JP6090463B2 - Work route creation device, work route creation method, work route creation program, and recording medium - Google Patents

Description

  The present invention relates to a work route creation device, a work route creation method, and a work route creation program. More specifically, the present invention relates to work route creation for creating a route when working at a plurality of work points in a work using a robot by offline programming. The present invention relates to a device, a work route creation method, a work route creation program, and a recording medium.

  In recent years, in order to teach the operation of a robot, programming is often performed using computer simulation. This is called offline programming.

  Such off-line programming is applied to various operations using a robot. For example, in robot-based welding, a path without interference is automatically created offline for welding a welding point (also called a welding point) on a workpiece (panel) with a welding gun attached to the robot. It is used to do.

  For example, in the first place, it is natural that the welding gun and the workpiece come into contact with each other around the welding point. Conventionally, after all of the periphery of such a welding point is deleted, an interference check of a path connecting the welding points is performed. That is, the periphery of the welding point is removed from the area where the interference check is performed.

JP 2000-61880 A

  However, in the prior art, when creating a route for performing a plurality of welding operations, when there is a welding point between the welding point and the welding point that does not perform the operation on that route (referred to as a work point that is not a work target) Thus, the interference check is not performed around the work point that is not the work target. For this reason, when a path created in the prior art is loaded onto an actual robot, if there is a work point that is not the work target between the welding point where the work is performed, the shape of the work point that is not the work target May interfere.

  Therefore, an object of the present invention is to create a path without interference even when there are work points that do not perform work in the path when creating a path for working at a plurality of work points by offline programming. It is to provide a work route creation device.

  Another object is to create a route that does not interfere even if there are work points that do not work in the route when creating a route for working at multiple work points by offline programming. It is to provide a route creation method.

  Yet another object is to create a work path that can create a path without interference even if there are work points that do not work in the path when creating a path when working at multiple work points by offline programming. It is to provide a creation program and a recording medium storing the program.

  In order to achieve the above object, a welding path creation apparatus according to the present invention includes a work point selection unit that selects two work points from a plurality of work points and sets a path connecting the two work points. The welding path creation device has a region setting unit that sets a work point region that is not subjected to interference check at the time of interference check for a plurality of work points excluding at least two work points. This welding path creation device has a work point area invalid portion that invalidates a work point area set to such another work point when there is another work point between two selected work points. . And this welding path | route preparation apparatus has an interference check part which carries out interference check of the path | route which connects two work points.

  According to another aspect of the present invention, there is provided a welding path creation method comprising: selecting two work points from a plurality of work points and setting a path connecting the two work points; and at least two work If there is another work point between the two selected work points and the stage of setting a work point area where interference check is not performed for a plurality of work points other than points, The operation point area set to “1” is invalidated, and an interference check is performed on a route connecting the two operation points.

  In addition, a welding path creation program according to the present invention for achieving the above other object includes a step of selecting two work points from a plurality of work points and setting a path connecting the two work points; and at least two work If there are other work points between the step of setting a work point area where interference check is not performed when performing interference check for a plurality of work points excluding a point, and another work point between the two selected work points, the other work point A path for performing work is generated by causing the computer to execute a step of invalidating the work point area set to, and a step of performing an interference check on a path connecting the two work points.

  Furthermore, the present invention for achieving the other object is a computer-readable recording medium storing the work route creation program.

  According to the present invention, when there is another work point between the two selected work points, the region where the interference check set for such another work point is not performed is invalidated. For this reason, even when there is a work point that does not work on the route, it is possible to appropriately perform the interference check, and it is possible to prevent interference from occurring at the work point that does not work and its peripheral part.

It is a block diagram for demonstrating the structure of the system containing a work route creation apparatus. It is a main flowchart of a work route (welding route) creation procedure. It is a subroutine flowchart which investigates the feasibility of the path | route which connects between two work points (welding point) linearly. It is a subroutine flowchart of an interference check. It is explanatory drawing for demonstrating a straight path | route. It is explanatory drawing for demonstrating the distance and angle between two work points (welding point). It is explanatory drawing explaining an escape point. It is explanatory drawing explaining an escape point. It is a work top view for explaining a work point (welding point) field and a work point (welding point) neighborhood field. It is an image figure of route creation when a straight route cannot be performed. It is a flowchart explaining the preparation procedure of an extraction path | route. It is a subroutine flowchart explaining the detail of the preparation procedure of a drawing path | route. It is explanatory drawing for demonstrating the operation | movement at the time of preparation of an extraction path | route. It is a flowchart explaining the preparation procedure of an avoidance path | route. It is an image figure of drawing route and avoidance route creation.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Moreover, the size and ratio of each member in the drawings are exaggerated for convenience of explanation, and are different from the actual size and ratio.

  FIG. 1 is a block diagram for explaining the configuration of a system including a work route creation device.

  In this system, a computer 11 and a server 12 are connected by a network 13.

  The computer 11 serves as a work route creation device. The computer 11 automatically creates a route passing through a plurality of work points by executing a program created according to a work route creation procedure described later. Therefore, the computer 11 functions as a work point selection unit, a region setting unit, a work point region invalid unit, and an interference check unit.

  The server 12 stores data necessary for creating a work route. The data necessary for creating the work path stores, for example, as the work-related data, the shape of the work to be worked (work target), the position of the work point on the work, the pressing direction for each work point, and the like. In addition, the server 12 includes, as robot-related data, the type and shape of the robot that performs the work (there is data such as the shape and operation for an offline program for each robot that is normally used), and the tool used for the work (for example, a welding gun) Data such as the shape is stored. Note that the data related to the workpiece may be directly acquired from a CAD device or the like that designs the workpiece, instead of the server 12 described above. Further, the robot-related data may be stored in the computer 11 itself serving as a work route creation device.

  The network 13 is a communication line for exchanging data between the computer 11 and the server 12. The network 13 is usually a general LAN or the like, but a dedicated line may be used.

  The network 13 is connected to a robot controller 14 for operating the robot. Thereby, the work path created by the computer 11 can be loaded onto the robot controller 14. Of course, when the robot controller 14 is not connected to the network 13, the created work path is separately recorded in another storage medium or the like and then transported to the robot controller 14 for loading.

