Calibration method, calibration device and computer readable storage medium

Abstract

The invention discloses a calibration method, a calibration device and a computer readable storage medium, and the method comprises the steps: controlling a robot end effector to move until line laser emitted by a laser welding seam tracker coincides with a marking line on a calibration plate, and recording a first pose matrix T and a first position matrix M; determining a target position matrix K; moving the robot after collision of an end effector of the robot occurs, enabling the line laser emitted by the laser welding seam tracker to coincide with the marking line, and recording a second pose matrix Ti and a second position matrix Mi; obtaining a second relative pose matrix T 'Laser after collision; determining a change matrix delta T; and according to the pose matrix and the change matrix of the tool center point of the robot end effector under the flange coordinate system before collision, the pose matrix of the tool center point under the flange coordinate system after collision is obtained. According to the method, the pose matrix of the tool center point under the flange coordinate system after collision is obtained by using the variable quantity of the pose matrix of the laser welding seam tracker before and after collision, the operation is simple, and the calibration precision is high.

Description

Technical Field

[0001] The present application relates to the field of automated control technology, and in particular to a calibration method, a calibration device, and a computer-readable storage medium. Background Art

[0002] After a robot end tool, such as a welding gun, collides, the position and posture of the welding gun will change, and the coordinate system of the welding gun needs to be recalibrated, that is, the pose matrix of the tool center point in the flange coordinate system needs to be recalibrated before operation can be restored. The calibration steps of the traditional tool center point pose matrix are cumbersome, time-consuming and labor-intensive, and require a high level of operator proficiency. The operator must accurately control the robot end to perform point-to-point alignment operations with a fixed tip point in four different postures. Whether the points in space are aligned is observed by the operator through his eyes, which inevitably introduces human observation errors, which can easily cause calibration failures or poor calibration accuracy. Summary of the invention

[0003] The present application provides a calibration method, a calibration device and a computer-readable storage medium to solve the problems of complicated calibration steps and low calibration accuracy in the prior art.

[0004] According to a first aspect of an embodiment of the present application, a calibration method is provided, the method comprising: when controlling the robot end effector to move until the line laser emitted by the laser weld tracker coincides with the marking line on the calibration plate, recording the first pose matrix T of the robot end flange in the robot's base coordinate system and the first position matrix M fed back by the laser weld tracker, wherein the laser weld tracker is fixedly mounted on the robot end effector, the calibration plate is provided with an execution line and the marking line, the marking line is perpendicular to the execution line, the execution line is the execution trajectory of the robot end effector, and the first position matrix M is the position matrix of the target intersection point formed by the intersection of the execution line and the marking line fed back by the laser weld tracker in the laser weld tracker coordinate system; according to the first pose matrix T, the first position matrix M and the first relative pose matrix T between the coordinate system of the laser weld tracker and the flange coordinate system of the robot Laser , determine the target position matrix K of the target intersection in the base coordinate system of the robot; after the robot end effector collides, while keeping the postures of the robot end effector and the robot end flange in the base coordinate system unchanged, move the position of the robot multiple times in succession, so that the line laser emitted by the laser weld tracker overlaps with the marking line multiple times in succession, and record the second posture matrix T of the robot end flange in the base coordinate system each time they overlap. i , the second position matrix M fed back by the laser weld trackeri ; , where i is an integer greater than or equal to 1, i represents the i-th time that the line laser emitted by the current laser weld tracker coincides with the marking line; according to the second posture matrix T recorded each time i , the second position matrix M i and the target position matrix K, and obtain the second relative position matrix T′ between the coordinate system of the laser weld tracker and the flange coordinate system of the robot after the collision Laser ; According to the first relative posture matrix T Laser And the second relative pose matrix T′ Laser , determine the change matrix ΔT; and obtain the pose matrix of the tool center point in the flange coordinate system after the collision according to the pose matrix of the tool center point of the robot end effector in the flange coordinate system before the collision and the change matrix.

