CN115723133B - A robot space weld automatic positioning and correction system based on virtual and real combination - Google Patents

Abstract

The present invention belongs to the field of intelligent manufacturing technology, and discloses a spatial weld automatic positioning and correction system based on a combination of virtual model and actual vision to control a robot to realize automatic welding, which can realize automatic tracking, positioning and welding of complex spatial welds. The system includes a virtual environment, a welding robot, a spatial weld optical tracking and visual recognition module, a motion trajectory generation module, an automatic positioning and interpolation fitting module, and a real-time trajectory correction and control module; a three-dimensional model of a workpiece to be welded, a workbench, a welding robot and a welding tool is imported in a relative posture in the virtual environment, and the user defines the spatial weld to be welded for the three-dimensional model based on the virtual environment. The motion trajectory generation module automatically generates the motion trajectory of the welding robot based on the spatial weld defined by the user, the spatial weld optical tracking and visual recognition module at the end of the welding robot obtains real-time weld information, the spatial weld positioning trajectory is obtained through the automatic positioning and interpolation fitting module, and the real-time trajectory correction and control module corrects the motion trajectory of the welding robot in real time. The present invention can import different models in a virtual environment to generate two-dimensional or three-dimensional welds, which is suitable for various welding workpieces and different welding environments. The user only needs to define the spatial weld to be welded in the virtual environment, and the welding robot can start welding along the user-defined weld, and automatically locate the weld trajectory and correct the deviation in real time. It has the advantages of wide applicability, simple operation and high welding precision.

Description

A robot space weld automatic positioning and correction system based on virtual and real combination

Technical Field

The present invention belongs to the field of intelligent manufacturing technology and robot automatic welding technology, and particularly relates to a robot space weld automatic positioning and deviation correction system based on virtual-real combination.

Background technique

In the field of welding engineering, there are various types of welding workpieces and various welding environments. Manual welding has high labor intensity, low efficiency, and difficult to ensure quality. Traditional welding robots work in a teaching programming control mode, which is time-consuming and labor-intensive, inefficient, and has high requirements for operators. The welding accuracy depends entirely on the experience of the instructor. Offline programming technology can better solve the problems existing in the teaching programming mode of welding robots, but welding stress and welding deformation will be generated during the welding process, resulting in deformation of the workpiece. Therefore, for complex spatial curve welds with long paths, there is a certain deviation between the offline programming results and the actual weld trajectory. Using correction technology to correct the motion trajectory of the welding robot in real time can better solve the problems existing in the offline programming mode. At present, most welding robots on the market use line structure scanning elements for real-time correction. By obtaining the depth information of the weld, the motion trajectory of the welding robot is corrected in real time and sent to the welding robot. The end effector of the welding robot moves to the welding starting point to automatically complete the welding work. Most of them are only suitable for plane welds, and the accuracy and accuracy of weld recognition directly affect the welding accuracy. Therefore, it is necessary to design a spatial weld automatic positioning and correction system suitable for various welding workpieces, various welding environments, especially three-dimensional complex welds.

Summary of the invention

In view of the shortcomings of the existing welding robot automatic welding technology, the purpose of the present invention is to provide a robot spatial weld automatic positioning and correction system based on the combination of virtual and real, which can import different models in a virtual environment to generate two-dimensional welds or three-dimensional welds, and is suitable for various welding workpieces and different welding environments. The user only needs to define the spatial weld to be welded in the virtual environment, and the welding robot can start welding along the user-defined weld, and automatically locate the weld trajectory and correct the deviation in real time. It has the advantages of wide applicability, easy operation and high welding precision.

