A real-time pose adjustment system and method for an arc welding manipulator

Abstract

The present application provides a real-time posture adjustment system and method for an arc welding manipulator, comprising: a welding manipulator; an end effector fixture; a welding gun, wherein the head of the welding gun points to a welding point on the surface of a workpiece to be welded; a laser ranging sensor, which acquires data information of at least two neighboring points on the surface of the workpiece to be welded, wherein the neighboring points are distributed on both sides of the welding point on the surface of the workpiece to be welded; a manipulator controller, which controls the movement of the welding manipulator to change the position of the welding gun head pointing to the surface of the workpiece to be welded and the angle of the welding gun; receives data information fed back by the laser ranging sensor, and generates an angle compensation instruction based on the data information, wherein the angle compensation instruction is used to control the welding manipulator to perform angle compensation on the welding gun during the welding process, so as to solve the problems that the installation method of the laser sensors on both sides of the welding gun in the existing welding system is not conducive to the operation of the manipulator; the measurement is affected by the strong welding light, which reduces the measurement accuracy and even causes failure; and the use occasions are limited.

Description

Technical Field

[0001] The present application relates to the field of industrial welding technology, and in particular to a real-time posture adjustment system and method for an arc welding robot. Background Art

[0002] Automated welding primarily refers to the unmanned operation of the entire welding production process, meaning that machines replace human actions. It is a comprehensive welding and process issue, and its main task is to establish a welding process flow that does not require direct human involvement in the welding process based on the adoption of advanced clamping and positioning methods and welding processes, thereby freeing people from dangerous working environments. Over the past decade, with the development of machine vision technology, the use of laser rangefinders to directly observe and capture the position and size of welds, analyze welding quality, and obtain automatic welding paths. By comparing with the calibrated position, the position error is transmitted to the robot controller in real time, and adjustments are made to the welding path to achieve closed-loop precise tracking of welds, which has become an important research direction.

[0003] The current welding system of a posture-adaptive robot includes a welding robot, a main control computer connected to the welding robot for communication, and a detection and tracking system connected to the main control computer for communication. The detection and tracking system includes a line laser sensor arranged on the welding gun for detecting the weld contour and two point laser sensors arranged on the welding gun on opposite sides of the welding gun; the main control computer obtains the standard posture of the welding robot based on the data measured by the two point laser sensors and the line laser sensor and adjusts the posture of the welding robot according to the standard posture, thereby continuously correcting the posture of the welding robot during the welding process, so that the welding robot is always in the standard posture to weld the workpiece, can adapt to welding operations of workpieces with large welding deformation, uneven welds, etc., and can achieve the predetermined welding quality.

[0004] However, this solution has obvious drawbacks in posture detection and correction strategies. For example, the installation method of the point laser sensors on both sides of the welding gun is not conducive to the operation of the robot in a small space, and their lateral dimensions far exceed the size of the robot's end effector itself; the triangulation route of the point laser sensor is affected by the interference of strong welding light, thereby reducing the measurement accuracy and even causing failure; the posture detection system cannot distinguish between horizontal welding and vertical welding, resulting in limited usage occasions. Summary of the Invention

[0005] The embodiments of the present application provide a real-time posture adjustment system and method for an arc welding robot to address the obvious drawbacks of existing welding systems in posture detection and correction strategies. For example, the installation method of the point laser sensors on both sides of the welding gun is not conducive to the operation of the robot in a small space, and their lateral dimensions far exceed the dimensions of the robot's end effector itself; the triangulation route of the point laser sensor is affected by the interference of strong welding light, thereby reducing the measurement accuracy and even causing failure; the posture detection system cannot distinguish between horizontal welding and vertical welding, resulting in technical problems such as limited usage occasions.

