A boiler round tube welding positioning method and terminal

Abstract

The present invention provides a method and terminal for positioning welding of boiler round tubes, which control a laser scanning device to move along a preset arrangement direction of the round tubes to obtain scanning data; confirm line scanning information corresponding to the round tubes in the scanning data according to a round tube recognition threshold; determine the center position of the round tube according to the line scanning information; adjust the welding center position of a welding robot according to the center position and perform welding operations; the present invention performs positioning through laser scanning and scans along a preset arrangement direction, and only scans the position of the round tube in one direction at a time, realizing layer-by-layer scanning, thereby increasing the accuracy of positioning the round tubes; and adjusts the welding center position of the robot according to the determined center position of the round tubes, thereby ensuring the correspondence between the welding position and the position of the round tubes; and calculating the position of the arc through the center of the circle also improves the efficiency of positioning the round tubes.

Description

Technical Field

[0001] The invention relates to the field of welding positioning, and in particular to a boiler round tube welding positioning method and a terminal. Background Art

[0002] The fixation between the round tube and the drum in the boiler is a difficult point in the process of boiler automation manufacturing; the round tube itself is an arc surface, and the drum is also an arc surface, which increases the difficulty of positioning the weld. Therefore, in the existing implementation method, manual welding is usually used to achieve the fixation between the round tube and the drum.

[0003] However, the space inside the drum is small, and the heat generated during welding is not easy to dissipate, resulting in an uncomfortable operating environment for welders and affecting welding efficiency. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a boiler round tube welding positioning method to realize automated boiler welding.

[0005] In order to solve the above technical problems, a technical solution adopted by the present invention is:

[0006] A boiler round tube welding positioning method comprises the following steps:

[0007] Control the laser scanning device to move along the preset arrangement direction of the round tube to obtain scanning data;

[0008] Confirming line scan information corresponding to the round tube according to the round tube recognition threshold and the scanning data;

[0009] Determining the center position of the circular tube according to the line scan information;

[0010] The welding center position of the welding robot is adjusted according to the center position of the circle and welding operation is performed.

[0011] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0012] A boiler round tube welding positioning terminal comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the following steps when executing the computer program:

[0013] Control the laser scanning device to move along the preset arrangement direction of the round tube to obtain scanning data;

[0014] Confirming line scan information corresponding to the round tube according to the round tube recognition threshold and the scanning data;

[0015] Determining the center position of the circular tube according to the line scan information;

[0016] The welding center position of the welding robot is adjusted according to the center position of the circle and welding operation is performed.

[0017] The beneficial effects of the present invention are as follows: positioning is performed by laser scanning and scanning is performed along a preset arrangement direction, so that the position of the circular tube is only scanned in one direction at a time, layer-by-layer scanning is achieved, the accuracy of positioning the circular tube is increased, and the welding center position of the robot is adjusted according to the determined center position of the circular tube, thereby ensuring the correspondence between the welding position and the position of the circular tube, and the position of the circular arc is calculated by the center of the circle, which also improves the efficiency of positioning the circular tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A flow chart of steps of a boiler round tube welding positioning method according to an embodiment of the present invention;

[0019] Figure 2 This is a structural schematic diagram of a boiler round tube welding positioning terminal according to an embodiment of the present invention;

[0020] Figure 3 It is a schematic diagram of the arrangement of circular tubes in a flat top view of the main circular tubes in an embodiment of the present invention;

[0021] Description of labels:

[0022] 1. A boiler round tube welding positioning terminal; 2. A processor; 3. A memory. DETAILED DESCRIPTION

[0023] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0024] Please refer to Figure 1 , a boiler round tube welding positioning method, comprising the steps of:

[0025] Control the laser scanning device to move along the preset arrangement direction of the round tube to obtain scanning data;

[0026] Confirming line scan information corresponding to the round tube according to the round tube recognition threshold and the scanning data;

[0027] Determining the center position of the circular tube according to the line scan information;

[0028] The welding center position of the welding robot is adjusted according to the center position of the circle and welding operation is performed.

