A pose calibration method for a multi-robot spatial measurement system

Abstract

Embodiments of the present application disclose a pose calibration method for a multi-robot space measurement system. In a specific embodiment, the method comprises establishing a measurement platform coordinate system; establishing a transmitting and receiving device coordinate system, a first and a second pose measurer coordinate system; establishing a laser tracker coordinate system, obtaining a first to third coordinate conversion relationship; establishing a first and a second robot coordinate system, obtaining a first and a second robot default tool coordinate, calculating a fourth and a fifth coordinate conversion relationship; obtaining a sixth to ninth coordinate conversion relationship, performing user coordinate calibration according to the first to ninth coordinate conversion relationship, and performing tool coordinate calibration; controlling the tool coordinate of the robot to make a specified trajectory motion in the measurement platform coordinate system; obtaining a tenth and an eleventh coordinate conversion relationship, calculating the actual pose of the robot according to the first to eleventh coordinate conversion relationship, and performing pose deviation compensation according to the deviation between the actual pose of the robot and the theoretical pose of the robot.

Description

Technical Field

[0001] This invention relates to the field of robot calibration methods. More specifically, it relates to a pose calibration method for a multi-robot spatial measurement system. Background Technology

[0002] Currently, most space measurement systems employ traditional mechanical structures. Due to the high precision required for machining and control, assembly errors between components are a major factor affecting the pose accuracy of the space measurement system, and the pose error of the assembled system is difficult to assess. Furthermore, with increasing frequencies, the requirements for the positioning accuracy of space measurement systems are not only higher, but also for accurate and convenient assessment of their overall pose error. Robots, with their advantages of high repeatability, calibrability, flexibility, high automation, and easy expansion, can achieve closed-loop calibration using laser trackers. This not only improves positioning accuracy but also facilitates convenient and accurate assessment of pose error.

[0003] Robot calibration is a prerequisite for accurate motion control and trajectory. The calibration process involves accurately determining the tool coordinates and user coordinates. The robot's tool central point (TCP) is the center of the endjoint by default. In the tool coordinate system, the TCP coordinates are (0, 0, 0, 0, 0, 0). However, in practical applications, various tooling fixtures are often installed at the robot's end effector to complete different tasks. Determining the coordinates of the new TCP point in the tool coordinate system and moving the robot's default TCP point to the transceiver (new TCP point) is called tool coordinate calibration. Furthermore, establishing user coordinates facilitates accurate robot trajectory control. Therefore, establishing appropriate user coordinates greatly simplifies complex motion control problems in the robot's base coordinate system and improves positioning accuracy. The process of establishing the user coordinate system is called user coordinate calibration.

[0004] The motion control and positioning accuracy of robots are closely related to calibration methods, especially when two or more robots work together. Collaborative calibration of robots is a prerequisite for ensuring spatial positioning accuracy. When using robots to build a spatial measurement system, the transformation and unification between multiple coordinate systems are crucial for high-precision calibration of tool coordinates and user coordinates, and accurate control of motion trajectories. Therefore, there is an urgent need to propose a calibration method for multi-robot spatial measurement systems to achieve collaborative calibration and closed-loop control of multiple robots. This method can not only improve the positioning accuracy of spatial pose but also facilitate accurate assessment of spatial pose errors, and can be extended to various types of spatial measurement systems. Summary of the Invention

[0005] The purpose of this invention is to provide a pose calibration method for a multi-robot spatial measurement system to solve at least one of the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of the present invention provides a pose calibration method for a multi-robot spatial measurement system, the method comprising:

[0008] Establish the coordinate system of the measurement platform;

[0009] Establish the coordinate system of the transmitting device, the coordinate system of the first attitude measuring device, the coordinate system of the receiving device, and the coordinate system of the second attitude measuring device;

[0010] Establish the coordinate system of the laser tracker and obtain the first coordinate transformation relationship, the second coordinate transformation relationship, and the third coordinate transformation relationship;

[0011] Establish the first robot coordinate system and the second robot coordinate system, obtain the default tool coordinates of the first robot and the second robot, and calculate the fourth coordinate transformation relationship and the fifth coordinate transformation relationship;

[0012] Obtain the sixth, seventh, eighth, and ninth coordinate transformation relationships; calculate the robot's user coordinates based on the first to the ninth coordinate transformation relationships and perform user coordinate calibration.

