Teaching system and teaching method for laser processing

Abstract

A teaching system (100) comprises: a sensor (54) for detecting the intensity of reflected light; and one or more processors (40) for providing the minimum and maximum values ​​of the irradiation angle formed by the angle between the normal of a workpiece (W) at each processing point and the laser light emitted from a processing head (50), and the coordinates of the processing point; generating teaching data capable of laser processing all processing points by using a laser light having a value greater than the minimum value and less than the maximum value; when executing an action program including the generated teaching data using a laser light set so that the intensity of the reflected light when the irradiation angle is at the minimum value is less than the allowable value, determining whether the intensity of the reflected light at all processing points exceeds a predetermined threshold value; if it is determined that the threshold value is exceeded, adjusting the minimum value of the corresponding processing point by a predetermined increment; and repeating the generation of teaching data using the most recent minimum value, determination, and adjustment of the minimum value until it is determined that the threshold value is not exceeded.

Description

Technical Field

[0001] The present disclosure relates to a teaching system and a teaching method for laser processing. Background Art

[0002] A teaching device that automatically generates teaching data is known in a laser processing system in which a processing head including a galvano scanner is mounted on the tip of a robot arm to perform processing such as welding on a workpiece (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-035404 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] If the laser irradiation angle is too small relative to the processing point, that is, if the laser is irradiated at a near-perpendicular angle to the processing surface, there is a risk that high-intensity reflected laser light will enter the processing head due to regular reflection of the laser light at the processing point. In this case, the processing operation may be stopped or the processing head may be damaged. Therefore, it is best to limit the minimum irradiation angle to minimize this situation.

[0008] On the other hand, the intensity of reflected light varies depending on the condition and material of the processing surface. Therefore, uniformly limiting the minimum irradiation angle would excessively restrict the laser irradiation range, making it difficult to create teaching data to achieve the desired cycle time. Therefore, it is desirable to create teaching data without excessively restricting the laser irradiation range.

[0009] Solutions for solving problems

[0010] One aspect of the present disclosure is a teaching system for laser processing, wherein the teaching system teaches the movement of a robot equipped with a processing head that emits laser light and the movement of the processing head, wherein the teaching system comprises: a sensor that detects the intensity of reflected light of the laser light that returns to the processing head from the surface of the processing object; and at least one processor that provides a minimum value and a maximum value of an irradiation angle consisting of an angle formed by a normal line of the processing object surface at each processing point and the laser light emitted from the processing head, and the coordinates of the processing point; generates teaching data capable of laser processing all the processing points by using the laser light at the irradiation angle that is greater than the minimum value and less than the maximum value; and generates teaching data by using the laser light at the irradiation angle that is greater than the minimum value and less than the maximum value. When the control device of the robot executes an action program including the teaching data using the laser that is set so that the intensity of the reflected light when the irradiation angle is the minimum value is below the allowable value, it is determined whether there is an intensity exceeding a specified threshold value among the intensities of the reflected light detected by the sensor at all the processing points; when it is determined that there is reflected light with an intensity exceeding the threshold value, the minimum value of the corresponding processing point is adjusted by a specified increment; and the generation, determination and adjustment of the teaching data using the most recently adjusted minimum value are repeated until it is determined that there is no reflected light with an intensity exceeding the threshold value. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 1 is a diagram showing the overall configuration of a teaching system according to one embodiment of the present disclosure.

[0012] Figure 2 This diagram shows the structure of the processing head including the optical sensor.

[0013] Figure 3 Yes, it is used Figure 1 This is a flowchart that explains the teaching method of the teaching system.

[0014] Figure 4 Yes Figure 3 This is a flowchart for explaining the operation program creation process.

[0015] Figure 5 Yes Figure 4 This is a flowchart for explaining the dot group determination process of the flowchart.

[0016] Figure 6 Yes Figure 4 This is a flowchart for explaining the motion speed determination process.

[0017] Figure 7 This is a diagram for explaining the grouping of dot groups.

[0018] Figure 8 This is a diagram showing an example of a plane defining a dot group.

[0019] Figure 9 This is a diagram for explaining optimization of grouping.

