CN114769988A

CN114769988A - Welding control method and system, welding equipment and storage medium

Info

Publication number: CN114769988A
Application number: CN202210562887.8A
Authority: CN
Inventors: 王霄腾; 王文华; 戴熙礼; 李肖; 周刚; 蒲英钊
Original assignee: China Railway Construction Heavy Industry Group Co Ltd
Current assignee: China Railway Construction Heavy Industry Group Co Ltd
Priority date: 2022-05-23
Filing date: 2022-05-23
Publication date: 2022-07-22
Anticipated expiration: 2042-05-23

Abstract

The application discloses a welding control method, a welding control system, welding equipment and a storage medium, and belongs to the technical field of visual tracking algorithm technology, which is used for improving welding precision and efficiency. The welding control method comprises the following steps: controlling a welding gun to move to an initial position, and determining a welding seam starting point of the workpiece by using a visual sensor; controlling the welding gun to move to the welding seam starting point, and acquiring welding seam data by using a visual sensor; judging whether the welding seam data acquired by the visual sensor contains a welding seam termination point; if yes, generating a welding track from the welding seam starting point to the welding seam ending point according to the welding seam data, and controlling a welding gun to weld the workpiece according to the welding track; if not, generating a trend space straight line according to the actual motion data of the welding gun, calculating a correction coordinate point, and controlling the welding gun to move to the correction coordinate point until the welding line data collected by the vision sensor contains a welding line termination point, so that the welding precision and efficiency are improved.

Description

Welding control method and system, welding equipment and storage medium

Technical Field

The present application relates to the field of visual tracking algorithm technology, and in particular, to a welding control method, a welding control system, a welding device, and a storage medium.

Background

With the development of manufacturing industry, many industries need to use a large amount of automatic and intelligent equipment to replace manual operation so as to improve the production efficiency and the operation quality. In the welding production operation of heavy industry, automatic welding is mostly adopted. However, for the welding of medium and heavy plates, there are many problems such as workpiece processing errors, position errors after clamping, thermal deformation of workpieces during welding, and displacement of clamping positions during welding operation, and these factors may cause the welding track to change during welding, and the welding operation track deviates from the actual welding line, thereby directly affecting the welding quality.

In order to ensure the quality and efficiency of welding seam welding, the related technology mainly adopts the automatic welding seam tracking technology to carry out automatic welding, and the existing automatic welding seam tracking mode mainly comprises the steps of installing a preposed optical vision type sensor on a welding gun tool of a welding robot, detecting and calculating the position of a characteristic point of a welding seam in real time through the sensor, and controlling the robot to carry out automatic tracking welding according to the position of the characteristic point. However, in the above manner, when the welding seam has a sudden change, the convergence of the tracking track is poor, and the welding accuracy is low.

Therefore, how to improve the welding precision and efficiency is a technical problem to be solved by those skilled in the art.

Disclosure of Invention

The purpose of the application is to provide a welding control method, a welding control system, a storage medium and a welding device, which can improve the welding precision and efficiency.

In order to solve the technical problem, the present application provides a welding control method, which is applied to a welding device, wherein a welding gun and a vision sensor are arranged on an execution mechanism of the welding device, the welding gun and the vision sensor move along with the execution mechanism, and the relative positions of the welding gun and the vision sensor remain unchanged, the welding control method includes:

controlling the welding gun to move to an initial position, and determining a welding seam starting point of a workpiece by using the vision sensor;

controlling the welding gun to move to the welding seam starting point, and acquiring welding seam data by using the vision sensor;

when the moving distance of the welding gun is larger than a preset value, judging whether the welding seam data collected by the vision sensor contains a welding seam termination point;

if yes, generating a welding track from the welding seam starting point to the welding seam ending point according to the welding seam data, and controlling the welding gun to weld the workpiece according to the welding track;

if not, generating a trend space straight line according to the actual motion data of the welding gun, calculating a correction coordinate point according to the trend space straight line, the welding line data and a similar triangle rule, and controlling the welding gun to move to the correction coordinate point until the welding line data collected by the vision sensor comprises the welding line end point.

Optionally, generating a trend space straight line according to the actual motion data of the welding gun includes:

selecting a first actual swing track point and a second actual swing track point from the actual motion data of the welding gun; the time corresponding to the second actual swing track point is later than the first actual swing track point;

and calculating trend space straight lines corresponding to all the motion coordinate points between the first actual swing track point and the second actual swing track point by using a least square straight line fitting algorithm.

Optionally, calculating a correction coordinate point according to the trend space straight line, the weld data, and the similar triangle rule, includes:

determining a first vertical line which passes through the first actual swing track point and is perpendicular to the trend space straight line, and setting an intersection point of the first vertical line and the trend space straight line as a first intersection point;

determining a second vertical line which passes through the second actual swing track point and is perpendicular to the trend space straight line, and setting an intersection point of the second vertical line and the trend space straight line as a second intersection point;

calculating the deviation of the central point of the actual groove according to the welding line data, the current swing amplitude and the deviation data;

calculating the coordinate of the first intersection point, the coordinate of the second intersection point and the deviation of the actual groove center point based on a similar triangle rule of dynamic displacement to obtain differential motion offsets of the welding gun in the X-axis direction, the Y-axis direction and the Z-axis direction;

and calculating the correction coordinate point according to the motion differential offset and the coordinates of the second intersection point.

Optionally, controlling the welding gun to move to the correction coordinate point until the weld data acquired by the vision sensor includes the weld end point includes:

step 1: controlling the welding gun to move to a correction coordinate point, and judging whether the welding seam data acquired by a visual sensor contains the welding seam termination point; if yes, judging that the welding seam data acquired by the vision sensor comprises the welding seam termination point; if not, entering the step 2;

step 2: reselecting a first actual swing track point and a new second actual swing track point from the actual motion data of the welding gun;

and 3, step 3: calculating trend space straight lines corresponding to all motion coordinate points between the first actual swing track point and the second actual swing track point by using a least square space straight line algorithm;

and 4, step 4: and (4) calculating a new correction coordinate point according to the trend space straight line, the welding line data acquired by the vision sensor and a similar triangle rule, and entering the step 1.

Optionally, calculating the actual groove center point deviation according to the weld data, the current swing amplitude and the deviation data, including:

calculating the deviation of the central point of the groove according to the welding line data;

determining the current swing amplitude according to the swing waveform and the working time of the welding gun;

subtracting the current swing amplitude and deviation data from the groove center point deviation to obtain the actual groove center point deviation of the actual groove center point deviation in the Y-axis and Z-axis directions; the deviation data comprises the deviation of the welding gun and the vision sensor in the Y-axis direction and the Z-axis direction, and the movement direction of the welding gun is the X-axis direction.

Optionally, judging whether the weld data collected by the vision sensor includes a weld end point includes:

and judging whether the welding seam data acquired by the vision sensor contains a welding seam termination point or not according to a system scanning period.

Optionally, generating a welding track from the welding seam starting point to the welding seam ending point according to the welding seam data includes:

fitting the welding line data through a median filtering method to obtain welding line characteristic points, and calculating a least square straight line fitting algorithm on the welding line characteristic points to obtain the welding track from the welding line starting point to the welding line ending point.