[0006] The first aspect of the present application provides a real-time posture adjustment system for an arc welding manipulator, comprising:

[0007] Welding manipulator;

[0008] An end effector jig connected to an operating end of the welding manipulator;

[0009] A welding gun, the root of which is arranged at the center of a side of the end effector fixture away from the welding manipulator, and the head of which is directed toward the welding point on the surface of the workpiece to be welded;

[0010] a laser ranging sensor, disposed on a side of the end effector fixture away from the welding robot, and configured to acquire data information of at least two neighboring points on the surface of the workpiece to be welded, wherein the neighboring points are distributed on both sides of the welding point on the surface of the workpiece to be welded;

[0011] A manipulator controller is provided on the welding manipulator and is configured to control the movement of the welding manipulator to change the position of the welding gun head pointing to the surface of the workpiece to be welded and the angle of the welding gun; and receive data information feedback from the laser ranging sensor, and generate an angle compensation instruction based on the data information. The angle compensation instruction is used to control the welding manipulator to compensate the angle of the welding gun during the welding process.

[0012] In some embodiments, the welding robot comprises:

[0013] base;

[0014] a first joint, one end of which is rotatably connected to the base;

[0015] a shoulder link rotatably connected to the other end of the first joint;

[0016] a second joint, the second joint being rotatably connected to the shoulder link;

[0017] a boom connecting rod, the boom connecting rod being rotatably connected to the second joint;

[0018] a third joint, the third joint being rotatably connected to the upper arm connecting rod;

[0019] A forearm rear section connecting rod, the forearm rear section connecting rod being rotatably connected to the third joint;

[0020] a fourth joint, one end of which is rotatably connected to the rear connecting rod of the forearm;

[0021] A front end connecting rod of the forearm, the front end connecting rod of the forearm being rotatably connected to the other end of the fourth joint;

[0022] a fifth joint, the fifth joint being rotatably connected to the front end connecting rod of the forearm;

[0023] In which, the robot controller is also configured to: send angle compensation instructions to the first joint, second joint, third joint, fourth joint and fifth joint respectively according to the angle compensation instruction, so as to adjust the position of the welding gun head pointing to the surface of the welded workpiece and the angle of the welding gun.

[0024] In some embodiments, the manipulator controller includes:

[0025] A receiving unit, configured to receive data information sent by the laser ranging sensor;

[0026] a calculation unit configured to calculate the welding angle θ1 according to the data information sent by the laser ranging sensor received by the receiving unit, calculate the welding compensation angle according to the welding angle θ1 and generate instruction information;

[0027] The control unit is configured to control the welding robot to move for welding and receive instruction information from the calculation unit to control the welding robot to perform angle compensation.

[0028] In some embodiments, two laser ranging sensors are provided, one on each side of the welding gun root on the end effector fixture, and each laser ranging sensor is used to obtain data information of a neighborhood point.

[0029] A second aspect of the present application provides a real-time posture adjustment method for an arc welding manipulator, which is applied to any of the above-mentioned real-time posture adjustment systems for an arc welding manipulator, comprising:

[0030] Based on the laser ranging sensor, a geometric model is established according to the relative position relationship between the welding gun and the welding plane. The known quantities a, h, s, d1, d2 and σ are determined according to the position coordinates C and D of the laser ranging sensor, the weld point coordinate O and the neighborhood point coordinates A and B in the geometric model. The data information is then generated and sent to the robot controller, where σ is the neighborhood length, s is the distance between the laser ranging sensor and the weld point, and d1 and d2 are the distances between the laser ranging sensor and the neighborhood points.

[0031] Based on the robot controller, the data information of the laser ranging sensor is received, and the welding angle θ1 is determined using the cosine theorem formula, where the cosine theorem formula is as follows:

[0032]

[0033] Calculate welding angles θ1 and θ2 based on the robot controller;

[0034] Welding compensation angle based on θ1 and θ2 calculated by the robot controller Calculate and compensate the welding angle according to the Control the robot to perform angle compensation.

[0035] In some embodiments, the method for real-time posture adjustment of an arc welding robot further includes:

[0036] Receive data information sent by the laser ranging sensor based on the receiving unit;

[0037] The calculation unit calculates the welding angle θ1 based on the data information sent by the laser ranging sensor received by the receiving unit, calculates the welding compensation angle based on the welding angle θ1 and generates instruction information;

[0038] The control unit receives instruction information from the calculation unit and controls the welding robot to perform angle compensation.