[0013] Calculate the robot's tool coordinates based on the first coordinate transformation relationship to the ninth coordinate transformation relationship and perform tool coordinate calibration;

[0014] The tool coordinates of the robot are controlled to move along a specified trajectory in the coordinate system of the measurement platform.

[0015] Obtain the tenth coordinate transformation relationship and the eleventh coordinate transformation relationship, calculate the actual pose of the robot based on the first coordinate transformation relationship to the eleventh coordinate transformation relationship, and perform pose deviation compensation based on the deviation between the actual pose of the robot and the theoretical pose of the robot.

[0016] Optionally, it is characterized in that,

[0017] The first coordinate transformation relationship is the transformation relationship between the coordinate system of the measurement platform and the coordinate system of the laser tracker;

[0018] The second coordinate transformation relationship is the positional relationship between the coordinate system of the launching device and the coordinate system of the first pose measuring device;

[0019] The third coordinate transformation relationship is the positional relationship between the receiving device coordinate system and the second pose measuring device coordinate system.

[0020] Optionally, it is characterized in that,

[0021] The fourth coordinate transformation relationship is the positional relationship between the first pose measuring device coordinate system and the first robot default tool coordinate system;

[0022] The fifth coordinate transformation relationship is the positional relationship between the second pose measuring device coordinate system and the second robot default tool coordinate system.

[0023] Optionally, it is characterized in that,

[0024] The sixth coordinate transformation relationship is the transformation relationship between the default tool coordinates of the first robot under any pose and the first robot coordinate system;

[0025] The seventh coordinate transformation relationship is the transformation relationship between the default tool coordinates of the second robot and the coordinate system of the second robot under any pose;

[0026] The eighth coordinate transformation relationship is the transformation relationship between the first pose measuring device coordinate system and the laser tracker coordinate system;

[0027] The ninth coordinate transformation relationship is the transformation relationship between the second pose measuring device coordinate system and the laser tracker coordinate system.

[0028] Optionally, the step of calculating the robot's user coordinates based on the first coordinate transformation relationship to the ninth coordinate transformation relationship and performing user coordinate calibration includes...

[0029] The user coordinates of the first robot are calculated and the user coordinates of the first robot are calibrated based on the sixth coordinate transformation relationship, the eighth coordinate transformation relationship, the first coordinate transformation relationship and the fourth coordinate transformation relationship.

[0030] The user coordinates of the second robot are calculated and calibrated based on the seventh coordinate transformation relationship, the ninth coordinate transformation relationship, the first coordinate transformation relationship, and the fifth coordinate transformation relationship.

[0031] Optionally, the step of calculating the robot's tool coordinates based on the first coordinate transformation relationship to the ninth coordinate transformation relationship and performing tool coordinate calibration includes...

[0032] Calculate the tool coordinates of the first robot based on the fourth coordinate transformation relationship and the second coordinate transformation relationship, and then calibrate the tool coordinates of the first robot.

[0033] The tool coordinates of the second robot are calculated and calibrated based on the fifth coordinate transformation relationship and the third coordinate transformation relationship.

[0034] Optionally, the tenth coordinate transformation relationship is the pose relationship between the first pose measuring device coordinate system and the measuring platform coordinate system.

[0035] The eleventh coordinate transformation relationship is the pose relationship between the second pose measuring device coordinate system and the measuring platform coordinate system.

[0036] Optionally, calculating the robot's actual pose based on the first coordinate transformation relationship to the eleventh coordinate transformation relationship includes...