[0005] According to a second aspect of an embodiment of the present application, a calibration device is provided, including: a first recording unit, for recording a first pose matrix T of the robot end flange in the robot's base coordinate system and a first position matrix M fed back by the laser weld tracker when the robot is controlled to move until the line laser emitted by the laser weld tracker coincides with a marking line on a calibration plate, wherein the laser weld tracker is fixedly mounted on the robot end effector, an execution line and the marking line are provided on the calibration plate, the marking line is perpendicular to the execution line, the execution line is an execution trajectory of the robot end effector, and the first position matrix M is a position matrix of a target intersection point formed by the intersection of the execution line and the marking line fed back by the laser weld tracker in the laser weld tracker coordinate system; and a first determination unit, for determining a first relative pose matrix T between the coordinate system of the laser weld tracker and the flange coordinate system of the robot according to the first pose matrix T, the first position matrix M, and the first relative pose matrix T between the coordinate system of the laser weld tracker and the flange coordinate system of the robot. Laser , determine the target position matrix K of the target intersection in the base coordinate system of the robot; a second recording unit is used to move the position of the robot multiple times after the robot end effector collides, while keeping the postures of the robot end effector and the robot end flange in the base coordinate system unchanged, so that the line laser emitted by the laser weld tracker coincides with the marking line multiple times, and record the second posture matrix T of the robot end flange in the base coordinate system each time the two coincide. i , the second position matrix M fed back by the laser weld tracker i ; , wherein i is an integer greater than or equal to 1, i represents the i-th time that the line laser emitted by the current laser weld tracker coincides with the marking line; a second determination unit is used to determine the second posture matrix T recorded each time i, the second position matrix M i and the target position matrix P, and obtain the second relative position matrix T′ between the coordinate system of the laser weld tracker and the flange coordinate system of the robot after the collision Laser ; A third determination unit, configured to determine the relative position matrix T according to the first relative position matrix T Laser And the second relative pose matrix T′ Laser , determine the change matrix ΔT; a fourth determination unit, used to obtain the pose matrix of the tool center point in the flange coordinate system after the collision according to the pose matrix of the tool center point of the robot end effector in the flange coordinate system before the collision and the change matrix.

[0006] A third aspect of an embodiment of the present application provides a calibration device, which includes a processor and a memory, wherein the processor is coupled to the memory, wherein program data is stored in the memory, and the processor implements the steps in any of the above methods by executing the program data in the memory.

[0007] A fourth aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program can be executed by a processor to implement the steps in any of the above methods.

[0008] The beneficial effect is as follows: before the robot collides, the method of the present application controls the robot end effector to move until the line laser emitted by the laser weld tracker coincides with the marking line on the calibration plate, and records the first pose matrix T of the robot end flange in the robot's base coordinate system and the first position matrix M fed back by the laser weld tracker. After the robot end effector collides, while keeping the poses of the robot end effector and the robot end flange in the base coordinate system unchanged, the position of the robot is moved multiple times in succession, so that the line laser emitted by the laser weld tracker coincides with the marking line multiple times in succession, and each time they coincide, the second pose matrix T of the robot end flange in the base coordinate system is recorded. i , the second position matrix M fed back by the laser weld tracker i . According to the pose matrix of the tool center point of the robot end effector in the flange coordinate system before the collision, the change of the pose matrix of the end flange in the robot's base coordinate system before and after the collision, and the change of the position matrix of the target intersection point fed back by the laser weld tracker in the laser weld tracker coordinate system, the pose matrix of the tool center point of the robot end effector in the flange coordinate system after the collision is obtained. This application uses a laser weld tracker to identify the welds on the calibration plate, which has high recognition accuracy and is simpler to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0010] Figure 1 It is a structural schematic diagram of an implementation method of a calibration board of the present application;

[0011] Figure 2 It is a flow chart of an implementation method of the calibration method of the present application;

[0012] Figure 3 It is a structural schematic diagram of an implementation method of the calibration device of the present application;

[0013] Figure 4 It is a structural schematic diagram of another implementation mode of the calibration device of the present application;

[0014] Figure 5 It is a structural schematic diagram of an implementation method of a computer-readable storage medium of the present application. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0016] It should be noted that the terms "first" and "second" in this application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0017] At present, robot application scenarios are becoming more and more complex, and the robot's working space is becoming smaller and smaller. When the robot works in a small space, it is very likely to collide with the workpiece or obstacles in the environment. The robot's running trajectory is based on the TCP point of the robot's end effector (such as a welding gun) as the end point along the trajectory of the execution line (such as a weld). Once a collision occurs on the robot's end effector (such as a welding gun), the TCP point of the robot's end effector will inevitably change. When the position of the TCP changes, it is necessary to recalibrate the tool coordinate system of the robot's end effector. If the tool coordinate system is not recalibrated, a series of problems such as trajectory errors, weld offsets, and gun cleaning collisions will occur.

[0018] For ease of understanding, the calibration of the "pose matrix of the tool center point of the robot end effector in the flange coordinate system" is the calibration of the "tool coordinate system". The flange coordinate system is: the end of the robot is the origin, the flange surface is the coordinate plane, the direction perpendicular to the flange surface is the positive direction of the z-axis, and the right-hand rule determines the coordinate system in other directions.