The application also provides a welding control system, is applied to welding equipment, be provided with welder and vision sensor on welding equipment's the actuating mechanism, welder with vision sensor follows actuating mechanism removes, just welder with vision sensor's relative position remains unchanged, welding control system includes:

the starting point determining module is used for controlling the welding gun to move to an initial position and determining a welding seam starting point of a workpiece by using the vision sensor;

the data acquisition module is used for controlling the welding gun to move to the welding seam starting point and acquiring welding seam data by using the vision sensor;

the judging module is used for judging whether the welding seam data acquired by the vision sensor contains a welding seam termination point or not when the moving distance of the welding gun is larger than a preset value;

the operation module is used for generating a welding track from the welding seam starting point to the welding seam ending point according to the welding seam data if the welding seam data acquired by the vision sensor contains the welding seam ending point, and controlling the welding gun to weld the workpiece according to the welding track;

and the correction module is used for generating a trend space straight line according to the actual motion data of the welding gun if the welding seam data acquired by the vision sensor does not contain the welding seam termination point, calculating a correction coordinate point according to the trend space straight line, the welding seam data and a similar triangle rule, and controlling the welding gun to move to the correction coordinate point until the welding seam data acquired by the vision sensor contains the welding seam termination point.

The application also provides a storage medium on which a computer program is stored, wherein the computer program realizes the steps executed by the welding control method when executed.

The application also provides welding equipment, which comprises an execution mechanism, a memory and a processor, wherein the execution mechanism is provided with a welding gun and a visual sensor, the welding gun and the visual sensor move along with the execution mechanism, the relative position of the welding gun and the visual sensor is kept unchanged, a computer program is stored in the memory, and the processor calls the computer program in the memory to realize the steps of the welding control method.

The application provides a welding control method, which is applied to welding equipment, wherein a welding gun and a visual sensor are arranged on an actuating mechanism of the welding equipment, the welding gun and the visual sensor move along with the actuating mechanism, and the relative positions of the welding gun and the visual sensor are kept unchanged, and the welding control method comprises the following steps: controlling the welding gun to move to an initial position, and determining a welding seam starting point of a workpiece by using the vision sensor; controlling the welding gun to move to the welding seam starting point, and acquiring welding seam data by using the vision sensor; when the moving distance of the welding gun is larger than a preset value, judging whether the welding line data collected by the vision sensor contains a welding line termination point; if yes, generating a welding track from the welding seam starting point to the welding seam ending point according to the welding seam data, and controlling the welding gun to weld the workpiece according to the welding track; if not, generating a trend space straight line according to the actual motion data of the welding gun, calculating a correction coordinate point according to the trend space straight line, the welding line data and a similar triangle rule, and controlling the welding gun to move to the correction coordinate point until the welding line data collected by the vision sensor comprises the welding line termination point.

The welding equipment provided by the application comprises the welding gun and the vision sensor, the welding gun and the vision sensor move synchronously, the vision sensor is used for monitoring the welding seam of the workpiece in real time, and the welding gun is controlled to carry out welding operation based on detected welding seam data, so that guiding information is provided for tracking the welding seam. Generating a trend space straight line based on the actual motion data of the welding gun, and calculating a correction coordinate point according to the trend space straight line, the welding line data and a similar triangle rule; when the welding gun track has the deviation, the correction coordinate point can correct the welding gun to the welding seam area, the execution of the welding gun is guaranteed to be in the welding seam area, and meanwhile, the stable welding wire dry elongation is guaranteed. The application also provides a welding control system, a storage medium and welding equipment at the same time, and the welding control system, the storage medium and the welding equipment have the beneficial effects and are not described in detail herein.

Drawings

In order to more clearly illustrate the embodiments of the present application, the drawings required for the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained by those skilled in the art without inventive effort.

Fig. 1 is a flowchart of a welding control method according to an embodiment of the present disclosure;

FIG. 2 is a schematic technical configuration diagram of an automatic welding seam tracking method according to an embodiment of the present disclosure;

fig. 3 is a schematic view of an original point cloud of a weld groove cross-section image provided in the embodiment of the present application;

fig. 4 is a cross-sectional view of a weld groove after median filtering according to an embodiment of the present disclosure;

FIG. 5 is a schematic diagram of a fitted trend spatial straight line provided in an embodiment of the present application;

FIG. 6 is a graph illustrating a variation of a welding swing with time according to an embodiment of the present disclosure;

FIG. 7 is an analysis diagram of a differential dynamic tracking algorithm provided in an embodiment of the present application;

FIG. 8 is a flow chart of an automated weld tracking method provided by an embodiment of the present application;

FIG. 9 is a schematic diagram illustrating a trajectory comparison of an embodiment of the present application with a conventional weld tracking scheme;

fig. 10 is a schematic diagram illustrating a comparison between the welding track convergence effect of the embodiment of the present application and the conventional seam tracking scheme.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Referring to fig. 1, fig. 1 is a flowchart of a welding control method according to an embodiment of the present disclosure, and the specific steps may include:

s101: controlling the welding gun to move to an initial position, and determining a welding seam starting point of a workpiece by using the vision sensor;

the embodiment can be applied to welding equipment, wherein a welding gun and a visual sensor are arranged on an executing mechanism of the welding equipment, the welding gun and the visual sensor move along with the executing mechanism, and the relative positions of the welding gun and the visual sensor are kept unchanged.

The vision sensor includes, but is not limited to, a 3D camera and a laser sensor, and is used to acquire characteristics of an object to be recognized (e.g., a workpiece), collect complete, clear and stable weld data (e.g., weld cross-section image information and depth information), and provide guidance information for subsequent weld tracking.

Before this step, the welding equipment or the welding system can be started, and the internal data of the equipment or the system is initialized, so that the welding gun automatically runs to the initial position. After the welding gun is moved to the initial position, the welding seam starting point can be searched by using the visual sensor. Specifically, the contour obtained by scanning with the vision sensor can be automatically matched with the target contour, and after N successful matches are obtained, the initial point of the weld joint is obtained according to the previous N matching results. The target profile may be a profile of a weld of a standard workpiece, and a standard weld starting point may be marked on the profile of the weld of the standard workpiece.

S102: controlling the welding gun to move to the welding seam starting point, and acquiring welding seam data by using the vision sensor;

before the step, an operation of judging whether the initial point of the weld joint is successfully obtained or not may exist, if the initial point of the weld joint is successfully obtained, the vision sensor is located at the initial point of the weld joint, the welding gun may be controlled to move towards the initial point of the weld joint (for example, the welding gun runs along the direction of the X axis), and in the process, the vision sensor detects the weld joint at the initial section. And fitting weld joint data obtained by the vision sensor to weld joint characteristic points and fitting n groups of weld joint midpoints by a median filtering method from the detection starting point to the welding gun starting point, namely the leading distance of the vision sensor. And (3) forming a number set point { (xi, yi, zi) |1 ≦ i ≦ n } for the middle points of the n groups of welding seams, obtaining an operation trend track of the initial section of the welding seams by using a least square straight line fitting combination algorithm, and caching the operation trend track into a system. And if the welding seam starting point is not obtained successfully, the operation of searching the welding seam starting point is executed again until the welding seam starting point is obtained successfully. And the welding gun can start welding work after moving to the starting point of the welding seam. The welding gun can execute work according to the cached welding track of the initial welding section, the actual motion coordinate point is transmitted to the system for caching according to the scanning frequency of the control system, and meanwhile, a vision sensor at the front end collects welding seam data (such as a welding seam image).