[0037] The actual pose of the first robot is calculated based on the second coordinate transformation relationship and the tenth coordinate transformation relationship;

[0038] The actual pose of the second robot is calculated based on the eleventh coordinate transformation relationship and the third coordinate transformation relationship.

[0039] Optionally, the pose deviation compensation based on the deviation between the robot's actual pose and its theoretical pose includes...

[0040] A new target pose is generated based on the deviation between the actual pose and the theoretical pose of the first robot, and the tool coordinate motion of the first robot is controlled in the coordinate system of the measurement platform to compensate for the pose deviation of the first robot.

[0041] A new target pose is generated based on the deviation between the actual pose and the theoretical pose of the second robot, and the tool coordinate motion of the second robot is controlled in the coordinate system of the measurement platform to compensate for the pose deviation of the second robot.

[0042] Optionally, the tool coordinates of the controlled robot move along a specified trajectory in the coordinate system of the measurement platform, including...

[0043] The tool coordinates of the first robot are controlled to move in a semi-circular trajectory pointing towards the center of the circle within the coordinate system of the measurement platform with a preset radius and a preset incident angle;

[0044] The tool coordinates of the second robot are controlled to move in a semi-circular trajectory pointing towards the center of the circle within the coordinate system of the measurement platform, with a preset radius and a preset incident angle; wherein...

[0045] The preset radius ranges from 0 mm to 1000 mm; the preset incident angle ranges from 0° to 45°.

[0046] The beneficial effects of this invention are as follows:

[0047] This invention provides a pose calibration method for a multi-robot spatial measurement system, which enables collaborative calibration and closed-loop control of multiple robots. It not only improves the positioning accuracy of spatial pose but also facilitates accurate evaluation of spatial pose errors. This invention solves the calibration problem of multi-robot spatial measurement systems, improves positioning accuracy, and can be extended to various forms of spatial measurement systems. Attached Figure Description

[0048] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0049] Figure 1 A schematic diagram of the structure of the dual-robot space measurement system provided in an embodiment of the present invention is shown.

[0050] Figure 2 This diagram illustrates the establishment of the coordinate system of the measurement platform in the pose calibration method of the multi-robot spatial measurement system provided in an embodiment of the present invention.

[0051] Figure 3 This diagram illustrates the coordinate system of the laser tracker fitting measurement platform in the pose calibration method of the multi-robot spatial measurement system provided in an embodiment of the present invention.

[0052] Figure 4 This diagram illustrates the establishment of the launch device coordinate system in the pose calibration method of the multi-robot spatial measurement system provided in an embodiment of the present invention.

[0053] Figure 5 This diagram illustrates the coordinate system of the laser tracker fitting the emission device in the pose calibration method of the multi-robot spatial measurement system provided in an embodiment of the present invention.

[0054] Figure 6 This diagram illustrates the three-position method in the pose calibration method of the multi-robot spatial measurement system provided in an embodiment of the present invention.

[0055] Figure 7 This diagram illustrates the robot control connection in the pose calibration method of the multi-robot spatial measurement system provided in an embodiment of the present invention.

[0056] Figure 8 This diagram illustrates the real-time compensation process in the pose calibration method of the multi-robot spatial measurement system provided in an embodiment of the present invention.

[0057] Figure 9 The diagram shows a test image of the measurement platform in the pose calibration method of the multi-robot spatial measurement system provided in an embodiment of the present invention.

[0058] Figure 10This diagram illustrates the phase center test diagram of the antenna horn in the transmitting device during the pose calibration method of the multi-robot spatial measurement system provided in this embodiment of the invention.

[0059] Figure 11 This diagram illustrates the establishment of the first robot coordinate system in the pose calibration method of the multi-robot spatial measurement system provided in an embodiment of the present invention.

[0060] Figure 12 This diagram illustrates the establishment of a second robot coordinate system in the pose calibration method of a multi-robot spatial measurement system provided in an embodiment of the present invention.