[0029] From the above description, it can be seen that the beneficial effects of the present invention are: positioning is performed by laser scanning and scanning is performed along a preset arrangement direction, so that the position of the circular tube is only scanned in one direction at a time, and layer-by-layer scanning is realized, thereby increasing the accuracy of the positioning of the circular tube, and adjusting the welding center position of the robot according to the determined center position of the circular tube, thereby ensuring the correspondence between the welding position and the position of the circular tube, and calculating the position of the arc by the center of the circle also improves the efficiency of positioning the circular tube.

[0030] Further, the line scan information corresponding to the round tube confirmed in the scan data according to the round tube recognition threshold includes:

[0031] Confirming line scan information corresponding to a single round tube according to a first round tube recognition threshold;

[0032] According to the second round tube recognition threshold, it is confirmed whether the currently scanned round tube is the last round tube in the preset arrangement direction. If so, the laser scanning device is reset to scan the next row of round tubes in the preset arrangement direction.

[0033] From the above description, it can be seen that the line scan information corresponding to a single circular tube is confirmed according to the first circular tube recognition threshold. If the circular tube is the last circular tube along the preset arrangement direction, the laser scanning device is reset to scan the next row of circular tubes corresponding to the preset arrangement direction, thereby realizing row-by-row scanning of the circular tubes and improving the scanning accuracy.

[0034] Further, the line scan information corresponding to the round tube confirmed in the scan data according to the round tube recognition threshold includes:

[0035] Acquire scanning points in the scanning data and coordinate values ​​of each scanning point;

[0036] If the number of scanning points whose coordinate values ​​are greater than the recognition threshold reaches a first preset value, the line scan information corresponding to the circular tube starts to be recorded until a scanning point whose coordinate value is less than the recognition threshold appears, at which time the line scan information is recorded; the line scan information includes a line scan identifier and a line scan length.

[0037] From the above description, it can be seen that the coordinate values ​​corresponding to the scanning points in the scanning data are obtained. If the number of coordinate values ​​greater than the recognition threshold reaches a first preset value, it means that the line scan information is recorded at this time, and the scanning results are disassembled and analyzed according to the recognition threshold, which reduces the amount of single analysis and improves the accuracy of the analysis, so that the final circular tube contour and center position are more accurate.

[0038] Further, determining the center position of the circular tube according to the line scan information includes:

[0039] Get the longest maximum line scan length and the shortest minimum line scan length;

[0040] The coordinate value of the center position is obtained according to the average value of the starting coordinate value and the ending coordinate value of the maximum line scan length and the average value of the starting coordinate value and the ending coordinate value of the minimum line scan length.

[0041] From the above description, it can be seen that the coordinates of the center position are obtained according to the average value of the coordinate values ​​of the maximum line scan length and the minimum line scan length, which can neutralize the errors generated during the scanning process.

[0042] Furthermore, the step of adjusting the welding center position of the welding robot according to the circle center position and performing the welding operation further includes:

[0043] The moving path of the welding robot is set according to the center position of the next round tube in the scanning direction.

[0044] From the above description, it can be seen that when performing welding operation at the current position, the center position of the next round tube can be obtained from the scanning information. If the moving path of the welding robot is set, the operation of the next round tube can be performed immediately, which improves the efficiency of the operation.

[0045] Please refer to Figure 2 A boiler round tube welding positioning terminal includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the following steps are implemented:

[0046] Control the laser scanning device to move along the preset arrangement direction of the round tube to obtain scanning data;

[0047] Confirming line scan information corresponding to the round tube according to the round tube recognition threshold and the scanning data;

[0048] Determining the center position of the circular tube according to the line scan information;

[0049] The welding center position of the welding robot is adjusted according to the center position of the circle and welding operation is performed.