[0019] The laser weld tracker used in this application is a commonly used device in the field of automated welding. The device is mainly composed of a line laser transmitter, a camera and an image processor. When the laser weld tracker is working, the line laser is emitted by the line laser transmitter, and the line laser is irradiated on the weld to be welded. The line laser is photographed by the camera, and an image is formed after imaging. The angle relationship between the camera and the laser transmitter is known, and the weld position information at the position where the line laser is irradiated can be obtained through automatic calculation by the system. The laser weld tracker has a high accuracy in identifying the position information of the weld, and its recognition accuracy can reach less than 1mm, and the recognition position accuracy and stability are much higher than manual teaching.

[0020] This application uses the characteristics of the laser weld tracker that can identify the weld position with high precision to design a calibration plate, which is fixed at any position in the robot workspace. Figure 1 , Figure 1 It is a structural schematic diagram of an implementation method of the calibration plate of the present application. The calibration plate can be a rectangular plate with an execution line and a marking line set on its surface. The marking line is perpendicular to the execution line, and the intersection of the marking line and the execution line forms a target intersection. The execution line in the present application is the execution trajectory of the robot's end effector, that is, the weld.

[0021] In this application, the laser weld tracker is fixedly installed at the end of the robot end effector (such as a welding gun), so that the relative position of the laser weld tracker and the robot end effector is fixed, and the two can be regarded as a whole. When the pose matrix of the tool center point in the flange coordinate system changes, the pose matrix of the laser weld tracker in the flange coordinate system changes synchronously, and the amount of change is the same. The change in the pose matrix of the laser weld tracker before and after the collision is recorded as ΔT (that is, the "change matrix ΔT" mentioned below). If the change ΔT of the pose matrix of the laser weld tracker before and after the collision can be obtained, the change ΔT of the pose matrix of the tool center point in the flange coordinate system can be obtained. Tool , because ΔT Tool ≈ΔT.

[0022] Before the robot end effector collides, the hand-eye calibration method is used to calibrate the robot end effector to obtain the pose matrix T of the tool center point of the robot end effector in the flange coordinate system before the collision. Tool , determine the pose matrix T of the tool center point of the robot end effector in the flange coordinate system after the collision according to the following formula: Tool_new :

[0023] T Tool_new =T Tool ×ΔT Tool

[0024] Due to ΔT Tool ≈ΔT, then T Tool_new =T Tool ×ΔT

[0025] Among them, T Tool is the pose matrix of the tool center point of the robot end effector in the flange coordinate system before the collision, and ΔT is the change matrix.

[0026] From the above, we can know that T Tool_new , the following introduces the method for calculating ΔT.

[0027] See also Figure 2 , Figure 2 : is a flow chart of an implementation method of the present application. In one implementation method, the calibration method includes:

[0028] S110: When controlling the robot end effector to move until the line laser emitted by the laser weld tracker coincides with the marking line on the calibration plate, record the first pose matrix T of the robot end flange in the robot's base coordinate system and the first position matrix M fed back by the laser weld tracker, wherein the laser weld tracker is fixedly mounted on the robot end effector, and the calibration plate is provided with an execution line and a marking line, the marking line is perpendicular to the execution line, the execution line is the execution trajectory of the robot end effector, and the first position matrix M is the position matrix of the target intersection formed by the intersection of the execution line and the marking line fed back by the laser weld tracker in the laser weld tracker coordinate system.

[0029] Before the collision, the robot end effector is controlled to move so that the line laser emitted by the laser weld tracker coincides with the marking line on the calibration plate. The intersection of the line laser and the execution line (weld) after the coincidence is the target intersection. The first position matrix T of the robot end flange in the robot's base coordinate system and the first position matrix M fed back by the laser weld tracker are recorded by the first recording unit. Among them, the first position matrix M is the position matrix of the target intersection formed by the intersection of the execution line fed back by the laser weld tracker and the marking line.

[0030] S120: Based on the first pose matrix T, the first position matrix M, and the first relative pose matrix T between the coordinate system of the laser weld tracker and the flange coordinate system of the robot Laser , determine the target position matrix K of the target intersection in the robot's base coordinate system.

[0031] Before using the laser weld tracker, the first relative pose matrix T between the coordinate system of the laser weld tracker and the flange coordinate system of the robot has been calibrated by the hand-eye calibration method. Laser It should be noted that the hand-eye calibration method refers to the position and posture relationship between the camera coordinate system and the flange coordinate system or the tool coordinate system. Among them, the first relative position and posture matrix T Laser is the relative pose matrix between the coordinate system of the laser weld tracker and the flange coordinate system of the robot. The coordinate system of the laser weld tracker is: a coordinate system created with the camera of the laser weld tracker as the origin.