[0020] Figure 10 This is a diagram showing an example of the density of welding time.

[0021] Figure 11 This is a diagram for explaining the density of welding time.

[0022] Figure 12 This is a diagram for explaining the optimization of the movement order between groups.

[0023] Figure 13 This is a diagram for explaining determination of the weldable period.

[0024] Figure 14 This is a diagram for explaining the minimum value of the weldable period and the irradiation angle.

[0025] Figure 15 This is a diagram for explaining determination of the dotting order. DETAILED DESCRIPTION

[0026] Hereinafter, a teaching system 100 for laser processing and a teaching method according to an embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0027] like Figure 1 As shown, the teaching system 100 of this embodiment is a system that irradiates a workpiece (processing object) with laser from a processing head 50 installed at the front end of the robot 10, and generates teaching data for the movement of the robot 10 and the movement of the processing head 50 for implementing laser welding (laser processing).

[0028] The robot 10 is, for example, a vertical articulated robot. The machining head 50 includes a galvano-scanner (hereinafter simply referred to as a scanner) 51 and can emit laser light at a desired angle within a predetermined angle range.

[0029] The scanner 51 has the following functions: scanning the laser light sent from the laser oscillator 30 via the optical fiber in a two-dimensional direction orthogonal to the optical axis by driving the half mirror 52, and driving the focusing lens 53 in the optical axis direction to move the focal position in the optical axis direction.

[0030] In addition, if Figure 1 As shown, the teaching system 100 includes a light sensor (sensor) 54 provided on the machining head 50 and at least one processor 40 .

[0031] like Figure 2As shown, the optical sensor 54 detects the intensity of reflected light branched by the half mirror 52 on the way back from the surface of the workpiece W through the scanner 51 on the optical path between the laser oscillator 30 connected to the machining head 50 and the scanner 51 .

[0032] In the teaching method of this embodiment, as Figure 3 As shown, the processor 40 generates an operating program (teaching data) (step S1), and causes the control device 20 to execute the generated operating program (step S2). When the operating program is executed, the marking point P is reset to P=1 (step S3).

[0033] In addition, during the execution of the action program, the intensity I of the reflected light is detected by the optical sensor 54. R (Step S4), the processor 40 determines the intensity I of the detected reflected light R Whether it exceeds a predetermined threshold value Th (step S5). Then, based on the determination result, the processor 40 adjusts the minimum value θ of the irradiation angle for each spot. min，P (Step S6).

[0034] When the processor 40 generates an operation program (step S1), the minimum value θ of the irradiation angle of the laser beam at each marking point is input. min，P , maximum value θ max，P , and the position (coordinates) of the punching point (processing point). Then, through the minimum value θ min，P Above and less than the maximum value θ max，P Here, the irradiation angle is the angle between the normal line of the workpiece W surface at each welding point and the laser beam emitted from the machining head 50.

[0035] The minimum value of the laser irradiation angle θ min，P The initial value of Pθ is set to min =0.

[0036] The maximum value of the laser irradiation angle θ max，P The angle is set to an angle at which welding can be performed appropriately at all the welding points P.

[0037] Specifically, according to Figure 4 The generation of the operation program by the processor 40 is implemented according to the flowchart shown.

[0038] First, in the processor 40, in addition to the above-mentioned irradiation angle and welding position, various data required for the operation program creation process such as model data of the robot 10, fixture, and workpiece W, welding time and welding pattern of each welding point are also read (step S11).

[0039] Various data may be stored in advance in a storage device such as a memory, or may be input through an operation unit, or may be input from an external device via a network.

[0040] Next, a process of determining dot groups is performed (step S12). The groups satisfy the following criteria (1) and (2).

[0041] (1) The distance between the path of the robot 10 passing through the marking group and each marking point is the operating range (scanning range) of the machining head 50 .

[0042] (2) When line segments corresponding to the welding time are defined along the path at the foot of a perpendicular line drawn from each marking point to the path of the robot 10, the density of the line segments corresponding to the welding time should be uniform on the path.

[0043] Figure 5 It means in Figure 4 As an example, the flowchart of the details of the determination process of the dot group performed in step S12 is shown. Figure 7 The situation of grouping the dot group G0 shown on the left side of is explained.

