Demonstration-free welding collection control method and system and welding equipment

Abstract

The invention discloses a teaching-free welding collection control method and system and welding equipment. A teaching-free welding collection control method is applied to welding equipment, a welding robot of the welding equipment comprises a welding gun and a camera, the welding gun and the camera move along with a moving mechanism, the relative position of the welding gun and the camera is kept unchanged, and the teaching-free welding collection control method comprises the steps that a three-dimensional virtual model of a workpiece to be welded is built, creating a three-dimensional virtual model coordinate system; based on the three-dimensional virtual model coordinate system, a welding seam track data set of the to-be-processed welding seam is collected; calculating a camera motion trail data set required by the camera to execute the photographing action according to the welding seam trail data set; and the camera movement track data set is sent to the robot, the robot carries out scanning operation according to the camera movement track data set, and data obtained through scanning are processed to obtain an actual welding track data set.

Description

Technical Field

[0001] The present application relates to the technical field of welding control, and particularly relates to a teaching-free welding acquisition control method, system and welding equipment. Background Art

[0002] Industrial welding robots are widely used in the field of welding technology. When used properly, they can significantly improve work efficiency and welding quality. At present, the most common usage is to complete welding work by manually teaching and programming the welding trajectory, which has relatively high requirements for operators and requires them to have certain programming capabilities. At the same time, for samples with a large number of welds, operators need to spend a lot of time on teaching work. The increase in on-site teaching work time obviously squeezes the actual welding work time of industrial welding robots and reduces the usage efficiency of industrial welding robots.

[0003] Therefore, those skilled in the art need to solve the technical problems of reducing the operation difficulty of on-site operators and improving the usage efficiency of industrial welding robots. Summary of the Invention

[0004] The purpose of the present application is to provide a teaching-free welding acquisition control method, system and welding equipment to reduce the operation difficulty of on-site operators and improve the usage efficiency of industrial welding robots.

[0005] To solve the above technical problems, the present application provides a teaching-free welding acquisition control method, which is applied to a welding equipment. The welding robot of the welding equipment includes a welding torch and a camera. The welding torch and the camera move along with a moving mechanism, and the relative positions of the welding torch and the camera remain unchanged. The teaching-free welding acquisition control method includes: Construct a three-dimensional virtual model of the workpiece to be welded and create a three-dimensional virtual model coordinate system; Collect a weld trajectory data set of the weld to be processed based on the three-dimensional virtual model coordinate system; Calculate a camera movement trajectory data set required for the camera to perform a photographing action according to the weld trajectory data set; Send the camera movement trajectory data set to the robot. The robot performs a scanning operation according to the camera movement trajectory data set and processes the scanned data to obtain an actual welding trajectory data set.

[0006] Optionally, collecting a weld trajectory data set of the weld to be processed based on the three-dimensional virtual model coordinate system includes: selecting the weld to be processed on the three-dimensional virtual model, setting a collection point every N millimeters along the weld to be processed, where the value range of N is from 0.1 millimeter to 0.3 millimeter. Based on the three-dimensional virtual model coordinate system, record the coordinates of the collection points in the weld trajectory data set. The weld trajectory data set also includes the start coordinates and end coordinates of the weld to be processed.

[0007] Optionally, a collection point is set every 0.2 millimeters along the weld to be processed.

[0008] Optionally, a camera motion trajectory dataset required for the camera to perform a photographing action is calculated according to the weld trajectory dataset, including: Step 1: Determine the starting coordinate and the ending coordinate of the weld to be processed, calculate the direction vector of the weld to be processed according to the starting coordinate and the ending coordinate, and use the direction vector as the positive direction of the X-axis, and the direction in which the welding end of the welding torch extends perpendicularly to the X-axis is the positive direction of the Z-axis. Based on the known positive direction of the X-axis and the positive direction of the Z-axis, the positive direction of the Y-axis is obtained according to the right-hand rule; Step 2: Calibrate the TCP of the welding torch through a four-point calibration method, and obtain the TCP of the camera through a hand-eye calibration method. Both the TCP of the camera and the TCP of the welding torch are data obtained relative to the center of the sixth flange of the robot axis. Calculate the difference between the TCP of the camera and the TCP of the welding torch to obtain an offset; Step 3: Combine the offset and the weld trajectory dataset to calculate the camera motion trajectory dataset required for the camera to perform a photographing action.