[0032] The first pose matrix T, the first position matrix M, the first relative pose matrix T Laser Substitute the following formula to obtain the target position matrix K before collision:

[0033] Determine the target position matrix K according to the following formula:

[0034]

[0035] Among them, T is the first pose matrix of the robot end flange in the robot base coordinate system, T Laseris the first relative pose matrix between the coordinate system of the laser weld tracker and the flange coordinate system of the robot, and M is the first position matrix of the target intersection point formed by the intersection of the execution line fed back by the laser weld tracker and the marking line in the laser weld tracker coordinate system.

[0036] The target intersection is the intersection of the execution line (weld) and the marking line. The target position matrix K is the relative pose matrix of the target intersection in the robot's base coordinate system. The target position matrix K before the collision can be calculated by the formula get.

[0037] S130: After the robot collides, while keeping the postures of the robot end effector and the robot end flange in the base coordinate system unchanged, the position of the robot is moved multiple times in succession, so that the line laser emitted by the laser weld tracker coincides with the marking line multiple times in succession, and each time the coincidence occurs, the second posture matrix T of the robot end flange in the base coordinate system is recorded. i , the second position matrix M fed back by the laser weld tracker i , where i is an integer greater than or equal to 1, and i represents that the line laser emitted by the laser weld tracker currently coincides with the marking line for the i-th time.

[0038] After the robot collides, this embodiment moves the position of the robot four times in succession, keeping the posture of the robot's end effector and the robot's end flange in the base coordinate system unchanged during the movement, and only changes the position of the end effector through translation. The direction of the end effector translation can be: horizontal translation relative to the calibration plate, and / or translation in the direction away from / close to the calibration plate.

[0039] When the line laser emitted by the laser weld tracker coincides with the marking line for the first time, the second recording unit records the second posture matrix T1 and the second position matrix M1.

[0040] Among them, the second posture matrix T1 is the posture matrix of the robot end flange in the base coordinate system after the collision, and the second position matrix M1 is the position matrix of the target intersection feedback by the laser weld tracker in the laser weld tracker coordinate system after the collision.

[0041] When the line laser emitted by the laser weld tracker coincides with the marking line for the second time, the second posture matrix T2 and the second position matrix M2 are recorded.

[0042] Among them, the second posture matrix T2 is the posture matrix of the robot end flange in the base coordinate system after the collision, and the second position matrix M2 is the position matrix of the target intersection feedback by the laser weld tracker in the laser weld tracker coordinate system after the collision.

[0043] When the line laser emitted by the laser weld tracker coincides with the marking line for the third time, the second posture matrix T3 and the second position matrix M3 are recorded.

[0044] Among them, the second posture matrix T3 is the posture matrix of the robot end flange in the base coordinate system after the collision, and the second position matrix M3 is the position matrix of the target intersection feedback by the laser weld tracker in the laser weld tracker coordinate system after the collision.

[0045] When the line laser emitted by the laser weld tracker coincides with the marking line for the fourth time, the second posture matrix T4 and the second position matrix M4 are recorded.

[0046] Among them, the second posture matrix T4 is the posture matrix of the robot end flange in the base coordinate system after the collision, and the second position matrix M4 is the position matrix of the target intersection feedback by the laser weld tracker in the laser weld tracker coordinate system after the collision.

[0047] In other embodiments, while keeping the posture of the robot end effector and the robot end flange unchanged in the base coordinate system, the position of the robot end effector can be moved five times, six times, seven times, or more times in succession, so that the line laser emitted by the laser weld tracker coincides with the marking line multiple times in succession, and the corresponding second posture matrix T of the end effector is recorded. i , the second position matrix M fed back by the laser weld tracker i The calibration accuracy can be further improved by moving the machine multiple times and recording the relevant data.

[0048] S140: Based on the second posture matrix T recorded each time i , the second position matrix M i And the target position matrix K, the second relative pose matrix T′ between the coordinate system of the laser weld tracker and the flange coordinate system of the robot after the collision is obtained Laser .

[0049] After the robot collides, the position of the target intersection on the calibration plate remains unchanged, and is still the intersection of the execution line and the marking line. The target position matrix K of the target intersection remains unchanged. However, the position of the end effector and the position of the laser weld tracker change, and the relative pose matrix between the coordinate system of the laser weld tracker and the flange coordinate system of the robot changes, which is recorded as T′ Laser . T′ Laser is the second relative pose matrix T′ between the coordinate system of the laser weld tracker and the flange coordinate system of the robot after the collision Laser .

