Assembly position analysis method and system based on ship assembly automatic assembling and welding equipment

Abstract

The invention provides an assembly position analysis method and system based on ship assembly automatic assembling and welding equipment, and the method comprises the steps: obtaining a three-dimensional model of assembly completion, and exporting an XML file; analyzing model coordinates of key vertexes of the bottom plate and the rib plate from the XML file; according to the key vertexes of the rib plates, determining model coordinates of grabbing points of each rib plate; obtaining machine tool coordinates of key vertexes on the bottom plate identified by the automation equipment; calculating a coordinate transformation matrix between the model coordinates of the bottom plate and the machine tool coordinates; and based on the model coordinates of the key vertexes of the rib plate and the model coordinates of the grabbing points, converting the model coordinates of the rib plate to a machine tool coordinate system by utilizing the coordinate transformation matrix to obtain the assembly position of the rib plate. According to the method, assembly position analysis in the ship assembly process is achieved, efficient and accurate automatic assembly and welding are achieved, the method has remarkable advantages in practical application, and the modernization and intelligentization process of ship manufacturing is promoted.

Description

Technical Field

[0001] The present invention relates to the field of shipbuilding technology, and in particular to an assembly position analysis method and system based on a small-scale automatic assembly and welding device for a ship, and also to a corresponding computer terminal and a computer-readable storage medium. Background Art

[0002] At present, during the assembly process of ship subassembly, the welding positions of bottom plates and rib plates are often measured and positioned manually, which has the problems of low precision and low efficiency. Although automated equipment has been applied in this field, it still faces the technical problem of how to accurately analyze the assembly position.

[0003] The existing ship panel automatic assembly technology usually has the following technical problems:

[0004] At present, during the assembly process of a ship, the welding positions of the bottom plate and the rib plate are often measured and positioned manually, which results in low precision.

[0005] The manual measurement and positioning process is not only time-consuming but also requires a lot of human resources.

[0006] When performing assembly position analysis, the complex calculation process in the prior art may lead to errors and inefficiencies.

[0007] When selecting the grasping point of the rib plate, the existing technology may not ensure that the grasping point is within the contour, resulting in grasping failure.

[0008] After searching, it was found that the Chinese invention patent application "A method and system for automatic assembly of ship subassemblies" with publication number CN118833364A includes: importing assembly 3D model files; extracting subassembly part data; obtaining the grabbing position, assembly position and welding edge of the parts to be assembled according to the subassembly part data; visually scanning the bottom plate parts and the parts to be assembled to determine the positions of the bottom plate parts and the parts to be assembled in the visual coordinate system; determining the positions of the bottom plate parts and the parts to be assembled in the device coordinate system; determining the assembly position and grabbing position of the parts to be assembled in the device coordinate system; obtaining the position and state of the grabbing device in the device coordinate system, controlling the grabbing device to grab the parts to be assembled, and assembling the welding edge of the parts to be assembled to the assembly position; obtaining the position and state of the welding device in the device coordinate system, and controlling the welding device to weld the parts to be assembled. However, the method is not perfect in the analysis method of welds and components, especially in the coordinate transformation and positioning optimization of the rib plate and the bottom plate, and does not provide a detailed solution; the method lacks a comprehensive description of the method for determining the grabbing point, and cannot guarantee the effective grabbing of the parts.

[0009] In summary, the above patent technology still does not solve the technical problems existing in the existing ship group automatic assembly technology. Currently, no description or report of similar technology to the present invention has been found, and similar information at home and abroad has not been collected. Summary of the invention

[0010] In view of the above-mentioned deficiencies in the prior art, the present invention provides an assembly position analysis method and system based on a small-scale automatic assembly and welding device for ships, which is used to accurately locate the assembly and welding positions of the bottom plate and the rib plate.

[0011] According to one aspect of the present invention, there is provided an assembly position analysis method based on a small-scale automatic assembly and welding device for a ship, comprising:

[0012] Obtain the 3D model of the group assembly and export it to an XML file;

[0013] Parsing the model coordinates of the key vertices of the base plate and the rib plate from the XML file;

[0014] Determine the model coordinates of the grabbing point of each rib plate according to the key vertices of the rib plate;

[0015] Obtaining machine tool coordinates of key vertices on the base plate identified by the automation equipment;

[0016] Calculate the coordinate transformation matrix between the model coordinates of the base plate and the machine tool coordinates;

[0017] Based on the model coordinates of the key vertices of the rib plate and the model coordinates of the grabbing points, the model coordinates of the rib plate are transformed into the machine tool coordinate system using the coordinate transformation matrix to obtain the assembly position of the rib plate.