[0009] Optionally, the welding device performs a photographing and scanning operation according to the camera motion trajectory dataset, and processes the scanned data to obtain an actual welding trajectory dataset, including: Step 1: The welding device performs a photographing and scanning operation according to the camera motion trajectory dataset to obtain a two-dimensional point cloud dataset of the weld to be processed, and transmits the two-dimensional point cloud dataset to the industrial control computer of the welding system; Step 2: Through light plane conversion, convert the two-dimensional point cloud dataset into a three-dimensional point dataset in the base coordinate system; Step 3: Perform quadratic fitting on the three-dimensional point dataset, filter out abnormal data in the three-dimensional point dataset, and fit out an actual welding trajectory dataset. The welding trajectory dataset is stored in the industrial control computer. The welding trajectory dataset corresponds one-to-one with the weld to be processed. After selecting the weld to be processed recorded in the industrial control computer, the industrial control computer can transmit the welding trajectory dataset to the welding robot, and the welding robot can perform corresponding welding work according to the welding trajectory dataset.

[0010] The present application also provides a teaching-free welding acquisition control system, which is applied to a welding device. The welding robot of the welding device includes a welding torch and a camera. The welding torch and the camera move with a moving mechanism, and the relative positions of the welding torch and the camera remain unchanged. The teaching-free welding acquisition control system includes: The welding trajectory simulation module is used to build a three-dimensional virtual model of the workpiece to be welded, create a coordinate system for the three-dimensional virtual model, and at the same time be able to collect a weld trajectory data set of the weld to be processed based on the coordinate system of the three-dimensional virtual model; The scanning trajectory generation module is used to process the weld trajectory data set and generate a camera movement trajectory data set required for the camera to perform a photographing action; The robot scanning and welding module is used to control the movement of the camera according to the camera movement trajectory data set and perform a photographing and scanning operation; The welding trajectory generation module is used to process the scanned data to obtain an actual welding trajectory data set.

[0011] The present application also provides a welding device, including an industrial control computer and a welding robot. The welding robot includes a PLC, a moving mechanism, a welding torch, and a camera. The welding torch and the camera are fixedly arranged on the moving mechanism and move with the moving mechanism, and the relative positions of the welding torch and the camera remain unchanged. The industrial control computer can communicate with the PLC. The industrial control computer is provided with a first processor and a first memory, and the PLC is provided with a second processor and a second memory. Computer programs are respectively stored in the first processor and the second processor. The first processor calls the computer program in the first memory and the second processor calls the computer program in the second memory to implement the above-mentioned teaching-free welding acquisition control method.

[0012] One or more technical solutions provided in the present application have at least the following technical effects or advantages: There is no need for on-site teaching programming by operators. The work of manually teaching and programming the welding trajectory, which originally relied on on-site operators, is optimized to the work of backend technicians modeling and calculating the camera movement trajectory data set, collecting data using the camera according to the camera movement trajectory data set, and finally fitting an actual welding trajectory data set. Such optimization, on the one hand, reduces the operation difficulty of on-site operators while keeping backend technicians away from dangerous working environments. On the other hand, the operations based on the calculated and collected data are more scientific and accurate than manual teaching, reducing the time for on-site debugging of the welding robot and improving the usage efficiency of the welding robot. The present application also provides a teaching-free welding acquisition control system and a welding device, which also have the above beneficial effects and will not be elaborated here. Description of the Drawings

[0013] Figure 1 is a flowchart of a teaching-free welding acquisition control method provided by an embodiment of the present application; Figure 2 is a schematic diagram of the principle of a teaching-free welding acquisition control system provided by an embodiment of the present application; Figure 3It is a schematic structural diagram of some components of a welding device provided by an embodiment of the present application. Detailed implementation manners

[0014] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings of the present application. Obviously, the described embodiments of the present application are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0015] Please refer to Figure 1 , Figure 1 It is a flowchart of a teaching-free welding acquisition control method provided by an embodiment of the present application. The specific steps may include: S101: Build a three-dimensional virtual model of the welding workpiece, select a fixed point as the origin of the three-dimensional virtual model coordinate system, and create a three-dimensional virtual model coordinate system based on the origin; Among them, this embodiment can be applied to a welding device. The welding robot of the welding device includes a welding torch and a camera. The welding torch and the camera move with a moving mechanism, and the relative positions of the welding torch and the camera remain unchanged.

