Offline calibration device and system

Abstract

The present invention relates to the technical field of converter steelmaking, and in particular to an offline calibration device and system. The offline calibration device comprises: an offline calibration frame, including a calibration bracket and a water outlet simulation mounting plate, one side of the water outlet simulation mounting plate is connected to the calibration bracket, and the other side is provided with at least three first positioning columns with consistent concentric axes; an auxiliary calibration tool comprises a calibration block and a second positioning column arranged on the calibration block and corresponding to the first positioning column; a long water outlet clamp, connected to the end of a machine arm for clamping the long water outlet, by connecting the auxiliary calibration tool to the long water outlet clamp, the end of the first positioning column and the end of the second positioning column are aligned for visual calibration; the water outlet simulation mounting plate simulates the water outlet environment in actual production, so that the calibration result is consistent with the actual situation without affecting the actual production.

Description

Technical Field

[0001] The invention relates to the technical field of converter steelmaking, and in particular to an off-line calibration device and system. Background Art

[0002] In high-temperature, high-demand industrial environments such as steel smelting, the existing technical solution is to use robots and their machine vision to intelligently replace the shroud to replace manual methods.

[0003] Since the robot's operation of changing the shroud requires extremely high precision, any slight deviation may lead to production accidents or product quality problems. For example, when the visual device moves slightly, it needs to be recalibrated, including hand-eye calibration, tool calibration, and ladle mechanism disassembly and assembly of the shroud calibration.

[0004] Moreover, hand-eye calibration, tool calibration, and ladle mechanism disassembly and assembly long nozzle calibration are three interrelated but independent calibration processes. Each process takes a lot of time and manpower, and has high requirements on the skills and experience of the operator. When the position of the visual camera changes slightly, all three calibration processes need to be repeated, increasing the complexity and cost of production. In addition, in the actual production process, the high temperature and radiation during hot ladle make the calibration work impossible, limiting the feasibility of the calibration operation. If the current frequent lifting of cold ladle for calibration is used, it will affect production efficiency and may even cause unnecessary damage to production equipment.

[0005] Based on this, this application is filed. Summary of the invention

[0006] In response to the above technical problems, the purpose of this application is to provide a calibration device for use at the long nozzle installation of the ladle mechanism, that is, an offline calibration device and system, which is intended to automatically calibrate the long nozzle installation of the ladle and the end effector of the robot offline.

[0007] In the first aspect of the present application, an offline calibration device is provided, comprising: an offline calibration frame, comprising a calibration bracket and a drain outlet simulation mounting plate, wherein one side of the drain outlet simulation mounting plate is connected to the calibration bracket, and the other side is provided with at least three first positioning columns with consistent concentric axes; an auxiliary calibration tool, comprising a calibration block and a second positioning column arranged on the calibration block and corresponding to the first positioning column; a long water outlet clamp, connected to the end of a robot arm for clamping the long water outlet, and by connecting the auxiliary calibration tool to the long water outlet clamp, the end of the first positioning column and the end of the second positioning column are aligned for visual calibration.

[0008] In a further embodiment of the present application, there are three first positioning columns which are equally spaced around the circumference, the three first positioning columns are concentric with the calibration block, the ends of the first positioning column and the second positioning column are both conical; and / or the calibration block is annular.

[0009] In a further solution of the present application, the long water nozzle clamp includes a planar portion and a plurality of groove portions; the calibration block includes an inlay portion protruding in the vertical direction away from the second positioning column, and a horizontal flange in the radial direction; the calibration block is inserted into the groove portion through the inlay portion to constrain the circumferential rotational freedom, and the horizontal flange and the planar portion are in surface contact.

[0010] In a further scheme of the present application, the offline calibration device also includes: a long water nozzle storage rack, including a storage bracket and a long water nozzle slot and a plurality of positioning surfaces arranged on the storage bracket, the long water nozzle slot is used to place the long water nozzle of the ladle; the calibration bracket can be installed on the storage bracket through the plurality of positioning surfaces; wherein, the long water nozzle storage rack includes placing layers arranged in a stepped manner at different heights, and each placing layer includes at least two long water nozzle slots.

[0011] In a further scheme of the present application, a plurality of connecting plates of equal height are arranged on the drain simulation mounting plate, which are connected to the calibration bracket through the connecting plates; a plurality of extension blocks are arranged on the same surface of the drain simulation mounting plate and the first positioning column, and when the end of the first positioning column and the end of the second positioning column are aligned, the extension block is abutted against the surface of the calibration block where the second positioning column is arranged; and the drain simulation mounting plate includes an identification mark portion, and the number of the identification mark portions is at least two.