S103: when the moving distance of the welding gun is larger than a preset value, judging whether the welding seam data collected by the vision sensor contains a welding seam termination point; if yes, go to step S104; if not, entering S105;

the preset value specifically refers to a distance at which the correction of the motion trajectory of the welding gun needs to be started, and when the moving distance of the welding gun is greater than the preset value, the relevant operations from S103 to S105 can be executed, the preset value can be determined according to the distance between the welding gun and the vision sensor, and the distance is positively correlated with the preset value. The moving distance of the welding torch refers to the moving distance of the welding torch after the welding torch starts from the initial position. Specifically, the present embodiment may determine whether the weld data acquired by the vision sensor includes a weld end point according to a system scanning period.

S104: generating a welding track from the welding seam starting point to the welding seam ending point according to the welding seam data, and controlling the welding gun to weld the workpiece according to the welding track;

the starting point of the welding line is the starting point of the welding operation, the end point of the welding line is the end point of the welding operation, and after the vision sensor collects the end point of the welding line, a welding track from the starting point of the welding line to the end point of the welding line can be generated according to the welding line data collected in the moving process, so that a welding gun can be instructed to weld the workpiece according to the welding track. Specifically, in this embodiment, the weld data may be fitted by a median filtering method to obtain weld feature points, and the weld feature points are calculated by a least square straight line fitting algorithm to obtain the welding trajectory from the weld starting point to the weld ending point.

S105: generating a trend space straight line according to actual motion data of the welding gun, calculating a correction coordinate point according to the trend space straight line, the welding line data and a similar triangle rule, and controlling the welding gun to move to the correction coordinate point until the welding line data collected by the vision sensor comprises the welding line termination point.

If the vision sensor does not detect the welding seam termination point, generating a trend space straight line of actual operation of the welding gun according to actual motion data of the welding gun, further calculating a correction coordinate point based on the trend space straight line, the welding seam data collected by the vision sensor and a similar triangle rule, and controlling the welding gun to move to the correction coordinate point until the welding seam data collected by the vision sensor contains the welding seam termination point. After the welding gun is controlled to move to the correction coordinate point, whether a welding seam end point is included in welding seam data newly collected by the vision sensor can be judged, and if the welding seam end point is included, the operation enters S104; and if the welding seam end point is not included, generating a new correction coordinate point to control the welding gun to move to the new correction coordinate point. The operation of searching the weld joint end point is similar to the operation of searching the weld joint starting point, and can be obtained by matching the actually acquired contour with the target contour. The trend space straight line is used for describing the actual motion trend of the welding gun. The similar triangle rule may be a similar triangle rule based on dynamic displacement, and specifically, a motion differential offset in the axis Y, Z direction may be obtained by constructing a similar triangle according to a differential ratio of the welding gun in the X, Y, Z axis direction, and a correction coordinate point may be determined according to the motion differential offset.

The welding equipment provided by the embodiment comprises the welding gun and the vision sensor, wherein the welding gun and the vision sensor move synchronously, the vision sensor is used for monitoring the welding seam of the workpiece in real time, and the welding gun is controlled to perform welding operation based on the detected welding seam data so as to provide guiding information for tracking the welding seam. Generating a trend space straight line based on the actual motion data of the welding gun, and calculating a correction coordinate point according to the trend space straight line, the welding line data and a similar triangle rule; when the welding gun track has deviation, the correction coordinate point can correct the welding gun to the welding seam area, the execution of the welding gun is guaranteed to be in the welding seam area, and meanwhile, the stable welding wire dry elongation is guaranteed.

Further introduction to the corresponding embodiment of FIG. 1 may be by generating job trend lines in the following manner: selecting a first actual swing track point and a second actual swing track point from the actual motion data of the welding gun; the time corresponding to the second actual swing track point is later than that of the first actual swing track point; and calculating trend space straight lines corresponding to all the motion coordinate points between the first actual swing track point and the second actual swing track point by utilizing a least square straight line fitting algorithm.

Correspondingly, taking the example that the actual motion data includes the first actual swing track point and the second actual swing track point, the embodiment can calculate the correction coordinate point in the following manner: determining a first vertical line which passes through the first actual swing track point and is perpendicular to the trend space straight line, and setting an intersection point of the first vertical line and the trend space straight line as a first intersection point; determining a second vertical line which passes through the second actual swing track point and is perpendicular to the trend space straight line, and setting an intersection point of the second vertical line and the trend space straight line as a second intersection point; calculating the deviation of the central point of the actual groove according to the welding line data, the current swing amplitude and the deviation data; calculating the coordinate of the first intersection point, the coordinate of the second intersection point and the deviation of the actual groove center point based on a similar triangle rule of dynamic displacement (as shown in fig. 7), so as to obtain differential motion offsets of the welding gun in the directions of an X axis, a Y axis and a Z axis; and calculating the correction coordinate point according to the motion differential offset and the coordinates of the second intersection point.

Specifically, the searching for the weld end point in this embodiment may include:

step A1: controlling the welding gun to move to a correction coordinate point, and judging whether the welding seam data collected by a visual sensor contains the welding seam termination point; if yes, judging that the welding seam data acquired by the vision sensor comprises the welding seam termination point; if not, go to step A2;

step A2: reselecting a first actual swing track point and a new second actual swing track point from the actual motion data of the welding gun;

step A3: calculating trend space straight lines corresponding to all motion coordinate points between the first actual swing track point and the second actual swing track point by using a least square space straight line algorithm;

step A4: and calculating a new correction coordinate point according to the trend space straight line, the welding line data acquired by the vision sensor and a similar triangle rule, and entering the step A1.

Specifically, the calculating the actual groove center point deviation in the present embodiment may include: calculating the deviation of the central point of the groove according to the welding line data; determining the current swing amplitude according to the swing waveform and the working time of the welding gun; subtracting the current swing amplitude and deviation data from the groove center point deviation to obtain the actual groove center point deviation of the actual groove center point deviation in the Y-axis and Z-axis directions; the deviation data comprises the deviation of the welding gun and the vision sensor in the Y-axis direction and the Z-axis direction, and the movement direction of the welding gun is the X-axis direction.