  Next, the work route creation procedure will be described. FIG. 2 is a main flowchart of a procedure for creating a work route, FIG. 3 is a subroutine flowchart for examining the establishment of a route that connects two work points linearly, and FIG. 4 is a subroutine flowchart for an interference check.

  The basic configuration in this work route creation procedure is to create a route that connects two work points linearly first, check for interference in the straight route, determine if there is no interference, determine the route, If there is and cannot be connected in a straight line, another route is created.

  Here, a route connecting the work points linearly will be described. Here, a welding point will be described as an example of a work point.

  FIG. 5 is an explanatory diagram for explaining a straight path. As shown in the figure, the path that linearly connects the two welding points is a straight path that goes directly to the next welding point 2 after welding the welding point 1 set on the workpiece 100. Here, after welding, for example, when the tool is a welding gun, it means that the gun tip is slightly separated from the workpiece after the welding gun is opened.

  Such a straight path is characterized in that the movement time of the robot or tool is short and the amount of axial movement of the robot is small, so that the operation time of the robot can be shortened. However, for example, when the distance is large, it cannot operate linearly. In addition, for example, when there is an obstacle on the way, it cannot operate linearly. Also, it cannot move linearly even if it cannot move outside the robot axis range. As described above, even two welding points may not always operate linearly. In such a case, a route for moving after the tool is once pulled out is created separately (the creation of another route will be described later).

  An example of a work route creation procedure will be described with reference to FIGS. In the following description, a procedure for creating a work path when performing a joining operation for joining a plurality of members, particularly when performing a welding operation for welding a plurality of members will be described. In the welding operation, the robot holds a welding gun as a tool. The working point is a welding point (joining point) for performing a joining operation for joining a plurality of members.

  Prior to this procedure, the computer 11 acquires necessary data from the server 12 and stores it in its own storage device. The data to be acquired is the workpiece shape, the working point (welding point) position, and the pressurizing direction at the time of working (welding). These data are, for example, coordinate values in a three-dimensional coordinate space. In addition, you may make it take out from the server 12 whenever it becomes needed instead of memorize | storing in the memory | storage device in the computer 11. FIG.

  The main flow will be described with reference to FIG. 2 (in the following description, each step in all the flows is abbreviated as “S”).

  First, the computer 11 determines the first welding point from a plurality of welding points on the workpiece (S1). This first welding point becomes the starting point of the entire path set here.

  Subsequently, the computer 11 determines whether there is a next welding point to be processed (S2), and if there is a next welding point to be processed, selects it (S3). The welding points selected in S1 to S3 are selected in a predetermined order. The predetermined order is assigned to a plurality of welding points that can be advanced in the same direction by the designer, for example, based on experience. In addition, when a plurality of weld points are crossed, an order is assigned so as to proceed in a certain direction and then proceed in another direction. If it is determined in S2 that there is no next welding point, the process proceeds to S9.

  Two welding points are selected by S1 to S3 (when it is determined that there is a next welding point in S2). That is, the first welding point is selected by S1, and the next welding point is selected by S2 and S3. Then, if there is a next welding point due to this main flow, the next welding point is selected in S3. Thereby, two welding points are selected one after another, and the subsequent processing is performed.

  Subsequently, the computer 11 examines whether or not the two welding points can be linearly connected based on the distance and the angle (S4). In this process, whether or not the two welding points can be linearly connected is examined by the distance and angle between the two welding points.

  FIG. 6 is an explanatory diagram for explaining the distance and angle between two welding points. The distance and angle to be judged are (1) the distance between two welding points, (2) the angle in the pressurization direction of the two welding points, and (3) the angle in the welding gun entry direction of the two welding points. is there.

  (1) The distance between two welding points is a distance connecting two welding points as a straight line. If this distance is too long, it may be possible to perform welding faster by pulling out once to change the movement path or combining with other welding points, rather than moving between such two points. Therefore, a threshold is set for the distance between two points, and when the threshold is exceeded, the two points are not connected by a straight line. This distance threshold is a predetermined value.

  An example of how to determine this distance threshold is as follows. The speed when moving the straight line along the workpiece with the welding gun open is slower than when moving the welding gun away from the workpiece. On the other hand, when the welding gun is pulled out of the workpiece and put back into the next welding point, it takes time to pull out the welding gun and enter the workpiece, although the moving speed when moving away from the workpiece is fast. For this reason, in many cases, the longer the distance that can be moved away from the workpiece, the longer the distance that can be moved at high speed. Therefore, in consideration of the time required for such a movement operation, a distance that is faster to be extracted once is obtained in advance than the linear movement along the workpiece as it is. A threshold value should be used.

  (2) The angle in the pressurizing direction of the two welding points is an angle with respect to the panel surface which is a workpiece (α1 and α2 in the drawing). If the angles α1 and α2 in the pressurizing direction of the two welding points are different, the angle of the welding gun must be changed. In that case, it may take time to change the angle of the welding gun. A situation where it takes time to change the angle of the welding gun is, for example, a case where high-speed rotation is impossible because the operation is performed near the workpiece. In addition, the angle cannot be changed only by the axis at the tip of the robot arm, and it takes time even when the other axes of the robot are operated. Assuming such a case, if the difference in pressure direction between the two points is less than a preset angle threshold, the two points are connected by a straight line, and if the difference is greater than the threshold, It shall not be connected by a straight line. That is, when α1−α2 <the angle threshold, the lines are connected by a straight line.

  This angle threshold is a predetermined value, but most preferably it is possible to weld two weld points without changing the angle of the welding gun (ie, welding two panels). The allowable value of the pressure angle in this case is about 45 degrees (−22.5 to 22.5 degrees) when the perpendicular to the panel is 0 degree, and therefore, most preferably, two points of pressure are applied. The difference in the angle of the direction should be 45 degrees, and since it will not take much time to rotate the welding gun, it should be determined in consideration of the rotation of the gun. Also good.