[0050] According to T1, T2, T3, T4 and M1, M2, M3, M4 recorded in step S130, and according to the formula of the target position matrix K in step S120, we get:

[0051]

[0052] in, make Substituting into formula ① and expanding it, we get:

[0053]

[0054] Then: R1*R′ Laser *M1+R1*P′ Laser +P1=K Formula⑤

[0055] Further, according to Similarly, we get:

[0056] R2*R′ Laser *M2+R2*P′ Laser +P2=K Formula ⑥

[0057] R3*R′ Laser *M3+R3*P′ Laser +P3=K Formula ⑦

[0058] R4*R′ Laser *M4+R4*P′ Laser +P4=K Formula⑧

[0059] Since in step S130, after the robot collides, the position of the robot is moved four times successively, and the posture of the robot end effector and the robot end flange in the base coordinate system is kept unchanged when the robot end effector is moved, so R1 = R2 = R3 = R4, and the following equation can be obtained by subtracting formulas ⑤, ⑥, ⑦, and ⑧ from each other:

[0060] R1*R′ Laser *(M2-M1)=P1-P2 Formula i

[0061] R1*R′ Laser *(M3-M2)=P2-P3 Formula ii

[0062] R1*R′ Laser *(M4-M3)=P3-P4 Formula iii

[0063] in, is the attitude matrix, which is obtained according to T1. M2-M1, P1-P2, M3-M2, P2-P3, M4-M3, P3-P4 can also be obtained by simple calculation. The above formula i, formula ii, formula iii are written as the equation relationship of AX=XB,

[0064] The optimal solution can be obtained by using the singular value decomposition method or the least squares method, and R′ can be obtained. Laser :

[0065]

[0066] in, is the inverse matrix of R1.

[0067] According to the formula K=T×T in step S120 Laser ×M to calculate the target position matrix K, and calculate R′ according to formula I Laser , K and R′ Laser Substitute into formula ⑤ to obtain P Laser :

[0068]

[0069] According to formula I and formula II, we can get:

[0070]

[0071] S150: Based on the first relative posture matrix T Laser And the second relative pose matrix T′ Laser , determine the change matrix ΔT.

[0072] The second relative pose matrix T′ between the coordinate system of the laser weld tracker and the robot end flange in the base coordinate system after the collision Laser , which can be considered as the first relative pose matrix T between the coordinate system of the laser weld tracker and the robot end flange in the base coordinate system before the collision Laser Multiply it by the change matrix ΔT to get:

[0073] T′ Laser =T Laser ×ΔT

[0074] From this we can obtain:

[0075]

[0076] in, T Laser The inverse matrix of .

[0077] S160: Based on the pose matrix T of the tool center point of the robot end effector in the flange coordinate system before the collision Tool And the change matrix ΔT, get the pose matrix T of the tool center point in the flange coordinate system after the collision Tool_new .

[0078] Due to ΔTTool ≈ΔT, we can get:

[0079] T Tool_new =T Tool ×ΔT

[0080] As can be seen from the above, the present application fixes the laser weld tracker and the robot end effector together so that the changes in the pose matrices of the two before and after the collision are the same. The change in the pose matrix of the tool center point of the robot end effector in the flange coordinate system can be derived by solving the change matrix of the laser weld tracker. The calibration of the laser weld tracker and the tool coordinate system can be completed by translating the robot four times. The method disclosed in the present application does not require the robot's posture to be changed during the calibration process. Only a simple translation operation is required to complete the calibration. Compared with the traditional calibration method, it is easier to operate. At the same time, it utilizes the high recognition accuracy of the laser weld tracker. Combined with the calculation algorithm disclosed in the present application, the calibration result is more accurate. Furthermore, the laser weld tracker belongs to the contactless recognition of welds, and the recognition efficiency is much higher than the contact positioning recognition, and the application scenarios are wider.

[0081] See also Figure 3 , Figure 3 It is a structural diagram of an implementation of a calibration device of the present application. The calibration device 100 includes a first recording unit 110, a first determining unit 120, a second recording unit 130, a second determining unit 140, a third determining unit 150 and a fourth determining unit 160.

[0082] The first recording unit 110 is used to record the first posture matrix T of the robot's end flange in the robot's base coordinate system and the first position matrix M fed back by the laser weld tracker when controlling the robot to move until the line laser emitted by the laser weld tracker coincides with the marking line on the calibration plate, wherein the laser weld tracker is fixedly mounted on the end of the robot's end effector, and an execution line and a marking line are provided on the calibration plate, wherein the marking line is perpendicular to the execution line, and the execution line is the execution trajectory of the robot's end effector, and the first position matrix M is the position matrix of the target intersection formed by the intersection of the execution line and the marking line fed back by the laser weld tracker in the laser weld tracker coordinate system.