The object of the present invention is achieved through the following approaches: a robot space weld automatic positioning and correction system based on virtual and real combination, including a virtual environment, a welding robot, a space weld tracking and identification module, a motion trajectory generation module, an automatic positioning and interpolation fitting module, and a real-time trajectory correction and control module;

The virtual environment is used to import three-dimensional models of workpieces to be welded, workbenches, welding robots and welding tools, and simulate and display the motion states of these three-dimensional models; based on the virtual environment, users manage and interact with the three-dimensional models therein, and perform weld trajectory definition, spatial weld trajectory generation and welding process simulation operations;

The weld trajectory definition refers to the user defining the weld trajectory by selecting points, drawing lines, and selecting surfaces on the workpiece model to be welded in the virtual environment;

The spatial weld trajectory generation refers to generating a coherent spatial weld trajectory through geometric calculation and fitting based on the weld trajectory defined by the user;

The spatial welds include two-dimensional welds and three-dimensional welds;

The spatial weld tracking and identification module includes but is not limited to structured light, planar vision, 3D vision, laser tracking and infrared tracking, which is used to obtain weld information in real time;

The motion trajectory generation module refers to a module that automatically generates the motion trajectory of the welding robot based on the weld trajectory defined by the user in the virtual environment or the weld trajectory defined based on artificial intelligence analysis, and inputs the scanning advance amount, the motion step distance of the welding robot, and the end tool offset;

The end tool offset refers to the distance between the end welding tool position of the welding robot and the weld trajectory selected by the user, and its value is defined by the user according to different welding processes, welding tool types and powers;

The scanning advance amount refers to the position advance amount of the sensor carried by the spatial weld tracking and identification module relative to the welding tool in the moving direction, and its value is defined according to the field of view of the sensor;

The automatic positioning and interpolation fitting module locates the weld trajectory based on the real-time weld information obtained by the spatial weld tracking and identification module, and generates the weld trajectory through interpolation fitting;

The real-time trajectory correction and control module determines whether the motion trajectory of the welding robot generated by the motion trajectory generation module meets the welding process requirements based on the real-time weld information obtained by the spatial weld tracking and recognition module: if the requirements are met, the welding task is performed according to the generated motion trajectory; if not, the motion trajectory is corrected in real time;

When the system performs automatic welding tasks, the following steps are included:

Step 1: Control the welding robot so that the end of the welding robot is close to the workpiece to be welded, and control the spatial weld tracking and recognition module at the end of the welding robot to collect image information of the workpiece to be welded, and calculate the relative posture of the workpiece to be welded and the welding robot;

Step 2: Import the workpiece model to be welded and the welding robot model into the virtual environment in relative posture, and define a virtual space weld tracking and recognition module with parameters consistent with the space weld tracking and recognition module;

Step 3: The user selects the weld trajectory to be welded on the workpiece to be welded in the virtual environment, defines the end tool offset, the motion step of the welding robot, and the scanning advance, and the motion trajectory generation module generates the welding robot motion trajectory;

Step 4: simulate the robot motion trajectory in a virtual environment, and perform motion interference, collision avoidance, and singular point detection; if collision, interference, or motion singularity occurs during the simulation, re-execute step 3 until the simulation test result meets the requirements; if the simulation test result meets the requirements, derive the welding robot motion trajectory;

Step 5: Determine the type of sensor in the spatial weld tracking and recognition module. If it is a planar array visual recognition element, continue to execute; if it is a line structure scanning element, jump to step 7a;

Step 6a, controlling the virtual welding robot in the virtual environment to move according to the welding robot motion trajectory that meets the simulation detection requirements in step 4; during the movement, using the virtual space weld tracking and recognition module installed at the end of the virtual welding robot to collect virtual image information of the workpiece model to be welded in the virtual environment in real time;

The real-time acquisition of virtual image information of the workpiece model to be welded in the virtual environment means that when the virtual welding robot moves in units of motion steps, the virtual space weld tracking and recognition module acquires virtual image information at the sampling frequency of the carried sensor.