[0050] The beneficial effects of the present invention are as follows: positioning is performed by laser scanning and scanning is performed along a preset arrangement direction, so that the position of the circular tube is only scanned in one direction at a time, layer-by-layer scanning is achieved, the accuracy of positioning the circular tube is increased, and the welding center position of the robot is adjusted according to the determined center position of the circular tube, thereby ensuring the correspondence between the welding position and the position of the circular tube, and the position of the circular arc is calculated by the center of the circle, which also improves the efficiency of positioning the circular tube.

[0051] Further, the line scan information corresponding to the round tube confirmed in the scan data according to the round tube recognition threshold includes:

[0052] Confirming line scan information corresponding to a single round tube according to a first round tube recognition threshold;

[0053] According to the second round tube recognition threshold, it is confirmed whether the currently scanned round tube is the last round tube in the preset arrangement direction. If so, the laser scanning device is reset to scan the next row of round tubes in the preset arrangement direction.

[0054] From the above description, it can be seen that the line scan information corresponding to a single circular tube is confirmed according to the first circular tube recognition threshold. If the circular tube is the last circular tube along the preset arrangement direction, the laser scanning device is reset to scan the next row of circular tubes corresponding to the preset arrangement direction, thereby realizing row-by-row scanning of the circular tubes and improving the scanning accuracy.

[0055] Further, the line scan information corresponding to the round tube confirmed in the scan data according to the round tube recognition threshold includes:

[0056] Acquire scanning points in the scanning data and coordinate values ​​of each scanning point;

[0057] If the number of scanning points whose coordinate values ​​are greater than the recognition threshold reaches a first preset value, the line scan information corresponding to the circular tube starts to be recorded until a scanning point whose coordinate value is less than the recognition threshold appears, at which time the line scan information is recorded; the line scan information includes a line scan identifier and a line scan length.

[0058] From the above description, it can be seen that the coordinate values ​​corresponding to the scanning points in the scanning data are obtained. If the number of coordinate values ​​greater than the recognition threshold reaches a first preset value, it means that the line scan information is recorded at this time, and the scanning results are disassembled and analyzed according to the recognition threshold, which reduces the amount of single analysis and improves the accuracy of the analysis, so that the final circular tube contour and center position are more accurate.

[0059] Further, determining the center position of the circular tube according to the line scan information includes:

[0060] Get the longest maximum line scan length and the shortest minimum line scan length;

[0061] The coordinate value of the center position is obtained according to the average value of the starting coordinate value and the ending coordinate value of the maximum line scan length and the average value of the starting coordinate value and the ending coordinate value of the minimum line scan length.

[0062] From the above description, it can be seen that the coordinates of the center position are obtained according to the average value of the coordinate values ​​of the maximum line scan length and the minimum line scan length, which can neutralize the errors generated during the scanning process.

[0063] Furthermore, the step of adjusting the welding center position of the welding robot according to the circle center position and performing the welding operation further includes:

[0064] The moving path of the welding robot is set according to the center position of the next round tube in the scanning direction.

[0065] From the above description, it can be seen that when performing welding operation at the current position, the center position of the next round tube can be obtained from the scanning information. If the moving path of the welding robot is set, the operation of the next round tube can be performed immediately, which improves the efficiency of the operation.

[0066] The above-mentioned boiler round tube welding positioning method and terminal of the present invention can be applied to the welding of round tubes and drums in the boiler manufacturing process, and will be described below through specific implementation methods.