  However, for example, when the pressurizing directions are reversed at two points, that is, when it is necessary to rotate the welding gun by 180 degrees, it is impossible to rotate the workpiece with the workpiece sandwiched between the welding guns. Accordingly, when the angle at which the welding gun cannot be rotated, that is, when the angle is changed so that the workpiece and the welding gun come into contact with each other by the rotating operation of the welding gun, the welding gun is not connected linearly. Therefore, the threshold value of the angle is an angle within a range of an angle change at which the workpiece and the welding gun do not contact each other, preferably an angle range in which the angle can be changed by the time toward the next welding point, and more preferably the angle change. This is the angle at which welding is possible without having to

  (3) The angle in the welding gun approach direction of the two welding points is an angle at which the welding gun enters from the outside of the workpiece toward the welding point with respect to the traveling direction of the welding gun (β1 and β2 in the drawing). When two welding points are connected by a straight line and moved, it is convenient not to change this approach angle. On the other hand, when this angle is greatly different, it takes time because the direction of the welding gun cannot be changed only with the axis at the tip of the robot arm. Therefore, when the approach angles are greatly different, the straight line is not connected. A threshold value is also provided for this approach angle, and when it is less than the threshold value, it is connected linearly, and when it is greater than or equal to the threshold value, it is not connected linearly. That is, when β1−β2 <the threshold value of the approach angle, the lines are connected linearly.

  The threshold value of the approach angle is, for example, an angle that changes the angle so that the operation time for changing the direction of the welding gun becomes longer than the time for moving the linear distance.

  The thresholds such as the distance between the welding points (1) to (3), the angle in the pressurizing direction, and the angle in the gun approach direction are all exemplified, and are derived based on the experience of the welding path designer. May be.

  By determining whether or not such a straight path is established, it is not necessary to perform an interference check or the like.

  As a result of checking whether or not the two welding points can be linearly connected in S4, the computer 11 checks the establishment of the linear path (S5: YES). (Establishment check) (S6). In S6, an interference check between the welding gun and the workpiece in the straight path is also performed. The detailed procedure of this straight path feasibility check will be described later.

  On the other hand, if the computer 11 checks whether or not the two welding points can be linearly connected in S4, and if it cannot be linearly connected (S5: NO), the two welding points currently selected are selected. Is stored as a welding point that cannot be connected by a straight line (S20), and the process returns to S2. If there is a next welding point in this step (S2: YES), the computer 11 selects the next welding point (S3). At this stage, the welding point previously selected in S3 and the welding point selected in S3 this time are two welding points. Then, the computer 11 continues the subsequent processing.

  If the computer 11 determines that the straight path is established as a result of S6 (S7: YES), the computer 11 stores the two welding points as a path that can be connected linearly (S8). Then, the computer 11 returns to S2 and continues the subsequent processing.

  On the other hand, if the computer 11 determines that the line path is established as a result of S6 (S7: NO), the computer 11 stores the two welding points as a welding point that cannot be connected by a straight line (S20), and goes to S2. Return and continue the subsequent processing.

  If the next welding point does not exist in S2 (S2: NO), the computer 11 determines whether there is a welding point stored in S20, and if there is no welding point stored here ( S9: NO), that is, if there are no two welding points that could not be linearly connected, all the welding points become a linearly connected path, and this is stored as the final welding path (S10). . Then, the process ends.

  On the other hand, if there is a path stored in S20 (S9: YES), the computer 11 obtains another path for the two welding points that could not be linearly connected in S10 (S30). The creation of this alternative route will be described later. After creating another route in S30, the computer 11 stores the final route (S10) and ends all processing.

  Next, a procedure for examining the feasibility of a path that linearly connects the welding points will be described with reference to FIG.

  This procedure is a subroutine of S6 of the main flow described above, and is a procedure for checking the feasibility between welding points that are targets for creating a linearly connecting route.

  Basically, if a linear route is established, that route is adopted; otherwise, it is not established.

  First, the computer 11 sets interference check tolerance (S61). The interference check tolerance is a reference value for determining that interference has occurred, and is a distance (clearance) that defines how far the objects need to be separated during the interference check.

  Although details will be described later, in this procedure, in the interference check procedure, the clearance is initially increased, and if it is determined that there is interference, the clearance is gradually decreased and repeated interference checks are performed. (That is, check again by narrowing the space between objects). For this reason, the clearance value is set in advance from the largest value to the smallest value by the designer (a reduction ratio may be set in advance).

  In this embodiment, the interference check place is divided into a plurality of areas, and a clearance suitable for each area is set. Furthermore, the amount of reduction of the clearance is different for each object to be checked for interference. For this reason, a clearance value and a reduced value are set in advance for each region and object (stored in the computer 11). And in this S61, it sets every time it performs the process of S61 in order until a clearance becomes the minimum value (S73).

  In this procedure, when there is interference as will be described later, the clearance is repeated with a small clearance, but it is determined whether or not to repeat depending on whether or not a predetermined minimum clearance has been reached. (S73). Therefore, it is not necessary to set the number of repetitions. Alternatively, the clearance can be reduced at a predetermined rate. In such a case, after the number of repetitions is determined and the interference check is performed for the number of repetitions, the repetition ends (therefore, in this case, it is necessary to count the number of repetitions. It ’s good)

  Next, the clearance point is set while changing the distance in the direction opposite to the pressurizing direction of the welding point (S62). This is done for each of the two weld points. 7 and 8 are explanatory diagrams for explaining the escape point.

  As shown in FIG. 7, the escape point is normally set on the opposite side to the pressurizing direction.

  As shown in FIG. 8A, the servo gun (welding gun) 200 has a hand shape including a movable portion 201 and a fixed portion 202. The movable part 201 and the fixed part 202 are provided with welding tips 201a and 202a. Here, the portions of the welding tips 201a and 202a are also referred to as welding gun tips. The other parts are called other than the tip part. Although not shown in the figure, at the time of interference check, each part of the robot to which the welding gun is attached is also subject to interference check.

  Such a servo gun (welding gun) 200 comes into contact with the workpiece 100 by applying pressure during welding, but it is necessary to separate the welding tip from the workpiece for the next movement. As shown in FIG. 8B, when the welding tips 201a and 202a are separated from the workpiece 100, the position on the fixed portion side is a clearance point. The distance from the surface of the workpiece welding point to the escape point is the escape point distance ng.