The above process is exemplified below, and the first actual wobble track point is

The second actual swing track point is

The correction coordinate point is

When the welding gun is positioned

When the vision sensor is at P_A', when the welding gun is at

The time vision sensor is located at P_B′，

The welding gun moves to the detection point P of the proximity sensor_A' (i.e., dot)

) Or to a correction point

And automatically matching the profile obtained by scanning the sensor with the target profile, and acquiring X-axis coordinates of the welding seam termination point according to the previous N matching results after N successful matching is unsuccessful. And if the welding seam termination point is successfully obtained, adopting the data cached in the system before to keep the tracking track on the corrected preset track until the welding is finished. If the acquisition of the weld joint termination point is unsuccessful, the following steps are carried out:

a) welding gun to

Dot or

Then, the cached welding starting point is connected to

Dot or

Calculating the actual welding operation trend space straight line L by the coordinates of all the actually arrived track points₁。

b) Welding gun at

Time of day (i.e. sensor proximity)

Dot), the vision sensor is at the detection point P_AThe obtained welding seam information is subjected to median filtering and linear fitting to calculate and cache the position of the welding seam central line, and a trend space straight line L is combined₁The differential offset is obtained by adopting a similar triangle rule based on dynamic displacement

Thereby calculating the next target control point, namely the correction point

And the coordinates are sent to an actuator for control.

The embodiment can repeat the above steps when the welding gun moves to the correction point

And after correcting the deviation in the Y-axis direction and the Z-axis direction, searching the welding seam termination point in the next system scanning period until the welding seam termination point is searched.

Referring to fig. 2, fig. 2 is a schematic technical configuration diagram of an automatic welding seam tracking method according to an embodiment of the present application, in fig. 2, 1 denotes an end effector, 2 denotes a rail, 3 denotes a table, 4 denotes a workpiece, 5 denotes a welding gun, 6 denotes a welding seam, and 7 denotes a vision sensor. The embodiment can solve the problem that the tracking track is poor in convergence when a welding seam is suddenly changed in the existing tracking method, and ensures that the welding gun works in the welding seam area. In the automatic weld tracking process, the weld is detected in real time based on the front vision sensor, the depth information and the section information are contained, and the current welding gun position information and the detection data of the sensor are cached. The executing mechanism of the embodiment can be a rail-mounted trolley, the welding equipment comprises a motion control system and a central processing unit, the motion control system transmits motion target point information to the central processing unit, the central processing unit transmits position and speed information of each shaft to the motion control system, and the vision sensor transmits welding seam image information to the central processing unit. As shown in fig. 2, the relative positions of the end actuator and the workpiece to be fixed on the worktable are kept unchanged as much as possible during the welding operation. The tip actuator has a welding torch and a vision sensor mounted thereon for movement with the tip actuator. In the welding process, the relative positions of the welding gun and the visual sensor are kept unchanged, and the angles of the welding gun in the XYZ motion direction and the visual sensor in the XYZ detection direction are consistent. The end effector is driven by at least 3 motors and is movable in XYZ axes, and the sensor position coordinates and the welding torch position coordinates are set so that the difference between the sensor position coordinates and the welding torch position coordinates in the XYZ axes is F, W, H. In the welding process, the actuating mechanism drives the welding gun to execute swing operation along the welding seam of the workpiece until the groove is uniformly filled. The visual sensor can set a scanning period, weld depth information and groove section outline information are obtained in real time in the welding operation process, data processing and fitting calculation are carried out in a central processing unit, and finally deviation data of a weld center point and a welding gun are obtained, so that the aim of guiding an execution mechanism to carry the welding gun to carry out dynamic compensation in the direction of eliminating errors is fulfilled.

The motion control system comprises a PLC (Programmable Logic Controller), a motor driver and a motor. The PLC signal input end and the PLC signal output end are connected with a signal end in a motor driver, the speed and the position of the motor of the actuating mechanism are controlled through high-speed pulses sent by the PLC output end, and the running speed and the real-time position of the motor of the actuating end are fed back to the PLC input end in real time through the driver. The PLC communication module is connected with the central processing unit communication module in a bus communication mode and adopts a TCP/IP mode for communication. And setting the scanning period of the PLC to be 10-100 ms, and sending the position and speed information of each shaft motor to the central processing unit in real time according to the scanning period. Setting the scanning period of a central processing unit to be 10-100 ms, sending a moving target control point to a computing unit CPU of a PLC (programmable logic controller) by a central processing unit communication unit according to the scanning period, calculating the number of pulses and the pulse output frequency by the CPU in the PLC, and finally controlling each shaft motor to reach the target point position according to the set speed. The central processor communication unit is used for receiving the real-time data of each shaft actuating motor sent by the PLC and caching the real-time data to the storage unitFinally, the online monitoring and control of the actuating mechanism are realized. The central processing unit is used for processing data, the computing unit calls a computer program stored in the storage unit, the computer program is used for performing online monitoring with PLC data, processing detection data obtained by the vision sensor, executing a differential dynamic operation compensation algorithm, calculating coordinates of a target point of a swing operation track, and finally sending the coordinates to the motion control system through the communication unit, so that the execution mechanism moves to the target point, and dynamically rectifying the deviation in the direction of eliminating the welding line deviation. The central processing unit storage unit is used for caching the track point data actually reached by the mechanism, and storing a program for processing the data and calculating a target point. In the embodiment, a mature robot can be used for replacing an actuating mechanism, a single chip microcomputer is used for replacing a PLC controller, and a communication mode of a motion control system and a central processing unit is replaced by a wired network or a wireless 4G network or a wireless 5G network. The embodiment can also adopt the weld characteristic points detected by the fitting sensor to calculate the welding trend space straight line L₁。

The implementation process of executing the automatic welding seam tracking method in the central processing unit is as follows:

step B1, starting the system to start working, initializing the internal data of the system, and automatically operating the welding gun to the initial position;

and step B2, searching a welding seam starting point, automatically matching the contour obtained by scanning with the visual sensor with the target contour, and obtaining the welding seam starting point according to the matching results of the previous N times after N times of successful matching are obtained.

And step B3, if the initial point of the welding seam is successfully obtained, the sensor is located at the initial point of the welding seam, the welding gun runs along the X-axis direction, the sensor detects the welding seam of the initial section, the welding seam data obtained by the sensor is fitted to characteristic points of the welding seam through a median filtering method from the detection initial point to a to-be-welded area of the initial point of the welding gun, namely the front distance of the sensor, and the middle points of n groups of welding seams are fitted. And (3) forming a number set point { (xi, yi, zi) |1 ≦ i ≦ n } from the middle points of the n groups of welding seams, obtaining an operation trend track of the initial section of the welding seam by using a least square straight line fitting combination algorithm, and caching the operation trend track into the system. And if the welding seam starting point is not obtained successfully, returning to the step 2 and repeating until the welding seam starting point is obtained successfully.

Step B4, the welding gun reaches the starting point of the welding seam along the X-axis direction, and the welding work is started;

and step B5, executing work according to the cached welding track of the initial section of the welding seam, transmitting the actual motion coordinate point to a cache in the system according to the scanning frequency of the control system, and simultaneously acquiring the welding seam image by a vision sensor at the front end.