[0067] Please refer to Figure 1 , Embodiment 1 of the present invention is:

[0068] A boiler round tube welding positioning method comprises the following steps:

[0069] S0, initial point setting, the robot arm moves the laser scanning device to the center of the main round tube to be welded, establishes the earth coordinate system, the mobile coordinate system and the laser positioning coordinate system, and manually selects the non-hole laser scanning as the starting point position (x, y zero point), the mobile coordinate system and the laser positioning coordinate system, and changes the coordinates during use, and focuses the laser;

[0070] In an optional embodiment, a geodetic coordinate system is established according to the overall placement position of the boiler; the main axis xyz of the drum is located according to the center position of the main circular tube, that is, the mobile coordinate system of the corresponding robot arm; the geodetic coordinate system is located with respect to the specific position in the real environment, and the mobile coordinate system is established based on the robot that moves the main axis of the entire main circular tube. The laser scanning of the circular tube position at the end of the robot obtains the relative coordinates with the mobile coordinate system, so it is necessary to establish these three coordinate systems, and realize positioning through the conversion between the coordinate systems;

[0071] S1, controlling the laser scanning device to move along the preset arrangement direction of the round tubes to obtain scanning data; that is, the scanning data of the round tubes can be obtained row by row;

[0072] S2. Confirming line scan information corresponding to the round tube according to the round tube recognition threshold and the scan data, including:

[0073] S21, confirming the line scan information corresponding to a single round tube according to the first round tube recognition threshold: obtaining the scanning points in the scanning data and the coordinate values ​​of each of the scanning points; if the number of scanning points whose coordinate values ​​are greater than the first round tube recognition threshold reaches a first preset value, starting to record the line scan information corresponding to the round tube, and ending the recording of the line scan information when a scanning point whose coordinate value is less than the first round tube recognition threshold appears; the line scan information includes a line scan identifier and a line scan length;

[0074] In an optional embodiment, the scanning starts from the non-hole area, that is, the area where there is no round tube. Figure 3, where the circle represents the cross section of the circular tube. The number of scanning points corresponding to the two line scans tangent to the cross section of the circular tube will change. When scanning the area where there is no circular tube, the number of scans will change again. If it suddenly exceeds the threshold, it means that a circular tube is found. If it is lower than the threshold, it means that it has reached a non-hole position, and this interval belongs to a circular tube.

[0075] In an optional implementation, i is used to represent the number of rows of cylinders in a preset arrangement direction, j is used to represent the number of cylinders in each row, and k is used to represent the number of line scans of each cylinder. Then:

[0076] S211, obtain the coordinate value (X) of the scanning point in the scanning data i* ,Y i* ,Z i* ), because data can only be obtained through laser, the current coordinates are compared with the main tube radius by the laser corresponding to the moving coordinate system. The total number of i and j can be calculated based on the corresponding parameters of the main tube and the tube to be welded, that is, it is known. If Z ij* >Z g When the number of scanning points reaches a first preset value, the line scanning information corresponding to the round tube starts to be recorded; wherein Z g Indicates the first round tube recognition threshold. If the value is less than this value, it means that the position does not belong to the round tube range; until Z ij* <Z g , end recording the line scan information, and record the line scan identifier and line scan length of the line scan information;

[0077] When Z ij* >Z g When the number of scanning points reaches the first preset value, it means that the round tube has been scanned. Since the round tube penetrates the inner wall of the main round tube, if the laser scan hits the inner coordinate Z value of the round tube hole, it will become larger, and on the tube wall it will be smaller than a certain value (at least smaller than the radius of the main round tube, and this value can be obtained in the boiler drum design drawing). Therefore, according to the line scan threshold, it can be marked that a line scan of the round tube has been completed;

[0078] S212, when Z appears ij* >Z g When Z appears, start recording the line scan information corresponding to the round tube. ij* <Z g , end recording the line scan information, and record the line scan identifier and line scan length of the line scan information;

[0079] S213, loop through S212 until Z appears ijk <Z g ; Then the j-th circular tube corresponds to k line scans;

[0080] That is, step S211 is to find the first line scan corresponding to the round tube in the scanning direction, and step S212 is to loop to obtain the remaining line scans;