[0044] First, the point group G0 is grouped into temporary point groups (step S21). A group defines multiple points to be welded while the robot 10 operates according to a single motion command. Within a group, the robot 10 operates according to a single motion command, while the machining head 50 performs a scanning motion, thereby welding each point in the group.

[0045] In one motion command, the robot 10 moves along a straight line at a constant speed. Here, as an example, the dot group G0 is divided into Figure 7 The three dot groups G1 to G3 are shown on the right side of FIG.

[0046] Next, for each of the dot groups G1 to G3, a path of the robot 10 passing through the center of the dot group is determined (step S22). The straight line passing through the center of the dot group is obtained by, for example, the least square method.

[0047] As an example, for dot group G1, path R1 is determined as the line that minimizes the sum of the squares of the distances from each dot 101-105 to path R1. Since dot positions are in three-dimensional space, each dot 101-105 is actually distributed in three-dimensional space. However, the path is determined by defining a plane that passes through the average position of each dot position and assuming that each dot 101-105 exists at the position where each dot 101-105 is projected onto this plane.

[0048] The plane passing through the average position of each dot position can be calculated using, for example, the least squares method (or the Newell algorithm). Through the processing in step S22, paths R1, R2, and R3 are determined as the paths of dot groups G1, G2, and G3, respectively. Paths R1, R2, and R3 can also be determined as the paths along a plane defined by the foot of a perpendicular line drawn from the laser irradiation position to the plane defining dot groups G1, G2, and G3.

[0049] Alternatively, the plane projected by the points 101 to 105 of the point groups R1, R2, and R3 may be defined as a plane inclined relative to the horizontal direction based on the distribution of the points 101 to 105 (the shape of the weld surface). Figure 8 As shown, the plane H1 defining the dot group G1 is preferably defined as a plane inclined relative to the plane H2 defining the dot group G2.

[0050] By determining the plane in this manner, it is possible to set a plane that matches the distribution of the dot groups. Figure 8 The figure also shows an example of the operating range of the machining head 50 set at the laser irradiation positions D1 and D2. While the robot 10 is on the path corresponding to the dot group G2, the machining head 50 can be directed toward the plane H2 by controlling the posture of the robot 10.

[0051] Next, for each dot group R1, R2, and R3, it is checked whether each dot 101 to 105 is within the operating range of the machining head 50 (step S23). For example, regarding dot group G1, this check in step S23 can be performed based on whether the distance from each dot 101 to 105 to path R1 is within the operating range of the machining head 50. If a dot is found outside the operating range of the machining head 50, the grouping is restarted from step S21.

[0052] Next, the grouping is optimized based on the distribution of the points within the point group and the welding time of each point (steps S24 to S26). Figure 9 The dot groups shown illustrate the optimization of grouping.

[0053] exist Figure 9 In the example of , dots 131 to 138 are distributed in one dot group G10. The path P10 is a path set by the process of step S22 for the dot group G10.

[0054] As described above, the robot 10 moves at a constant speed during the motion corresponding to one motion command. Therefore, if the robot 10's motion speed is set to a low level in the densely populated area 140 so that the robot 10 can complete welding of all the popped areas 131 to 135, the robot 10 will move at an unnecessarily low speed in the sparsely popped area 141.

[0055] Therefore, in this case, dividing the dot group G10 into the dot group of part 140 and the dot group of part 141 can further improve the average speed of the robot 10. In other words, it can be said that grouping is preferably performed so that the distribution of dots within one dot group is uniform.

[0056] However, it is also necessary to consider that the welding time for each point is different.

[0057] Therefore, as shown in FIG. 10 , a line segment is defined on path P10, centered at the foot of a perpendicular line drawn from each of points 131 to 138 onto the path, and having a length corresponding to the welding time for each of points 131 to 138. This line segment corresponds to the welding time for one point during the movement time of the robot 10 along path P10, and is therefore hereinafter referred to as the welding time.

[0058] As an example, in Figure 10 In FIG. 1 , a welding time 132 s is set centered at a position 132 c of the foot of a perpendicular line drawn from the strike point 132 to the path P10 . Figure 10 In the figure, for convenience, each welding time is represented by a thick double-arrow line.