Step 6b, according to the motion trajectory of the welding robot derived in step 4, control the actual welding robot to start moving from the starting point of the motion trajectory and with the motion step defined in step 3;

Step 6c: While the actual welding robot is moving, the space weld tracking and recognition module at the end of the welding robot is used to collect real image information of the workpiece to be welded in real time;

Step 6d, using the virtual image information collected in step 6a as a template image, matching the real image information collected in step 6c with the template image in real time;

Step 6e: input the real-time matching result into the automatic positioning and interpolation fitting module, perform real-time identification and positioning of the weld trajectory selected by the user in step 3, and control the welding robot to move continuously with the movement step defined in step 3;

The real-time identification and positioning of the weld trajectory selected by the user in step 3 means that when the welding robot moves according to the welding robot motion trajectory generated by the weld trajectory selected by the user, the spatial weld trajectory within the current field of view is obtained by real-time matching through the array recognition element, and the spatial weld trajectory within the previous field of view, the spatial weld trajectory within the current field of view, and the weld trajectory selected by the user are calculated through interpolation fitting to obtain a coherent spatial weld trajectory.

Step 6f, repeating steps 6b to 6e until the tracking task of the current weld is completed and the positioning track of the current weld is obtained;

Step 6g, repeating steps 6a to 6f, completing one weld tracking task each time, until all weld trajectories selected by the user in step 3 are tracked, and the positioning trajectory of the corresponding weld trajectories is obtained, then jumping to step 8;

Step 7a, controlling the welding robot to move according to the motion trajectory derived in step 4 and the motion step defined in step 3; while the welding robot is moving, the line structure scanning element carried by the spatial weld tracking and recognition module installed at the end of the welding robot collects the spatial weld geometry information of the workpiece to be welded in real time;

Step 7b, input the collected spatial weld geometry information into the automatic positioning and interpolation fitting module, perform real-time identification and positioning of the weld trajectory selected by the user in step 3, and control the welding robot to move continuously with the movement step defined in step 3 until the current weld tracking task is completed, and obtain the positioning trajectory of the current weld trajectory;

The real-time identification and positioning of the weld trajectory selected by the user in step 3 refers to that when the welding robot moves according to the welding robot motion trajectory generated by the weld trajectory selected by the user, the spatial weld geometry information is obtained by scanning with a line structure scanning element, and the obtained spatial weld geometry information and the weld trajectory selected by the user are calculated by interpolation fitting to obtain a coherent spatial weld trajectory.

Step 7c, repeating steps 7a and 7b until all weld seam tracks selected by the user in step 3 are tracked, and the positioning tracks of the corresponding weld seam tracks are obtained, and then proceeding to the next step;

Step 8. Input the positioning trajectory obtained in step 6g or step 7c into the motion trajectory generation module to generate the motion trajectory of the welding robot, control the welding robot to move according to the trajectory, and perform the welding task. During the movement and welding process, the spatial weld trajectory is obtained based on the spatial weld tracking and recognition module and input into the real-time trajectory correction and control module for real-time correction to eliminate the trajectory deviation caused by thermal deformation.

The spatial weld tracking and identification module identifies the spatial weld trajectory and inputs it into the real-time trajectory correction and control module for real-time correction, and its specific method and steps are as follows:

If the sensor carried is a planar array vision element, the actual spatial weld trajectory within the current field of view is identified by the spatial weld tracking and recognition module, and its maximum deviation from the positioning trajectory within the current field of view is calculated to determine whether the deviation affects the welding quality;

If it affects the welding quality, the starting point of the positioning trajectory within the current field of view is used as the starting point of the interpolation fitting, and the three-dimensional coordinates of the end point of the actual spatial weld trajectory within the current field of view are used as the end point. The interpolation fitting calculation is performed to obtain the corrected spatial weld trajectory, and the corrected welding robot motion trajectory is input into the motion trajectory generation module to obtain the corrected welding robot motion trajectory, and the welding robot motion trajectory is updated;

If the welding quality is not affected, move according to the original positioning trajectory;

If the carried sensor is a linear structure scanning element, the actual spatial weld geometry information under the current scanning field of view is obtained through the spatial weld tracking and recognition module, and the maximum deviation value between the spatial weld geometry information under the current scanning field of view and the positioning trajectory is calculated to determine whether the deviation value affects the welding quality;

If it affects the welding quality, the three-dimensional coordinates of the positioning trajectory corresponding to the welding tool at the end of the current welding robot are used as the starting point of the interpolation fitting, and the three-dimensional coordinates of the actual spatial weld geometry information under the current scanning field of view are identified as the end point. The interpolation fitting calculation is performed to obtain the corrected spatial weld trajectory, and the corrected welding robot motion trajectory is input into the motion trajectory generation module to update the welding robot motion trajectory.

