 17 is toward the limit of that limit region. Even when the position of tool 17 is contained within a limit region, it is not performed if the drive direction of tool 17 is not toward the limit of that limit region. Furthermore, even when the drive direction of tool 17 is toward the limit of the limit region, it is not performed if the position of tool 17 is not contained within the limit region. This is because in either of these cases, tool 17 will not reach its movable limit, or the probability of it reaching its limit is significantly low.

[0053] In this embodiment, the reduction value of the drive command value reduction control is not particularly limited, as long as it is less than the absolute value of the initially calculated drive command value. However, for example, if the current position coordinate of the tool in the X-axis or Y-axis direction is set as P, and the predetermined function that changes through the position coordinate P is set as β(P) (β(P) is a value of 0 to 1), and the drive command value to the auxiliary drive device 12 is set as ΔD, it can be reduced to satisfy ΔD´=β(P). The value of the drive instruction for ΔD.

[0054] Here, the function β(P) is defined as any function that varies from 0 to 1, without any particular limitation. However, for example, if the current position coordinates of tool 17 in the X-axis or Y-axis direction are set to P, the coordinates of the entire movable range of tool 17 in the X-axis or Y-axis direction are set to R, and any adjustment constant greater than 0 is set to γ, then the function β(P) can be set to β(P) = γ. |(RP) / R|. Here, |(RP) / R| on the right represents the ratio of the limit region to the total movable range R. The closer P is to the limit region's limit, the more β(P) converges to 0. Therefore, the closer the current position coordinate P of tool 17 is to the limit region's limit, the smaller the drive command value ΔD´ (the greater the decrease in the drive command value), thus effectively preventing tool 17 from reaching its movable limit.

[0055] Figure 7 This is a top view illustrating the operation of the tool performed by the line tracing system and line tracing method according to embodiments of the present invention. Figure 6 In the state shown, the movement L1 in the X-axis direction and the movement L2 in the Y-axis direction relative to the target track TT were independently calculated. However, as shown in the figure, the movement L2 in the Y-axis direction reached the limit of the movable range of the Y-axis. A drive command value equivalent to the movement L2 was output to the Y-axis actuator 125 relative to the Y-axis direction. However, the XY table of the auxiliary drive device 12 (specifically, the slider 123 opposite to the beam 122) reached the movable limit at the physical and mechanical levels, so it could not be driven with the amount of movement L2. Therefore, the actual tool 17' deviated relative to the target track TT, as shown in the figure.

[0056] In contrast, in this embodiment, the Y-axis movement L2 initially calculated according to the above process is reduced to L2', and a drive command value ΔD' corresponding to this movement L2' is output to the Y-axis actuator 125. As a result, the tool 17'' moves to the position obtained by combining the vectors of the X-axis movement L1 and the Y-axis movement L2'. Consequently, the tool 17'' does not reach its limit of mobility but overlaps with the target track TT.

[0057] Next, we will explain its function. Figure 8 This is a flowchart illustrating the processes performed by the control device 16 according to an embodiment of the present invention. The processes in this flowchart are performed in the control device 16 at predetermined time intervals.

[0058] First, in step S1, the movement amount ΔD of tool 17 is calculated. The calculation of this movement amount ΔD is as follows: Figure 3As explained, the movement amount ΔDx of tool 17 in the X-axis direction is determined based on the data from the first track detection device 14, and the movement amount ΔDy of tool 17 in the Y-axis direction is determined based on the data from the second track detection device 15.

[0059] In the next step S2, it is determined whether the current position of tool 17 in either the X-axis or Y-axis direction is contained within the limit region of the movable range of tool 17. Specifically, with the current position coordinate of tool 17 in either the X-axis or Y-axis direction set to P, the movable range coordinate of tool 17 in either the X-axis or Y-axis direction set to R, and the margin constant set to a (a is a constant from 0 to 1), it is determined whether the position of tool 17 satisfies |P|≥|a|. R|. Furthermore, if neither the X-axis nor the Y-axis direction is satisfied, proceed to step S4, where drive command values ​​corresponding to the movement amounts ΔDx and ΔDy calculated in step S1 are output to the X-axis actuator 124 and the Y-axis actuator 125.

[0060] Conversely, when |P|≥|a is satisfied in either the X-axis or Y-axis direction. In the case of R|, proceed to step S3 for that axis direction; for the axis direction where the condition is not met, proceed to step S4. Regarding the condition where |P|≥|a is not met... In step S4, the drive command value corresponding to the movement amount ΔDx and ΔDy calculated in step S1 is output to the X-axis actuator 124 or the Y-axis actuator 125 in the direction of the axis R|.