[0059] First, the density (degree of density) of the welding time on the path P10 is calculated (step S24). In this case, the density of the welding time can also be expressed as the degree of concentration of the welding time.

[0060] For example, Figure 11 As shown in the upper section of FIG. , the wide intervals d1 and d2 between the welding times SG1 , SG2 , and SG3 set on the path P10 correspond to a low density (sparse) welding time state.

[0061] In contrast, Figure 11 As shown in the lower section of FIG, a state in which the intervals d11 and d12 between welding times SG10, SG11, and SG12 are narrow corresponds to a state in which the welding time density is high (dense state). A state in which the intervals between adjacent welding times are wide indicates that the speed of robot 10 can be increased in the portion on path P10 corresponding to those welding times. In contrast, a state in which the intervals between adjacent welding times are narrow indicates that the speed of robot 10 cannot be increased in the portion on path P10 corresponding to those welding times.

[0062] Therefore, the density variation (difference in density) of the welding time set on the path of a certain welding point group is evaluated and regrouped when the density variation is high. This can improve the speed of the overall welding operation by reducing the density variation of the welding time of each welding point group.

[0063] Specifically, a value representing density variation is calculated for the intervals between weld times along a path set for a particular dot group (step S24). For example, density variation of weld times can be calculated by finding the density of weld times for each small interval of a fixed length along the path and then calculating the density based on the deviation. Next, an evaluation value is calculated such that the smaller the density variation, the higher the score (step S25).

[0064] Next, it is determined whether the evaluation value of each dot group is greater than a predetermined threshold value (step S26). If there is a group with an evaluation value less than the predetermined threshold value, the group is grouped again to increase the evaluation value, and the process from step S21 is repeated.

[0065] If the evaluation values ​​of all dot groups are greater than the threshold, the process proceeds to step S27. This loop process allows the dot grouping to be optimized. For example, a genetic algorithm can be used in this optimization loop process.

[0066] In step S27, the movement sequence between the dotting groups and the dotting sequence within the dotting group are optimized. Figure 12 The grouping and path determination are shown on the left.

[0067] exist Figure 12 In the example on the left side of FIG, the welding target spot group is divided into three spot groups G201 to G203, and paths P201 to P203 are set in each spot group G201 to G203. The moving directions of the paths P201 to P203 set in the spot groups G201 to G203 and the moving order between the spot groups G201 to G203 are optimized (step S27). Figure 12 The state before optimization is shown on the left, and the state after optimization is shown on the right. In the state before optimization, the order of dot groups G201 to G203 is dot group G201 → dot group G203 → dot group G202.

[0068] Furthermore, dot group G201 is assigned a dot sequence from bottom to top in the diagram, dot group G203 is assigned a dot sequence from bottom to top in the diagram, and dot group G202 is assigned a dot sequence from left to right in the diagram. It can be appreciated that, before optimization, the total travel distance between dot groups G201 to G203 is relatively long, indicating room for improvement.

[0069] exist Figure 12In the optimized state on the right side, the order of movement between dot groups G201 to G203 is dot group G201 → dot group G202 → dot group G203. In addition, dot group G201 is determined to be in a dot order from bottom to top, dot group G202 is determined to be in a dot order from left to right, and dot group G203 is determined to be in a dot order from top to bottom.

[0070] It can be understood that in the optimized state, the total distance of movement between the dot groups is minimized. As a method of determining the movement sequence that minimizes the total distance of movement between the dot groups, various methods known in the art for solving the so-called traveling salesman problem can be used. Figure 4 The dot group determination process (step S12) in the flowchart of FIG.

[0071] Then, in Figure 4 In step S13 of the flowchart, the operation speed of the robot 10 of each marking group is determined. Figure 6 1 is a flowchart showing the details of the operation speed determination process. First, a temporary operation speed of each dotting group is set (step S31).

[0072] For all the welding point groups, the temporary operation speed can be set to a low speed that is considered to be able to smoothly weld the welding points of each welding point group. Alternatively, a representative speed based on experience can be set for each welding point group.