[0012] 8. In the second aspect of the present application, an offline calibration method is also provided, comprising: The offline calibration method comprises:

[0013] Control the end of the robot arm to move to the first preset position coordinate, and connect the auxiliary calibration tool to the long shroud holder;

[0014] Obtain the second position coordinates of the offline calibration frame;

[0015] After inputting the preset calibration program according to the second position coordinates and running it, a fixed-position image acquisition device is used to obtain calibration image information of the first positioning column and the second positioning column; based on the calibration image information, it is determined whether the end of the first positioning column and the end of the second positioning column are aligned to determine whether the calibration is successful; if the calibration is successful, the current second position coordinates are input into the preset running program to update the running program.

[0016] In a further scheme of the present application, determining whether the end of the first positioning column and the end of the second positioning column are aligned based on the calibration image information includes: obtaining a regional point cloud of the second positioning column; projecting the regional point cloud onto two intersecting vertical planes: a first projection plane and a second projection plane, respectively, to obtain a first projection image and a second projection image; fitting the endpoint coordinates of the second positioning column in the first projection image and the second projection image, respectively; and judging whether the end of the first positioning column and the end of the second positioning column are aligned based on the endpoint coordinates.

[0017] In a further scheme of the present application, the first projection image and the second projection image respectively fit the endpoint coordinates of the first positioning column and the second positioning column, including: according to the contour retrieval algorithm, in the first projection image, obtaining the first contour image of the second positioning column, and respectively obtaining the first vertex coordinates in the first contour image; according to the contour retrieval algorithm, obtaining the second contour image of the second positioning column in the second projection image, and respectively obtaining the second vertex coordinates in the second contour image; determining the first straight line according to the first vertex coordinates, and determining the second straight line according to the second vertex coordinates; determining that the end of the first positioning column and the end of the second positioning column are aligned when it is judged that all of the following conditions are met: the first straight line and the second straight line are both horizontal; the horizontal difference between the first vertex coordinates and the endpoint coordinates of the first positioning column is within a preset threshold range, and the horizontal difference between the second vertex coordinates and the endpoint coordinates of the first positioning column is within a preset threshold range.

[0018] In a further scheme of the present application, the offline calibration method also includes: in the case of unsuccessful calibration, based on a first difference vector between the first vertex coordinates and the known first positioning column endpoint coordinates, and a second difference vector between the second vertex coordinates and the known first positioning column endpoint coordinates; calculating a target vector in combination with the first difference vector and the second difference vector to adjust the end of the robot arm through the target vector.

[0019] In a second aspect of the present application, an offline calibration system is provided, comprising the offline calibration device as described above; a robotic arm, the end of which is connected to a long nozzle clamp; and a visual device connected to the robotic arm.

[0020] In summary, the offline calibration device and method provided by the embodiments of the present invention include at least the following technical effects:

[0021] 1. By setting the first and second positioning columns with the same concentric axis, the center calibration and plane calibration can be carried out simultaneously, and high-precision alignment and positioning can be achieved, thereby improving the accuracy and reliability of the calibration; in addition, the drain simulation mounting plate simulates the drain environment in actual production, so that the calibration result is consistent with the actual situation without affecting the actual production. The stable connection between the calibration bracket and the drain simulation mounting plate, as well as the connection between the long drain clamp and the end of the robot arm, ensure the quick-change characteristics of the entire calibration device during the calibration process.

[0022] 2. Significantly reduce manual intervention, thereby speeding up the calibration process. Especially in the high-temperature, high-radiation steel smelting environment, it avoids the safety risks that may be caused by direct operation by personnel, and also saves labor costs. It also allows calibration without affecting the normal production process, avoiding the interruption of production due to calibration, and improving production continuity.

[0023] 3. The calibration method corresponding to the offline calibration device can be fully automated, and its calibration process helps to maintain the consistency of the calibration process, thereby improving the calibration accuracy.

[0024] Other features and advantages of the embodiments of the present invention will be described in the following specific implementation examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 A schematic diagram of the structure of the off-line calibration device provided in an embodiment of the present application from a front view perspective;

[0027] Figure 2 A schematic diagram of the structure of an auxiliary calibration tool and a shroud holder in a separated state in an off-line calibration device provided in an embodiment of the present application;

[0028] Figure 3 This is an axial schematic diagram of an auxiliary calibration tool and a shroud holder in a separated state in an off-line calibration device provided in an embodiment of the present application;

[0029] Figure 4 It is an axial schematic diagram of the auxiliary calibration tool and the long nozzle clamp in the offline calibration device provided in the embodiment of the present application in a combined state;

[0030] Figure 5A schematic diagram of a first axis side view of an offline calibration frame in an offline calibration device provided in an embodiment of the present application;

[0031] Figure 6 A schematic diagram of a second axis side view of an offline calibration frame in an offline calibration device provided in an embodiment of the present application;

[0032] Figure 7 This is an axial schematic diagram of an offline calibration device provided in an embodiment of the present application;

[0033] Figure 8 A schematic diagram of the structure of an off-line calibration device provided in an embodiment of the present application;

[0034] Fig. 9 The overall flow chart of the offline calibration method provided in the embodiment of the present application;

[0035] Fig.10 A flowchart of step S40 in the offline calibration method provided in an embodiment of the present application;

[0036] Fig.11 A flowchart of step S43 in the offline calibration method provided in an embodiment of the present application; and

[0037] Fig.12 A further flow chart of the offline calibration method provided in the embodiment of the present application; Fig.13 This is a schematic diagram of a case where the first positioning column and the second positioning column provided in an embodiment of the present application have a relatively significant level difference.