  The escape point position is initially set to 10 mm or the like (the most used distance) as the escape point distance ng, for example. If not satisfied by the interference check, the escape point position is lowered little by little (for example, by 1 mm) (by increasing the escape point distance ng) (S72). The welding point and clearance point distance ng cannot exceed the maximum opening amount (stroke) of the welding gun. If the clearance point position is lowered (if the clearance point distance ng is increased), naturally, the distance between the welding tip 201a on the movable portion side and the workpiece is shortened when the welding gun is opened. For this reason, the clearance point distance ng cannot exceed the maximum opening amount (stroke) of the welding gun, and the maximum opening amount becomes the limit value for setting the clearance point position (however, the thickness of the plate to be welded and the maximum opening amount) Considering that sometimes the contact between the welding tip 201a on the movable part side and the workpiece is not taken into consideration, the limit value for setting the clearance point position should be set somewhat smaller (for example, about 1 mm) than the maximum opening amount. become).

  Subsequently, the computer 11 sets welding guns having different maximum opening amounts (strokes) (S63). The opening amount varies depending on the type of welding gun. For example, in the case of a general welding gun, values such as 34 mm, 60 mm, 80 mm,... Are set in advance (stored in the computer 11). First, a 34 mm welding gun is set, then a 60 mm welding gun, then an 80 mm welding gun, and the like are set in the order of gradually increasing welding guns. This is repeated until the welding gun with the largest opening amount is reached (S71).

  By creating the path between the welding points in consideration of the opening amount of the welding gun, it is possible to create a path that is linearly connected with high probability.

  The computer 11 performs an interference check after S61-63 (S64). The procedure of the interference check will be described later.

  If there is no interference as a result of the interference check (S65: YES), the computer 11 temporarily stores that this route is established as a straight route (S66) and returns to the main routine. Thereafter, S7 is YES in the main routine, and the subsequent processing is continued.

  On the other hand, if interference occurs as a result of the interference check (S65: NO), the computer 11 determines whether or not the welding gun opening amount at this time is the welding gun with the maximum opening amount (preliminary setting). S71). The opening amount of the welding gun is as described above.

  As a result of the determination in S71, if the welding gun having the maximum opening amount is not set, the computer 11 returns to S63 and sets the welding gun having the next larger opening amount than the currently set welding gun. Then, the subsequent processing is continued.

  If the computer 11 determines in S71 that the welding gun has the maximum opening amount (S71: YES), then whether or not the escape point has been lowered to the lowest position set in advance as described above. Is determined (S72). As a result of the determination in S72, the computer 11 returns to S62 and sets an escape point that is lower than the currently set escape point if the escape point is not set to the lowest (bottom) position at this time. To do. Then, the subsequent processing is continued.

  If the computer 11 determines in S72 that it is the lowest escape point (S72: YES), it subsequently determines whether the clearance is the smallest value set in advance as described above. (S73). If the clearance is not set to the smallest value at this time as a result of the determination in S73, the computer 11 returns to S61 and sets a clearance point that is lower than the currently set clearance point. Then, the subsequent processing is continued.

  If the computer 11 determines in S73 that the clearance is set to the smallest value, there are no various settings that can avoid further interference at that time, so this straight path is not established. This is temporarily stored (S74). Then, the process returns to the main routine. Thereafter, S7 becomes NO in the main routine, and the subsequent processing is continued. If the computer 11 determines in S73 that the clearance is not the minimum value, the computer 11 instructs to reduce the clearance for the object that has been checked for interference in the interference check described later (S75), and returns to S61. Become. In S <b> 61, the computer 11 is set so as to reduce the clearance with respect to the object for which the interference check is performed in the interference check described later. Thereafter, the processing is continued.

  Next, an interference check procedure will be described with reference to FIG.

  First, the computer 11 divides the path for interference check into regions (S641). Here, the region is divided by paying attention to each welding point on the straight path. The region is divided into three regions: (a) a welding point region, (b) a region near the welding point, and (c) a free space region (that is, a region outside the region near the welding point). FIG. 9 is a work plan view for explaining a welding point region and a region near the welding point.

  (A) The welding point area is a portion in the vicinity of the welding tip in contact with the workpiece, and here, the clearance range (distance from the workpiece surface to the clearance point) is a circumferential range having a radius from the hit point center. . Since this welding point region includes a portion that comes into contact with the workpiece by the welding operation of the welding gun, the interference check between the welding gun tip and the workpiece is not performed. However, it should not interfere with jigs and equipment during welding work. It is more efficient to pass the gun tip and jig / equipment as close as possible. Therefore, the interference check is performed with as little clearance as possible in this region (the clearance used here will be described later).

  (B) The region near the welding point is a portion that is outside the welding point region but close to the welding point. Here, it is set as the range of the circumference where the distance from the center of the hit point is the distance from the welding point region to the position where the workpiece enters at least between the welding tips (that is, the welding gun tip). In other words, it is a circumferential range in which the distance from the center of the hit point on the line drawn from the center of the hit point to the welding gun intrusion direction to the workpiece end is a radius (in FIG. 8, it is shown as the workpiece end in the intrusion direction).

  The region near the welding point may be a region including such a circumferential range or more. Moreover, it is not necessary to set the region near the welding point at the last position where the workpiece enters between the welding tips. However, if it is too wide, it will be the same as the free space described later. Thus, in the present embodiment, the approach is expanded to an approach point that is a position where the direction of the welding gun is changed or a speed is changed in order to make the welding gun tip end toward the welding point.

  In the vicinity of the welding point, the tip of the welding gun needs to be close to the workpiece for welding, so it is preferable that the clearance is as small as possible (details will be described later). It should be noted that, except for the tip of the gun, a large clearance can be secured, and it is preferable not to interfere even at high speed operation.

  (C) Free space is an area other than the above (a) and (b) (not shown). Accordingly, the region is outside the region near the welding point and within the movable range of the robot. In this free space, since the tip of the welding gun and the workpiece are separated, a clearance larger than that in the vicinity of the welding point is taken so that the robot can be operated at high speed.

  Next, the computer 11 checks whether there is another welding point on the path (S642). As a result, if there is no other welding point (S643: YES), the process proceeds to the next S644 as it is. On the other hand, when there is another welding point on the path ((in the case of FIG. 8) S643: NO), the computer 11 invalidates (not assumes) the detected other welding point (S650). Thereafter, the process proceeds to the next S644. Thereby, the welding point area | region set to the other welding point does not exist.

  In the prior art, even a welding point that exists on the path but does not perform a welding operation is not subjected to an interference check because it is a welding point region as it is. In the present embodiment, the interference check can be performed even at such a welding point by the process of S642.