[0016] S102: Select the weld to be processed on the three-dimensional virtual model, set a collection point every 0.2 millimeters along the processed weld, and record the coordinates of the collection points in the weld track data set based on the three-dimensional virtual model coordinate system. The weld track data set also includes the start coordinates and end coordinates of the weld to be processed; Among them, setting a collection point every 0.2 millimeters can obtain an optimized data point distribution, ensuring that the weld track data set will neither cause an increased processing burden due to too many data points nor be unable to accurately describe the weld track due to too few data points, which is beneficial to obtaining an accurate camera motion track data set later; Steps S101 and S102 can be completed in the welding track simulation module.

[0017] S103: Determine the start coordinates and end coordinates of the weld to be processed, calculate the direction vector of the weld to be processed according to the start coordinates and end coordinates, and use the direction vector as the positive direction of the X-axis. The direction in which the welding end of the welding torch extends perpendicular to the X-axis is the positive direction of the Z-axis. According to the right-hand rule, based on the known positive direction of the X-axis and the positive direction of the Z-axis, obtain the positive direction of the Y-axis; S104: Calibrate the TCP of the welding torch through the four-point calibration method, and obtain the TCP of the camera through the hand-eye calibration method. Both the TCP of the camera and the TCP of the welding torch are data obtained relative to the center of the robot axis six flange. Calculate the difference between the TCP of the camera and the TCP of the welding torch to obtain the offset; Among them, the camera TCP refers to the center of the imaging plane of the camera, or the optical center of the camera lens; the torch TCP refers to the origin of the torch tool coordinate system, and the torch TCP represents the position of the tip of the welding wire when the torch performs welding operations; the flange center of the robot axis six generally refers to the flange center of the sixth axis of the industrial robot. In an industrial robot, each axis has its specific motion range and function, and the sixth axis is usually the axis where the robot end effector is located.

[0018] S105: Calculate the camera motion trajectory dataset required for the camera to perform the photographing action by combining the offset and the weld seam trajectory dataset; Among them, the specific method of calculating the camera motion trajectory dataset required for the camera to perform the photographing action by combining the offset and the weld seam trajectory dataset can be to offset the to-be-processed weld seam selected in step S102 along the negative direction of the Z axis in step S103 by a distance of a fixed camera field of view range, so as to obtain a new trajectory, which is the camera motion trajectory required for the camera to perform the photographing action. The distance of a fixed camera field of view range offset is the offset calculated in step S104. From the perspective of data, it means that the coordinate of each data point of the weld seam trajectory dataset in the coordinate system set in step S103 is offset by a value of the offset along the negative direction of the Z axis; A series of operations from step S103 to step S105 are completed in the scan trajectory generation module.

[0019] S106: The welding equipment performs photographing and scanning operations according to the camera motion trajectory dataset, obtains the two-dimensional point cloud dataset of the to-be-processed weld seam, and transmits the two-dimensional point cloud dataset to the industrial control computer of the welding equipment; Among them, step S106 is completed by means of the robot scanning and welding module, and the robot scanning and welding module is arranged in the welding robot.

[0020] S107: Convert the two-dimensional point cloud dataset into a three-dimensional point dataset in the base coordinate system through light plane conversion; S108: Perform quadratic fitting on the three-dimensional point dataset, filter out the abnormal data in the three-dimensional point dataset, and fit out the actual welding trajectory dataset; Among them, step S107 and step S108 are implemented by the welding trajectory generation module, and finally the actual welding trajectory dataset is generated, successfully replacing the traditional manual teaching for collecting welding trajectory data.