[0038] The reference numerals are described as follows:

[0039] 100. Offline calibration device;

[0040] 10. Offline calibration frame; 11. Calibration bracket; 12. Downspout simulation installation plate; 121. Identification mark portion; 122. Connecting plate; 123. Extension block; 13. First positioning column; 14. Hanging bracket;

[0041] 20. Auxiliary calibration tool; 21. Calibration block; 211. Inlay portion; 212. Horizontal flange; 22. Second positioning column;

[0042] 30. Long shroud holder; 31. Plane portion; 32. Groove portion;

[0043] 40. shroud storage rack; 40a. placement layer; 41. storage bracket; 411. shroud slot; 412. positioning surface; 200. offline calibration system; 201. robotic arm; 202. visual device. DETAILED DESCRIPTION

[0044] The terms "second direction", "first direction", "third direction", "inside", "outside" and the like that appear below to indicate orientation or positional relationships, unless otherwise specified, are to be understood as being based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0045] In addition, if there is a feature defined as "first" or "second", it is only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Features defined as "first" or "second" may explicitly or implicitly include at least one of the defined features. If there is a description of "plurality", the general meaning is to include at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0046] In this application, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed" and so on should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection, it can be a direct connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0047] In the description of this specification, if the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" appear, it means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0048] Reference Figure 1 and Figure 2The present application first provides an offline calibration device 100, including an offline calibration frame 10, an auxiliary calibration tool 20 and a long shroud clamp 30. In the present offline calibration frame 10, the calibration frame 11 and the shroud simulation mounting plate 12 are included. The shroud simulation mounting plate 12 is connected to the calibration frame 11 on one side, and is provided with at least three first positioning columns 13 with consistent concentric axes on the other side; the auxiliary calibration tool 20 includes a calibration block 21 and a second positioning column 22 provided on the calibration block 21 and corresponding to the first positioning column 13; the long shroud clamp 30 is connected to the end of the robot arm for clamping the long shroud, and by connecting the auxiliary calibration tool 20 to the long shroud clamp 30, the end of the first positioning column 13 and the end of the second positioning column 22 are aligned to calibrate the visual device.

[0049] It should be noted that the visual device at the end of the robot arm in the present application is the object to be calibrated, and the offline calibration device 100 is a device used to calibrate the long visual device, which is usually used in a non-production environment (i.e., "offline" as defined in this application) to ensure the accuracy and reliability of the visual device in the process.

[0050] The calibration bracket 11 in the offline calibration frame 10 is firmly fixed on the ground or other devices to play a supporting role. The downspout simulation mounting plate 12 is a structure that simulates the downspout installation position of the ladle mechanism in actual production, and is used to simulate the installation environment of the long shroud on the production line. One side is connected to the calibration bracket 11, and the other side is provided with an auxiliary structure for positioning, namely the first positioning column 13: the first positioning column 13 is at least three and has the same concentric axis and is installed together on the downspout simulation mounting plate 12, which is used to provide a precise positioning reference to help calibrate the position and direction of the long shroud clamp 30.

[0051] It is understandable that more than three first positioning columns 13 can determine a fixed calibration reference circle center, and the ends of the first positioning columns 13 are all located in the same plane to achieve the center and plane calibration. The calibration block 21 in the auxiliary calibration tool 20 is used to cooperate with the long nozzle clamp 30 to perform the calibration operation, and the second positioning column 22 is integrated with the calibration block 21, corresponding to the first positioning column 13 on the downspout simulation mounting plate 12.

[0052] Furthermore, the shroud holder 30 is a mechanical device for holding the shroud, and is usually installed at the end of a robot arm or similar equipment. It is precisely installed at the end of the robot arm to ensure that the shroud can be stably and accurately held and moved in a high-temperature ladle environment. The calibration block 21 is connected to the shroud holder 30, so that the calibration block 21 can move with the shroud holder 30.

[0053] During the calibration process, the second positioning column 22 (located on the calibration block 21) needs to be precisely aligned with the first positioning column 13 (located on the shroud simulation mounting plate 12) to ensure that the position and direction of the shroud holder 30 meet the calibration requirements. This alignment is usually achieved by manually adjusting the position of the shroud holder 30 and observing whether the first positioning column 13 and the second positioning column 22 overlap. When the two are aligned, it can be indicated that the center and plane dual calibration is completed.

[0054] In the embodiment of the present application, there are three first positioning posts 13 and they are arranged at equal intervals around the circumference; the calibration block 21 is annular, and the three first positioning posts 13 and the calibration block 21 are concentric with each other.