[0061] In the next step S3, it is determined whether the driving direction of tool 17 is towards the limit of the limit region. Specifically, with the current position coordinate of tool 17 in the X-axis or Y-axis direction set to P, and the driving command value to the auxiliary drive device 12 set to ΔD, it is determined whether the driving direction of tool 17 satisfies P. ΔD≥0. Furthermore, P is not satisfied in the driving direction of tool 17. When ΔD≥0, proceed to step S4 with respect to the axis direction. In step S4, output the drive command value corresponding to the movement ΔDx and ΔDy calculated in step S1 to the X-axis actuator 124 or the Y-axis actuator 125.

[0062] In contrast, the driving direction of tool 17 satisfies P If ΔD ≥ 0, proceed to step S5 to reduce the drive command value relative to the satisfied axis direction. Specifically, when the current position coordinate of the tool in the X-axis or Y-axis direction is set to P, and a predetermined function that changes through this position coordinate P is set to β(P) (β(P) is a value from 0 to 1), and the drive command value to the auxiliary drive device 12 is set to ΔD, reduce it until ΔD' = β(P). The driving instruction value of ΔD is ΔD´.

[0063] Therefore, as Figure 7 As shown, even if the current position of tool 17 is within the limit region of the movable range of tool 17 in the Y-axis direction (step S2), and the driving direction of tool 17 is towards the limit of the limit region (step S3), the movement amount in the Y-axis direction is reduced to L2'. Therefore, tool 17'' moves to the position after the vector combination of the movement amount L1 in the X-axis direction and the movement amount L2' in the Y-axis direction. As a result, tool 17'' will not reach the movable limit, but will overlap with the target track TT.

[0064] Figure 9 This is a top view showing the operation of the tool performed by the line tracing system 1 and line tracing method according to embodiments of the present invention. Figure 7 The diagram shows the behavior of tool 17 after the drive command value of tool 17 has been reduced. Figure 9 The left figure shows Figure 7 The tool 17 is shown at time t0 and the tool 17´´ at the next time t1. Figure 9 The middle figure shows the situation where the movable origin 12C at time t1 moves downward in the XY coordinate direction at a subsequent time t2. Figure 9 The right figure shows the situation where the movable origin 12C at time t1 moves upward in the XY coordinate direction at a subsequent time t3.

[0065] like Figure 9 As shown in the middle diagram, when the movable origin 12C at time t1 moves downwards in the XY coordinate direction at a subsequent time t2, tool 17 moves towards the movable origin 12C of the entire movable range E, thus moving away from the movable limit. Additionally, as... Figure 9 As shown in the right figure, when the movable origin 12C at time t1 moves upward in the XY coordinate direction at the subsequent time t3, the tool 17 approaches the movable limit further. However, in this case, the control of reducing the drive command value also plays a role in preventing the tool 17 from reaching the movable limit.

[0066] As described above, the path tracking system 1 and path tracking method of this embodiment use a secondary drive device 12 that drives the tool 17 along a direction parallel to the machining surface of the workpiece W, and a main drive device 11 that drives the secondary drive device 12 along three orthogonal axes XYZ. A target track TT of the tool 17 is set on the machining surface of the workpiece W in a detectable manner. Using the target track TT as a reference, the entire movable range E of the tool 17, implemented by the secondary drive device 12, is set. Within the entire movable range E, a basic track BT of the secondary drive device 12, implemented by the main drive device 11, is set. While the secondary drive device 12 is driven along the basic track BT by the main drive device 11, the tool 17 is driven along the... When the target track TT is driven, a first track detection device 14, which moves with the tool 17 and detects the position of the target track TT relative to the X-axis direction of the workpiece W, and a second track detection device 15, which moves with the tool 17 and detects the position of the target track TT relative to the Y-axis direction of the workpiece W (which is not parallel to the X-axis direction), are used. Based on the position of the target track TT relative to the X-axis direction detected by the first track detection device 14, the tool 17 is driven along the X-axis direction by the secondary drive device 12. Simultaneously, based on the position of the target track TT relative to the Y-axis direction detected by the second track detection device 15, the tool 17 is driven along the Y-axis direction by the secondary drive device 12. In this line tracing method, When the position of the tool 17 driven by the secondary drive device 12 is within the limit region of its movable range in either the X-axis or Y-axis direction, and the driving direction of the tool 17 driven by the secondary drive device 12 is towards the limit of the limit region, the drive command value to the secondary drive device 12 relative to either the X-axis or Y-axis direction is reduced. Therefore, the tool 17'' will not reach its movable limit but will overlap with the target track TT. As a result, even if there are setting errors in the machining machine or workpiece W, such as the main drive device 11 and the secondary drive device 12, it can be addressed. Furthermore, even if the workpiece W is moving, it can be addressed, further reducing training time or program creation time. Moreover, even if the target track TT of the tool 17 has a complex shape, the movement time of the tool 17 can be shortened.