[0073] Next, use Figure 4 The path of the robot 10 determined in step S12 of the flowchart and the motion speed of each dotting group determined in step S31 are used to generate a motion program for the robot 10, and a motion simulation of the robot 10 is performed (step S32). By performing the motion simulation, the position data of the robot 10 in each interpolation cycle (hereinafter also referred to as the motion path) is obtained.

[0074] Next, using the motion path of the robot 10 obtained by the motion simulation of the robot 10, the period corresponding to the range in which each spot can be welded on the motion path of the robot 10 (hereinafter referred to as the weldable period) is calculated (step S33). Figure 13 As shown, regarding the motion path L1 of the robot 10 , the processing here will be described by taking the case of obtaining the weldable period during which the weldable spot 151 is welded as an example.

[0075] First, the position of the processing head 50 installed on the front end of the arm of the robot 10 (specifically, for example, the position of the focusing lens 53 in the processing head 50) is calculated based on the position on the movement path L1 of the robot 10, and the path of the laser connecting the position of the processing head 50 and the position of the dot 151 is calculated.

[0076] At this time, when the following conditions (1), (2), and (3) are satisfied, it is determined that the path of the laser beam is capable of welding.

[0077] (1) The laser path does not interfere with the workpiece W and the fixture;

[0078] (2) The path of the laser is the range of motion of the processing head 50;

[0079] (3) The irradiation angle, which is the angle between the normal direction of the workpiece W and the laser beam at each marking position, is within a predetermined allowable range.

[0080] Furthermore, condition (3) is applied to avoid uneven laser irradiation intensity on the workpiece W, maintain welding quality, and prevent adverse effects caused by reflected light. The period corresponding to the range of the laser path determined to be capable of continuous welding on the motion path L1 is the weldable period for each spot determined in step S33.

[0081] exist Figure 13 In the example, reference numeral L101 indicates the weldable period. The weldable period can also be determined at multiple locations along the motion path L1. Furthermore, since the weldable period L101 must be longer than the welding time of the target point, any range that does not meet this time limit is discarded.

[0082] In this case, since the minimum value of the irradiation angle θ is input for each dot, min，P and the maximum value θ max，P , therefore, the minimum value θ is not satisfied at the irradiation angle min，P Above and less than the maximum value θ max，P In the case of the condition, it is removed from the weldable period L101. Figure 14 As shown, the minimum value of the irradiation angle θ min，P The area indicated by the following oblique lines (hollow area) is irradiated with laser light.

[0083] Therefore, during the movement of the robot 10 along the motion path L1, Figure 14 As shown by the middle dotted line, when the laser is irradiated on the path LL1 passing through the hollow area, the welding period can be interrupted. Figure 14 As shown by the solid line, by controlling the machining head 50 so as to irradiate the laser light along the path LL2 avoiding the hollow area, the weldable period can be continued and a weldable period that satisfies the welding time can be ensured.

[0084] Next, the weldable period for each point determined in step S33 is used to determine the position and time for welding each point (step S34). Here, as a first condition, the welding time for each point is taken into consideration, and the welding time is determined so as to reliably meet the welding time for each point, regardless of the order of the start time of the weldable period for each point.

[0085] For example, suppose there are two points A and B with the same welding time of 1 second. The weldable period for point A is from 1 to 4 seconds after the start of the operation, while the weldable period for point B is from 1.1 to 2.1 seconds after the start of the operation. In this case, point A can be welded first, but if point A is welded from 1 to 2 seconds, point B cannot be welded. In this case, in step S34, point B is welded from 1.1 to 2.1 seconds, and then from 2.1 to 3.1 seconds.

[0086] In addition, in step S34, as the second condition, if there is a point that can be welded first based on the positional relationship between the action path, the workpiece w, and the fixture, regardless of the order of the points, then the point is welded first. Figure 15 As shown, the arrangement of the weld points along motion path L2 is in the order of weld points 161 and 162. However, when viewed from motion path L2, weld point 161 is hidden behind protrusion 180 of workpiece W, and weld point 162 may be welded first. In this case, weld point 161 is welded first at position 202 on motion path L2, and weld point 162 is welded later at position 203.