[0055] Since the three first positioning posts 13 can define a central axis and their end points can define a plane, the three first positioning posts 13 are arranged at equal intervals around the circumference (i.e., the circumferential direction formed around a central point), so that the relative positions between the first positioning posts 13 are uniform, providing a more stable and accurate positioning reference.

[0056] The calibration block 21 is designed to be annular. The annular structure not only matches the coaxial axis of the first positioning column 13, but also can achieve lightweight while avoiding interference with other structures.

[0057] The three first positioning columns 13 and the calibration block 21 are designed to be coaxially consistent, which means that the coaxial axes between the two coincide. During the calibration process, when the calibration block 21 (connected with the shroud holder 30) is placed on the shroud simulation mounting plate 12, the shroud holder 30 can be accurately calibrated by ensuring that the central axis of the calibration block 21 coincides with the central axis of the first positioning column 13.

[0058] like Figures 2 to 4 In the embodiment of the present application, the long nozzle clamp 30 includes a plane portion 31 and a plurality of groove portions 32; the calibration block 21 includes an inlay portion 211 protruding in the vertical direction away from the second positioning column 22, and a horizontal flange 212 in the radial direction; the calibration block 21 is inserted into the groove portion 32 through the inlay portion 211 to constrain the circumferential rotational freedom, and at the same time, the horizontal flange 212 and the plane portion 31 are in surface contact.

[0059] It can be understood that the plane portion 31 is a flat area, which is used to provide a stable support surface to ensure the flatness of the calibration block 21. The calibration block 21 includes an inlay portion 211 and a horizontal flange 212. The inlay portion 211 is a portion that protrudes in the vertical direction away from the second positioning column 22, which allows the calibration block 21 to be firmly connected to the groove portion 32 of the long nozzle clamp 30 by plugging. This connection method not only fixes the position of the calibration block 21, but also limits its rotational freedom in the circumferential direction, ensuring the stability and accuracy of the operation.

[0060] When the calibration block 21 is mounted on the long nozzle clamp 30, the inlay portion 211 is inserted into the groove portion 32, achieving a firm connection between the two. This connection method is not only convenient and quick to connect, but also limits the rotational freedom of the calibration block 21 in the circumferential direction, and also ensures its stable positioning in other directions. At the same time, the surface contact between the horizontal flange 212 and the plane portion 31 further enhances the stability and flatness of the connection. This dual constraint design enables the calibration block 21 to maintain precise position during operation, thereby meeting various precise control requirements.

[0061] like Figures 5 to 7 The drain simulation installation plate 12 is provided with identification marking parts 121, and the number of identification marking parts 121 is at least two. The visual device on the machine wall can collect at least two double identification marking parts 121, and record and calibrate the position coordinates and posture of the drain simulation installation plate 12, as well as the position relationship of the drain simulation installation plate 12 relative to the long drain clamp 30 through algorithms such as geometric transformation and coordinate conversion.

[0062] In a further embodiment of the present application, the ends of the first positioning column 13 and the second positioning column 22 are both conical. The point design makes the ends of the positioning columns a precise contact point, reducing the position deviation that may be caused by excessive contact area. This high-precision contact method helps to achieve more accurate positioning and alignment and reduce error accumulation.

[0063] The offline calibration frame 10 can be placed on the ground or on other equipment.

[0064] In a preferred embodiment, the offline calibration device 100 further includes a shroud storage rack 40; the shroud storage rack 40 includes a storage bracket 41, a shroud slot 411 and a plurality of positioning surfaces 412 arranged on the storage bracket 41, the shroud slot 411 is used to place the ladle shroud; the calibration bracket 11 can be installed on the storage bracket 40 through the plurality of positioning surfaces 412. By using these positioning surfaces, the calibration bracket 11 can be conveniently installed on the shroud storage rack 40, thereby forming an integrated calibration and storage system.

[0065] The advantages of this integrated design are that the storage, calibration and replacement of the shroud can be completed at the same location, reducing the movement and transfer between equipment, further streamlining the equipment to reduce the floor space, and improving work efficiency. At the same time, due to the precise fit between the calibration bracket 11 and the shroud storage rack 40, the accuracy and reliability of the calibration process can also be ensured.

[0066] In the embodiment of the present invention, a hanging bracket 14 is provided on the calibration bracket 11, and the hanging bracket 14 is used to be hung by a lifting device, so as to install or remove the calibration bracket 11 as a whole from the long shroud storage rack 40. The hanging bracket 14 is installed on the calibration bracket 11 to provide a mounting point, so as to facilitate hanging on the lifting device, so as to use the lifting device to mount on the hanging bracket 14, and move it out of a certain position / move it back to the long shroud storage rack 40.