[0067] Furthermore, in the line tracking system 1 and line tracking method of this embodiment, when the current position coordinates of the tool 17 in the X-axis direction or the Y-axis direction are set to P, the movable range coordinates of the tool 17 in the X-axis direction or the Y-axis direction are set to R, and the margin constant is set to a (a is a constant from 0 to 1), the position of the tool 17 satisfies |P|≥|a|. In the case of R|, it is determined that the position of tool 17 is contained within the limit region. Therefore, the margin constant can be set to the desired value, thereby enabling the setting of the desired safety rate. Furthermore, tool 17´´ will not reach its movable limit but will overlap with the target track TT. As a result, even if there are setting errors in the machining machine or workpiece W, such as the main drive unit 11 and the auxiliary drive unit 12, it can be addressed. In addition, even if the workpiece W is moving, it can be addressed, further reducing training time or program creation time. Moreover, even if the target track TT of tool 17 has a complex shape, the movement time of tool 17 can be shortened.

[0068] Furthermore, in the line tracking system 1 and line tracking method of this embodiment, when the current position coordinates of the tool 17 in the X-axis direction or the Y-axis direction are set to P, and the drive command value to the auxiliary drive device 12 is set to ΔD, the drive direction of the tool 17 satisfies P. When ΔD≥0, the driving direction of tool 17 is determined to be towards the limit of the limit region, thus the direction of tool 17 can be easily determined. Furthermore, tool 17´´ will not reach its movable limit, but will overlap with the target track TT. As a result, even if there are setting errors in the main drive unit 11 and the auxiliary drive unit 12, or in the workpiece W, these can be addressed. Additionally, even if the workpiece W is moving, this can be addressed, further reducing training time or program creation time. Moreover, even if the target track TT of tool 17 has a complex shape, the movement time of tool 17 can be shortened.

[0069] Furthermore, in the line tracking system 1 and line tracking method of this embodiment, when the current position coordinate of the tool 17 in the X-axis direction or the Y-axis direction is set to P, the predetermined function that changes through the position coordinate P is set to β(P) (β(P) is a value of 0 to 1), and the drive command value to the sub-drive device 12 is set to ΔD, the value is reduced to satisfy ΔD´=β(P). The drive command value of ΔD allows for the setting of the desired reduction value according to a predetermined function. Furthermore, tool 17´´ will not reach its movable limit but will overlap with the target track TT. As a result, even if there are setting errors in the main drive unit 11, auxiliary drive unit 12, or workpiece W, it can be addressed. Additionally, it can be addressed even if workpiece W is moving, further reducing training time or program creation time. Moreover, even if the target track TT of tool 17 has a complex shape, the movement time of tool 17 can be shortened.

[0070] Furthermore, in the line tracking system 1 and line tracking method of this embodiment, when the current position coordinates of the tool 17 in the X-axis direction or the Y-axis direction are set to P, the movable range coordinates of the tool 17 in the X-axis direction or the Y-axis direction are set to R, and any adjustment constant greater than 0 is set to γ, β(P) is set to β(P) = γ. Therefore, the closer the current position coordinate P of tool 17 is to the limit of the limit region, the smaller the drive command value ΔD´ (the greater the reduction in the drive command value). This effectively prevents tool 17 from reaching its movable limit. Furthermore, tool 17´´ will not reach its movable limit but will overlap with the target track TT. As a result, even if there are setting errors in the main drive unit 11 and the auxiliary drive unit 12, or in the workpiece W, it can be addressed. Additionally, even if the workpiece W is moving, it can be addressed, further reducing training time or program creation time. Moreover, even if the target track TT of tool 17 has a complex shape, the movement time of tool 17 can be shortened.

[0071] Furthermore, in the above embodiments, the main drive device 11 and the auxiliary drive device 12 are constituted by different devices, but a single device (e.g., a robot) may also have the functions of both the main drive device 11 and the auxiliary drive device 12.

[0072] Explanation of the label

[0073] 1…Line tracing system

[0074] 11…Main drive unit

[0075] 111…Mechanical arm

[0076] 12… Auxiliary drive unit

[0077] 12C…Modible origin

[0078] 121…Frame

[0079] 122…Liang

[0080] 123… Slider

[0081] 124…X-axis actuator

[0082] 125…Y-axis actuator

[0083] 13… Track setting device

[0084] 14…First Track Detection Device

[0085] 15…Second Track Detection Device

[0086] 16…Control device

[0087] 17… tools

[0088] 2… Fixture

[0089] W…workpiece

[0090] TT…Target Orbit

[0091] BT…Basic Track

[0092] A1, A2... Detection areas

[0093] Positions P1, P2...