[0083] The first determination unit 120 is connected to the first recording unit 110, and determines the first relative posture matrix T between the first posture matrix T, the first position matrix M, and the coordinate system of the laser weld tracker and the robot end flange in the base coordinate system of the robot. Laser , determine the target position matrix K of the target intersection in the robot's base coordinate system.

[0084] The second recording unit 130 is used to move the position of the robot multiple times after the robot collides, while keeping the postures of the robot end effector and the robot end flange in the base coordinate system unchanged, so that the line laser emitted by the laser weld tracker overlaps with the marking line multiple times, and record the second posture matrix T of the robot end flange in the base coordinate system each time they overlap. i , the second position matrix M fed back by the laser weld tracker i , where i is an integer greater than or equal to 1, and i indicates that the line laser emitted by the current laser weld tracker coincides with the marking line for the i-th time.

[0085] The second determination unit 140 is connected to the first determination unit 120 and the second recording unit 130, and is used to determine the second posture matrix T recorded each time. i , the second position matrix M i And the target position matrix K, the second relative pose matrix T′ between the coordinate system of the laser weld tracker and the flange coordinate system of the robot after the collision is obtained Laser .

[0086] The third determination unit 150 is connected to the first determination unit 120 and the second determination unit 140, and is used to determine the first relative position matrix T Laser And the second relative pose matrix T′ Laser , determine the change matrix ΔT.

[0087] The fourth determining unit 160 is connected to the third determining unit 150 and is used to determine the position matrix T of the tool center point of the robot end effector in the flange coordinate system before the collision. Tool And the change matrix ΔT, get the pose matrix T of the tool center point in the flange coordinate system after the collision Tool_new .

[0088] In some implementations, the first determining unit 120 is specifically configured to:

[0089] Determine the target pose matrix K according to the following formula:

[0090]

[0091] Among them, T is the first pose matrix of the robot end flange in the robot base coordinate system, T Laser is the first relative pose matrix between the coordinate system of the laser weld tracker and the flange coordinate system of the robot, and M is the first position matrix of the target intersection point formed by the intersection of the execution line fed back by the laser weld tracker and the marking line in the laser weld tracker coordinate system.

[0092] In some implementations, the second determining unit 140 is specifically configured to:

[0093] Determine the attitude matrix R′ according to the following formula Laser :

[0094]

[0095] Determine the position matrix P′ according to the following formula Laser :

[0096]

[0097] Determine the second relative pose matrix T′ according to the following formula Laser :

[0098]

[0099] in, T1, T2, T3, and T4 are the second pose matrices recorded when the line laser emitted by the laser weld tracker coincides with the marking line for the first, second, third, and fourth times after the robot collides, respectively. M1, M2, M3, and M4 are the second position matrices recorded when the line laser emitted by the laser weld tracker coincides with the marking line for the first, second, third, and fourth times after the robot collides, respectively. K is the target position matrix.

[0100] in, In the figure, the first column represents the component of the OX axis of the flange coordinate system of the robot in the three axis directions of the base coordinate system of the robot, which is called the unit principal vector; the second column represents the component of the OY axis of the flange coordinate system of the robot in the three axis directions of the base coordinate system of the robot; the third column represents the component of the OZ axis of the flange coordinate system of the robot in the three axis directions of the base coordinate system of the robot;

[0101] in, It represents the position of the center O of the flange coordinate system of the robot in the base coordinate system of the robot.

[0102] Among them, the calibration device 100 executes the calibration method in any of the above-mentioned implementation modes when working. The detailed calibration method can be found in the above-mentioned related content and will not be repeated here.

[0103] The calibration device 100 may specifically be any device with algorithm processing capability, such as a robot control cabinet, a computer, etc., and is not limited here.

[0104] See also Figure 4 , Figure 42 is a schematic diagram of the structure of an embodiment of a calibration device 200 of the present application. The calibration device 200 includes a processor 210 and a memory 220. The processor 210 is coupled to the memory 220. The memory 220 stores program data. The processor 210 implements the steps in any of the above-mentioned implementation methods by executing the program data in the memory 220. The detailed steps can be found in the above-mentioned implementations and will not be repeated here.

[0105] The calibration device 200 may be a robot control cabinet, and its specific structure is not limited herein.

[0106] See also Figure 5 , Figure 5 The computer-readable storage medium 300 stores a computer program 310, which can be executed by a processor to implement the steps in any of the above methods.