[0061] Figure 13 This diagram illustrates the relationship between coordinates and incident angle in the pose calibration method of a multi-robot spatial measurement system provided in an embodiment of the present invention.

[0062] Figure 14 This diagram illustrates the control trajectory in the pose calibration method of the multi-robot spatial measurement system provided in an embodiment of the present invention.

[0063] Figure 15 The diagram shows a schematic of the spatial measurement system structure, including a control cabinet, in the pose calibration method of the multi-robot spatial measurement system provided in an embodiment of the present invention. Detailed Implementation

[0064] To more clearly illustrate the present invention, the following description, in conjunction with embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0065] The motion control and positioning accuracy of robots are closely related to calibration methods, especially when two or more robots work together. Cooperative calibration of robots is a prerequisite for ensuring spatial positioning accuracy. When using robots to build a spatial measurement system, the transformation and unification between multiple coordinate systems are crucial for high-precision calibration of tool coordinates and user coordinates, and accurate control of motion trajectories. Therefore, how to achieve cooperative calibration and closed-loop control of multiple robots, which can not only improve the positioning accuracy of spatial pose but also facilitate accurate assessment of spatial pose errors and expand its application to various types of spatial measurement systems, is an urgent problem to be solved.

[0066] In view of this, one embodiment of the present invention provides a pose calibration method for a multi-robot spatial measurement system. The method includes: establishing a measurement platform coordinate system; establishing a transmitter coordinate system, a first pose measuring device coordinate system, a receiver coordinate system, and a second pose measuring device coordinate system; establishing a laser tracker coordinate system and obtaining a first coordinate transformation relationship, a second coordinate transformation relationship, and a third coordinate transformation relationship; establishing a first robot coordinate system and a second robot coordinate system, obtaining the first robot default tool coordinates and the second robot default tool coordinates, and calculating a fourth coordinate transformation relationship and a fifth coordinate transformation relationship; obtaining a sixth coordinate transformation relationship, a seventh coordinate transformation relationship, an eighth coordinate transformation relationship, and a ninth coordinate transformation relationship; calculating the robot's user coordinates based on the first coordinate transformation relationship to the ninth coordinate transformation relationship and performing user coordinate calibration; calculating the robot's tool coordinates based on the first coordinate transformation relationship to the ninth coordinate transformation relationship and performing tool coordinate calibration; controlling the robot's tool coordinates to move along a specified trajectory in the measurement platform coordinate system; obtaining a tenth coordinate transformation relationship and an eleventh coordinate transformation relationship; calculating the robot's actual pose based on the first coordinate transformation relationship to the eleventh coordinate transformation relationship; and performing pose deviation compensation based on the deviation between the robot's actual pose and its theoretical pose.

[0067] In a specific example, the space measurement system includes a laser tracker, a measurement platform, a first robot, a second robot, a transmitter connected to the first robot, a first pose measuring device connected to the transmitter, a receiver connected to the second robot, and a second pose measuring device connected to the receiver.

[0068] In a specific example, the main tasks include establishing the coordinate system of the measurement platform, establishing the coordinate system of the transmitter and receiver, coordinate transformation, multi-robot tool coordinate calibration, multi-robot user coordinate calibration, multi-robot motion trajectory control, and real-time compensation of robot target pose, thus realizing the calibration of a multi-robot-based spatial measurement system.

[0069] In a specific example, such as Figure 1As shown, the system comprises one measurement platform, two robots, one transceiver set (i.e., transmitter and receiver), one laser tracker, and two pose measuring devices (T-mac1 and T-mac2). The calibration process involves unifying and transforming the coordinates of the measurement platform, the base coordinates of robot 1 (the first robot), the base coordinates of robot 2 (the second robot), the coordinates of the transmitter (the transmitter), the coordinates of the receiver (the receiver), the coordinates of the first pose measuring device T-mac1 and the second pose measuring device T-mac2, and the coordinates of the laser tracker. This yields the robot's tool coordinates and user coordinates, using the measurement platform coordinate system as a reference and the transmitter and receiver coordinates as control points. This completes the robot tool coordinate calibration and user coordinate calibration. The tool coordinate points are controlled to move along a trajectory within the user coordinate system. The transmitter and receiver are monitored by repeatedly acquiring the T-mac1 and T-mac2 coordinates (e.g., using the measurement platform as the coordinate system) in real time, and the deviation from the target pose is compensated in real time until the current pose error meets the requirements.