If the welding quality is not affected, move according to the original positioning trajectory.

Combining all the above technical solutions, the advantages of the present invention are: the present invention can import different models in a virtual environment to generate two-dimensional welds or three-dimensional welds, which is suitable for various welding workpieces and different welding environments. The user only needs to define the spatial weld to be welded in the virtual environment, and the welding robot can start welding along the user-defined weld, and automatically identify the weld trajectory and correct it in real time. It has the advantages of wide applicability, simple operation and high welding precision.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention is further described in detail below. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the scope of the present invention.

Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

The robot space weld automatic positioning and correction system based on virtual-real combination provided in the embodiment of the present invention comprises a virtual environment, a welding robot, a space weld tracking and identification module, a motion trajectory generation module, an automatic positioning and interpolation fitting module, and a real-time trajectory correction and control module;

The virtual environment is used to import three-dimensional models of workpieces to be welded, workbenches, welding robots and welding tools, and simulate and display the motion states of these three-dimensional models; based on the virtual environment, users manage and interact with the three-dimensional models therein, and perform weld trajectory definition, spatial weld trajectory generation and welding process simulation operations;

The weld trajectory definition refers to the user defining the weld trajectory by selecting points, drawing lines, and selecting surfaces on the workpiece model to be welded in the virtual environment;

The spatial weld trajectory generation refers to generating a coherent spatial weld trajectory through geometric calculation and fitting based on the weld trajectory defined by the user;

The spatial welds include two-dimensional welds and three-dimensional welds;

The spatial weld tracking and identification module includes but is not limited to structured light, planar vision, 3D vision, laser tracking and infrared tracking, which is used to obtain weld information in real time;

The motion trajectory generation module refers to a module that automatically generates the motion trajectory of the welding robot based on the weld trajectory defined by the user in the virtual environment or the weld trajectory defined based on artificial intelligence analysis, and inputs the scanning advance amount, the motion step distance of the welding robot, and the end tool offset;

The end tool offset refers to the distance between the end welding tool position of the welding robot and the weld trajectory selected by the user, and its value is defined by the user according to different welding processes, welding tool types and powers;

The scanning advance amount refers to the position advance amount of the sensor carried by the spatial weld tracking and identification module relative to the welding tool in the moving direction, and its value is defined according to the field of view of the sensor;

The automatic positioning and interpolation fitting module locates the weld trajectory based on the real-time weld information obtained by the spatial weld tracking and identification module, and generates the weld trajectory through interpolation fitting;

The real-time trajectory correction and control module determines whether the motion trajectory of the welding robot generated by the motion trajectory generation module meets the welding process requirements based on the real-time weld information obtained by the spatial weld tracking and recognition module: if the requirements are met, the welding task is performed according to the generated motion trajectory; if not, the motion trajectory is corrected in real time;

When the system performs automatic welding tasks, the following steps are included:

Step 1: Control the welding robot so that the end of the welding robot is close to the workpiece to be welded, and control the spatial weld tracking and recognition module at the end of the welding robot to collect image information of the workpiece to be welded, and calculate the relative posture of the workpiece to be welded and the welding robot;

Step 2: Import the workpiece model to be welded and the welding robot model into the virtual environment in relative posture, and define a virtual space weld tracking and recognition module with parameters consistent with the space weld tracking and recognition module;