[0107] Among them, the computer-readable storage medium 300 can specifically be a device that can store the computer program 310, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, or it can also be a server that stores the computer program 310. The server can send the stored computer program 310 to other devices for execution, or it can also execute the stored computer program 310 by itself.

[0108] The above description is only an embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A calibration method, characterized in that: The method comprises: When the robot end effector is controlled to move until the line laser emitted by the laser weld tracker coincides with the marking line on the calibration plate, the first position matrix T of the robot end flange in the robot base coordinate system and the first position matrix M fed back by the laser weld tracker are recorded, wherein the laser weld tracker is fixedly mounted on the robot end effector, the calibration plate is provided with an execution line and the marking line, the marking line is perpendicular to the execution line, the execution line is the execution trajectory of the robot end effector, and the first position matrix M is the position matrix of the target intersection formed by the intersection of the execution line and the marking line fed back by the laser weld tracker in the laser weld tracker coordinate system; According to the first posture matrix T, the first position matrix M and the first relative posture matrix T between the coordinate system of the laser weld tracker and the flange coordinate system of the robot Laser , determine the target position matrix K of the target intersection in the base coordinate system of the robot; After the robot end effector collides, while keeping the postures of the robot end effector and the robot end flange in the base coordinate system unchanged, the position of the robot is moved multiple times in succession, so that the line laser emitted by the laser weld tracker overlaps with the marking line multiple times in succession, and at each overlap, the second posture matrix T of the robot end flange in the base coordinate system is recorded. i , the second position matrix M fed back by the laser weld tracker i , where i is an integer greater than or equal to 1, and i represents that the line laser emitted by the laser weld tracker currently coincides with the marking line for the i-th time; According to the second pose matrix T recorded each time i , the second position matrix M i and the target position matrix K, and obtain the second relative position matrix T′ between the coordinate system of the laser weld tracker and the flange coordinate system of the robot after the collision Laser ; According to the first relative pose matrix T Laser And the second relative pose matrix T′ Laser , determine the change matrix ΔT; According to the pose matrix of the tool center point of the robot end effector in the flange coordinate system before the collision and the change matrix, the pose matrix of the tool center point in the flange coordinate system after the collision is obtained.

2. The method according to claim 1, characterized in that According to the first relative posture matrix T Laser And the second relative pose matrix T′ Laser , the step of determining the change matrix ΔT comprises: The change matrix ΔT is determined according to the following formula: in, is the inverse matrix of the first relative pose matrix, and T′Laser is the second relative pose matrix.

3. The method according to claim 1, characterized in that The step of obtaining the pose matrix of the tool center point of the robot end effector in the flange coordinate system after the collision according to the pose matrix of the tool center point in the flange coordinate system before the collision and the change matrix comprises: Determine the pose matrix T of the tool center point of the robot end effector in the flange coordinate system after the collision according to the following formula Tool_new : T Tool_new =T Tool ×ΔT Among them, T Tool is the pose matrix of the tool center point of the robot end effector in the flange coordinate system before the collision, and ΔT is the change matrix.

4. The method according to claim 1, characterized in that: The first relative posture matrix T between the first posture matrix T, the first position matrix M, and the coordinate system of the laser weld tracker and the flange coordinate system of the robot Laser , the step of determining the target position matrix K of the target intersection point in the base coordinate system of the robot comprises: The target position matrix K is determined according to the following formula: Wherein, T is the first pose matrix of the robot end flange in the robot base coordinate system, T Laser is the first relative pose matrix between the coordinate system of the laser weld tracker and the flange coordinate system of the robot, and M is the first position matrix of the target intersection point formed by the intersection of the execution line and the marking line fed back by the laser weld tracker in the laser weld tracker coordinate system.

5. The method according to claim 1, characterized in that The second posture matrix T recorded each time i , the second position matrix M i and the target position matrix K, and obtain the second relative position matrix T′ between the coordinate system of the laser weld tracker and the flange coordinate system of the robot after the collision Laser The steps include: Determine the attitude matrix R′ according to the following formula Laser : Determine the position matrix P′ according to the following formula Laser : Determine the second relative pose matrix T′ according to the following formula Laser : in, T1, T2, T3, and T4 are respectively the second pose matrices recorded when the line laser emitted by the laser weld tracker coincides with the marking line for the first, second, third, and fourth times after the robot collides, M1, M2, M3, and M4 are respectively the second position matrices recorded when the line laser emitted by the laser weld tracker coincides with the marking line for the first, second, third, and fourth times after the robot collides, and K is the target position matrix; in, In the figure, the first column represents the component of the OX axis of the flange coordinate system of the robot in the three axis directions of the base coordinate system of the robot, which is called the unit principal vector; the second column represents the component of the OY axis of the flange coordinate system of the robot in the three axis directions of the base coordinate system of the robot; the third column represents the component of the OZ axis of the flange coordinate system of the robot in the three axis directions of the base coordinate system of the robot; in, It represents the position of the center O of the flange coordinate system of the robot in the base coordinate system of the robot.