[0070] In a specific example, such as Figure 2 and Figure 3 As shown, the measurement platform serves as the coordinate system reference for this space measurement system, and measurements are performed using a laser tracker and a 0.5' target sphere. Assuming the upper surface of the measurement platform is square, the specific steps are as follows: Two points are selected on each side of the measurement platform (e.g., usually the two ends), and measurements are taken using the laser tracker, resulting in a total of 8 coordinate points. These 8 points determine 4 straight lines, which in turn determine 4 intersection points. These 4 intersection points determine two intersecting lines, thus defining a plane and an intersection point. The intersection point is the origin of the test platform's coordinate system, the plane is the XOY plane, and the normal is the Z-axis. This coordinate system is defined as the measurement platform coordinate system S. W .

[0071] In a specific example, if the measuring platform has other shapes, a similar method can be used to measure and obtain the coordinate system of the plane on which the measuring platform is located.

[0072] In a specific example, consider a dual-robot bow-shaped spatial measurement system. This system consists of Robot 1 (Yaskawa MOTOMAN-MH24), Robot 2 (Yaskawa MOTOMAN-MH24), a template support (e.g., a measurement platform containing a calibration metal plate), a transmitting antenna (e.g., a 20dB standard gain horn antenna), a receiving antenna (e.g., a 20dB standard gain horn antenna), a Leica AT960 laser tracker, T-mac1 and T-mac2, a computer, and an Ethernet switch.

[0073] Furthermore, such as Figure 9As shown, a Laser Tracker and a 0.5-inch (0.5') target ball were used to measure the template support. Two points were selected at each end of the four sides of the metal plate of the template support (i.e., the measurement platform), and the laser tracker was used for measurement. The coordinate set (CSPT) was obtained with the laser tracker coordinates as a reference, including 8 coordinate points: P1(x, y, z) = (3184.84mm, -2379.26mm, -364.81mm), P2(x, y, z) = (3276.82mm, -2265.33mm, -363.82mm), P3(x, y, z) = (3282.45mm, -2242.50mm, -363.64mm), P4(x, y, z) = (3282.45mm, -2242.50mm, -363.64mm), P5(x, y, z) = (3282.45mm, -2242.50mm, -363.64mm), P6(x, y, z) = (3282.45mm, -2242.50mm, -363.64mm), P4(x, y, z) = (3282.45mm, -2242.50mm, -363.64mm), P5 ... , z) = (3168.45mm, -2150.28mm, -363.03mm), P5 (x, y, z) = (3133.25mm, -2156.35mm, -363.13mm), P6 (x, y, z) = (3051.77mm, -22 57.09mm, -364.01mm), P7 (x, y, z) = (3049.14mm, -2285.53mm, -364.25mm), P8 (x, y, z) = (3164.31mm, -2378.67mm, -364.84mm).

[0074] Furthermore, using the "Create Line" function in the laser tracker's software (Spatial Analyzer, SA), four straight lines were fitted. These four lines intersected to obtain four intersection points. Two intersecting lines were then fitted to each of these four intersection points. The plane containing these two intersecting lines is the template support plane, denoted as the XOY plane. The intersection point of the two intersecting lines is the center point of the template support, denoted as O. The normal direction is the Z-axis. This coordinate system is defined as S. W .