[0018] According to another aspect of the present invention, there is provided an assembly position analysis system based on a small-scale automatic assembly and welding device for a ship, comprising:

[0019] XML file acquisition module, which is used to obtain the 3D model of the group assembly and export the XML file;

[0020] A key model coordinate acquisition module, which is used to parse the model coordinates of the key vertices of the bottom plate and the rib plate from the XML file;

[0021] A grasping point model coordinate acquisition module, which is used to determine the model coordinates of the grasping point of each rib plate according to the key vertices of the rib plate;

[0022] A base plate machine tool coordinate acquisition module, which is used to acquire the machine tool coordinates of key vertices on the base plate identified by the automation equipment;

[0023] A coordinate transformation matrix calculation module, which is used to calculate the coordinate transformation matrix between the model coordinates of the base plate and the machine tool coordinates;

[0024] A module for determining the assembly position of the rib plate converts the model coordinates of the rib plate into the machine tool coordinate system based on the model coordinates of the key vertices of the rib plate and the model coordinates of the grab points, using the coordinate transformation matrix, to obtain the assembly position of the rib plate.

[0025] According to a third aspect of the present invention, there is provided a computer terminal comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, can be used to execute the method described above in the present invention, or to run the system described above in the present invention.

[0026] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, can be used to execute the method described above in the present invention, or to run the system described above in the present invention.

[0027] Due to the adoption of the above technical solution, the present invention has at least one of the following beneficial effects compared with the prior art:

[0028] The present invention adopts XML parsing method, which can realize effective information extraction of three-dimensional models, and solves the technical problems of low efficiency and easy error in the traditional manual information extraction process;

[0029] The present invention adopts model dimension reduction and ray method, which can realize effective determination of grasping points, solve the problem of difficulty in determining the position of grasping points in complex geometric shapes, ensure that the grasping points are located inside the contour, and improve the reliability of grasping operations;

[0030] The present invention adopts homogeneous coordinate transformation, which can realize accurate conversion from model coordinates to machine tool coordinates, solves the problem of accurate positioning of automation equipment between different coordinate systems, and ensures accurate assembly of rib plate and base plate;

[0031] The present invention combines XML parsing method, model dimensionality reduction and ray method as well as homogeneous coordinate transformation to realize assembly position analysis in the process of ship assembly, ensure efficient, accurate and automated assembly and welding, overcome the problems of large manual positioning error, low efficiency and insufficient assembly accuracy in the prior art, have significant advantages in practical applications, and promote the modernization and intelligentization of shipbuilding.

[0032] The present invention realizes accurate positioning of the base plate and the rib plate by calculating the coordinate transformation matrix, thereby improving the assembly accuracy.

[0033] The present invention utilizes automated equipment and the technology of analyzing three-dimensional models to greatly improve assembly efficiency and reduce assembly time and labor costs.

[0034] The present invention converts a three-dimensional model into a two-dimensional model and degenerates a circular arc into a straight line, thereby simplifying the calculation process and improving the calculation accuracy and efficiency.

[0035] The present invention determines whether a grasping point is within a contour by using a ray method, and adjusts the coordinates of the grasping point when necessary to ensure the reliability of the grasping point.

[0036] The present invention adopts a magnetic suction manipulator in combination with the method of the present invention to realize the automatic welding of the bottom plate and the rib plate during the ship assembly process, reduces human intervention, and improves the automation level and consistency of the welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0038] Figure 1 The present invention is a flowchart of an assembly position analysis method based on a small-scale automatic assembly and welding equipment for ships in a preferred embodiment of the present invention.

[0039] Figure 2 It is a schematic diagram of the component modules of the assembly position analysis system based on the ship group automatic assembly and welding equipment in a preferred embodiment of the present invention.

[0040] Figure 3 Schematic diagram of the coordinate transformation matrix calculation process in a preferred embodiment of the present invention.

[0041] Figure 4 It is a schematic diagram of a base plate and a rib plate before assembly in a specific application example of the present invention.

[0042] Figure 5 It is a schematic diagram of a base plate and a rib plate assembled in a specific application example of the present invention. DETAILED DESCRIPTION

[0043] The following is a detailed description of the embodiments of the present invention: This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

[0044] The existing automatic assembly technology for ship sub-assemblies usually has problems such as low precision, time-consuming process, large amount of human resources required, errors and inefficiency in assembly position analysis, and failure to grasp when selecting the gripping points of the ribs. In response to the above problems, an embodiment of the present invention provides an assembly position analysis method based on automatic assembly and welding equipment for ship sub-assemblies. The method calculates the coordinate transformation matrix by analyzing the vertex coordinates of the three-dimensional model and combining it with the recognition coordinates of the automation equipment to achieve precise positioning of the bottom plate and the ribs; at the same time, the three-dimensional model is processed to determine the appropriate gripping points of the automation equipment. This method not only solves many defects in the prior art and improves assembly accuracy and efficiency, but also promotes the modernization and intelligence of the shipbuilding process.