[0094] Pt…Target Location

[0095] P…Set point

[0096] R1, R2... Detection areas

[0097] E…Full range of motion

Claims

1. A line tracing method, wherein, The system employs a secondary drive unit that drives the tool in a direction parallel to the workpiece's machining surface, and a main drive unit that drives the secondary drive unit in three orthogonal axial directions. The target path of the tool is set on the machined surface of the workpiece in a detectable manner. Using the target track as a reference, the full range of motion of the tool, achieved by the secondary drive device, is set. Within the entire range of motion, a basic track for the secondary drive device, implemented by the primary drive device, is established. While driving the secondary drive device along the basic track via the main drive device, the tool is also driven along the target track via the secondary drive device. A first track detection device moves with the tool to detect the position of the target track relative to the X-axis direction of the workpiece, and a second track detection device moves with the tool to detect the position of the target track relative to the Y-axis direction of the workpiece, which is not parallel to the X-axis direction. Based on the position of the target track relative to the X-axis direction detected by the first track detection device, the tool is driven along the X-axis direction by the secondary drive device. Simultaneously, based on the position of the target track relative to the Y-axis direction detected by the second track detection device, the tool is driven along the Y-axis direction by the secondary drive device. In this line tracing method, When the position of the tool driven by the secondary drive device is contained within the limit region of the tool's movable range in either the X-axis direction or the Y-axis direction, and the drive direction of the tool driven by the secondary drive device is toward the limit region, the drive command value to the secondary drive device relative to either the X-axis direction or the Y-axis direction is reduced.

2. The line tracing method according to claim 1, wherein, In a case where a current position coordinate of the X-axis direction or the Y-axis direction of the tool is set as P, a coordinate of the movable range of the X-axis direction or the Y-axis direction of the tool is set as R, a margin constant is set as a, and a position of the tool satisfies |P|≥|a R|, it is determined that the position of the tool is included in the limit region, wherein a is a constant of 0 to 1.

3. The line tracing method according to claim 1 or 2, wherein, In the case where the current position coordinates of the X-axis direction or the Y-axis direction of the tool are set as P, and the driving command value to the sub driving device is set as ΔD, the driving direction of the tool satisfies P ΔD ≥ 0, it is determined that the driving direction of the tool is toward the limit of the limit region.

4. The line tracing method according to any one of claims 1 to 3, wherein, In a case where the current position coordinate of the X-axis direction or the Y-axis direction of the tool is set as P, a prescribed function that changes by the position coordinate P is set as β(P), and a drive command value to the sub-driving device is set as ΔD, the drive command value is reduced to satisfy ΔD' = β(P) ΔD, where β(P) is a value of 0 to 1.

5. The line tracing method according to claim 4, wherein, With the current position coordinates of the tool in the X-axis direction or the Y-axis direction set to P, the coordinates of the movable range of the tool in the X-axis direction or the Y-axis direction set to R, and any adjustment constant greater than 0 set to γ, β(P) is set to β(P) = γ. |(RP) / R|.

6. A line tracing system, comprising: A secondary drive unit that drives the tool in a direction parallel to the workpiece; The main drive unit drives the auxiliary drive unit along three orthogonal axes. The first track detection device moves together with the tool to detect the target track of the tool in the X-axis direction relative to the workpiece, the target track of the tool being set in a detectable manner on the machining surface of the workpiece. The second track detection device moves together with the tool to detect the target track in the Y-axis direction relative to the workpiece which is not parallel to the X-axis direction; as well as The control device controls the main drive device and the auxiliary drive device based on the detection results of the first track detection device and the second track detection device. The control device uses the target track as a reference to set the full range of motion of the tool, which is achieved by the secondary drive device. Within the entire range of motion, a basic track for the secondary drive device, implemented by the primary drive device, is established. While the main drive device drives the auxiliary drive device along the basic track, the auxiliary drive device also drives the tool along the target track. Based on the position of the target track relative to the X-axis direction detected by the first track detection device, the tool is driven along the X-axis direction by the secondary drive device. Simultaneously, based on the position of the target track relative to the Y-axis direction detected by the second track detection device, the tool is driven along the Y-axis direction by the secondary drive device. When the position of the tool driven by the secondary drive device is contained within the limit region of the tool's movable range in either the X-axis direction or the Y-axis direction, and the drive direction of the tool driven by the secondary drive device is toward the limit region, the drive command value to the secondary drive device relative to either the X-axis direction or the Y-axis direction is reduced.

7. The line tracking system according to claim 6, wherein, It also has a track setting device that sets the target track of the tool on the workpiece surface in a detectable manner.

Images