[0039] In some embodiments, the relative position relationship between the welding gun and the surface of the welded workpiece includes: plane welding, vertical horizontal welding, and vertical vertical welding.

[0040] In some embodiments, when performing horizontal welding, if the inclination angle between the welding gun and the welding surface is 70-80°, the angle compensation reference value of the robot controller is 75°; when performing vertical welding, if the inclination angle between the welding gun and the welding surface is 40-55°, the angle compensation value of the robot controller is 45°.

[0041] In some embodiments, the method for real-time posture adjustment of an arc welding robot further includes:

[0042] After the preset welding time is completed, the detection process begins. The robot controller receives data from the laser rangefinder. During the detection process, the welding process is paused.

[0043] After calculating the welding compensation angle according to the welding angle θ1 and generating instruction information, the welding process is entered again, and the control unit receives the instruction information of the calculation unit to control the welding robot to perform angle compensation.

[0044] The present application provides a real-time posture adjustment system and method for an arc welding manipulator, comprising: a welding manipulator; an end effector fixture, wherein the end effector fixture is connected to the operating end of the welding manipulator; a welding gun, wherein the root of the welding gun is arranged at the center of a side of the end effector fixture away from the welding manipulator, and the head of the welding gun points to the welding point on the surface of the workpiece to be welded; a laser ranging sensor, which is arranged on the side of the end effector fixture away from the welding manipulator and is configured to obtain data information of at least two neighboring points on the surface of the workpiece to be welded, wherein the neighboring points are distributed on both sides of the welding point on the surface of the workpiece to be welded; and a manipulator controller, which is arranged at the welding point. The receiving manipulator is configured to control the movement of the welding manipulator to change the position of the welding gun head pointing to the surface of the workpiece to be welded and the angle of the welding gun; and receive data information feedback from the laser ranging sensor, and generate an angle compensation instruction according to the data information. The angle compensation instruction is used to control the welding manipulator to perform angle compensation on the welding gun during the welding process, so that the laser ranging sensors arranged on both sides of the welding gun will not affect the operation of the manipulator; will not be affected by strong light interference during welding, thereby reducing the measurement accuracy or even causing failure; it can distinguish between horizontal welding and vertical welding, and will not limit the use occasions. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0046] Figure 1 Schematic diagram of the structure of the real-time posture adjustment system of the arc welding manipulator in this application;

[0047] Figure 2 This is a schematic diagram of the connection structure of the welding robot in this application;

[0048] Figure 3 This is a structural schematic diagram of the relative position relationship between the welding gun and the welding plane in the case of plane welding in this application;

[0049] Figure 4Schematic diagram of the geometric model of the welding gun and the welding plane in the case of plane welding in this application;

[0050] Figure 5 This is a structural diagram of the relative position relationship between the welding gun and the welding plane in the case of horizontal welding of the vertical surface in this application;

[0051] Figure 6 Schematic diagram of the geometric model of the welding gun and the welding plane in the case of horizontal welding of the vertical surface in this application;

[0052] Figure 7 This is a structural diagram of the relative position relationship between the welding gun and the welding plane in the case of vertical welding of the vertical surface in this application;

[0053] Figure 8 Schematic diagram of the geometric model of the welding gun and the welding plane in the case of vertical welding in this application;

[0054] Figure 9 This is a schematic diagram of the welding-testing process timing in this application.

[0055] Description of reference numerals:

[0056] 1-Welding robot; 11-Base; 12-First joint; 13-Shoulder link; 14-Second joint; 15-Upper arm link; 16-Third joint; 17-Rear section link of forearm; 18-Fourth joint; 19-Front end link of forearm; 20-Fifth joint; 2-End effector fixture; 3-Welding gun; 4-Laser ranging sensor; 5-Robot controller; 51-Receiving unit; 52-Computing unit; 53-Control unit. DETAILED DESCRIPTION