[0021] S109: The welding trajectory dataset is stored in the industrial control computer. The welding trajectory dataset corresponds to the to-be-processed weld seam one by one. After selecting the recorded to-be-processed weld seam in the industrial control computer, the industrial control computer can transmit the welding trajectory dataset to the welding robot; S110: The robot performs welding work according to the welding trajectory dataset.

[0022] Please refer to Figure 2 , the present application also provides a teaching-free welding acquisition control system, which is applied to a welding device. The welding robot of the welding device includes a welding torch and a camera. The welding torch and the camera move with a moving mechanism, and the relative positions of the welding torch and the camera remain unchanged. The teaching-free welding acquisition control system includes: A welding trajectory simulation module, which is used to build a three-dimensional virtual model of a workpiece to be welded, create a three-dimensional virtual model coordinate system, and at the same time be able to collect a weld trajectory data set of a weld to be processed based on the three-dimensional virtual model coordinate system; A scanning trajectory generation module, which is used to process the weld trajectory data set and generate a camera movement trajectory data set required for the camera to perform a photographing action; A robot scanning and welding module, which is used to control the movement of the camera according to the camera movement trajectory data set and perform a photographing and scanning operation; A welding trajectory generation module, which is used to process the scanned data to obtain an actual welding trajectory data set.

[0023] The welding trajectory simulation module, the scanning trajectory generation module and the welding trajectory generation module are usually set in the industrial control computer of the welding device. The industrial control computer has strong computing power and fast computing speed. Therefore, the industrial control computer completes the main data operations; the robot scanning and welding module is usually integrated in the welding robot. Refer to Figure 2 , the robot scanning and welding module controls the movement of the camera according to the camera movement trajectory data set and performs a photographing and scanning operation. The scanned data is transmitted from the welding robot to the industrial control computer, and the industrial control computer processes the data to obtain an actual welding trajectory data set. The industrial control computer then transmits the welding trajectory data set to the welding robot, and the welding robot performs welding according to the welding trajectory data set.

[0024] The present application also provides a welding device, which includes an industrial control computer and a welding robot. The welding robot includes a PLC, a moving mechanism, a welding torch and a camera. The welding torch and the camera are fixedly arranged on the moving mechanism and move with the moving mechanism, and the relative positions of the welding torch and the camera remain unchanged. The industrial control computer can communicate with the PLC. The industrial control computer is provided with a first processor and a first memory, and the PLC is provided with a second processor and a second memory. Computer programs are respectively stored in the first processor and the second processor. The first processor calls the computer program in the first memory and the second processor calls the computer program in the second memory to implement the above-mentioned teaching-free welding acquisition control method. In an industrial automation system, the industrial control computer and the PLC usually work together to jointly implement the monitoring and control of industrial equipment. The industrial control computer, as the upper computer, is responsible for processing a large amount of data and information, making high-level decisions and calculations, and at the same time communicating with the PLC to transfer control instructions to the PLC. The PLC, as the lower computer, is responsible for executing the control instructions sent by the industrial control computer and performing specific control operations on industrial equipment. In this process, information sharing and collaborative work are achieved between the industrial control computer and the PLC through data exchange and communication protocols.

[0025] It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

Claims

1. A teaching-free welding acquisition control method, characterized in that: Applied to welding equipment, the welding robot of the welding equipment includes a welding gun and a camera, the welding gun and the camera move with the moving mechanism, and the relative positions of the welding gun and the camera remain unchanged, the teaching-free welding acquisition control method includes: Build a 3D virtual model of the workpiece to be welded and create a 3D virtual model coordinate system; Collecting a weld trajectory data set of the weld to be processed based on the three-dimensional virtual model coordinate system; Calculate a camera motion trajectory dataset required for the camera to perform a photographing action according to the weld trajectory dataset; The camera motion trajectory dataset is sent to the robot, the robot performs a scanning operation according to the camera motion trajectory dataset, and processes the scanned data to obtain an actual welding trajectory dataset.