[0067] The drain simulation mounting plate 12 is provided with a plurality of connecting plates 122 of equal height, which are connected to the calibration bracket 11 through the connecting plates 122. That is, the connecting plate 122 is a connector between the drain simulation mounting plate 12 and the calibration bracket 11. It is connected to the calibration bracket 11 in a specific manner (such as bolt connection, welding or other fastening methods) to ensure the stability and accuracy of the entire calibration system. And the connecting plates 122 are designed to be equal in height, that is, their heights are consistent, which helps to achieve a level and stable connection between the calibration bracket 11 and the drain simulation mounting plate 12. The equal height design can also reduce the installation error caused by the height difference and improve the calibration accuracy.

[0068] A plurality of extension blocks 123 are arranged on the same surface of the shroud simulation mounting plate 12 and the first positioning column 13. When the end of the first positioning column 13 is aligned with the end of the second positioning column 22, the extension block 123 abuts against the surface of the calibration block 21 provided with the second positioning column 22. By observing the extension block 123, it can be determined whether the auxiliary calibration tool 20 is installed flatly on the long shroud holder 30.

[0069] It is understood that, under normal circumstances, the extension block 123 is in contact with the first positioning column 13 to provide an additional visual reference point. The calibration personnel can carefully observe the connection position between the extension block 123 and the calibration block 21 (especially the second positioning column 22). If the extension block 123 is tightly against the calibration block 21 and no obvious gap or misalignment is observed, it can be determined that the auxiliary calibration tool 20 has been installed flatly and accurately on the long nozzle clamp 30.

[0070] The long water nozzle storage rack 40 includes placement layers 40a arranged in a stepped manner at different heights. The long water nozzle slot 411 and the positioning surface 412 are arranged on each placement layer 40a, thereby allowing long water nozzles of multiple different heights or lengths to be stored simultaneously in the same storage rack, thereby improving the utilization rate of the storage space.

[0071] In the embodiment of the present invention, each placement layer includes at least two shroud slots 411 . According to actual needs, the shroud storage rack 40 can be designed with more shroud slots 411 or fewer shroud slots 411 .

[0072] In summary, the offline calibration device 100 provided in the embodiment of the present application achieves high-precision alignment and positioning by setting the first positioning column 13 and the second positioning column 22 with the same concentric axis, thereby improving the accuracy and reliability of calibration;

[0073] The drain simulation mounting plate 12 simulates the drain environment in actual production, so that the calibration result is consistent with the actual situation. The stable connection between the calibration bracket 11 and the drain simulation mounting plate 12, and the connection between the long drain clamp 30 and the end of the robot arm, ensure the stability of the entire calibration device during the calibration process. The close cooperation between the auxiliary calibration tool 20 and the long drain clamp 30 further enhances the reliability of the calibration.

[0074] Furthermore, those skilled in the art should understand that if the offline calibration device 100 provided in the embodiment of the present application; all or part of the sub-modules involved in each product are combined and replaced through embodiments such as fusion, simple change, mutual transformation, etc., such as the placement and movement of each component, or designing an offline calibration device 100; or a detachable design; or the product it constitutes is set as one, such as an integrated design; all the combined components can form a device / apparatus / system with specific functions, and using such a device / apparatus / system to replace the corresponding components of the present application also falls within the protection scope of the present application.

[0075] like Figure 8 The embodiment of the present application also provides an offline calibration system 200, including the offline calibration device 100, a robotic arm 201 and a visual device 202 as described above; wherein the end of the robotic arm 201 is connected to the long nozzle clamp 30; the visual device 202 is connected to the robotic arm 201.

[0076] like Fig. 9 Based on the above-mentioned offline calibration device 100, an offline calibration method provided in an embodiment of the present application includes:

[0077] Step S10, controlling the end of the robot arm to move to a preset first position coordinate, and connecting the auxiliary calibration tool 20 to the long shroud holder 30;

[0078] Step S20, obtaining the second position coordinates of the offline calibration frame;

[0079] Step S30, after inputting a preset calibration program according to the second position coordinates and running it, using a fixed position image acquisition device to obtain calibration image information of the first positioning column and the second positioning column;

[0080] Step S40: determining whether the end of the first positioning post and the end of the second positioning post are aligned according to the calibration image information to determine whether the calibration is successful;

[0081] Step S50: When the calibration is successful, the current second position coordinates are input into a preset operating program to update the operating program.

[0082] The robot arm controls its end to move to the placement area of ​​the auxiliary calibration tool 20 according to a preset program or instruction. The position coordinates of this area are known, so the robot arm can navigate the end directly to this position. That is, in this step, the robot arm does not actually need to perform additional measurements or identifications. When the end of the robot arm reaches above or near the auxiliary calibration tool 20, the inlay part is aligned and inserted into the groove part on the auxiliary calibration tool 20. This plug-in method is usually designed to be both stable and easy to operate to ensure that it does not accidentally fall off during the calibration process.

[0083] It should be noted that the "second position coordinates" in step S20 are the positions of the offline calibration frame acquired by the visual device on the robot arm through image acquisition. Specifically, a number of easily identifiable feature points pre-set on the offline calibration frame, namely the identification mark part 121 mentioned above, are identified through an image processing algorithm, and the second position coordinates are calculated based on their positions in the image.