  The range for checking whether there is any other welding point on the path is the reach range of the welding gun tip with the straight path as the center line. This means that if there is another welding point within the reach of the welding gun tip, if there is no interference check for that welding point as in the past, it will not be checked that there is an obstacle in that part. Become. Therefore, such a check omission can be avoided by examining whether or not there is another contact point in the reach of the welding gun tip with the straight line as the center line.

  Next, the computer 11 acquires an interference check target (S644). The target of the interference check includes a robot, a welding gun tip, a workpiece (panel), and other jigs / equipment other than the welding gun tip. Specifically, (i) a workpiece other than the robot and the gun tip, (ii) a jig and equipment other than the robot and the gun tip, (iii) a welding gun tip against the workpiece, and (iv) a welding gun tip pair. Perform four types of interference checks for jigs and equipment. In S644, the data of the object is read out in the order from (i) to (iv) (S648 described later). Although the interference check between the workpiece and the jig / equipment is not performed, the interference check between the robot and the welding gun tip may be performed.

  Next, the computer 11 reads and sets the clearance value for each area and object set in S61 (S645).

  Here, the detail of the clearance used for an interference check is demonstrated. The clearance value is basically determined based on the following concept (set in advance).

  For each region and object, an appropriate amount is set so that the value gradually becomes small so that a large clearance can be secured.

  First, (a) the clearance of the welding point region is checked for interference with other objects although the chuck of the welding gun is not performed at the welding gun tip. The clearance between the welding gun tip and other objects (such as jigs / equipment) is always very small because it moves to a position that is always close to the workpiece. For example, it is about the clearance point distance at the maximum (if the welding gun is changed, this value is also changed naturally). Further, since this area is close to the workpiece, the moving speed is slow, so there is no problem if such a small clearance can be secured. In addition, it is preferable that the clearance of the part other than the welding gun tip in this region and the clearance of the robot part be large so as not to interfere during movement. However, as described above, since the operation in this portion is slow, it does not have to be as large as free space. For example, the minimum value is assumed to be the minimum safe amount for the value that does not come into contact with vibrations during robot posture change or welding gun movement. On the other hand, the maximum value is not particularly limited, but may be a empirically sufficient value.

  Next, (b) the area near the welding point is also an area close to the workpiece, and the tip of the welding gun (welding tip portion) must not contact the workpiece or the like. On the other hand, even if this region is a portion other than the tip portion of the welding gun, a work exists between the movable portion and the fixed portion. For this reason, the clearance between the welding gun tip and the workpiece in this region is also set to a very small value. For example, the maximum distance is about the clearance point. Also, the clearance between the welding gun tip and other objects (such as jigs and equipment) other than the workpiece is larger than the clearance between the tip and the workpiece, but it is not necessary to be as large as the free space (smaller clearance). . This is because the movement speed is slow, so there is little vibration when moving the tip, so the clearance distance should be the minimum value, and the maximum value should be sufficient to contact other objects empirically. Good.

  In addition, it is preferable that the clearance of the part other than the welding gun tip in this region and the clearance of the robot part be large so as not to interfere during movement. However, since the operation in this part is slow, it does not have to be as large as free space. For example, the minimum value is assumed to be the minimum safe amount for the value that does not come into contact with vibrations during robot posture change or welding gun movement. On the other hand, the maximum value is not particularly limited, but may be a empirically sufficient value.

  Next, (c) in the free space, the posture of the welding gun and the robot changes at high speed and moves. For this reason, it is necessary to provide a large clearance that does not come into contact with all objects when moving at high speed. This is the same between the welding gun and the workpiece and between the welding gun and other objects (such as jigs and equipment) other than the workpiece. For example, it is assumed that a safe amount is expected to a value that does not interfere with a change in posture of the robot or vibration when the welding gun is moved at high speed. Moreover, it is good also as a value required from experience.

  Tables 1 to 3 show the summary of the clearances for each region and the object from the above-described way of thinking.

  When connecting the welding points in a straight line, the clearance near the welding point region is used because there are many cases where the welding route is close to the workpiece even if the route is in free space. In the case of a route that is pulled out from the welding point, the area is determined by the position of the welding tip, and the clearance to be used is determined.

  By using such clearance values, when the gun approaches the workpiece and performs welding, the gun can approach the workpiece, and the robot / gun (other than the tip) secures the specified clearance from the workpiece, jig, and equipment. Route can be created.

  Returning to FIG. 4, the description of the interference check procedure will be continued.

  The computer 11 reads and sets an object to be checked for interference in S644 and S645 and their clearances, and then performs an interference check (S646).

  The interference check is performed for all objects existing on the route. For example, it is assumed that a straight path is set from the welding point 1 to the welding point 2 at this stage. If the welding gun tip and the workpiece are specified as the object, check whether the welding gun tip does not interfere with the workpiece shape in the entire linear path from welding point 1 to welding point 2. become. Similarly, it is assumed that an object other than the welding gun tip and workpiece is designated as the object. In addition, when there are a plurality of objects other than the workpiece from the welding point 1 to the welding point 2, the interference between the plurality of objects and the welding gun tip is checked. At this time, the clearance is the value read in S645.

  If there is no interference in S646 (S647: YES), it is determined whether or not there is a next object (in the order of (i) to (iv) described above) (S648). If there is no next object (S648: YES), the absence of interference is temporarily stored (S649), and the process returns to S65. Thereafter, in S65, a straight path is established.

  On the other hand, if there is a next object (S648: NO), the process returns to S644 to acquire the next object, and the subsequent processing is continued.

  If there is interference in S647 (S647: YES), the presence of interference is temporarily stored at this stage (S652), and the process returns to S65. After that, since NO is obtained in S65, the processing is continued based on the judgments in S71 to 73 as described above. In particular, if the interference cannot be avoided even by replacing the welding gun or changing the clearance point, the clearance is changed to a small value in S61. Then, the interference check is further continued.

  Here, the reason why the clearance is reduced stepwise will be further described.