[0045] Specifically, Figure 1 As shown, the assembly position analysis method based on the ship group automatic assembly and welding equipment provided in this embodiment may include the following operations:

[0046] S1, obtain the 3D model of the group assembly and export it to an XML file;

[0047] S2, parse the model coordinates of the key vertices of the base plate and rib plate from the XML file;

[0048] S3, determining the model coordinates of the grabbing point of each rib plate according to the key vertices of the rib plate;

[0049] S4, obtaining the machine tool coordinates of the key vertices on the base plate identified by the automation equipment;

[0050] S5, calculating the coordinate transformation matrix between the model coordinates of the base plate and the machine tool coordinates;

[0051] S6, based on the model coordinates of the key vertices of the rib plate and the model coordinates of the grab point, the model coordinates of the rib plate and the grab point are converted to the machine tool coordinate system using a coordinate transformation matrix to obtain the assembly position of the rib plate.

[0052] In some preferred embodiments, the above S1, XML file includes a weld list and a parts list; wherein:

[0053] The weld list includes the serial number, start endpoint coordinates and end endpoint coordinates of each weld;

[0054] The parts list includes the serial number, edge line and its type, start endpoint coordinates and end endpoint coordinates of each part; each part is a plate-like part of equal thickness; the edge line types are straight lines and arcs; each rib in the part is vertically assembled on the base plate.

[0055] In some preferred implementations, the above S2, parsing the model coordinates of the key vertices of the bottom plate and the rib plate from the XML file, may further include the following operations:

[0056] S21, read the weld list and parts list of the XML file;

[0057] S22, distinguishing the bottom plate and the rib plate according to the part numbers in the parts list;

[0058] S23, select three vertices on the base plate model as key vertices;

[0059] S24, according to the weld information and part information of each rib plate model, determine the coordinates of the two end points of the corresponding weld edge, and select another point to constitute the key vertex of each rib plate model.

[0060] In some preferred embodiments, the above S3, determining the grabbing point of each rib plate according to the key vertices of the rib plate, may further include the following operations:

[0061] S31, converting the three-dimensional model of the rib plate into a two-dimensional model, degenerating the edge line of the rib plate from an arc to a straight line, and considering the contour of each two-dimensional model as a polygon;

[0062] S32, projecting the two endpoints of the weld edge in the key vertex of the determined rib plate into the two-dimensional model, moving the midpoint of the line connecting the two endpoints of the weld edge upward (in the Z-axis direction, the normal direction of the bottom plate plane, the opposite direction of gravity) by a fixed distance h as the grasping point of the magnetic suction manipulator, where h meets the spatial requirements of the manipulator operation;

[0063] S33, calculating the two-dimensional coordinates of the grasping point, and determining whether the grasping point is within the contour.

[0064] S34, when the grasping point is not within the contour, the grasping point is moved parallel to the weld edge, and S33 is repeated until a suitable grasping point is determined.

[0065] In some preferred implementations, the above S33, determining whether the grasping point is within the contour, may further include the following operations:

[0066] Using the ray method, a ray is drawn from the grab point. If the number of intersections with the contour edge is odd, it means that the grab point is inside the contour. If the number of intersections with the contour edge is even, it means that the grab point is outside the contour.

[0067] In some preferred implementations, the above S34 may further include the following operations:

[0068] When no suitable grab point is found, a prompt message is output.

[0069] In some preferred embodiments, the above S4, obtaining the machine tool coordinates of the key vertices on the bottom plate identified by the automation equipment, may further include the following operations:

[0070] The base plate is placed in the welding area through existing automation equipment such as AGV and manipulators, and the machine tool coordinates of the key vertices on the base plate are obtained using existing visual recognition equipment.

[0071] In some preferred embodiments, the above S5, calculating the coordinate transformation matrix between the model coordinates of the base plate and the machine tool coordinates, may further include the following operations:

[0072] S51, obtaining homogeneous coordinate representation according to the model coordinates and machine tool coordinates of the key vertices of the base plate;

[0073] S52, calculating the rotation matrix R and the translation vector t through translation and rotation transformation around the Z axis;

[0074] S53, the rotation matrix R and the translation vector t are combined into a homogeneous coordinate transformation matrix T, that is, the coordinate transformation matrix between the model coordinate system and the machine tool coordinate system is obtained.