[0087] Then, the movement speed is adjusted and optimized so that all the welding points can be welded and the cycle time can be shortened (step S35). For example, the following method can be considered: for all the welding point groups, the movement speed of the robot 10 is set to the same value, the movement speed is reduced until all the welding points can be welded, and then the movement speed is increased for each welding point group. When the optimization is achieved through the above process, the process ends. Figure 4 The motion speed determination process (step S13) of the flowchart is shown in FIG. In addition, if it is not optimized, the process starting from step S31 is repeated.

[0088] Next, the results obtained from the processing of steps S11 to S13 are used to generate the motion program for the robot 10 and the machining head 50 (step S14). The motion program for the robot 10 is created so that the robot 10 moves along the path set in all the dot groups by the processing of step S2 at the motion speed determined in step S13.

[0089] The motion program of the machining head 50 is created as a motion instruction group that specifies the position and posture of the machining head 50 so that when the robot 10 moves on the motion path according to the motion program, the laser is irradiated on each welding point within the entire welding time set for each welding point.

[0090] In this way, the optimal motion path of the robot 10 and the optimal timing for welding each spot can be automatically determined.

[0091] Next, the processor 40 sends the operation program generated in this manner to the control device 20, and sets the intensity IT of the laser light emitted from the machining head 50 to the allowable value I. R0 Next, the control device 20 is made to execute the action program (step S2). R0 For example, the intensity is set such that even if the surface of the workpiece w is irradiated with laser light, the workpiece w will not be welded, and even if regular reflection light from the surface of the workpiece w enters the machining head 50 , the machining head 50 will not be adversely affected.

[0092] During the execution of the action program, the intensity of the reflected light I is monitored by the optical sensor provided by the machining head 50. R (Step S4), the processor determines the intensity of the reflected light I R Whether it exceeds a predetermined threshold value Th (step S5).

[0093] The threshold value Th is calculated by, for example, the following formula (1).

[0094] Th≤I R0 ×I T / I S (1)

[0095] Here, I S is the intensity of the laser used in actual laser processing, I T It is the intensity of the laser light emitted from the machining head 50 during teaching.

[0096] That is, the threshold value Th is set to the intensity I of the reflected light during teaching. R The intensity I of the laser light emitted from the machining head 50 T The ratio is less than or equal to the allowed reflected light intensity I RO Relative to the intensity of the laser used in actual laser processing I S ratio.

[0097] The intensity of the reflected light I RIf the threshold value Th is exceeded, the minimum value θmin,p of the irradiation angle at the corresponding spot is increased by a predetermined increment Δθ (step S6), and the detection of reflected light is stopped. The system then waits until the welding time for the corresponding spot P ends (step S7). After the welding time for spot P ends, the process from step S4 onwards is repeated for the next spot P+1 (step S8) until the operation sequence ends (step S9).

[0098] If the intensity of the reflected light is within the threshold value Th, the process from step S4 is repeated until the operation program ends (step S9). R Is the intensity of the reflected light at any point I below the specified threshold value Th (step S10)? R If the threshold value Th is exceeded, the process from step S1 is repeated. R If the value is less than or equal to the threshold value Th, the final operation program is output (step S10A).

[0099] Thus, according to this embodiment, there are advantages in that the reflected light of the laser light on the surface of the workpiece w does not adversely affect the machining head 50 and the operation speed is determined so that all the welding points can be welded with the shortest cycle time.

[0100] That is, due to the different materials of the workpiece w or the surface conditions of the workpiece w, even if the intensity IS of the irradiated laser light is constant, the intensity I of the reflected light returning to the machining head 50 may vary. R According to this embodiment, the intensity of the reflected light I is automatically calculated for each dot in the entire action program. R Suppression at intensity I R0 The minimum value of the irradiation angle θ is as follows min，p , so it has the advantage that the operator does not need to manually adjust the action program.

[0101] In addition, the minimum value θ of the irradiation angle of each point P is set in advance. min，p The initial value θ min Set it to a larger value to suppress the intensity of reflected light in the entire action program. R The intensity of the reflected light I can be obtained by different methods. R Suppress the reflected light intensity to the allowable I R0 The minimum value of θ min，p , it is not necessary to excessively limit the irradiation angle range. This has the advantage of being able to easily achieve the desired cycle time for laser processing.