[0057] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0058] Because in some technologies, the welding system has obvious drawbacks in posture detection and correction strategies. For example, the installation method of the point laser sensors on both sides of the welding gun is not conducive to the operation of the manipulator in a small space, and its lateral size far exceeds the size of the manipulator's end effector itself; the triangulation route of the point laser sensor is affected by the interference of the strong welding light, thereby reducing the measurement accuracy and even causing failure; the posture detection system cannot distinguish between horizontal welding and vertical welding, resulting in limited use occasions. In order to solve this technical problem, the present application provides a real-time posture adjustment system and method for an arc welding manipulator. The real-time posture adjustment system and method for an arc welding manipulator are described below:

[0059] Depend on Figure 1 It can be seen that the first aspect of the present application provides a real-time posture adjustment system for an arc welding robot, comprising: a welding robot 1; an end effector fixture 2, the end effector fixture 2 being connected to the operating end of the welding robot 1; a welding gun 3, the root of the welding gun 3 being arranged at the center of a side of the end effector fixture 2 away from the welding robot 1, and the head of the welding gun 3 pointing to the welding point on the surface of the workpiece to be welded; a laser ranging sensor 4, arranged on the side of the end effector fixture 2 away from the welding robot 1, and configured to obtain data information of at least two neighboring points on the surface of the workpiece to be welded, wherein the neighboring points are distributed on both sides of the welding point on the surface of the workpiece to be welded; a robot controller 5, arranged on the welding robot 1, and configured to control the movement of the welding robot 1 to change the position of the head of the welding gun 3 pointing to the surface of the workpiece to be welded and the angle of the welding gun 3; and receiving data information fed back by the laser ranging sensor 4, generating an angle compensation instruction according to the data information, and the angle compensation instruction is used to control the welding robot 1 to perform angle compensation on the welding gun 3 during the welding process.

[0060] In this embodiment, the present application proposes a real-time posture adjustment system for an arc welding robot. The real-time posture adjustment system for an arc welding robot is composed of the end effector fixture 2 at the end of the welding robot 1, the laser ranging sensor 4, the analog input interface of the robot controller 5, and a software algorithm. It can accurately obtain the welding posture in real time under the strong light environment of the welding operation, and obtain the posture compensation parameters online according to the characteristics of the welding plane. Compared with the weld quality as a feedback parameter, the present application has better anti-interference and adaptability to the welding environment, and also has good secondary development characteristics. After the limited working point coordinate positioning of the working plane is performed through robot teaching, it can adapt to small changes in the working surface, provide real-time feedback on the welding posture of the working point, and provide online feedback on posture compensation. It also has the characteristics of resistance to strong light and high temperature.

[0061] The end effector fixture 2 is installed at the front end of the manipulator wrist (called a mechanical interface) to directly perform work tasks. Depending on the work task, it can be a clamp or a special tool, etc. Generally, professional manipulators have 2 to 6 degrees of freedom. The manipulator controller 5 completes specific actions by controlling the motors of each degree of freedom of the manipulator, while receiving information fed back by the sensor. The working principle of the laser ranging sensor 4 is that the laser diode emits a laser pulse at the target. After being reflected by the target, the laser is scattered in all directions. Part of the scattered light returns to the sensor receiver and is received by the optical system and imaged onto the avalanche photodiode. The avalanche photodiode is an optical sensor with an internal amplification function, so it can detect extremely weak light signals. By recording and processing the time from the emission of the light pulse to its return and reception, the target distance can be measured.