Step 3: The user selects the weld trajectory to be welded on the workpiece to be welded in the virtual environment, defines the end tool offset, the motion step of the welding robot, and the scanning advance, and the motion trajectory generation module generates the welding robot motion trajectory;

Step 4: simulate the robot motion trajectory in a virtual environment, and perform motion interference, collision avoidance, and singular point detection; if collision, interference, or motion singularity occurs during the simulation, re-execute step 3 until the simulation test result meets the requirements; if the simulation test result meets the requirements, derive the welding robot motion trajectory;

Step 5: Determine the type of sensor in the spatial weld tracking and recognition module. If it is a planar array visual recognition element, continue to execute; if it is a line structure scanning element, jump to step 7a;

Step 6a, controlling the virtual welding robot in the virtual environment to move according to the welding robot motion trajectory that meets the simulation detection requirements in step 4; during the movement, using the virtual space weld tracking and recognition module installed at the end of the virtual welding robot to collect virtual image information of the workpiece model to be welded in the virtual environment in real time;

The real-time acquisition of virtual image information of the workpiece model to be welded in the virtual environment means that when the virtual welding robot moves in units of motion steps, the virtual space weld tracking and recognition module acquires virtual image information at the sampling frequency of the carried sensor.

Step 6b, according to the motion trajectory of the welding robot derived in step 4, control the actual welding robot to start moving from the starting point of the motion trajectory and with the motion step defined in step 3;

Step 6c: While the actual welding robot is moving, the space weld tracking and recognition module at the end of the welding robot is used to collect real image information of the workpiece to be welded in real time;

Step 6d, using the virtual image information collected in step 6a as a template image, matching the real image information collected in step 6c with the template image in real time;

Step 6e: input the real-time matching result into the automatic positioning and interpolation fitting module, perform real-time identification and positioning of the weld trajectory selected by the user in step 3, and control the welding robot to move continuously with the movement step defined in step 3;

The real-time identification and positioning of the weld trajectory selected by the user in step 3 means that when the welding robot moves according to the welding robot motion trajectory generated by the weld trajectory selected by the user, the spatial weld trajectory within the current field of view is obtained by real-time matching through the array recognition element, and the spatial weld trajectory within the previous field of view, the spatial weld trajectory within the current field of view, and the weld trajectory selected by the user are calculated through interpolation fitting to obtain a coherent spatial weld trajectory.

Step 6f, repeating steps 6b to 6e until the tracking task of the current weld is completed and the positioning track of the current weld is obtained;

Step 6g, repeating steps 6a to 6f, completing one weld tracking task each time, until all weld trajectories selected by the user in step 3 are tracked, and the positioning trajectory of the corresponding weld trajectories is obtained, then jumping to step 8;

Step 7a, controlling the welding robot to move according to the motion trajectory derived in step 4 and the motion step defined in step 3; while the welding robot is moving, the line structure scanning element carried by the spatial weld tracking and recognition module installed at the end of the welding robot collects the spatial weld geometry information of the workpiece to be welded in real time;

Step 7b, input the collected spatial weld geometry information into the automatic positioning and interpolation fitting module, perform real-time identification and positioning of the weld trajectory selected by the user in step 3, and control the welding robot to move continuously with the movement step defined in step 3 until the current weld tracking task is completed, and obtain the positioning trajectory of the current weld trajectory;

The real-time identification and positioning of the weld trajectory selected by the user in step 3 refers to that when the welding robot moves according to the welding robot motion trajectory generated by the weld trajectory selected by the user, the spatial weld geometry information is obtained by scanning with a line structure scanning element, and the obtained spatial weld geometry information and the weld trajectory selected by the user are calculated by interpolation fitting to obtain a coherent spatial weld trajectory.

Step 7c, repeating steps 7a and 7b until all weld seam tracks selected by the user in step 3 are tracked, and the positioning tracks of the corresponding weld seam tracks are obtained, and then proceeding to the next step;

Step 8. Input the positioning trajectory obtained in step 6g or step 7c into the motion trajectory generation module to generate the motion trajectory of the welding robot, control the welding robot to move according to the trajectory, and perform the welding task. During the movement and welding process, the spatial weld trajectory is obtained based on the spatial weld tracking and recognition module and input into the real-time trajectory correction and control module for real-time correction to eliminate the trajectory deviation caused by thermal deformation.