[0102] In this embodiment, the minimum value θ of the laser irradiation angle is set to min，p The initial value θmin It is set to zero, but it can also be set to a value other than zero. For example, when welding a workpiece w with a surface close to a mirror surface, the minimum value θ of the irradiation angle is set to zero. min，p When it is zero, there is obviously a reflection light intensity exceeding the allowable I R0 The reflected light of the processing head 50 is incident on the processing head 50. In this case, by using the minimum value θ min，p Initial value θ other than zero min , which can eliminate more than one useless processing at the beginning and shorten the time of searching for the appropriate minimum value.

[0103] In addition, in this embodiment, a vertical articulated robot is exemplified as the robot 10 , but the robot is not limited thereto, and other types of robots may be used. In addition, a laser scanning device other than the galvano-scanner 51 may be used.

[0104] In addition, in this embodiment, although laser welding is exemplified as the laser processing, it is also applicable to any other laser processing instead.

[0105] Description of reference numerals:

[0106] 10. Robot

[0107] 20 Control device

[0108] 40 processors

[0109] 50 processing head

[0110] 54 Light sensor (sensor)

[0111] 100 Teaching System

[0112] W Workpiece (object to be processed)

[0113] Th threshold

[0114] θ min Minimum

[0115] θ max Maximum

[0116] Intensity of IR reflected light

Claims

1. A teaching system for laser processing, wherein the teaching system teaches the movement of a robot equipped with a processing head for emitting laser light and the movement of the processing head, wherein: have: a sensor that detects the intensity of the reflected light of the laser beam that returns to the processing head from the surface of the processing object; and at least one processor, The processor provides a minimum value and a maximum value of an irradiation angle formed by an angle between a normal line of the surface of the object to be processed and the laser light emitted from the processing head at each processing point, and the coordinates of the processing point, and generates teaching data capable of laser processing all the processing points using the laser light at the irradiation angle that is greater than the minimum value and less than the maximum value; When the robot control device executes an operation program including the teaching data using the laser light set so that the intensity of the reflected light when the irradiation angle is at the minimum value is equal to or less than an allowable value, determining whether any of the intensities of the reflected light detected by the sensor at all the processing points exceeds a predetermined threshold value; When it is determined that the reflected light has an intensity exceeding the threshold, adjustment is performed so that the minimum value at the corresponding processing point is increased by a predetermined increment; The generation of the teaching data using the most recently adjusted minimum value, the determination, and the adjustment of the minimum value are repeated until it is determined that the reflected light having an intensity exceeding the threshold does not exist.

2. The teaching system according to claim 1, wherein: The initial teaching data is generated by setting the minimum value to zero.

3. The teaching system according to claim 1, The initial teaching data is generated by setting the minimum value to a value other than zero.

4. A teaching method for laser processing, wherein the teaching method teaches the movement of a robot equipped with a processing head for emitting laser light and the movement of the processing head, wherein: The following steps are involved: providing a minimum value and a maximum value of an irradiation angle formed by an angle between a normal line of a surface of a workpiece and the laser light emitted from the processing head at each processing point, and the coordinates of the processing point, and generating teaching data capable of laser processing all the processing points by using the laser light at the irradiation angle being greater than the minimum value and less than the maximum value; When the control device of the robot executes an operation program including the teaching data using the laser light set so that the intensity of the reflected light of the laser light returned from the surface of the object to the processing head when the irradiation angle is the minimum value is equal to or less than an allowable value, determining whether the intensity of the reflected light of the laser light returned from the surface of the object to the processing head at all the processing points exceeds a predetermined threshold value; When it is determined that the reflected light has an intensity exceeding the threshold, adjustment is performed so that the minimum value at the corresponding processing point is increased by a predetermined increment; The generation of the teaching data using the most recently adjusted minimum value, the determination, and the adjustment of the minimum value are repeated until it is determined that the reflected light having an intensity exceeding the threshold does not exist.

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