[0062] Depend on Figure 2It can be seen that the welding robot 1 includes: a base 11 for fixing the welding robot 1 in one place; a first joint 12, one end of the first joint 12 is rotatably connected to the base 11, and the first joint 12 controls the welding robot 1 to make a circular motion based on the center of the contact surface between the first joint 12 and the base 11; a shoulder link 13, the shoulder link 13 is rotatably connected to the other end of the first joint 12; a second joint 14, the second joint 14 is rotatably connected to the shoulder link 13, and the second The joint 14 controls the welding manipulator 1 to adjust its height up and down; the arm link 15, the arm link 15 is rotatably connected to the second joint 14; the third joint 16, the third joint 16 is rotatably connected to the arm link 15, and the third joint controls the welding manipulator 1 to perform precise adjustment up and down, thereby ensuring that the welding gun 3 can accurately align with the welding point for welding; the rear arm link 17, the rear arm link 17 is rotatably connected to the third joint 16; the fourth joint 18, one end of the fourth joint 18 The fourth joint 18 is rotatably connected to the rear link 17 of the forearm, and controls the front end link 19 of the forearm to rotate, thereby controlling the rotation of the welding gun 3 so that it can accurately align with the welding spot for welding; the front end link 19 of the forearm, the front end link 19 of the forearm is rotatably connected to the other end of the fourth joint 18; the fifth joint 20, the fifth joint 20 is rotatably connected to the front end link 19 of the forearm, and the fifth joint 20 controls the end effector fixture 2 to rotate around the outer axis of the fifth joint 20, thereby controlling the swing angle of the welding gun 3 to ensure that the welding gun 3 can accurately align with the welding spot for welding; wherein, the manipulator controller 5 is further configured to: send angle compensation instructions to the first joint 12, the second joint 14, the third joint 16, the fourth joint 18 and the fifth joint 20 respectively according to the angle compensation instruction, so as to adjust the position of the head of the welding gun 3 pointing to the surface of the workpiece and the angle of the welding gun 3, and the rotation directions of the first joint 12, the second joint 14, the third joint 16, the fourth joint 18 and the fifth joint 20 are as follows: Figure 2 shown.

[0063] Depend on Figure 1 It can be seen that the manipulator controller 5 includes: a receiving unit 51, configured to receive the data information sent by the laser ranging sensor 4; a calculation unit 52, configured to calculate the welding angle θ1 based on the data information sent by the laser ranging sensor 4 received by the receiving unit 51, and calculate the welding compensation angle based on the welding angle θ1 and generate instruction information; a control unit 53, configured to control the welding manipulator 1 to move for welding and receive the instruction information of the calculation unit 52 to control the welding manipulator 1 to perform angle compensation.

[0064] Among them, the receiving unit 51 is an element of the manipulator controller 5 used to receive the data information sent by the laser ranging sensor 4; the calculation unit 52 is a program element of the manipulator controller 5 used to calculate the welding angle θ1 according to the data information sent by the laser ranging sensor 4 received by the receiving unit 51, and calculate the welding compensation angle according to the welding angle θ1 and generate instruction information; the control unit 53 is an element of the manipulator controller 5 used to control the welding manipulator 1 to move for welding and receive the instruction information of the calculation unit 52 to control the welding manipulator 1 to perform angle compensation, so that the manipulator controller 5 completes the control of the welding manipulator 1 to move to change the position of the head of the welding gun 3 pointing to the surface of the workpiece to be welded and the angle of the welding gun 3; and receives the data information fed back by the laser ranging sensor 4, and generates an angle compensation instruction according to the data information, and the angle compensation instruction is used to control the welding manipulator 1 to perform angle compensation on the welding gun 3 during the welding process.

[0065] In this embodiment, two laser ranging sensors 4 are provided, which are respectively arranged on both sides of the root of the welding gun 3 on the end effector fixture 2. Each laser ranging sensor 4 is used to obtain data information of a neighborhood point. The placement method of the end effector fixture 2 and the laser ranging sensor 4 is the structural innovation of this application. In addition, the posture calculation method of the measurement point and different welding planes is a software innovation, and the posture compensation strategy is given with the manipulator controller 5 as the system core as the system innovation. This solution currently obtains the best match in terms of design cost, structural miniaturization, anti-interference and accuracy. The laser ranging sensors 4 can use more than two, or be combined with other sensors as facade sensing, etc., but the core idea is still welding posture collection and compensation.