[0075] like Figure 3 As shown, specifically:

[0076] The above S51, obtaining homogeneous coordinate representation according to the model coordinates and machine tool coordinates of the key vertices of the base plate, may further include the following operations:

[0077] The 3D coordinates of the model coordinates and the machine tool coordinates are added with a fourth dimension, and the value of the fourth dimension is set to 1, which is the homogeneous coordinate representation of the model coordinates and the machine tool coordinates.

[0078] The above S52, calculating the rotation matrix R and the translation vector t through translation and rotation transformation around the Z axis, may further include the following operations:

[0079] First, select two key vertices of the base plate, subtract the model coordinates of these two points to get vector v1, and then subtract the machine coordinates corresponding to these two points to get vector v2. Calculate the trigonometric functions cosθ and sinθ of the angle between vectors v1 and v2 to form the rotation matrix R. Specifically, R is a 3-row 3-column matrix, whose diagonal elements are cosθ, cosθ and 1, the 1st row and 2nd column element is -sinθ, the 2nd row and 1st column element is sinθ, and the rest of the positions are 0.

[0080] After obtaining the rotation matrix R, select any key vertex of the base plate, subtract the matrix product of the rotation matrix R and the model coordinates of this point from the machine tool coordinates of this point, and you can get the translation vector t.

[0081] S53, the rotation matrix R and the translation vector t are combined into a homogeneous coordinate transformation matrix T, which may further include the following operations:

[0082] T is a matrix with 4 rows and 4 columns. The elements in the first 3 rows and 3 columns are the rotation matrix R. The elements in the first 3 rows and 4 columns are the translation vector t. The elements in the 4th row and 4th column are 1, and the rest of the positions are 0.

[0083] In some preferred embodiments, the above S6, based on the model coordinates of the key vertices of the rib plate and the model coordinates of the grab point, uses a coordinate transformation matrix to transform the model coordinates of the rib plate and the grab point into the machine tool coordinate system to obtain the assembly position of the rib plate, and may further include the following operations:

[0084] S61, based on the model coordinates of the key vertices of the rib plate and the model coordinates of the grasping points, obtain homogeneous coordinate representations of the model coordinates of the key vertices and grasping points of each rib plate; multiply the homogeneous coordinate representations by a coordinate transformation matrix to perform coordinate transformation to obtain machine tool coordinates of the key vertices and grasping points of the rib plate;

[0085] S62, calculating the angle of the weld edge in the XY plane of the machine tool coordinate system, and determining the assembly position and posture of the rib plate;

[0086] S63, plans the angle and movement trajectory of the robot to grasp the rib plate according to the machine tool coordinates of the grasping point and the angle of the weld edge.

[0087] In some preferred embodiments, the above S62, calculating the angle of the weld edge in the XY plane of the machine tool coordinate system and determining the assembly position and posture of the rib plate, may further include the following operations:

[0088] The key vertices of the rib plate include the two endpoints of the weld edge. Subtracting the machine coordinates of these two endpoints can get the direction vector of the rib plate, which is set as (x, y, z). Since the rib plates are installed perpendicular to the base plate, the direction vector is in the XY plane of the machine coordinate system. The counterclockwise rotation angle of the rib plate weld relative to the positive semi-axis of the machine coordinate system is arctan (y / x).

[0089] In some preferred embodiments, the above S63, planning the angle and movement trajectory of the manipulator grabbing the rib plate according to the machine tool coordinates of the grabbing point and the angle of the weld edge, may further include the following operations:

[0090] The robot will first grab the rib plate according to the pre-marked grabbing point and grabbing direction, and align the robot's rotation axis with the Z axis of the machine tool coordinate system. According to the angle of the weld edge of the rib plate, the robot rotates to the corresponding angle, and then translates to the machine tool coordinate of the grabbing point to place the rib plate in the appropriate position.

[0091] Based on the same inventive concept, an embodiment of the present invention further provides an assembly position analysis system based on a small-scale automatic assembly and welding device for ships.

[0092] Specifically, Figure 2 As shown, the assembly position analysis system based on the ship group automatic assembly and welding equipment provided in this embodiment may include the following modules:

[0093] XML file acquisition module, which is used to obtain the 3D model of the group assembly and export the XML file;

[0094] Key model coordinate acquisition module, which is used to parse the model coordinates of the key vertices of the base plate and rib plate from the XML file;

[0095] A grasping point model coordinate acquisition module, which is used to determine the model coordinates of the grasping point of each rib plate according to the key vertices of the rib plate;

[0096] A base plate machine tool coordinate acquisition module, which is used to acquire the machine tool coordinates of key vertices on the base plate identified by the automation equipment;

[0097] A coordinate transformation matrix calculation module, which is used to calculate the coordinate transformation matrix between the model coordinates of the base plate and the machine tool coordinates;

[0098] The module for determining the assembly position of the rib plate is based on the model coordinates of the key vertices of the rib plate and the model coordinates of the grasping point. The module uses the coordinate transformation matrix to transform the model coordinates of the rib plate and the grasping point into the machine tool coordinate system to obtain the assembly position of the rib plate.