Step B6, moving the welding gun to the detection point P of the proximity sensor_A' (i.e., dots)

) Or to a correction point

And automatically matching the contour obtained by scanning the sensor with the target contour, and acquiring X-axis coordinates of the welding seam termination point according to the previous N-time matching results after N-time successful matching is unsuccessful. If the welding seam termination point is successfully obtained, the tracking track is kept on the corrected preset track until the welding is finished by adopting the data cached in the system before. If the acquisition of the weld joint termination point is unsuccessful, the following steps are carried out:

a) welding gun to

Dot or

Then, the cached welding starting point is connected to

Dot or

Calculating a trend space straight line L by coordinates of all actually arrived track points₁。

b) Welding gun at

Time of day (i.e. sensor proximity)

Dots), the vision sensor is at the detection point P_AThe obtained welding seam information is subjected to median filtering and linear fitting to calculate the position of the welding seam central line and cache the position, and a trend space straight line L is combined₁Obtaining differential offset by adopting similar triangle rule based on dynamic displacement

Thereby calculating the next target control point, namely the correction point

And the coordinates are sent to an actuator for control.

Step B7, repeating step B6, when the welding gun moves to the correction point

According to the method, the operation trend straight line is fitted based on the coordinate points actually reached by the welding gun, the coordinates of the correction points are calculated, when the execution track of the welding gun has deviation in the welding process, the welding gun can be corrected into the welding seam area, the correction track is smooth, the execution tool welding gun is ensured to be in the welding seam area, and meanwhile, the stable dry elongation of the welding wire is also ensured. In the embodiment, the position of a correction point is calculated once in each scanning period of the system, and the position of the correction point is close to the detection point. And welding seam tracking deviation rectification is carried out in each scanning period, so that the real-time performance of dynamic tracking is improved, and the tracking convergence effect is enhanced. The real-time deviation correction of the Y direction and the Z direction is carried out during welding, the welding line tracking device can adapt to the welding line tracking of zigzag welding lines, swing welding, workpiece height change and workpiece deformation in the welding process, and is convenient to use and popularize.

Specifically, in steps B2 to B7, the executing mechanism carries a vision sensor to scan and acquire an image of the welding seam groove at a constant speed along the X-axis direction, i.e., the working direction, and the vision sensor image acquisition module performs 2D contour scanning on the groove cross section to acquire a welding seam point cloud, wherein the exposure of the vision sensor is 20 to 40, and the binarization thresholds 114 to 124 are combined together to adjust the reality, the virtuality and the stability of the acquired point cloud data to acquire an original point cloud of the groove cross section image, as shown in fig. 3, fig. 3 is an original point cloud schematic diagram of the welding seam groove cross section image provided by the embodiment of the present application. In order to remove noise in the point cloud of the original image and retain contour information in the groove cross-section image, a median filtering method is adopted in a central processing unit to obtain an image after median filtering, as shown in fig. 4, fig. 4 is a welding groove cross-section image processed by median filtering provided by the embodiment of the application. The noise can be effectively inhibited through a median filtering method, the value of one point in the digital sequence is replaced by the median of each point value in one neighborhood of the point, and the surrounding point cloud value is close to the true value, so that the isolated noise point is eliminated. The embodiment can improve the accuracy of straight line extraction, thereby improving the accuracy of the cross-sectional profile.

In the step B2 and the step B6, the weld initial point and the weld end point are detected, N frames of weld cross-section images are collected by using a vision sensor, the weld cross-section contour image is extracted through median filtering, and the extracted image contour is automatically matched with the target contour. And after N times of successful matching are obtained, obtaining the X coordinate position of the welding starting point according to the previous N times of matching results, and obtaining the X coordinate position of the welding finishing point if the matching is unsuccessful.

In the steps B2-B6, the characteristic points and the discontinuous points of the laser profile are subjected to linear fitting, and the straight line intersection points on the two sides of the groove are obtained and are used as the characteristic points of the welding seam, namely the center point of the groove.

In step B3, the initial stage of the weld detection is the leading distance F between the welding gun and the vision sensor (i.e. the distance between the welding gun and the vision sensor in the X-axis direction), and the actuator-mounted sensor operates at the uniform speed along the X-axis. In the motion process, the vision sensor collects n section information, the point cloud data of the groove section of the corresponding detection point can be matched according to the change of the X-axis coordinate, and n welding seam characteristic points, namely central coordinate points, namely (xi, yi, zi), (i is 1, 2.

A least square fitting method of a spatial straight line is adopted to obtain a trend central point fitting straight line L0 in the space, wherein, assuming that a given number set point { (xi, yi, zi) |1 ≦ i ≦ n }, for the best fitting straight line, the groove central point is made to pass through or approach the points as much as possible, as shown in FIG. 5, FIG. 5 is a schematic diagram of the fitted trend spatial straight line provided by the embodiment of the application, and a welding gun takes the straight line L0 as the central point and the swing amplitude as the central point

In the Y direction, performing positive or negative swing operation, or having swing amplitude

Positive or negative swing work is performed in the Z direction. In fig. 5, three axes represent an X axis, a Y axis, and a Z axis. The trend of the swing welding swing amplitude with time is shown in fig. 6, fig. 6 is a graph of the trend of the swing welding swing amplitude with time provided by the embodiment of the present application, W in fig. 6 represents the maximum swing amplitude,

the real-time swing during welding is shown, and the T swing represents the moment when the real-time swing is 0. If swing welding is not needed, then the swing amplitude

And

are all 0.

A least squares fit of a spatial line, the spatial line L0 simplified form:

that is to say that the temperature of the molten steel,

in the above formula, a, b, c and d represent the slope and intercept of a space straight line

Conversion to matrix form is:

the I point of the central point of the groove meets the following conditions:

then there are:

multiplication between the left and right

Then there is

Finally, find out

In the steps B4 and B5, the welding gun runs to the starting point of the welding seam, and the execution mechanism executes work according to the cached operation track of the initial section of the welding seam, namely the welding gun fits the straight line L based on the trend central point₀And carrying out swing operation in the Y-axis direction or the Z-axis direction, transmitting actual motion coordinate point data to a system for caching in real time according to the scanning period of the system through a motion control system, and simultaneously collecting a weld image by a vision sensor at the front end.

In step B6, searching for the end point of the weld seam during the welding operation, if the end point of the weld seam is not obtained successfully, when the X-axis coordinate of the welding gun approaches to the coordinate of the X-axis coordinate of the welding gun of the execution toolF, when the welding gun moves to a detection point corresponding to the starting point of the welding seam, namely

After that, the swing compensation deviation rectifying operation is started to be performed by using the differential offset, as shown in fig. 7, fig. 7 is an analysis diagram of a differential dynamic tracking algorithm provided in the embodiment of the present application.

Actual swinging track point of welding gun

Dot

When the welding gun is in point

When the vision sensor is at the detection point P_A'. When the welding gun is in point

When the sensor is at the detection point P_B', point

Is located at a point

And the current vision sensor detection point P_A' in between.