  When an interference check is performed, there is a case where a route that is established with a certain clearance cannot be obtained. In particular, since the clearance between the workpiece (panel), jig, and equipment other than the robot and welding gun tip is large, there are many cases where large clearance cannot be secured when the jig and equipment are dense and the space is small. Therefore, in order to secure the clearance at the tip of the gun and determine the path, lower the clearance other than the tip of the robot / gun gradually and find the path that is established (change the clearance to be smaller in steps) ). This means that it is possible to create a route even if the clearance is a little narrower than when it is impossible to create a route when it is necessary to secure sufficient clearance between the object other than the robot and the tip of the welding gun, but it cannot be secured. This is to give priority.

  This clearance change is performed as a final means for finding a route. Therefore, as described above, after changing the opening amount of the welding gun and the clearance point, an instruction to reduce the clearance is given (processing of S73 and S75). In other words, in the creation of a path that connects the welding points linearly, the clearance is reduced when sufficient clearance cannot be secured even if the amount of opening of the gun and the position of the escape point are changed. Otherwise, it would be the same as checking with a small clearance from the beginning. In other words, in this order, it is possible to create a route so as to provide a wider clearance, rather than creating a route with a critical clearance from the beginning.

  In addition, since the larger clearance is gradually reduced in the step change and the other clearances are left as they are, there are times when the value of the reduced clearance becomes the same as the value of the other clearances. In this case, (i) the current point is set as the limit of the clearance step change and the clearance cannot be further reduced, or (ii) all the clearances are reduced simultaneously thereafter (robot and gun tip clearance). In order to prevent the reversal phenomenon of the above), it is recommended to perform up to a certain limit value. Either method can be used, but in the end, all will create a route with minimal clearance.

  By doing this, a route that can secure a sufficient clearance is created with the highest priority, and the probability that a non-interfering route can be created even in a place where it cannot be created.

  By creating a path between welding points using the procedure described above, it is possible to set an appropriate clearance distance (interval) between the robot and welding gun and workpieces, jigs, equipment, etc. A path with a short movement distance of the welding gun, which is a straight line, can be automatically created.

  Next, a case where a straight route cannot be created will be described. That is, it is a process in the case where two welding points are stored as unweldable welding points by S20 described above.

  Here, an example in which another route is automatically created when such a straight route cannot be created will be described. In creating another route, the computer 11 functions as a separate route creating unit by executing a procedure described later.

  FIG. 10 is an image diagram of route creation when a straight route is not possible. Here, it is assumed that there are welding points 1 to 4 as in (a) the initial state. When a welding path is created from this state (a), as shown in (b), welding points 1, 2, 3, and 4 can create a straight path, and welding points 3 and 4 can create a straight path. Suppose there wasn't. In such a case, another path that is not a straight line is created between the welding points 3 and 4 as shown in FIG.

  For this purpose, it is necessary to pull out the welding gun at one end from the workpiece, so that a drawing path is created. The pulling path requires a path that descends from the welding point and pulls outward from the workpiece end so that the welding gun can be reliably separated from the welding point and the workpiece (panel).

  Furthermore, as another route, an avoidance route that connects the drawing routes is required. In other words, the separate route includes an extraction route and an avoidance route. Here, the starting side original position to the first welding point and the last welding point to the end side original position are also created. The avoidance path may be any path that can avoid interference because the welding gun is already away from the workpiece.

  A procedure for creating the extraction route will be described. FIG. 11 is a flowchart for explaining a procedure for creating a drawing path.

  First, the computer 11 takes out one welding point for creating a drawing path (S201). This is one of the two welding points stored in S20.

  Next, the computer 11 creates an extraction route (S202). Details of this processing will be described later.

  Next, the computer 11 determines whether or not the extraction route has been created (S203). Here, if the computer 11 can create the extraction route, the computer 11 adopts the route (S204). The extracted extraction route is temporarily stored.

  Next, the computer 11 searches for a welding point for creating the next drawing path (S205). If there is no next welding point (S206: YES), it will be complete | finished. On the other hand, if there is a next welding point (S206: NO), the process returns to S201, and the computer 11 takes out the welding point found by the search. Thereafter, the computer 11 continues the subsequent processing. If the computer 11 cannot create the drawing path in S203 (S203: NO), the computer 11 records that fact (S207) and moves to the welding point for creating the next drawing path. The point where the drawing path cannot be created recorded in S207 is a welding point where another path cannot be created. Therefore, the fact is displayed on the computer 11 to inform the designer.

  Next, the details of the extraction route creation procedure will be described. FIG. 12 is a subroutine flowchart for explaining the details of the procedure for creating the extraction path. This flow is a subroutine of S202. FIG. 13 is an explanatory diagram for explaining the operation in creating the extraction path.

  First, the computer 11 sets the interference check tolerance of the extraction path (S301). In this case, the interference check tolerance is set in the same manner as in the case of creating a straight line route. Therefore, the clearance is gradually reduced every time the process proceeds to S301 after the second time. If the clearance cannot be further reduced (S302: YES), the computer 11 determines that the extraction path cannot be created (S312) and ends the process. If it becomes impossible to create the extraction route (S312), that is, the creation of another route is impossible, so that it may be displayed and all the processing may be terminated (the same applies to the case of coming to S312). On the other hand, if the clearance can be further reduced in S302, the subsequent processing is continued.

  Next, the computer 11 sets the escape point 1 in the direction opposite to the pressurizing direction of the welding point (S303). In this case, a clearance point is created at a position in the direction opposite to the pressurizing direction as in the case of creating a straight line. In the case of the drawing path, as shown in FIG. 13A, the escape point immediately below the welding point is defined as “escape point 1”. In addition, the escape point is gradually lowered every time the process proceeds to S303 after the second time. If the computer 11 determines that the escape point cannot be lowered any more (S304: YES), the computer 11 ends the process as drawing path creation impossible (S312). On the other hand, if the escape point can be further lowered in S304, the subsequent processing is continued.

  Next, the computer 11 sets the escape point 2 from the escape point 1 (S305). “Escape point 2” is an escape point for separating the welding gun from the welding point. At this time, the distance to the escape points 1-2 is set. The initial value of this distance is the distance at which the welding gun can be charged and separated from the workpiece. If the initial value is not satisfied, the distance is shortened little by little every time it comes to S305. If the distance from the escape point 1 to 2 cannot be further shortened (S306: YES), the computer 11 terminates the processing as a drawing path cannot be created (S312). On the other hand, if the distance from the escape points 1 to 2 can be further shortened in S306, the subsequent processing is continued.