[0084] Specifically, one or more template images suitable for the identification mark part are predefined, and these template images include the specific area or shape, color, etc. of the identification mark part 121 on the calibration frame. After the visual device captures the identification mark part 121, the real-time image is matched with the template image to find the coordinate result of the most similar area, and the second position coordinate currently obtained is calculated based on the matching result and the camera's internal parameters (focal length, optical center, etc.) and external parameters (positional relationship between the camera and the end of the robot arm).

[0085] When detecting the identification mark portion 121 in the image, a feature detection algorithm may be used, including but not limited to SIFT, SURF, ORB, etc.

[0086] The control system will pass the previously calculated second position coordinates as input parameters to the calibration program, and the control system will start the program and guide the robot arm to move accordingly according to the input coordinate values. The calibration program will control the robot arm to accurately move its end to the target position according to the preset instructions and parameters. Under normal circumstances, the sharp points at the ends of the first and second positioning columns will just butt against each other at the target position.

[0087] A fixed image acquisition device is installed near the calibration position, and ensures that it can clearly capture the first positioning column and the second positioning column. When the robot arm drives the auxiliary calibration tool to move to the second position, the fixed image acquisition device is triggered to capture, thereby capturing calibration image information.

[0088] The received calibration image information is then parsed, and this step includes but is not limited to edge detection, contour recognition, feature matching, etc., to determine whether the end of the first positioning column and the end of the second positioning column appear aligned in the image. If the two are aligned, it can be considered that the robot arm has successfully reached the predetermined position, that is, the calibration is successful at this time. Then the control system will input the currently calculated second position coordinates (that is, the position of the end of the robot arm when the calibration is successful) as the correct position information into the preset operating program. This operating program may be the program used by the robot arm to perform its daily tasks. It contains the various target positions that the robot arm needs to move to and the corresponding action instructions. By updating the position information in the operating program, it can be ensured that the robot arm can accurately move to the correct position when performing tasks.

[0089] In summary, the offline calibration method provided in the embodiment of the present application realizes automatic control of the offline calibration process through a preset calibration program and an image acquisition device. Once the calibration program is started, the robot arm will automatically move to the target position according to the predetermined path and parameters, and obtain the necessary calibration image information. This process does not require manual intervention, reducing manpower input. It also avoids production interruptions and delays in manual operations, ensuring the continuity of production.

[0090] like Fig.10 In an optional solution of the present application, in step S40, determining whether the end of the first positioning post and the end of the second positioning post are aligned according to the calibration image information includes:

[0091] Step S41, obtaining the regional point cloud of the second positioning column;

[0092] Step S42, projecting the regional point cloud onto two intersecting vertical planes: a first projection plane and a second projection plane, respectively, to obtain a first projection image and a second projection image;

[0093] Step S43, fitting the endpoint coordinates of the second positioning column in the first projection image and the second projection image respectively;

[0094] Step S44: determining whether the end of the first positioning post and the end of the second positioning post are aligned according to the endpoint coordinates.

[0095] In step S41, it is preferred to directly adopt region segmentation, that is, to obtain a region point cloud containing only the second positioning column by cutting a fixed region in space.

[0096] In a specific method, step S41 includes:

[0097] Step S411, segmenting the point cloud region of interest from the original point cloud data in the calibration image information by using a preset spatial bounding box;

[0098] Step S412: register the point cloud region of interest, delete the point cloud portion of the first positioning column, and obtain the regional point cloud of the second positioning column.

[0099] First, a three-dimensional bounding box is defined in space. The bounding box should be large enough to contain the entire point cloud of the first and second positioning columns, but not too large to reduce unnecessary calculations. The point cloud of the target area is segmented from the original point cloud data using the defined bounding box, that is, only the point cloud that falls within the bounding box is retained.

[0100] Since the point cloud position of the first positioning column is fixed, a high-precision point cloud template of the first positioning column (referred to as template point cloud) can be acquired in advance.

[0101] Use a point cloud registration algorithm, preferably ICP registration, i.e., the Iterative Closest Point algorithm in PCL, to register the template point cloud with the first positioning column part in the target point cloud. The purpose is to find the part of the target point cloud that best matches the template point cloud. According to the transformation matrix obtained by the registration, the template point cloud is removed from the target point cloud, leaving the second positioning column point cloud after registration adjustment and possible noise point clouds.

[0102] The point cloud after removing the first positioning column is denoised to remove possible noise points or small stray point clouds. If the background is complex, the remaining point cloud can be further segmented using a clustering algorithm to ensure that the area point cloud of the second positioning column is completely extracted.

[0103] With the vertical direction (i.e., the extension direction of the first positioning column and the second positioning column) as the Z axis, the two perpendicular directions of the plane are the X axis and the Y axis respectively, and the coordinate axis center is O, the two intersecting vertical planes can be referred to as the XOZ plane and the YOZ plane. After projecting them, the first projection image and the second projection image can be obtained.