Motion track point of welding gun of actuating mechanism

Will be provided with

Assuming the number set point { (xi, yi, zi) |1 ≦ i ≦ n } for all m motion coordinate points to the initial point of the weld joint, and fitting a new trend space straight line L by applying the least square space straight line algorithm₁Namely:

tracing point

Dot

Line L in space of the trend₁Point of intersection of drop foot P_AAnd P_BPassing point

Point and new trend space straight line L₁A vertical straight line of L_A，L_AThe spatial straight line is:

b_Aand d_AIs L_AIntercept of a straight line, b₁And d₁Is L₁Intercept of a straight line, L_AStraight line and L₁The straight line intersects at the locus point P_A。

Wherein

For the real-time values of the coordinates of the actuators, which have been cached in the system, b can be determined here_AAnd d_AValue of, set point

With new trend space straight line L₁Intersection point P_A＝(X_A,Y_A,Z_A)；

Point P_ASimultaneously satisfies the new trend space straight line L₁Equation and the spatial straight line L perpendicular thereto_AThe equation, namely:

the coordinate P can be obtained by solving the formula_A(X_A,Y_A,Z_A) The same principle can be used to calculate the passing point

Point and new trend space straight line L₁Vertical straight line L_B：

b_BAnd d_BIs L_BIntercept of a straight line, L_BStraight line and L₁Straight line intersecting at locus point P_B。

Point P_BSimultaneously satisfies the new trend space straight line L₁And a spatial straight line L perpendicular thereto_BCan be solved to obtain the coordinate P_B(X_B,Y_B,Z_B) Value of (d), then a new trend space straight line L₁Upper P_A，P_BThe two-point deviation is:

X_AB＝X_A-X_B

Y_AB＝Y_A-Y_B

Z_AB＝Z_A-Z_B

welding gun at

At a point P detected by a vision sensor_A' the groove center point can be calculated by median filtering and fitting in the step B4, and the Y-axis deviation is

As shown in fig. 7, the Z-axis deviation is

Subtracting the current real-time swing respectively

And

subtracting the deviation F, W, H of the welding gun and the vision sensor in the XYZ direction, the deviation of the actual groove center point in the Y and Z axis directions is respectively:

wherein

The swing amplitude can be calculated according to the swing waveform and the working time period, as shown in fig. 6, if swing welding is not needed, the swing amplitude is calculated

Is 0.

In the XOY plane, referring to similar triangles as shown in fig. 7, the differential ratio of the X and Y directions can be calculated:

similarly, in the XOZ plane, the differential ratio of X and Z directions can be obtained:

the operation speed of the welding gun on the X axis is Vx, and the scanning period is T_SIn one scanning cycle, the differential amount in the X direction is:

y, Z differential offset of directional motion:

the differential deviation is calculated by using the detection point, and a new motion center point can be calculated

I.e. close to P_BPoint of (2), correction point

The center point is

The coordinate of the motion center point of the correction point is

Wherein:

real-time swing in Y-axis direction

Real-time swing in Z-axis direction

The swing amplitude can be estimated according to the swing waveform and the working time period as shown in fig. 6.

Welding gun point by point

As a center, the coordinates of the motion target point are

In step a, as shown in FIG. 7, while the welding torch is on

Time point, cache point

The actual coordinates of the weld joint are combined with all m motion coordinate points from the point to the initial point of the weld joint, the number set point is { (xi, yi, zi) |1 ≦ i ≦ n }, and a least square algorithm is applied to fit a trend space straight line L₁A group P is obtained through calculation_AAnd P_BTwo points, P_BIs the actual motion track

Point and trend space straight line L₁Point of intersection of drop foot, P_AIs the actual motion track

Point and trend space straight line L₁The point of intersection of the drop feet.

In step b, the welding gun is

When the sensor is in point, the Y-axis data measured by the sensor at the detection point

And Z-axis data

And caching the motion coordinate axis data and the sensor data of the welding gun of the actuating mechanism at the moment. When the welding gun of the actuating mechanism moves to approach the detection point P_AWhen it is, namely at

At the point, using a welding gun

When the vision sensor is in the detection point P_AData measured at' time, quoteCalculating correction point by using similar triangular differential offset algorithm

And (4) guiding the welding gun to move to a correction point by coordinates, and correcting the deviation in the Y direction and the Z direction. The method increases the real-time performance of the tracking data, strengthens the tracking convergence effect of the welding line, and ensures that the calculated track is closer to the actual welding line.

When the steps B6-B7 are repeated, in the steps a and B, when the welding gun is operated to a point

Hour, cache point

Actual coordinates or points of

Joint point

To all m +1 motion coordinate points of the initial point of the welding line, the number set point is { (xi, yi, zi) |1 ≦ i ≦ n }, and a least square algorithm is applied to fit a new trend space straight line L₁Changing the slope, a new set of P will be calculated_A，P_BTwo points, a new set P_BIs the actual motion track point of the previous group

And trend space straight line L₁Point of intersection of the drop foot, P_AIs the actual motion track point of the previous group

And trend space straight line L₁The point of intersection of the drop feet. The welding gun is arranged at the track point

While the data measured by the sensor at the current detection point compensates for the new correction point

And 6, repeating the step 6 until the end point of the welding seam is searched by the sensor.

According to the method, the operation trend space straight line of the welding actual track is calculated by substituting the actual motion track point into the least square algorithm, the straight line is substituted into the differential dynamic compensation algorithm, the correction point is calculated in each scanning period, the actual motion data and the sensor detection data are fused for operation, the integral fault tolerance of the system is improved, and the welding gun is ensured to be in the welding line range. The embodiment provides a differential dynamic tracking algorithm, reduces the compensation distance between a detection point and a correction point, corrects the deviation in the Y and Z directions, and can guide a welding gun tool in a welding seam through the algorithm even if the welding seam has sudden change, so that the real-time performance of tracking data is improved, and the tracking convergence effect is enhanced; the embodiment calculates the movement target point once in each system scanning period and executes target point position arrival once in each system scanning period, thereby effectively reducing operation errors and improving tracking precision.

Because the sensor and the welding gun have a front distance, the welding correction is not real-time, and a differential dynamic operation compensation algorithm is introduced, so that the compensation distance between a detection point and a correction point is shortened, and the real-time performance of welding seam tracking is improved. Meanwhile, the installation distance between the sensor and a welding gun tool can be increased, and the influence of noise such as arc light, scattered laser, metal splashing, reflection and the like on image acquisition of the sensor in the welding process is reduced. In the welding process, the embodiment brings the detection data of the vision sensor into a differential dynamic compensation algorithm, calculates the welding seam deviation in each scanning period, and performs deviation rectification in Y and Z directions once in each scanning period. When the position of the welding seam changes (thermal deformation in the welding process) or the actuating mechanism moves, the deviation between the welding seam and the welding gun can be calculated in real time, real-time correction is carried out, the welding gun is ensured to be in the welding seam area, the problem of low convergence speed caused by overlarge front distance of the sensor in the traditional tracking algorithm is solved, and the tracking effect is improved. For the operation of the repeated structural part, the starting point can be intelligently identified without teaching the starting point; when the deviation between the welding gun and the welding seam is large due to the fact that an actuating mechanism has misoperation in the welding process, the target track of the correction point is calculated by substituting the actual motion track point into the algorithm, a smooth welding track can be formed, the shaking of the welding gun in the welding process is weakened, and the fault tolerance of an actuating system can be improved by the method.