2. The teaching-free welding acquisition control method according to claim 1 is characterized in that: A weld trajectory data set of a weld to be processed is collected based on the three-dimensional virtual model coordinate system, including: selecting a weld to be processed on the three-dimensional virtual model, setting a collection point at intervals of N millimeters along the weld to be processed, where the value range of N is 0.1 millimeters to 0.3 millimeters, and based on the three-dimensional virtual model coordinate system, recording the coordinates of the collection points in the weld trajectory data set, where the weld trajectory data set also includes the starting point coordinates and the end point coordinates of the weld to be processed.

3. According to the teaching-free welding acquisition control method of claim 2, a acquisition point is set at an interval of 0.2 mm along the weld to be processed.

4. The teaching-free welding acquisition control method according to claim 1 is characterized in that: The camera motion trajectory dataset required for the camera to perform a photographing action is calculated according to the weld trajectory dataset, including: Step 1: Determine the starting point coordinates and the end point coordinates of the weld to be processed, calculate the direction vector of the weld to be processed according to the starting point coordinates and the end point coordinates, and take the direction vector as the positive direction of the X-axis, the direction in which the welding end of the welding gun extends perpendicularly to the X-axis as the positive direction of the Z-axis, and according to the right-hand rule, on the basis of knowing the positive directions of the X-axis and the Z-axis, obtain the positive direction of the Y-axis; Step 2: The welding gun TCP is calibrated by a four-point calibration method, and the camera TCP is obtained by a hand-eye calibration method. The camera TCP and the welding gun TCP are both data obtained relative to the center of the six flanges of the robot axis. The difference between the camera TCP and the welding gun TCP is calculated to obtain the offset; Step 3: Calculate the camera motion trajectory dataset required for the camera to perform a photo-taking action by combining the offset and the weld trajectory dataset.

5. The teaching-free welding acquisition control method according to claim 1 is characterized in that: The welding device performs a photo scanning operation according to the camera motion trajectory data set, and processes the scanned data to obtain a welding trajectory data set that conforms to the actual situation, including: Step 1: The welding equipment performs a photo scanning operation according to the camera motion trajectory data set to obtain a two-dimensional point cloud data set of the weld to be processed, and transmits the two-dimensional point cloud data set to an industrial computer of the welding equipment; Step 2: converting the two-dimensional point cloud data set into a three-dimensional point data set in a base coordinate system through optical plane conversion; Step 3: Perform secondary fitting on the three-dimensional point data set, filter out abnormal data in the three-dimensional point data set, and fit a welding trajectory data set that conforms to reality. The welding trajectory data set is stored in the industrial computer. The welding trajectory data set corresponds to the weld to be processed one by one. After selecting the recorded weld to be processed in the industrial computer, the industrial computer can transmit the welding trajectory data set to the welding robot, and the welding robot can perform corresponding welding work according to the welding trajectory data set.

6. A teaching-free welding acquisition control system, characterized in that: Applied to welding equipment, the welding robot of the welding equipment includes a welding gun and a camera, the welding gun and the camera move with the moving mechanism, and the relative positions of the welding gun and the camera remain unchanged, the teaching-free welding acquisition control system includes: A welding trajectory simulation module is used to build a three-dimensional virtual model of the workpiece to be welded and create a three-dimensional virtual model coordinate system, and can collect a weld trajectory data set of the weld to be processed based on the three-dimensional virtual model coordinate system; A scanning trajectory generation module is used to process the weld trajectory data set to generate a camera motion trajectory data set required for the camera to perform a photographing action; A robot scanning welding module is used to control the movement of the camera and perform photo scanning operations according to the camera motion trajectory data set; The welding trajectory generation module is used to process the scanned data to obtain an actual welding trajectory data set.

7. A welding device, characterized in that: The invention comprises an industrial computer and a welding robot, wherein the welding robot comprises a PLC, a mobile mechanism, a welding gun and a camera, wherein the welding gun and the camera are fixedly mounted on the mobile mechanism and move with the mobile mechanism, and the relative positions of the welding gun and the camera remain unchanged, the industrial computer can communicate with the PLC, the industrial computer is provided with a first processor and a first memory, the PLC is provided with a second processor and a second memory, computer programs are respectively stored in the first processor and the second processor, the first processor calls the computer program in the first memory and the second processor calls the computer program in the second memory to implement the teaching-free welding acquisition control method as described in any one of claims 1 to 5.

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