[0099] The work contents implemented by the above-mentioned functional modules are further described in detail below.

[0100] In the XML file acquisition module, the XML file provides a list of welds and parts. The weld list gives the serial number, start endpoint coordinates, end endpoint coordinates and other information of each weld; the parts list gives the serial number, edge line and its type and two endpoint coordinates of each part. Each part is a plate-like part of equal thickness, and the edge line is composed of only straight lines and arcs. Each rib plate is vertically assembled on the base plate.

[0101] The key model coordinate acquisition module includes the following tasks:

[0102] Read weld and parts lists from XML files;

[0103] Distinguish the base plate and rib plate according to the part number, and select three vertices on the base plate model as key vertices;

[0104] According to the weld information and part information of each rib plate, the coordinates of the two endpoints of the corresponding weld edge are determined, and another point is selected to constitute the key vertex of each rib plate.

[0105] The grab point model coordinate acquisition module includes the following tasks:

[0106] According to the characteristics of each part being plate-shaped and uniform in thickness, the three-dimensional model of the rib plate is converted into a two-dimensional model. To simplify the calculation, the arc is degenerated into a straight line, so that each two-dimensional contour is regarded as a polygon.

[0107] The two endpoints of the weld edge determined by the key model coordinate acquisition module are projected into the two-dimensional model, and the midpoint of the line connecting the two endpoints of the weld edge is moved upward (in the Z-axis direction, the normal direction of the bottom plate plane, and the opposite direction of gravity) by a fixed distance h as the grasping point of the magnetic suction manipulator. h must meet the spatial requirements of the manipulator operation.

[0108] Calculate the two-dimensional coordinates of the grab point and use the ray method to determine whether it is inside the contour. Specifically, draw a ray from the grab point. If the number of intersections with the contour edge is odd, it means that the grab point is inside the contour. If it is even, it means that it is outside the contour.

[0109] If the grab point is not within the contour, move the grab point parallel to the weld edge and repeat step 3.3 until a suitable grab point is determined. If no suitable grab point is found, a prompt message will pop up.

[0110] The base plate machine tool coordinate acquisition module includes the following tasks:

[0111] Existing automation equipment is already able to use AGV and manipulators to place the base plate in the welding area, and existing visual recognition equipment is already able to obtain the machine tool coordinates of the key vertices of the base plate.

[0112] The coordinate transformation matrix calculation module includes the following tasks:

[0113] According to the model coordinates and machine tool coordinates of the key vertices of the base plate, a homogeneous coordinate representation is obtained;

[0114] The transformation only involves translation and rotation around the Z axis, thereby calculating the rotation matrix R and the translation vector t;

[0115] R and t form a homogeneous coordinate transformation matrix T. The detailed calculation process is as follows Figure 3 shown.

[0116] The rib assembly position determination module includes the following tasks:

[0117] Obtain the homogeneous coordinate representation of the model coordinates of the key vertices and gripping points of each rib plate, multiply them by the coordinate transformation matrix T, perform coordinate transformation, and obtain their machine tool coordinates;

[0118] Calculate the angle of the weld edge in the XY plane of the machine tool coordinate system to determine the assembly position and posture of the rib plate.

[0119] According to the calculated machine coordinates of the grasping point and the calculated angle of the weld edge, the angle and movement trajectory of the robot grasping the rib plate are planned.

[0120] It should be noted that the steps in the method provided by the present invention can be implemented by using the corresponding components in the system, and those skilled in the art can refer to the technical solution of the system to implement the step flow of the method, and can also refer to the technical solution of the method to implement the composition of the system, that is, the embodiments in the system and the embodiments in the method can be understood as preferred examples of each other, which will not be elaborated here.

[0121] The technical solution provided by the above embodiment of the present invention is further described in detail below in conjunction with a specific application example.

[0122] This specific application example mainly includes the following parts:

[0123] 1. The analysis and conversion of the 3D model includes the following steps:

[0124] Step 1: Obtain the assembled 3D model of the ship group and export the XML file, which contains the geometric information, weld information and coordinate data of the parts.

[0125] Step 2: Use the parsing algorithm to extract the vertex coordinates of each part and the specific location of the weld from the XML file.

[0126] Step 3, convert the data in the 3D model into a 2D model, degenerate the arc into a straight line, so that the outer contour of each part can be regarded as a polygon.