Referring to fig. 8, fig. 8 is a flowchart of an automatic welding seam tracking method according to an embodiment of the present application, and the specific implementation process is as follows: after the system is initialized, the initial point search of the welding seam is started, the contour obtained by the sensor (visual sensor) is automatically matched with the target contour, and after N successful matches are obtained, the initial point of the welding seam is obtained according to the matching results of the previous N times. And judging whether the sensor is positioned at the initial point of the welding seam, if not, searching the initial point of the welding seam again, and if so, detecting the welding seam at the event end by using the sensor. And obtaining the welding track of the initial end of the welding seam through a median filtering and least square pointing fitting combined algorithm. And after the welding gun reaches the initial point of the welding seam, welding according to the welding track of the initial section, detecting the welding seam by using the sensor, and caching the coordinates of the track point actually reached by the welding gun and the detection data of the sensor. The welding gun moves to a monitoring point close to the sensor or moves to a correction point, and the sensor detects the welding seam. And caching the coordinates of the track points actually reached by the welding gun and the detection data of the sensor. And (4) starting weld end point search, automatically matching the profile obtained by scanning of the sensor with the target profile, and obtaining the weld end point according to the previous N matching results after N successful matching is obtained. Judging whether the sensor is positioned at the end point of the welding seam; if yes, the welding gun moves to the welding seam end point according to the cached data; if not, calculating the coordinates of the track points actually reached by the welding gun to obtain an operation trend space straight line L₁And calculating the calculus offset by using a similar triangle rule based on dynamic displacement, calculating the coordinate of the correction point and controlling to move according to the coordinate of the correction point.

Referring to fig. 9 and 10, fig. 9 is a schematic diagram illustrating a comparison between the actual weld seam, a front end operation trend space straight line, a weld seam tracking trajectory calculated by using a differential dynamic migration algorithm (i.e., the scheme provided in this embodiment), and a weld seam tracking trajectory calculated by using a conventional algorithm. Fig. 10 is a schematic diagram comparing the welding track convergence effect between the embodiment of the present application and the conventional welding track tracking scheme, and shows the actual welding seam center line, the conventional welding track convergence effect (dotted line), and the welding track convergence effect (middle solid line) after the differential dynamic shift algorithm (i.e., the scheme provided in this embodiment) is adopted. In order to ensure reliable and efficient welding quality of the welding seam, automatic welding is mostly carried out by adopting an automatic welding seam tracking technology. The existing automatic tracking mode based on the welding seam is mainly characterized in that a preposed optical visual sensor is arranged on a welding gun tool of a welding robot, the position of a characteristic point of the welding seam is detected and calculated in real time through the sensor, and the robot is controlled to carry out automatic tracking welding according to the position of the characteristic point. The existing welding seam tracking method has the following defects:

1. and (3) adopting a welding seam tracking method based on an absolute welding seam path, and introducing a non-uniform rational B spline interpolation mode to track the welding seam. And creating a stack, and caching the absolute welding seam track and the welding seam sampling point coordinate of the laser sensor in the stack. Searching a position coordinate nearest to the actual position coordinate PT of the welding gun in the stack, carrying out non-uniform rational B-spline interpolation by taking the nearest position coordinate and 3 position coordinates adjacent to the nearest position coordinate in front of and behind the nearest position coordinate as control points to obtain a deviation Err of the corresponding position coordinate PT' of the actual position coordinate PT of the welding gun on a welding seam track in the welding robot, and carrying out correction of the welding robot.

The tracking process in the above manner has a large error in the initial stage, which is mainly due to the initial position deviation between the welding gun and the workpiece to be tracked. And calculating the absolute welding seam track deviation between the actual position of the welding gun and the stack to correct the deviation, wherein the method is not suitable for swing welding tracking of a robot and welding seam tracking of medium and thick plates.

2. The detected weld joint characteristic points are two-dimensional information, and then plane linear fitting is carried out on each section of data respectively to obtain N xy-axis coordinates. Groove depth information is not detected, so that welding tracking deviation correction in the Z-axis direction cannot be realized, the welding line is not applicable to working conditions with changed groove heights of welding lines, and stable welding wire dry elongation cannot be guaranteed. According to the three-dimensional coordinates of the robot after the characteristic points of the welding seam are converted, a series of intermediate points are arranged between the starting point and the end point of the path to be used as transition, the pose of the welding robot when passing through the intermediate points is controlled, the intermediate points are estimated, the welding seam is not suitable when the welding seam has sudden change in the Y direction or the Z direction, and the tracking convergence effect of the welding seam is poor.

The embodiment adopts the three-dimensional vision sensor to detect the weld groove, contains depth and outline information, can carry out deviation rectification in the Y direction and the Z direction, and improves the welding operation precision. Based on the data of the vision sensor, a differential dynamic compensation algorithm is applied, the welding seam deviation is calculated in each scanning period, when the welding gun reaches the differential position close to a detection point, the deviation between the Y direction and the Z direction is dynamically corrected by using the differential, the operation error can be effectively reduced, and the accuracy of real-time tracking compensation is improved.

3. And (4) solving the characteristic points of the welding seam through active laser vision, and generating a welding track by the TCP point at the tool end of the robot along the sequence of the characteristic points of the welding seam. When the welding seam tracking is executed, the robot controller establishes a register queue and records a laser vision sensor position sequence corresponding to the welding seam characteristic point; and recording the deviation correcting values of the TCP points in the Y direction and the Z direction corresponding to the position sequence. The tool end TCP point of the robot is finely adjusted in Y direction and Z direction along the welding line direction to achieve the deviation correction amount of accurate positioning, interpolation is carried out between adjacent sequential position points of the tool end TCP point, and deviation correction in Y direction and Z direction is carried out when the position of each tracked welding line mark point is reached, so that deviation can be eliminated in X direction, Y direction and Z direction, and the TCP point at the tool end of the robot can be ensured to achieve the expected pose after being tracked by the three-dimensional welding line. The invention has the problems of complex system and more control flow nodes, and comprises a vision system controller, a precise positioning cross sliding table controller, a robot controller and the like, when the cross sliding table at the tail end of the robot moves to a weld joint characteristic point, more uplink and downlink data nodes are generated during deviation rectification, the data transmission time is increased, and the weld joint tracking data is not in real time, so that the welding quality is influenced. The welding seam tracking method is suitable for a simpler system, reduces data transmission time and has high system response speed.

In the automatic weld tracking process, the weld is detected in real time based on the front-mounted vision sensor, the depth information and the section information are contained, and the position information of the welding gun and corresponding detection data are cached. And introducing a least square algorithm, fitting an operation trend straight line by a coordinate point actually reached by the welding gun, and dynamically correcting the deviation between the Y direction and the Z direction by using a differential quantity when the welding gun reaches a differential quantity position close to a detection point by using a similar triangular differential quantity dynamic migration algorithm to realize real-time tracking of the welding seam in the welding process.

The embodiment of the present application further provides a welding control system, which may be applied to a welding device, where an execution mechanism of the welding device is provided with a welding gun and a vision sensor, the welding gun and the vision sensor move along with the execution mechanism, and a relative position of the welding gun and the vision sensor remains unchanged, the welding control system includes:

Further, the process that the correction module generates a trend space straight line according to the actual motion data of the welding gun comprises the following steps: selecting a first actual swing track point and a second actual swing track point from the actual motion data of the welding gun; the time corresponding to the second actual swing track point is later than the first actual swing track point; and calculating trend space straight lines corresponding to all the motion coordinate points between the first actual swing track point and the second actual swing track point by utilizing a least square straight line fitting algorithm.