The spatial weld tracking and identification module identifies the spatial weld trajectory and inputs it into the real-time trajectory correction and control module for real-time correction, and its specific method and steps are as follows:

If the sensor carried is a planar array vision element, the actual spatial weld trajectory within the current field of view is identified by the spatial weld tracking and recognition module, and its maximum deviation from the positioning trajectory within the current field of view is calculated to determine whether the deviation affects the welding quality;

If it affects the welding quality, the starting point of the positioning trajectory within the current field of view is used as the starting point of the interpolation fitting, and the three-dimensional coordinates of the end point of the actual spatial weld trajectory within the current field of view are used as the end point. The interpolation fitting calculation is performed to obtain the corrected spatial weld trajectory, and the corrected welding robot motion trajectory is input into the motion trajectory generation module to obtain the corrected welding robot motion trajectory, and the welding robot motion trajectory is updated;

If the welding quality is not affected, move according to the original positioning trajectory;

If the carried sensor is a linear structure scanning element, the actual spatial weld geometry information under the current scanning field of view is obtained through the spatial weld tracking and recognition module, and the maximum deviation value between the spatial weld geometry information under the current scanning field of view and the positioning trajectory is calculated to determine whether the deviation value affects the welding quality;

If it affects the welding quality, the three-dimensional coordinates of the positioning trajectory corresponding to the welding tool at the end of the current welding robot are used as the starting point of the interpolation fitting, and the three-dimensional coordinates of the actual spatial weld geometry information under the current scanning field of view are identified as the end point. The interpolation fitting calculation is performed to obtain the corrected spatial weld trajectory, and the corrected welding robot motion trajectory is input into the motion trajectory generation module to update the welding robot motion trajectory.

If the welding quality is not affected, move according to the original positioning trajectory.

The above are only embodiments of the present invention, and the common knowledge such as the known specific structure and/or characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims (5)

1. Automatic positioning and correcting system of robot space welding seam based on virtual-real combination, its characterized in that:

The system comprises a virtual environment, a welding robot, a space weld joint tracking and identifying module, a motion track generating module, an automatic positioning and interpolation fitting module and a real-time track rectifying and controlling module;

The virtual environment is used for importing three-dimensional models of a workpiece to be welded, a workbench, a welding robot and a welding tool, and simulating and displaying the motion states of the three-dimensional models; the user manages and interacts the three-dimensional model based on the virtual environment, and performs weld path definition, space weld path generation and welding process simulation operation;

The weld track definition means that a user defines a weld track on a workpiece model to be welded in a virtual environment in a point position selection, line drawing and surface selection mode;

The space weld joint track generation is to generate a coherent space weld joint track through geometric calculation and fitting based on a weld joint track defined by a user;

Wherein the spatial welds include two-dimensional welds and three-dimensional welds;

the space weld joint tracking and identifying module comprises, but is not limited to, structured light, plane vision, 3D vision, laser tracking and infrared tracking, and is used for acquiring weld joint information in real time;

the motion trail generation module is used for automatically generating a motion trail of the welding robot based on a welding seam trail defined by a user in a virtual environment or based on a welding seam trail defined by artificial intelligent analysis, and inputting a scanning advance, a motion step of the welding robot and a terminal tool offset;

wherein the end tool offset is the distance between the end welding tool position of the welding robot and the welding line track selected by the user, and the value of the end tool offset is defined by the user according to different welding processes, types and powers of the welding tools;

The scanning lead is the position lead of a sensor carried by the space weld joint tracking and identifying module relative to the welding tool in the moving direction, and the value of the scanning lead is defined according to the visual field range of the sensor;