[0127] Step 4: In the two-dimensional model, select the midpoint of the weld edge and move it upward by a fixed distance h as the grabbing point of the magnetic manipulator.

[0128] Step 5: Use the ray method to determine whether the grasping point is within the contour of the part. If not, adjust the coordinates of the grasping point until the requirements are met.

[0129] 2. Coordinate transformation and assembly position analysis include the following steps:

[0130] Step 1: Identify the machine tool coordinates of the three reference points on the base plate through automated equipment and record their specific coordinate values.

[0131] Step 2: Calculate the homogeneous coordinate transformation matrix between the model coordinate system and the machine tool coordinate system using the known three-dimensional model coordinates and the identified machine tool coordinates.

[0132] Step 3: Use the coordinate transformation matrix to transform the vertex coordinates of the rib plate from the model coordinate system to the machine tool coordinate system.

[0133] Step 4: According to the converted coordinates, guide the magnetic robot to accurately place the position and posture of the rib plate to ensure the precise docking of the rib plate with the base plate.

[0134] 3. Automated assembly and welding, including the following steps:

[0135] Step 1: The control system of the automation equipment reads the weld information parsed from the XML file, including the weld start point, end point and welding parameters.

[0136] Step 2: The magnetic manipulator takes the rib plate out of the silo according to the calculated grabbing point coordinates and moves it to the predetermined assembly position.

[0137] Step 3: The robot places the rib plate vertically on the base plate and uses automated equipment to monitor and adjust it in real time to ensure that the rib plate is accurately positioned.

[0138] Step 4: The welding robot automatically aligns the weld edge according to the weld information and performs welding operations to complete the connection between the base plate and the rib plate.

[0139] Step 5: After assembly is completed, the system detects the welding quality. If any abnormality is found, it will automatically correct or re-weld to ensure the welding quality.

[0140] like Figure 4 and Figure 5 The figure shows a schematic diagram of the bottom plate and the rib plate before assembly and a schematic diagram of the bottom plate and the rib plate after assembly.

[0141] An embodiment of the present invention further provides a computer terminal, comprising 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 processor can be used to execute any method of the above-mentioned embodiments of the present invention, or to run any system of the above-mentioned embodiments of the present invention.

[0142] Optionally, the memory is used to store programs; the memory may include volatile memory (English: volatile memory), such as random-access memory (English: random-access memory, abbreviated: RAM), such as static random-access memory (English: static random-access memory, abbreviated: SRAM), double data rate synchronous dynamic random access memory (English: Double Data Rate Synchronous Dynamic Random Access Memory, abbreviated: DDR SDRAM), etc.; the memory may also include non-volatile memory (English: non-volatile memory), such as flash memory (English: flash memory). The memory is used to store computer programs (such as applications, functional modules, etc. that implement the above method), computer instructions, etc., and the above computer programs, computer instructions, etc. can be partitioned and stored in one or more memories. And the above computer programs, computer instructions, data, etc. can be called by the processor.

[0143] The processor is used to execute the computer program stored in the memory to implement the various steps of the method or various modules of the system involved in the above embodiments. For details, please refer to the relevant descriptions in the above method and system embodiments.

[0144] The processor and the memory may be independent structures or integrated structures. When the processor and the memory are independent structures, the memory and the processor may be coupled and connected via a bus.

[0145] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, it can be used to execute any method of the above embodiments of the present invention, or to run any system of the above embodiments of the present invention.

[0146] Among them, computer-readable media include computer storage media and communication media, wherein the communication media include any media that facilitates the transmission of computer programs from one place to another. The storage medium can be any available medium that can be accessed by a general or special-purpose computer. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a user device. Of course, the processor and the storage medium can also be present in a communication device as discrete components.

[0147] In view of the problem of low precision in the current process of ship assembly, the welding positions of the bottom plate and the rib plate are often measured and positioned manually, and the present invention realizes the precise positioning of the bottom plate and the rib plate by calculating the coordinate transformation matrix, thereby improving the assembly accuracy.

[0148] In view of the problem that the manual measurement and positioning process in the prior art is not only time-consuming but also requires a large amount of manpower, the present invention utilizes automated equipment and the technology of analyzing three-dimensional models to greatly improve assembly efficiency and reduce assembly time and labor costs.

[0149] In order to solve the problem that the complex calculation process in the prior art may lead to errors and inefficiency when performing assembly position analysis, the present invention simplifies the calculation process and improves the calculation accuracy and efficiency by converting the three-dimensional model into a two-dimensional model and degenerating the arc into a straight line.

[0150] To address the problem that when selecting the grabbing point of the rib plate, the prior art may not be able to ensure that the grabbing point is within the contour, resulting in grabbing failure, the present invention uses the ray method to determine whether the grabbing point is within the contour, and adjusts the grabbing point coordinates when necessary to ensure the reliability of the grabbing point.