[0066] A second aspect of the present application provides a real-time posture adjustment method for an arc welding manipulator, which is applied to any of the above-mentioned real-time posture adjustment systems for an arc welding manipulator, comprising:

[0067] Based on the laser ranging sensor, a geometric model is established according to the relative position relationship between the welding gun and the welding plane. The known quantities a, h, s, d1, d2 and σ are determined according to the position coordinates C and D of the laser ranging sensor, the weld point coordinate O and the neighborhood point coordinates A and B in the geometric model, and data information is generated and sent to the robot controller, where σ is the neighborhood length, s is the distance between the laser ranging sensor and the weld point, and d1 and d2 are the distances between the laser ranging sensor and the neighborhood points. The selection of the neighborhood points depends on the accuracy of the laser ranging sensor, which is generally at the millimeter level and can reach the micron level with high accuracy. However, for the welding plane, the neighborhood can be relaxed to the centimeter level, and detection failure will not occur due to the curved surface within plus or minus 1-2 cm.

[0068] In this embodiment, for the measurement of the planar welding pose as Figure 3 shown, a geometric model can be established as Figure 4 shown, where O is the coordinate of the welding point, C and D are the position coordinates of the two laser range sensors respectively, and the corresponding measurement points are the coordinates of A and B in the neighborhood of point O. The length of the neighborhood is σ, and its value is much smaller than the length of the welding torch, which can be used to approximately represent the tiny local part of the complex welding plane, that is, it is not only applicable to the general plane but also can be used for the pose detection during the welding process of complex curved surfaces.

[0069] Based on the manipulator controller, the data information of the laser range sensor is received, and the welding angle θ1 is determined by using the cosine theorem formula. The cosine theorem formula is as follows;

[0070]

[0071] Based on the manipulator controller, the calculation of the welding angles θ1 and θ2 is completed; on the one hand, it is used for verification to improve the inspection accuracy, and on the other hand, it is used to cope with emergencies, such as irregular mutations of the welding curved surface, etc.

[0072] Based on the θ1 and θ2 calculated by the manipulator controller, the welding compensation angle is calculated, and according to the welding compensation angle the manipulator is controlled to perform angle compensation, so as to ensure that the welding torch 3 can accurately align with the welding point for welding work.

[0073] In this embodiment, the real-time pose adjustment method of the arc welding manipulator further includes:

[0074] Based on the receiving unit, the data information sent by the laser range sensor is received;

[0075] Based on the calculation unit, the welding angle θ1 is calculated according to the data information sent by the laser range sensor received by the receiving unit, and the welding compensation angle is calculated based on the welding angle θ1 and an instruction message is generated;

[0076] Based on the control unit, the instruction message of the calculation unit is received to control the welding manipulator to perform angle compensation.

[0077] In this embodiment, the relative position relationship between the welding torch and the surface of the welded part includes: planar welding as Figure 3 shown, vertical surface horizontal welding as Figure 5 shown, vertical surface vertical welding as Figure 7 shown. For Figure 6 the vertical surface welding (horizontal main view), the judgment condition is d1`<s, d2<s; for Figure 8 the vertical surface welding (vertical main view), the judgment condition is d1<s, d2`<s; for Figure 6 and Figure 8As the neighborhood length σ is much smaller than the welding gun length h, d1`≈d2 and d1≈d2` can be set respectively, and the welding gun angle (main view) can be obtained using the above cosine theorem formula.

[0078] In this embodiment, the ideal angle between the welding torch and the welding plane during arc welding is related to the welding torch's speed and the direction of movement relative to the weld seam, depending on the welding process requirements. A common rule of thumb is that for horizontal welding, if the welding torch is at a 70-80° angle to the welding surface, the robot controller's angle compensation reference value is 75°; for vertical welding, if the welding torch is at a 40-55° angle to the welding surface, the robot controller's angle compensation reference value is 45°. The welding compensation angle can be adjusted based on welding requirements.

[0079] In this embodiment, the method for real-time posture adjustment of an arc welding manipulator further includes:

[0080] After the preset welding time is completed, the detection process begins. The robot controller receives data from the laser rangefinder. During the detection process, the welding process is paused.

[0081] After calculating the welding compensation angle according to the welding angle θ1 and generating instruction information, the welding process is entered again, and the control unit receives the instruction information of the calculation unit to control the welding robot to perform angle compensation.