  Next, the computer 11 sets the direction of the escape point 2, and also sets the path from the welding point to the escape point 1 to the escape point 2 at this stage (S307). In order to set the direction of the escape point 2, as shown in FIG. 13C, the initial value is set to a direction away from the workpiece vertically, and when the initial value does not hold, the angle from the initial value with the escape point 1 as the center. Keep on. The direction of the angle (rotation direction) may be either clockwise or counterclockwise, but it may be rotated in one direction, and if it is not possible, it returns to the initial value and the angle is set in the plate edge direction. .

  If the initial value is not satisfied, an angle is added each time the process proceeds to S307 after the second time. If the computer 11 cannot rotate any more (S308: YES), the computer 11 terminates the process because it is impossible to create the extraction path (S312). On the other hand, if further rotation is possible in S308, the subsequent processing is continued.

  In S307, the route from the welding point to the escape point 1 to the escape point 2 is set from the information so far. As shown in FIG. 13D, the path from the welding point to the relief point 1 to the welding point 2 is set to the path from the welding point to the relief point 1, and then, the path from the welding point to the relief point 1 is perpendicular. Create escape point 1 and escape point 2.

  Next, the computer 11 examines the feasibility of the route in consideration of the gun opening amount (stroke) (S309 and 310). This is the same as the case of creating a route connecting to a straight line, and it is determined whether the temporary route (welding point to relief point 1 to relief point 2) created up to this point is established with guns of various opening amounts set in advance. Check sequentially.

  In other words, the check of establishment is performed by performing an interference check in the path from the welding point to the escape point 1 to the escape point 2.

  If the welding gun does not hold for all the opening amounts, the process returns to S309 to replace the welding gun with a larger opening amount, and the feasibility is checked. If the welding gun is exchanged (even if the gun with the largest opening amount is attached), if it is not established, the process returns to S307, the direction of the escape point 2 is reset, and the feasibility is checked. Further, if it does not hold even if the direction of the escape point 2 is reset, the process returns to S303, and the establishment is checked by lowering the escape point. If it does not hold even if the clearance point is further lowered, the process returns to S301 to reduce the clearance and check the feasibility.

  As described above, by considering the opening amount of the gun, setting the escape point 2 in various distances and directions, and searching for the route, the extraction route can be created with a high probability.

  Next, a procedure for creating an avoidance route will be described. FIG. 14 is a flowchart for explaining a procedure for creating an avoidance route. The avoidance path is between two target points (from the original position to the first welding point escape point 2, between the escape points 2 of the extraction path of the path that could not be linearly connected, and the last welding point escape point 2 Create at end position).

  First, the computer 11 takes out two points for creating an avoidance route (S401). The two points are the original position, the escape point 2 created by the above drawing route creation, and the like. That is, if it is an avoidance path from the original position, the escape point 2 of the first welding point is taken out. If it is the avoidance path of the welding points 3 and 4 made as the avoidance path, the escape point 2 of the welding point 3 and the escape point 2 of the welding point 4 are taken out. The same applies to other avoidance routes.

  Next, the computer 11 creates an avoidance route (S402). Here, the feasibility of the route between the two acquired points is also checked, but since it is basically a part away from the workpiece, generally known route setting may be performed. For example, it can be created using a generally known route plan (road map method or the like: reference book, Robot Motion Planning, Latombe 1991 edition or the like). Of course, the interference check method described as the present embodiment may be used.

  Next, the computer 11 determines whether an avoidance route has been created (S403). If an avoidance route can be created here, that route is adopted (S404). If the avoidance path cannot be created in S403 (S403: NO), the computer 11 records that fact (S407) and proceeds to the next avoidance path creation. The point where the avoidance path cannot be created recorded in S407 is a welding point where another path cannot be created. Therefore, the fact is displayed on the computer 11 to inform the designer.

  Next, the computer 11 searches for a point to create the next avoidance route (S405). If there is no next avoidance route creation point (S406: YES), the process ends. On the other hand, if there is a next avoidance route creation point (S406: NO), the process returns to S401, and the avoidance route creation point found by the search is taken out, and the subsequent processing is continued.

  FIG. 15 is an image diagram of the extraction route and the avoidance route creation described above. First, an extraction route is created as shown in FIG. 15 (a), and then an avoidance route is created as shown in FIG. 15 (b).

  In this embodiment, another route is automatically created. However, this is merely an example, and for a weld point that cannot be connected by a straight line, another route is manually created by the designer. You can do that.

  The effect by embodiment described above is demonstrated.

  (1) When there is another welding point that does not perform welding operation between two welding points that set the path, conventionally, the interference check is not performed on the portion having the welding point in advance. In this embodiment, the region of such other welding points is made invalid. Thus, even if there is another welding point that does not perform the welding operation between the two welding points that set the path, the interference check can be surely performed. Therefore, even if there is a welding point where welding is not performed in the path, it is possible to prevent the tip of the welding gun (particularly the welding tip) from coming into contact with the workpiece inadvertently at that portion.

  (2) A region having a radius corresponding to the clearance point from the welding point as a radius is set as the welding point region, and further, the distance from the center of the welding point to the workpiece end where the workpiece enters at least the open part of the welding gun. We decided to set the area near the welding point with a radius of. In this way, by focusing on the welding points and setting areas on the workpiece and outside the workpiece, an interference check suitable for each can be performed.

  (3) For each set region, a different clearance value is set in the region near the welding point and outside the region near the welding point (free space portion). As a result, it is possible to move closer positions while avoiding interference in the area inside the workpiece, while it is possible to perform interference check suitable for high-speed movement by setting a larger clearance outside the workpiece. it can.

  (4) If there is interference as a result of the interference check, the interference is checked again by reducing the clearance value in the route. This makes it possible to create a straight path, that is, the shortest path, even when complicated work shapes, jigs, and facilities are arranged.

  (5) Further, as a result of further interference check, when a path between two welding points cannot be created as a straight path, another path is created between the two welding points. In particular, in creating this separate path, a flank point 1 is created immediately below the welding point, and a flank point 2 is created from the flank point 1 to a position outside the workpiece. Then, the position of the escape point 2 is determined by rotating around the escape point 1. By creating such another route, it is possible to automatically create another route even between two points that cannot be connected by a straight line.