[0104] In both projection images, traverse all point clouds directly in each projection image and find the point with the largest Z coordinate. This point is considered to be the top endpoint of the second positioning column under that projection. Record the endpoint coordinates found under both projections. Since the projection is two-dimensional, each endpoint coordinate will only contain X and Z coordinates (for XOZ projection) or Y and Z coordinates (for YOZ projection).

[0105] It should be noted that when determining the endpoint coordinates, the coordinate range of the Z axis needs to be constrained to avoid being affected by factors such as point cloud data quality and noise. That is, the point with the largest Z coordinate is defined only if its Z coordinate is within a preset range, such as 120mm to 125mm, and only then can it be used as the endpoint coordinate. Exemplarily, first find the point with the maximum value in the Z direction at each second positioning column, and filter out the points with Z coordinates within the specified range. If there are no points after filtering, stop and throw an exception. Otherwise, use the point with the largest Z coordinate as the endpoint coordinate.

[0106] Assume that the end coordinates of the first positioning column are in the YOZ plane, recorded as (x1, z1). At the same time, the coordinates of the end (end point coordinates) of the second positioning column obtained by point cloud processing on the same plane are (x2, z2). The difference between x1 and x2 is obtained. When the difference is within the preset threshold range, it can be determined that they are aligned.

[0107] like Fig.11 Specifically, in step S43, the first projection image and the second projection image are respectively fitted with the endpoint coordinates of the first positioning column and the second positioning column, including:

[0108] Step S431, obtaining a first contour image of the second positioning column in the first projection image according to a contour retrieval algorithm, and respectively obtaining the coordinates of the first vertices in the first contour image;

[0109] Step S432, obtaining a second contour image of the second positioning column in the second projection image according to a contour retrieval algorithm, and respectively obtaining the coordinates of the second vertices in the second contour image;

[0110] Step S433, determining a first straight line according to the coordinates of the first vertex, and determining a second straight line according to the coordinates of the second vertex;

[0111] Step S434, when it is determined that all the following conditions are met, determine that the end of the first positioning column and the end of the second positioning column are aligned: the first straight line and the second straight line are both horizontal; the horizontal difference between the first vertex coordinates and the first positioning column endpoint coordinates is within a preset threshold range, and the horizontal difference between the second vertex coordinates and the first positioning column endpoint coordinates is within a preset threshold range.

[0112] The first straight line is determined according to the coordinates of the first vertex (i.e., fitting a straight line at three points on the first projection surface). The second straight line is determined according to the coordinates of the second vertex (i.e., fitting another straight line at three points on the second projection surface).

[0113] Compare the difference between the first vertex coordinate and the second vertex coordinate (representing the ends of the two locating columns) and the fixed end point coordinate of the first locating column in the horizontal direction (X-axis or Y-axis, depending on the projection direction). If both differences are within the preset threshold range, it can be considered that the ends of the two locating columns are basically aligned in the horizontal direction. At the same time, determine whether the first straight line and the second straight line are horizontal to ensure that the second locating column is consistent in both the x and y directions to avoid being affected by the uneven installation posture of the auxiliary calibration tool.

[0114] If any of the conditions in step S434 is not satisfied, it means that the end of the first positioning post and the end of the second positioning post are not aligned. Fig.13 As demonstrated, at this time, the first positioning column and the second positioning column have a relatively significant level difference (as shown in the figure, the two reference lines are far apart), and the calibration is unsuccessful at this time.

[0115] like Fig.12 , the offline calibration method also includes:

[0116] Step S60, if the calibration is unsuccessful, based on a first difference vector between the first vertex coordinates and the known first locating column endpoint coordinates, and a second difference vector between the second vertex coordinates and the known first locating column endpoint coordinates;

[0117] Step S70 , calculating a target vector by combining the first difference vector and the second difference vector, so as to adjust the end of the robot arm through the target vector.

[0118] The first difference vector is calculated by the vector difference between the first vertex coordinates and the known first positioning column endpoint coordinates during the calibration process of the robot arm end. The first difference vector reflects the spatial offset of the second positioning column on the first projection plane. Similarly, the second difference vector is obtained by the same logic, which characterizes the spatial offset of the second positioning column on the second projection plane. The two difference vectors represent the offsets in the horizontal and vertical directions respectively. The target vector is the two-dimensional combination of these two vectors, which can be obtained using matrix operations. The calculated target vector is used to guide the adjustment of the robot arm end, thereby realizing automatic offline calibration.