The automatic positioning and interpolation fitting module is used for positioning the weld track based on the real-time weld information obtained by the space weld tracking and identifying module and generating the weld track through interpolation fitting;

The real-time track deviation rectifying and controlling module judges whether the welding robot motion track generated by the motion track generating module meets the welding process requirements based on the real-time weld information obtained by the space weld tracking and identifying module: if the requirements are met, executing a welding task according to the generated motion trail; if not, correcting the motion trail in real time;

When the system executes the automatic welding task, the method comprises the following steps:

step 1, controlling a welding robot to enable the tail end of the welding robot to be close to a workpiece to be welded, controlling a space weld joint tracking and identifying module of the tail end of the welding robot to acquire image information of the workpiece to be welded, and calculating the relative pose of the workpiece to be welded and the welding robot;

Step 2, importing a workpiece model to be welded and a welding robot model into a virtual environment in a relative pose, and defining a virtual space weld tracking and identifying module consistent with the parameters of the space weld tracking and identifying module;

Step 3, selecting a welding seam track to be welded on a workpiece to be welded in a virtual environment by a user, defining an end tool offset, a movement step length and a scanning advance of a welding robot, and generating a welding robot movement track by a movement track generation module;

Step 4, simulating a motion trail of the robot in a virtual environment, and performing motion interference, collision avoidance and singular point detection; if collision, interference or singular movement occurs in the simulation process, the step 3 is re-executed until the simulation detection result meets the requirement; if the simulation detection result meets the requirement, deriving a welding robot motion track;

Step 5, judging the type of the sensor in the space weld joint tracking and identifying module, if the sensor is a planar array type visual identifying element, continuing to execute, and if the sensor is a line structure scanning element, jumping to the step 7a;

step 6a, controlling a virtual welding robot in a virtual environment, and moving according to the movement track of the welding robot meeting the simulation detection requirement in the step 4; in the motion process, virtual image information of a workpiece model to be welded in a virtual environment is acquired in real time by utilizing a virtual space weld joint tracking and identifying module arranged at the tail end of a virtual welding robot;

Step 6b, controlling the actual welding robot to start moving from the starting point of the motion track according to the motion track of the welding robot derived in the step 4, and starting moving at the motion step distance defined in the step 3;

Step 6c, acquiring real image information of a workpiece to be welded in real time by utilizing a welding robot tail end space weld joint tracking and identifying module while the actual welding robot moves;

Step 6d, real-time matching is carried out on the real image information acquired in the step 6c and the template image by taking the virtual image information acquired in the step 6a as the template image;

Step 6e, inputting a real-time matching result into an automatic positioning and interpolation fitting module, performing real-time identification positioning on the welding seam track selected by the user in the step 3, and controlling the welding robot to continuously move at the defined movement step distance in the step 3;

Step 6f, repeating the steps 6b to 6e until the tracking task of the current welding line is completed, and obtaining the positioning track of the current welding line;

Step 6g, repeatedly executing the steps 6a to 6f, completing a weld tracking task in each execution process until the tracking of all the weld trajectories selected by the user in the step 3 is completed, obtaining the positioning trajectories of the corresponding weld trajectories, and jumping to the step 8;

Step 7a, controlling the welding robot to move according to the motion trail derived in the step 4 and the motion step distance defined in the step 3; the method comprises the steps that when a welding robot moves, a line structure scanning element carried by a space weld joint tracking and identifying module arranged at the tail end of the welding robot acquires space weld joint geometric information of a workpiece to be welded in real time;

Step 7b, inputting the acquired geometric information of the space weld joint into an automatic positioning and interpolation fitting module, identifying and positioning the weld joint track selected by the user in the step 3 in real time, and controlling the welding robot to continuously move at the well defined movement step distance in the step 3 until the tracking task of the current weld joint is completed, so as to obtain the positioning track of the current weld joint track;

Step 7c, repeatedly executing the steps 7a and 7b until the tracking of all the weld trajectories selected by the user in the step 3 is completed, obtaining the positioning trajectories of the corresponding weld trajectories, and turning to the next step;

and 8, inputting the positioning track obtained in the step 6g or the step 7c to a motion track generation module to generate a motion track of the welding robot, controlling the welding robot to move according to the track, and executing a welding task, wherein in the moving and welding processes, the space weld track is obtained based on a space weld tracking and identifying module and is input to a real-time track deviation rectifying and controlling module to carry out real-time rectification so as to eliminate track deviation caused by thermal deformation.