[0081] S22, confirm whether the currently scanned circular tube is the last circular tube in the preset arrangement direction according to the second circular tube recognition threshold value, if so, reset the laser scanning device and scan the next row of circular tubes in the preset arrangement direction; the boiler drum drawing will indicate the angle within which the circular tubes are located, and the end position can be found by comparing the number of circular tubes with the reference drawing, and if the laser moves beyond a certain range without a change in the Z threshold value, that is, no new circular tube is found, it means that the scanning of one row is finished;

[0082] In an optional embodiment, when Z i* <Z g If the number of scanning points is less than the second preset value, it is judged as the last round tube; that is, no new round tube is found in this row;

[0083] In an optional embodiment, resetting the laser scanning device includes: comparing the laser distance in the z direction at the non-circular tube row, and fine-tuning the robot position to a value less than a fixed threshold in the z direction; specifically, the robot moving position will deviate from the preset main circular tube radius, so during the movement and comparison process, the non-hole distance scanned by the laser can be adjusted by comparing the distance with the main axis radius given in the drawing, which can be obtained by fine-tuning the robot;

[0084] S3, determining the center position of the circular tube according to the line scan information, including: obtaining the longest maximum line scan length and the shortest minimum line scan length; obtaining the coordinate value of the center position according to the average of the starting coordinate value and the ending coordinate value of the maximum line scan length and the starting coordinate value and the ending coordinate value of the minimum line scan length; that is, in step S2, the line scan length (for example, Figure 3 The distance between the two intersection points of a line scan and a circular tube section is the line scan length of the circular tube);

[0085] In an optional implementation, the center position is set to (r x ,r y ,r z ),in

[0086] In an optional embodiment, the r of adjacent round tubes is compared. z The distance between the coordinates is calculated, and the center position is adjusted according to the comparison result, that is, the robot arm is fine-tuned. z Fine-tune the robot arm based on the coordinates and the circle spacing designed on the drawing;

[0087] S4, adjusting the welding center position of the welding robot according to the center position of the circle and performing welding operation; setting the moving path of the welding robot according to the center position of the next round tube in the scanning direction; that is, obtaining the line scanning information of the next round tube in step S2 and returning to execute S3;

[0088] In an optional embodiment, after receiving a signal including the center position of a circle, the welding robot arm starts to work and drives the welding device to move so that the center of the flexible positioning rod at the bottom of the welding device moves to the center position of the circle.

[0089] In an optional embodiment, step S4 can be executed when the center position of the circle is received, that is, steps S1-S3 and step S4 are relatively independent and there is no need to wait until step S4 is completed before executing S1. Therefore, the scanning of the circular tube position and the welding process can be performed independently of each other, realizing scanning and welding at the same time, thereby improving welding efficiency.

[0090] Please refer to Figure 2 , Embodiment 2 of the present invention is:

[0091] A boiler round tube welding positioning terminal 1 comprises a processor 2, a memory 3 and a computer program stored in the memory 3 and executable on the processor 2. When the processor 2 executes the computer program, each step in the first embodiment is implemented.

[0092] In summary, the present invention provides a method and terminal for positioning welding of boiler round tubes, which scan and locate the round tubes to be welded in the boiler drum row by row by means of laser scanning, and calculate the center position of the round tubes. The welding robot locates the welding seam according to the center position, and utilizes the fixed shape of the round tubes to ensure the positioning accuracy while improving the scanning efficiency while scanning row by row; at the same time, utilizing the characteristics of the boiler drum surface, the position of the round tube is distinguished by the size of the Z coordinate, which also improves the scanning efficiency; at the same time, the scanning process and the welding process are set relatively independently, and the welding process can start positioning and welding as long as a center position is received during the welding process, and the scanning process does not need to wait for the welding to be completed, which further improves the efficiency of automatic boiler manufacturing. However, since the correlation line formed by the cylinder tube wall and the convection tube wall of the large waste heat boiler is a complex spatial curve, most of them still use manual entry into the cylinder to perform welding operations. The method provided by the present application is conducive to round tube welding positioning, which replaces manual search for round tube weld positions.