[0151] The present invention adopts a magnetic suction manipulator in combination with the method of the present invention to realize the automatic welding of the bottom plate and the rib plate during the ship assembly process, reduces human intervention, and improves the automation level and consistency of the welding.

[0152] All matters not covered in the above embodiments of the present invention are well known in the art.

[0153] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for analyzing assembly position based on a small-scale automatic welding equipment for ships, characterized in that: include: Obtain the 3D model of the group assembly and export it to an XML file; Parsing the model coordinates of the key vertices of the base plate and the rib plate from the XML file; Determine the model coordinates of the grabbing point of each rib plate according to the key vertices of the rib plate; Get the machine coordinates of the key vertices on the base plate; Calculate the coordinate transformation matrix between the model coordinates of the base plate and the machine tool coordinates; Based on the model coordinates of the key vertices of the rib plate and the model coordinates of the grabbing point, the model coordinates of the rib plate and the grabbing point are converted to the machine tool coordinate system using the coordinate transformation matrix to obtain the assembly position of the rib plate.

2. The assembly position analysis method based on the ship group automatic assembly and welding equipment according to claim 1 is characterized in that: The XML file includes a weld list and a parts list; wherein: The weld list includes the serial number, the starting endpoint coordinates and the ending endpoint coordinates of each weld; The parts list includes the serial number, edge line and its type, starting endpoint coordinates and ending endpoint coordinates of each part; each part is a plate-like part of equal thickness; the edge line types are straight lines and arcs; each rib plate in the part is vertically assembled on the base plate.

3. The assembly position analysis method based on the ship group automatic assembly and welding equipment according to claim 1 is characterized in that: The step of parsing the model coordinates of the key vertices of the bottom plate and the rib plate from the XML file includes: Read the weld list and parts list of the XML file; Distinguish the bottom plate and the rib plate according to the part numbers in the parts list; Select three vertices on the base plate model as key vertices; According to the weld information and part information of each rib plate model, the coordinates of the two endpoints of the corresponding weld edge are determined, and another point is selected to constitute the key vertex of each rib plate model.

4. The assembly position analysis method based on the ship group automatic assembly and welding equipment according to claim 1 is characterized in that: Determining the grabbing point of each rib plate according to the key vertices of the rib plate includes: The three-dimensional model of the rib plate is converted into a two-dimensional model, and the edge line of the rib plate is degenerated from an arc to a straight line, and the contour of each two-dimensional model is regarded as a polygon; The two endpoints of the weld edge in the determined key vertex of the rib plate are projected into the two-dimensional model, and the midpoint of the line connecting the two endpoints of the weld edge is moved upward by a fixed distance h as the grasping point of the magnetic suction manipulator, where h meets the space requirements for the operation of the manipulator; Calculate the two-dimensional coordinates of the grasping point and determine whether the grasping point is within the contour; When the gripping point is not within the contour, the gripping point is moved parallel to the weld edge, and S33 is repeated until a suitable gripping point is determined.

5. The assembly position analysis method based on the ship group automatic assembly and welding equipment according to claim 4 is characterized in that: Also includes any one or more of the following: -Determining whether the grasping point is within the contour comprises: Using the ray method, draw a ray from the grab point. If the number of intersections with the contour edge is odd, it means that the grab point is inside the contour. If the number of intersections with the contour edge is even, it means that the grab point is outside the contour. - Also includes: When no suitable grab point is found, a prompt message is output.

6. The assembly position analysis method based on the ship group automatic assembly and welding equipment according to claim 1 is characterized in that: The coordinate transformation matrix between the model coordinates of the calculation base plate and the machine tool coordinates includes: According to the model coordinates and machine tool coordinates of the key vertices of the base plate, a homogeneous coordinate representation is obtained; Calculate the rotation matrix R and translation vector t through translation and rotation around the Z axis; The rotation matrix R and the translation vector t are combined into a homogeneous coordinate transformation matrix T, that is, a coordinate transformation matrix between the model coordinate system and the machine tool coordinate system is obtained.