Further, the process of calculating the correction coordinate point by the correction module according to the trend space straight line, the welding line data and the similar triangle rule comprises the following steps: determining a first vertical line which passes through the first actual swing track point and is perpendicular to the trend space straight line, and setting an intersection point of the first vertical line and the trend space straight line as a first intersection point; determining a second vertical line which passes through the second actual swing track point and is perpendicular to the trend space straight line, and setting an intersection point of the second vertical line and the trend space straight line as a second intersection point; calculating the deviation of the center point of the actual groove according to the welding seam data, the current swing amplitude and the deviation data; calculating the coordinate of the first intersection point, the coordinate of the second intersection point and the deviation of the actual groove center point based on a similar triangle rule of dynamic displacement to obtain differential motion offsets of the welding gun in the X-axis direction, the Y-axis direction and the Z-axis direction; and calculating the correction coordinate point according to the motion differential offset and the coordinates of the second intersection point.

Further, the process that the welding gun is controlled by the correction module to move to the correction coordinate point until the welding seam data collected by the vision sensor comprises the welding seam termination point comprises the following steps: step 1: controlling the welding gun to move to a correction coordinate point, and judging whether the welding seam data collected by a visual sensor contains the welding seam termination point; if yes, judging that the welding seam data acquired by the vision sensor comprises the welding seam termination point; if not, entering the step 2; step 2: reselecting a first actual swing track point and a new second actual swing track point from the actual motion data of the welding gun; and step 3: calculating trend space straight lines corresponding to all motion coordinate points between the first actual swing track point and the second actual swing track point by using a least square space straight line algorithm; and 4, step 4: and (4) calculating a new correction coordinate point according to the trend space straight line, the welding line data acquired by the vision sensor and a similar triangle rule, and entering the step 1.

Further, the process that the correction module calculates the deviation of the actual groove center point according to the welding seam data, the current swing amplitude and the deviation data comprises the following steps: calculating the deviation of the central point of the groove according to the welding line data; determining the current swing amplitude according to the swing waveform and the working time of the welding gun; subtracting the current swing and the deviation data from the groove central point deviation to obtain actual groove central point deviations of the actual groove central point deviation in Y-axis and Z-axis directions; the deviation data comprises the deviation of the welding gun and the vision sensor in the Y-axis direction and the Z-axis direction, and the movement direction of the welding gun is the X-axis direction.

Further, the process of judging whether the welding seam data collected by the vision sensor contains the welding seam termination point by the judgment module comprises the following steps: and judging whether the welding seam data acquired by the vision sensor contains a welding seam termination point or not according to a system scanning period.

Further, the process of generating the welding track from the welding seam starting point to the welding seam ending point by the operation module according to the welding seam data comprises the following steps: fitting the welding line data through a median filtering method to obtain welding line characteristic points, and calculating a least square straight line fitting algorithm on the welding line characteristic points to obtain the welding track from the welding line starting point to the welding line end point.

Since the embodiment of the system part and the embodiment of the method part correspond to each other, please refer to the description of the embodiment of the method part for the embodiment of the system part, and details are not repeated here.

The present application also provides a storage medium having a computer program stored thereon, which when executed, may implement the steps provided by the above-described embodiments. The storage medium may include: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, an optical disk, or other various media capable of storing program codes.

The application also provides a welding device, which may include a memory and a processor, wherein the memory stores a computer program, and the processor may implement the steps provided by the above embodiments when calling the computer program in the memory. Of course, the welding device may also include various network interfaces, power supplies, and the like.

The embodiments are described in a progressive mode in the specification, the emphasis of each embodiment is on the difference from the other embodiments, and the same and similar parts among the embodiments can be referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description. It should be noted that, for those skilled in the art, it is possible to make several improvements and modifications to the present application without departing from the principle of the present application, and such improvements and modifications also fall within the scope of the claims of the present application.

It should also be noted that, in this specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Claims

1. A welding control method is characterized by being applied to welding equipment, wherein a welding gun and a visual sensor are arranged on an actuating mechanism of the welding equipment, the welding gun and the visual sensor move along with the actuating mechanism, and the relative positions of the welding gun and the visual sensor are kept unchanged, and the welding control method comprises the following steps:

2. The welding control method of claim 1, wherein generating a trend space straight line from actual motion data of the welding gun comprises:

and calculating trend space straight lines corresponding to all the motion coordinate points between the first actual swing track point and the second actual swing track point by utilizing a least square straight line fitting algorithm.

3. The weld control method according to claim 2, wherein calculating correction coordinate points based on the trend space straight line, the weld bead data, and a similar triangle rule includes:

4. The welding control method according to claim 3, wherein controlling the welding gun to move to the correction coordinate point until the weld data collected by the vision sensor includes the weld end point comprises:

and 2, step: reselecting a first actual swing track point and a new second actual swing track point from the actual motion data of the welding gun;

and step 3: calculating trend space straight lines corresponding to all motion coordinate points between the first actual swing track point and the second actual swing track point by using a least square space straight line algorithm;

5. The weld control method according to claim 3, wherein calculating an actual groove center point deviation from the weld data, the current swing, and the deviation data comprises:

subtracting the current swing and the deviation data from the groove central point deviation to obtain actual groove central point deviations of the actual groove central point deviation in Y-axis and Z-axis directions; the deviation data comprises the deviation of the welding gun and the vision sensor in the Y-axis direction and the Z-axis direction, and the movement direction of the welding gun is the X-axis direction.

6. The welding control method according to claim 1, wherein determining whether the weld data collected by the vision sensor includes a weld end point comprises:

7. The welding control method according to claim 1, wherein generating a welding trajectory from the weld start point to the weld end point based on the weld data includes:

fitting the welding line data through a median filtering method to obtain welding line characteristic points, and calculating a least square straight line fitting algorithm on the welding line characteristic points to obtain the welding track from the welding line starting point to the welding line end point.

8. A welding control system applied to welding equipment, wherein a welding gun and a visual sensor are arranged on an actuating mechanism of the welding equipment, the welding gun and the visual sensor move along with the actuating mechanism, and the relative positions of the welding gun and the visual sensor are kept unchanged, the welding control system comprises:

the operation module is used for generating a welding track from the welding seam starting point to the welding seam ending point according to the welding seam data if the welding seam data acquired by the vision sensor comprises the welding seam ending point, and controlling the welding gun to weld the workpiece according to the welding track;

9. A welding apparatus comprising an actuator on which a welding torch and a vision sensor are mounted, the welding torch and the vision sensor moving with the actuator and the relative positions of the welding torch and the vision sensor remaining unchanged, a memory in which a computer program is stored, and a processor which, when invoked on the computer program in the memory, carries out the steps of the welding control method according to any one of claims 1 to 7.

10. A storage medium having stored thereon computer-executable instructions which, when loaded and executed by a processor, carry out the steps of a weld control method according to any one of claims 1 to 7.