[0119] The various technical features described above can be combined arbitrarily. Although all possible combinations of these technical features are not described, any combination of these technical features should be considered to be covered by this specification as long as there is no contradiction in such combination.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still adjust the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these adjustments or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An off-line calibration device, characterized in that: include: An offline calibration frame comprises a calibration bracket and a drain outlet simulation mounting plate, wherein one side of the drain outlet simulation mounting plate is connected to the calibration bracket, and the other side is provided with at least three first positioning columns with consistent concentric axes; An auxiliary calibration tool, comprising a calibration block and a second positioning column arranged on the calibration block and corresponding to the first positioning column; A shroud clamp is connected to the end of the robot arm for clamping the shroud. By connecting the auxiliary calibration tool to the shroud clamp, the end of the first positioning column and the end of the second positioning column are aligned for visual calibration.

2. The off-line calibration device according to claim 1, characterized in that: The first positioning posts are three in number and are arranged at equal intervals around the circumference, the three first positioning posts and the calibration block are concentrically aligned, and the ends of the first positioning posts and the second positioning posts are both conical; and / or The calibration block is ring-shaped.

3. The off-line calibration device according to claim 1, characterized in that: The shroud holder comprises a plane portion and a plurality of groove portions; The calibration block comprises an inlay portion protruding in a vertical direction away from the second positioning column, and a horizontal flange in a radial direction; The calibration block is inserted into the slot portion through the inlay portion to constrain the circumferential rotational freedom, while the horizontal flange and the plane portion are in surface contact.

4. The off-line calibration device according to claim 1, characterized in that: The offline calibration device also includes: A shroud storage rack, comprising a storage bracket, a shroud clamping slot arranged on the storage bracket, and a plurality of positioning surfaces, wherein the shroud clamping slot is used for placing the ladle shroud; The calibration bracket can be installed on the storage bracket through the plurality of positioning surfaces; Wherein, the long shroud storage rack includes placement layers of different heights arranged in a stepped manner, and each placement layer includes at least two of the long shroud slots.

5. The off-line calibration device according to claim 1, characterized in that: The drain outlet simulation installation plate is provided with a plurality of connection plates of equal height, and is connected to the calibration bracket through the connection plates; A plurality of extension blocks are arranged on the same surface of the drain outlet simulation installation plate and the first positioning column, and when the end of the first positioning column is aligned with the end of the second positioning column, the extension block abuts against the surface of the calibration block on which the second positioning column is arranged; and The drain port simulation installation plate includes identification mark parts, and the number of the identification mark parts is at least two.

6. An off-line calibration method, applied to the off-line calibration device according to any one of claims 1 to 5, characterized in that: Offline calibration methods include: Control the end of the robot arm to move to the first preset position coordinate, and connect the auxiliary calibration tool to the long shroud holder; Obtain the second position coordinates of the offline calibration frame; After inputting a preset calibration program according to the second position coordinates and running it, a fixed-position image acquisition device is used to obtain calibration image information of the first positioning column and the second positioning column; Determine whether the end of the first positioning post and the end of the second positioning post are aligned according to the calibration image information to determine whether the calibration is successful; When the calibration is successful, the current second position coordinates are input into a preset operating program to update the operating program.

7. The off-line calibration method according to claim 6, characterized in that: The step of determining whether the end of the first positioning post and the end of the second positioning post are aligned according to the calibration image information includes: Obtaining a regional point cloud of the second positioning column; Projecting the regional point cloud onto two intersecting vertical planes: a first projection plane and a second projection plane, respectively, to obtain a first projection image and a second projection image; Fitting the endpoint coordinates of the second positioning column in the first projection image and the second projection image respectively; It is determined whether the end of the first positioning post and the end of the second positioning post are aligned according to the endpoint coordinates.

8. The off-line calibration method according to claim 6, characterized in that: The first projection image and the second projection image are respectively fitted with the endpoint coordinates of the first positioning column and the second positioning column, including: Acquire a first contour image of the second positioning column in the first projection image according to a contour retrieval algorithm, and respectively acquire first vertex coordinates in the first contour image; Acquire a second contour image of the second positioning column in the second projection image according to a contour retrieval algorithm, and respectively acquire the coordinates of the second vertices in the second contour image; Determine a first straight line according to the coordinates of the first vertex, and determine a second straight line according to the coordinates of the second vertex; When it is determined that all the following conditions are met, it is determined that the end of the first positioning column and the end of the second positioning column are aligned: the first straight line and the second straight line are both horizontal; the horizontal difference between the first vertex coordinates and the first positioning column endpoint coordinates is within a preset threshold range, and the horizontal difference between the second vertex coordinates and the first positioning column endpoint coordinates is within a preset threshold range.

9. The off-line calibration method according to claim 1, characterized in that: The offline calibration method also includes: In the case of unsuccessful calibration, a first difference vector between the first vertex coordinate and the known first locating column endpoint coordinate, and a second difference vector between the second vertex coordinate and the known first locating column endpoint coordinate; A target vector is calculated by combining the first difference vector and the second difference vector, so as to adjust the end of the robot arm by the target vector.

10. An off-line calibration system, characterized in that: include: The off-line calibration device according to any one of claims 1 to 5; A mechanical arm, the end of which is connected to the long shroud gripper; A visual device is connected to the robot arm.

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