7. The assembly position analysis method based on the ship group automatic assembly and welding equipment according to claim 6 is characterized in that: Also includes any one or more of the following: -According to the model coordinates and machine tool coordinates of the key vertices of the base plate, a homogeneous coordinate representation is obtained, including: Get the model coordinates of the key vertices of the base plate and the machine coordinates of the key vertices of the base plate: Adding a fourth dimension to the three-dimensional coordinates of the model coordinates and the machine tool coordinates, and setting the value of the fourth dimension to 1, thereby obtaining a homogeneous coordinate representation of the model coordinates and the machine tool coordinates; -The calculation of the rotation matrix R and the translation vector t by translation and rotation transformation around the Z axis includes: Firstly, two key vertices of the base plate are selected, and the two key vertices are subtracted from each other in the model coordinates to obtain a vector v1, and then the machine tool coordinates corresponding to the two key vertices are subtracted to obtain a vector v2; Calculate the trigonometric functions cosθ and sinθ of the angle between the vector v1 and the vector v2 to form a rotation matrix R; wherein R is a 3-row 3-column matrix, the diagonal elements of the matrix are cosθ, cosθ and 1, the first row and second column element of the matrix is ​​-sinθ, the second row and first column element of the matrix is ​​sinθ, and the remaining positions are 0; After obtaining the rotation matrix R, select any key vertex of the base plate, and subtract the matrix product of the rotation matrix R and the model coordinates of the key vertex from the machine coordinates of the key vertex to obtain the translation vector t; - The step of forming a homogeneous coordinate transformation matrix T from the rotation matrix R and the translation vector t comprises: The rotation matrix R and the translation vector t are combined into a homogeneous coordinate transformation matrix T, wherein the homogeneous coordinate transformation matrix T is a matrix of 4 rows and 4 columns, the elements of the first 3 rows and first 3 columns of the matrix are the rotation matrix R, the elements of the first 3 rows and fourth columns of the matrix are the translation vector t, the elements of the 4th row and 4th column of the matrix are 1, and the rest of the positions are 0.

8. The assembly position analysis method based on the ship group automatic assembly and welding equipment according to claim 1 is characterized in that: The model coordinates of the key vertices of the rib plate and the model coordinates of the grabbing point are converted into the machine tool coordinate system by using the coordinate transformation matrix to obtain the assembly position of the rib plate, including: Based on the model coordinates of the key vertices of the rib plate and the model coordinates of the grasping points, a homogeneous coordinate representation of the model coordinates of the key vertices and grasping points of each rib plate is obtained; the homogeneous coordinate representation is multiplied by the coordinate transformation matrix to perform coordinate transformation to obtain the machine tool coordinates of the key vertices and grasping points of the rib plate; Calculate the angle of the weld edge in the XY plane of the machine tool coordinate system to determine the assembly position and posture of the rib plate; According to the machine tool coordinates of the grasping point and the angle of the weld edge, the angle and movement trajectory of the manipulator grasping the rib plate are planned.

9. The assembly position analysis method based on the ship group automatic assembly and welding equipment according to claim 8 is characterized in that: Also includes any one or more of the following: - The calculation of the angle of the weld edge in the XY plane of the machine tool coordinate system to determine the assembly position and posture of the rib plate includes: According to the machine coordinates of the key vertices of the rib plate, the machine coordinates of the two end points of the weld edge are subtracted to obtain the direction vector (x, y, z) of the rib plate. Since the rib plate is installed perpendicular to the base plate, the direction vector (x, y, z) is in the XY plane of the machine coordinate system, and the counterclockwise rotation angle of the weld of the rib plate relative to the positive semi-axis of the machine coordinate system is arctan (y / x). - According to the machine tool coordinates of the grasping point and the angle of the weld edge, planning the angle and movement trajectory of the manipulator grasping the rib plate includes: The manipulator first grabs the rib plate according to the pre-marked grabbing point and grabbing direction, and makes the manipulator's rotation axis coincide with the Z-axis of the machine tool coordinate system. According to the calculated angle arctan (y / x) of the counterclockwise rotation of the weld of the rib plate relative to the positive half axis of the machine tool coordinate system, the manipulator rotates to the corresponding angle, and then translates to the machine tool coordinate of the grabbing point, so that the rib plate can be placed in the appropriate position.

10. An assembly position analysis system based on a small-scale automatic assembly and welding equipment for ships, characterized in that: include: XML file acquisition module, which is used to obtain the 3D model of the group assembly and export the XML file; A key model coordinate acquisition module, which is used to parse the model coordinates of the key vertices of the bottom plate and the rib plate from the XML file; A grasping point model coordinate acquisition module, which is used to determine the model coordinates of the grasping point of each rib plate according to the key vertices of the rib plate; A base plate machine tool coordinate acquisition module, which is used to acquire the machine tool coordinates of key vertices on the base plate identified by the automation equipment; A coordinate transformation matrix calculation module, which is used to calculate the coordinate transformation matrix between the model coordinates of the base plate and the machine tool coordinates; A module for determining the assembly position of the rib plate is used to convert the model coordinates of the key vertices of the rib plate and the model coordinates of the gripping points into the machine tool coordinate system using the coordinate transformation matrix to obtain the assembly position of the rib plate.

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