2. The automatic positioning and correcting system for the space weld joint of the robot based on virtual-real combination according to claim 1, wherein the automatic positioning and correcting system is characterized in that: the step 6a of collecting virtual image information of the workpiece model to be welded in real time refers to that when the virtual welding robot moves by taking the motion step as a unit, the virtual space weld joint tracking and identifying module collects the virtual image information at the sampling frequency of the carried sensor.

3. The automatic positioning and correcting system for the space weld joint of the robot based on virtual-real combination according to claim 1, wherein the automatic positioning and correcting system is characterized in that: in the step 6e, the real-time identification and positioning are performed on the welding seam track selected by the user in the step 3, that is, when the welding robot moves according to the welding robot motion track generated by the welding seam track selected by the user, the space welding seam track in the current visual field range is obtained through real-time matching of the area array type identification element, and the space welding seam track in the previous visual field range, the space welding seam track in the current visual field range and the welding seam track selected by the user are obtained through interpolation fitting calculation.

4. The automatic positioning and correcting system for the space weld joint of the robot based on virtual-real combination according to claim 1, wherein the automatic positioning and correcting system is characterized in that: in the step 7b, the real-time identification and positioning of the welding seam track selected by the user in the step 3 means that when the welding robot moves according to the welding robot motion track generated by the welding seam track selected by the user, the line structure scanning element scans to obtain the space welding seam geometric information, and the obtained space welding seam geometric information and the welding seam track selected by the user are subjected to interpolation fitting calculation to obtain a coherent space welding seam track.

5. The automatic positioning and correcting system for the space weld joint of the robot based on virtual-real combination according to claim 1, wherein the automatic positioning and correcting system is characterized in that: in the step 8, the space weld seam track is identified based on the space weld seam tracking and identifying module and is input into the real-time track deviation rectifying and controlling module for real-time rectification, and the specific method and the steps are as follows:

if the carried sensor is a planar array type visual element, the actual space weld joint track in the current visual field range is obtained through recognition of the space weld joint tracking and recognition module, the maximum deviation value of the actual space weld joint track and the positioning track in the current visual field range is calculated, and whether the welding quality is influenced is judged;

If the welding quality is affected, taking a starting point of a positioning track in the current visual field as an interpolation fitting starting point, taking a three-dimensional coordinate of an end point of an actual space welding seam track in the current visual field as the end point, carrying out interpolation fitting calculation to obtain a corrected space welding seam track, inputting the corrected space welding seam track into a motion track generation module to obtain a corrected welding robot motion track, and updating the welding robot motion track;

If the welding quality is not affected, moving according to the original positioning track;

If the carried sensor is a linear structure scanning element, the actual space weld geometrical information under the current scanning visual field is obtained through the recognition of the space weld tracking and recognition module, the maximum deviation value of the actual space weld geometrical information and the space weld geometrical information of the positioning track under the current scanning visual field is calculated, and whether the deviation value affects the welding quality is judged;

If the welding quality is affected, taking the three-dimensional coordinates of the positioning track corresponding to the welding tool at the tail end of the current welding robot as an interpolation fitting starting point, taking the three-dimensional coordinates of the actual space welding seam geometric information under the current scanning visual field as an end point, carrying out interpolation fitting calculation to obtain a corrected space welding seam track, inputting the corrected space welding seam track into a motion track generation module to obtain a corrected welding robot motion track, and updating the welding robot motion track;

if the welding quality is not affected, the welding device moves according to the original positioning track.