[0082] In this embodiment, Figure 9 It is the welding-measurement process sequence, the upper part represents the welding sequence, and the lower part represents the visual inspection sequence. 1 indicates that the area between the two dotted lines is the welding and detection stop process; 2 indicates that the area between the two dotted lines is the welding stop and detection process. The actual welding time is determined by the process requirements. Usually the measurement process time can be very short. By controlling the welding process with a standard pulse waveform, real-time measurement can be achieved and the strong light interference at the welding site can be minimized. The laser ranging sensor 4 is selected as a 4-20mA analog output type, and the currents I1 and I2 obtained represent the distances d1 (d1`) and d2 (d2`) respectively. Usually the manipulator controller is equipped with an analog input interface as standard, so the I1 and I2 obtained above are fully compatible with the analog interfaces port1 and port2 of the manipulator controller 5.

[0083] The above specific implementation methods further explain in detail the purpose, technical solutions and beneficial effects of the embodiments of the present application. It should be understood that the above are only specific implementation methods of the embodiments of the present application and are not intended to limit the scope of protection of the embodiments of the present application. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solutions of the embodiments of the present application should be included in the scope of protection of the embodiments of the present application.

Claims

1. A real-time posture adjustment system for an arc welding manipulator, characterized in that: include: Welding manipulator (1); An end effector jig (2), the end effector jig (2) being connected to an operating end of the welding manipulator (1); A welding gun (3), wherein the root of the welding gun (3) is arranged at the center of a side of the end effector fixture (2) away from the welding manipulator (1), and the head of the welding gun (3) points to the welding point on the surface of the workpiece to be welded; A laser ranging sensor (4) is provided on a side of the end effector fixture (2) away from the welding manipulator (1), and is configured to obtain data information of at least two neighboring points on the surface of the welded workpiece, wherein the neighboring points are distributed on both sides of the welding point on the surface of the welded workpiece; The laser distance measuring sensor (4) is further configured to establish a geometric model according to the relative position relationship between the welding gun and the welding plane, determine the known quantities a, h, s, d1, d2 and σ according to the position coordinates C and D of the laser distance measuring sensor, the welding point coordinate O and the neighborhood point coordinates A and B in the geometric model, and generate data information to be sent to the manipulator controller, wherein σ is the neighborhood length, s is the distance between the laser distance measuring sensor and the welding point, and d1 and d2 are the distances between the laser distance measuring sensor and the neighborhood points; the welding plane is a combined three-dimensional welding plane; A manipulator controller (5) is provided on the welding manipulator (1) and is configured to control the movement of the welding manipulator (1) to change the position of the head of the welding gun (3) pointing to the surface of the workpiece to be welded and the angle of the welding gun (3); and to receive data information fed back by the laser ranging sensor (4), and generate an angle compensation instruction based on the data information, wherein the angle compensation instruction is used to control the welding manipulator (1) to perform angle compensation on the welding gun (3) during the welding process; The manipulator controller (5) is further configured to receive data information from the laser ranging sensor (4) and determine the welding angle θ1 using a cosine theorem formula, wherein the cosine theorem formula is as follows: Welding compensation angle based on calculated θ1 Calculate and compensate the welding angle according to the Control the manipulator to perform angle compensation; Among them, when d1>s>d2, it is plane welding; when d1<s, d2<s, it is vertical horizontal welding or vertical vertical welding.

2. The real-time posture adjustment system for an arc welding robot according to claim 1, characterized in that: The welding manipulator (1) comprises: base (11); a first joint (12), one end of the first joint (12) being rotatably connected to the base (11); a shoulder link (13), the shoulder link (13) being rotatably connected to the other end of the first joint (12); a second joint (14), the second joint (14) being rotatably connected to the shoulder link (13); A boom connecting rod (15), the boom connecting rod (15) being rotatably connected to the second joint (14); a third joint (16), the third joint (16) being rotatably connected to the upper arm connecting rod (15); A forearm rear section connecting rod (17), wherein the forearm rear section connecting rod (17) is rotatably connected to the third joint (16); a fourth joint (18), one end of the fourth joint (18) being rotatably connected to the rear connecting rod (17) of the forearm; A forearm front end connecting rod (19), the forearm front end connecting rod (19) is rotatably connected to the other end of the fourth joint (18); a fifth joint (20), the fifth joint (20) being rotatably connected to the front end connecting rod (19) of the forearm; The manipulator controller (5) is further configured to send angle compensation instructions to the first joint (12), the second joint (14), the third joint (16), the fourth joint (18) and the fifth joint (20) respectively according to the angle compensation instruction, so as to adjust the position of the head of the welding gun (3) pointing to the surface of the welded workpiece and the angle of the welding gun (3).