[0093] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A boiler round tube welding positioning method, characterized in that: Includes steps: Control the laser scanning device to move along the preset arrangement direction of the round tube to obtain scanning data; confirming line scan information corresponding to the round tube in the scan data according to a round tube recognition threshold; Determining the center position of the circular tube according to the line scan information; Adjusting the welding center position of the welding robot according to the center position of the circle and performing welding operations; The step of confirming the line scan information corresponding to the round tube in the scan data according to the round tube recognition threshold comprises: Confirming line scan information corresponding to a single round tube according to a first round tube recognition threshold; According to the second round tube recognition threshold, it is confirmed whether the currently scanned round tube is the last round tube in the preset arrangement direction. If so, the laser scanning device is reset to scan the next row of round tubes in the preset arrangement direction.

2. A boiler round tube welding positioning method according to claim 1, characterized in that: The step of confirming the line scan information corresponding to the round tube in the scan data according to the round tube recognition threshold comprises: Acquire scanning points in the scanning data and coordinate values ​​of each scanning point; If the number of scanning points whose coordinate values ​​are greater than the recognition threshold reaches a first preset value, the line scan information corresponding to the circular tube starts to be recorded until a scanning point whose coordinate value is less than the recognition threshold appears, at which time the line scan information is recorded; the line scan information includes a line scan identifier and a line scan length.

3. A boiler round tube welding positioning method according to claim 2, characterized in that: Determining the center position of the circular tube according to the line scan information includes: Get the longest maximum line scan length and the shortest minimum line scan length; The coordinate value of the center position is obtained according to the average value of the starting coordinate value and the ending coordinate value of the maximum line scan length and the average value of the starting coordinate value and the ending coordinate value of the minimum line scan length.

4. A boiler round tube welding positioning method according to claim 1, characterized in that: The step of adjusting the welding center position of the welding robot according to the center position of the circle and performing the welding operation further includes: The moving path of the welding robot is set according to the center position of the next round tube in the scanning direction.

5. A boiler round tube welding positioning terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the following steps when executing the computer program: Control the laser scanning device to move along the preset arrangement direction of the round tube to obtain scanning data; Confirming line scan information corresponding to the round tube according to the round tube recognition threshold and the scanning data; Determining the center position of the circular tube according to the line scan information; Adjusting the welding center position of the welding robot according to the center position of the circle and performing welding operations; The step of confirming the line scan information corresponding to the round tube in the scan data according to the round tube recognition threshold comprises: Confirming line scan information corresponding to a single round tube according to a first round tube recognition threshold; According to the second round tube recognition threshold, it is confirmed whether the currently scanned round tube is the last round tube in the preset arrangement direction. If so, the laser scanning device is reset to scan the next row of round tubes in the preset arrangement direction.

6. A boiler round tube welding positioning terminal according to claim 5, characterized in that: The step of confirming the line scan information corresponding to the round tube in the scan data according to the round tube recognition threshold comprises: Acquire scanning points in the scanning data and coordinate values ​​of each scanning point; If the number of scanning points whose coordinate values ​​are greater than the recognition threshold reaches a first preset value, the line scan information corresponding to the circular tube starts to be recorded until a scanning point whose coordinate value is less than the recognition threshold appears, at which time the line scan information is recorded; the line scan information includes a line scan identifier and a line scan length.

7. A boiler round tube welding positioning terminal according to claim 6, characterized in that: Determining the center position of the circular tube according to the line scan information includes: Get the longest maximum line scan length and the shortest minimum line scan length; The coordinate value of the center position is obtained according to the average value of the starting coordinate value and the ending coordinate value of the maximum line scan length and the average value of the starting coordinate value and the ending coordinate value of the minimum line scan length.

8. A boiler round tube welding positioning terminal according to claim 5, characterized in that: The step of adjusting the welding center position of the welding robot according to the center position of the circle and performing the welding operation further includes: The moving path of the welding robot is set according to the center position of the next round tube in the scanning direction.

Images