  As described above, the embodiment to which the present invention is applied, mainly the case where the tool is a welding gun and the work point operated by the tool is a welding point, has been described. However, the present invention is not limited to the above embodiment. For example, the work performed by the robot includes joining other than welding. Joining includes, for example, adhesion, screwing, and the like in addition to welding. Further, the work includes drilling (punching), engraving, dyeing, marking, measurement and the like in addition to joining. In order to perform these operations, various tools are attached to the robot. The work route creation device, the work route creation procedure, and the work route creation program described in the above embodiment can also be applied to work using such various tools.

  Further, the program including the procedure described in this embodiment may be stored in a computer-readable recording medium. A function as a work route creation device can be implemented by installing a program from this recording medium into a computer. Such a recording medium is not particularly limited, and examples thereof include an optical disk (CD-ROM, DVD, etc.), a magnetic disk, and the like. A server connected to a computer via a network is also a recording medium.

  The present invention is construed by the claims, and is not construed as being limited to the above-described embodiment which is an application example of welding.

  Furthermore, this application is based on the JP Patent application number 2013-193537 for which it applied on September 18, 2013, The content of those indications is referred and is incorporated as a whole.

1-4 working points (welding points),
11 Computer,
12 servers,
13 network,
14 Robot controller,
100 work (panel),
200 Servo gun (tool: welding gun),
201 movable part,
202 fixing part,
201a, 202a Welding tips.

Claims (22)

A work point selector that selects two work points from a plurality of work points and sets a route connecting the two work points;
An area setting unit that sets a work point area that does not perform interference check when performing interference check on the plurality of work points excluding at least the two work points;
When there is another work point between the two selected work points, the work point area invalid part which invalidates the work point area set to the other work point;
An interference check unit for performing an interference check on a route connecting the two work points;
A work route creation device having   The work path creation device according to claim 1, wherein the work point is a joint point for performing a joint work for joining a plurality of members.   The work path creation device according to claim 2, wherein the joining point is a welding point. The region setting unit sets, as the welding point region, a region having a radius corresponding to a clearance point around the welding point as a radius,
The work path creation device according to claim 3, further comprising a welding point vicinity region having a radius from a center of the welding point to a workpiece end where the workpiece enters at least a portion where the welding gun is open.   The interference check unit performs interference check by setting different clearance values in a region near the welding point and a region outside the region near the welding point as a clearance between the welding gun tip and the workpiece during the interference check. The work route creation device according to claim 4.   The work path creation device according to claim 1, wherein the interference check unit performs interference check again by reducing a clearance value in the path when interference occurs as a result of the interference check. As a result of the interference check by the interference check unit, when another path between the two selected work points cannot be created as a straight path, there is further provided another path creation unit for creating another path between the two selected work points. And
The separate path creation unit creates a clearance point 1 immediately below the work point for creating the separate path, creates a clearance point 2 from the clearance point 1 to a position outside the workpiece, and further the clearance point 2 The work path creation device according to claim 1, wherein the position is obtained by rotating around the escape point 1. Selecting two work points from a plurality of work points and setting a route connecting the two work points;
Setting a work point area where interference check is not performed when performing interference check on the plurality of work points excluding at least the two work points;
When there is another work point between the two selected work points, invalidating the work point area set to the other work point;
Checking the path connecting the two work points for interference;
A method for creating a work route.   The work route creation method according to claim 8, wherein the work point is a joint point for performing a joint work for joining a plurality of members.   The work path creation method according to claim 9, wherein the joining point is a welding point. The step of setting the welding point region that does not perform the interference check, the region having a radius equivalent to the escape point centered on the welding point is set as the welding point region
The work path creation method according to claim 10, further comprising setting a welding point vicinity region having a radius from a center of the welding point to a workpiece end where the workpiece enters at least a portion where the welding gun is open.   In the interference check step, the interference check is performed by setting different clearance values in the region near the welding point and the region outside the region near the welding point as the clearance between the welding gun tip and the workpiece during the interference check. The work route creation method according to claim 11.   13. The work route creation method according to claim 8, wherein when the interference check results in the interference check, the interference check is performed again by reducing the clearance value in the route. . As a result of performing the interference check in the step of performing the interference check, when it is not possible to create a straight path between the two selected work points, the method further includes a step of creating another path between the two selected work points,
The step of creating another route is to create a relief point 1 immediately below the work point for creating the another route, create a relief point 2 from the relief point 1 to a position outside the workpiece, and further to the escape point. The work path creation method according to any one of claims 8 to 13, wherein the position of the point 2 is obtained by rotating around the escape point 1 to be established. Selecting two work points from a plurality of work points and setting a route connecting the two work points;
Setting a work point area that does not perform interference check when performing interference check on the plurality of work points excluding at least the two work points;
When there is another work point between the two selected work points, invalidating the work point area set to the other work point;
Interference checking a route connecting the two work points;
A work route creation program that creates a route to work by running a computer.   The work route creation program according to claim 15, wherein the work point is a joint point for performing a joint work for joining a plurality of members. The work path creation program according to claim 16, wherein the joining point is a welding point. The step of setting the welding point region without the interference check, the region having a radius corresponding to the escape point centered on the welding point is set as the welding point region,
18. The work path creation program according to claim 17, further comprising setting a welding point vicinity region having a radius from a center of the welding point to a workpiece end where the workpiece enters at least a portion where the welding gun is open.   In the interference check step, the interference check is performed by setting different clearance values in the region near the welding point and the region outside the region near the welding point as the clearance between the welding gun tip and the workpiece during the interference check. The work route creation program according to claim 18.   The work route creation program according to any one of claims 15 to 19, wherein, when the interference check is performed as a result of the interference check, the interference check is performed again by reducing a clearance value in the route. . As a result of the interference check in the interference check step, when the selected two work points cannot be created as a straight path, the method further includes a step of creating another path between the two selected work points,
The step of creating another route is to create a relief point 1 immediately below the work point for creating the another route, create a relief point 2 from the relief point 1 to a position outside the workpiece, and further to the escape point. The work path creation program according to any one of claims 15 to 20, wherein the position of the point 2 is obtained by rotating around the escape point 1 to be established.   A computer-readable recording medium storing the work route creation program according to any one of claims 15 to 21.