6. A calibration device, characterized in that: include: A first recording unit is used to record the first position matrix T of the robot end flange in the robot base coordinate system and the first position matrix M fed back by the laser weld tracker when the robot is controlled to move until the line laser emitted by the laser weld tracker coincides with the marking line on the calibration plate, wherein the laser weld tracker is fixedly mounted on the robot end effector, the calibration plate is provided with an execution line and the marking line, the marking line is perpendicular to the execution line, the execution line is the execution trajectory of the robot end effector, and the first position matrix M is the position matrix of the target intersection formed by the intersection of the execution line and the marking line fed back by the laser weld tracker in the laser weld tracker coordinate system; A first determination unit is connected to the first recording unit, and determines a first relative posture matrix T between the coordinate system of the laser weld tracker and the flange coordinate system of the robot according to the first posture matrix T, the first position matrix M, and the first relative posture matrix T between the coordinate system of the laser weld tracker and the flange coordinate system of the robot. Laser , determine the target position matrix K of the target intersection in the base coordinate system of the robot; The second recording unit is used to move the position of the robot multiple times after the robot end effector collides, while keeping the postures of the robot end effector and the robot end flange in the base coordinate system unchanged, so that the line laser emitted by the laser weld tracker overlaps with the marking line multiple times, and record the second posture matrix T of the robot end flange in the base coordinate system each time the two overlap. i , the second position matrix M fed back by the laser weld tracker i , where i is an integer greater than or equal to 1, and i represents that the line laser emitted by the laser weld tracker currently coincides with the marking line for the i-th time; A second determining unit, connected to the first determining unit and the second recording unit, is used to determine the second posture matrix T recorded each time. i , the second position matrix M i and the target position matrix P, and obtain the second relative position matrix T′ between the coordinate system of the laser weld tracker and the flange coordinate system of the robot after the collision Laser ; A third determining unit is connected to the first determining unit and the second determining unit, and is used to determine the relative position matrix T according to the first relative position matrix T Laser And the second relative pose matrix T′ Laser , determine the change matrix ΔT; The fourth determination unit is connected to the third determination unit and is used to obtain the pose matrix of the tool center point in the flange coordinate system after the collision based on the pose matrix of the tool center point of the robot end effector in the flange coordinate system before the collision and the change matrix.

7. The calibration device according to claim 6, characterized in that: The first determining unit is specifically configured to: Determine the target position matrix K according to the following formula: Wherein, T is the first pose matrix of the robot end flange in the robot base coordinate system, T Laser is the first relative pose matrix between the coordinate system of the laser weld tracker and the flange coordinate system of the robot, and M is the first position matrix of the target intersection point formed by the intersection of the execution line and the marking line fed back by the laser weld tracker in the laser weld tracker coordinate system.

8. The calibration device according to claim 6, characterized in that: The second determining unit is specifically configured to: Determine the attitude matrix R′ according to the following formula Laser : Determine the position matrix P′ according to the following formula Laser : Determine the second relative pose matrix T′ according to the following formula Laser : in, T1, T2, T3, and T4 are respectively the second pose matrices recorded when the line laser emitted by the laser weld tracker coincides with the marking line for the first, second, third, and fourth times after the robot collides, M1, M2, M3, and M4 are respectively the second position matrices recorded when the line laser emitted by the laser weld tracker coincides with the marking line for the first, second, third, and fourth times after the robot collides, and K is the target position matrix; in, In the figure, the first column represents the component of the OX axis of the flange coordinate system of the robot in the three axis directions of the base coordinate system of the robot, which is called the unit principal vector; the second column represents the component of the OY axis of the flange coordinate system of the robot in the three axis directions of the base coordinate system of the robot; the third column represents the component of the OZ axis of the flange coordinate system of the robot in the three axis directions of the base coordinate system of the robot; in, It represents the position of the center O of the flange coordinate system of the robot in the base coordinate system of the robot.

9. A calibration device, characterized in that: The calibration device includes a processor and a memory, the processor is coupled to the memory, program data is stored in the memory, and the processor implements the steps in the method according to any one of claims 1 to 5 by executing the program data in the memory.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program can be executed by a processor to implement the steps in the method according to any one of claims 1 to 5.

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