3. The real-time posture adjustment system for an arc welding manipulator according to claim 1, characterized in that: The manipulator controller (5) comprises: A receiving unit (51) configured to receive data information sent by the laser ranging sensor (4); A calculation unit (52) is configured to calculate a welding angle θ1 based on the data information sent by the laser ranging sensor (4) and received by the receiving unit (51), calculate a welding compensation angle based on the welding angle θ1, and generate instruction information; The control unit (53) is configured to control the welding robot (1) to move for welding and receive instruction information from the calculation unit (52) to control the welding robot (1) to perform angle compensation.

4. The real-time posture adjustment system for an arc welding robot according to claim 1, characterized in that: Two laser distance measuring sensors (4) are provided, which are respectively arranged on both sides of the root of the welding gun (3) on the end effector fixture (2), and each laser distance measuring sensor (4) is used to obtain data information of a neighborhood point.

5. A method for real-time posture adjustment of an arc welding manipulator, applied to a real-time posture adjustment system of an arc welding manipulator according to any one of claims 1 to 4, characterized in that: include: Based on the laser ranging sensor, a geometric model is established according to the relative position relationship between the welding gun and the welding plane. The known quantities a, h, s, d1, d2 and σ are determined according to the position coordinates C and D of the laser ranging sensor, the weld point coordinate O and the neighborhood point coordinates A and B in the geometric model. The data information is then generated and sent to the robot controller, where σ is the neighborhood length, s is the distance between the laser ranging sensor and the weld point, and d1 and d2 are the distances between the laser ranging sensor and the neighborhood points. Based on the robot controller, the data information of the laser ranging sensor is received, and the welding angle θ1 is determined using the cosine theorem formula, where the cosine theorem formula is as follows: Calculate welding angles θ1 and θ2 based on the robot controller; Welding compensation angle based on θ1 and θ2 calculated by the robot controller Calculate and compensate the welding angle according to the Control the robot to perform angle compensation.

6. The method for real-time posture adjustment of an arc welding robot according to claim 5, characterized in that: Also includes: Receive data information sent by the laser ranging sensor based on the receiving unit; The calculation unit calculates the welding angle θ1 based on the data information sent by the laser ranging sensor received by the receiving unit, calculates the welding compensation angle based on the welding angle θ1 and generates instruction information; The control unit receives instruction information from the calculation unit and controls the welding robot to perform angle compensation.

7. The method for real-time posture adjustment of an arc welding robot according to claim 5, characterized in that: The relative position relationship between the welding gun and the surface of the workpiece includes: flat welding, vertical horizontal welding, and vertical vertical welding.

8. The method for real-time posture adjustment of an arc welding robot according to claim 7, characterized in that: When performing horizontal welding, if the inclination angle between the welding gun and the welding surface is 70-80°, the angle compensation reference value of the robot controller is 75°; when performing vertical welding, if the inclination angle between the welding gun and the welding surface is 40-55°, the angle compensation value of the robot controller is 45°.

9. The method for real-time posture adjustment of an arc welding robot according to claim 5, characterized in that: Also includes: After the preset welding time is completed, the detection process begins. The robot controller receives data from the laser rangefinder. During the detection process, the welding process is paused. After calculating the welding compensation angle according to the welding angle θ1 and generating instruction information, the welding process is entered again, and the control unit receives the instruction information of the calculation unit to control the welding robot to perform angle compensation.

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