[0075] Specifically, S W for

[0076]

[0077] In a specific example, the transceiver device includes a transmitter and a receiver, fixed to the flange ends of robot 1 and robot 2 respectively, serving as the tool coordinates (i.e., TCP points) for the actual robot control. The transmitter and receiver fixtures respectively hold the first pose measuring device T-mac1 and the second pose measuring device T-mac2. A laser tracker and a 0.5' target ball are used to measure the transmitter and receiver. Assuming the transmitter and receiver are rectangular horns, the specific steps are as follows: Select two points on each side of the transmitter's horn opening (e.g., usually the two ends), and use the laser tracker to measure, obtaining a total of 8 coordinate points. These 8 points can determine 4 straight lines, which in turn determine 4 intersection points. These 4 intersection points determine two intersecting lines, which in turn determine a plane and an intersection point. The intersection point is the origin of the transmitter's coordinate system, the plane is the X1O1Y1 plane, and the normal is the Z1 axis. This coordinate system is defined as the transmitter coordinate system (i.e., the transmitter device coordinate system), denoted as S. TX1 ,like Figure 4 and Figure 5 As shown.

[0078] In a specific example, while keeping the transmitting robot 1 stationary, the coordinate system of the first pose measuring device is obtained by measuring the transmitting T-mac1 using a laser tracker, denoted as S. TM1 .

[0079] In a specific example, the receiving end coordinate system (i.e., the receiving device coordinate system) is similarly obtained, denoted as S. TX2 The receiver's T-mac2 coordinate system (i.e., the second pose measuring device coordinate system) is denoted as S. TM2 .

[0080] In a specific example, if the transmitter and receiver are of other shapes, a similar method can be used to measure and obtain the transmitter coordinate system and receiver coordinate system.

[0081] In a specific example, such as Figures 10-12As shown, the transceiver device of the arc-shaped spatial measurement system includes a transmitting antenna and a receiving antenna. A Laser tracker and a 0.5′ target sphere are used to measure the transmitting and receiving antennas. Robot 1 is connected to the transmitting antenna. Two points are selected on each side of the antenna's horn (e.g., usually the two ends). Using the coordinate system of the template support measurement platform as a reference, the laser tracker is used for measurement. Starting from the lower left of the horn, the measurement proceeds clockwise to obtain the coordinate set (LBK1), which includes eight coordinate points: P1(x, y, z) = (-135.77mm, 475.57mm, 632.26mm), P2(x, y, z) = (-130.21mm, 477.44mm, 644.80mm), P3(x, y, z) = (-129.42mm, 484.4 ... 5mm, 651.56mm), P4 (x, y, z) = (-132.13mm, 491.86mm, 651.69mm), P5 (x, y, z) = (-136.97mm, 496.75mm, 645.77mm), P6 (x, y, z) = (-1 43.14mm, 494.70mm, 631.99mm), P7 (x, y, z) = (-143.15mm, 487.89mm, 625.72mm), P8 (x, y, z) = (-140.79mm, 480.45mm, 625.69mm).

[0082] Furthermore, these eight points determine four straight lines, which in turn determine four intersection points. These four intersection points define two intersecting lines, which in turn define a plane and the intersection point. The intersection point is the geometric center of the transmitting antenna, the plane is the X1O1Y1 plane, and the normal is the Z1 axis. This coordinate system is the transmitting antenna coordinate system, denoted as S. TX1 .

[0083] Specifically, S TX1 for

[0084]

[0085] In a specific example, while keeping robot 1 stationary, the coordinates of T-mac1 are measured using a laser tracker with reference to the coordinate system of the template support measurement platform, denoted as S. TM1 .

[0086] Specifically, S TM1 for

[0087]

[0088] In a specific example, according to the above method, with the template support measurement platform coordinate system as the reference, starting from the first point at the upper right of the receiving antenna horn mouth and measuring counterclockwise, a coordinate set (LBK2) group is obtained, and 8 coordinate points are obtained, which are respectively P1(x, y, z) = (398.77mm, 705.00mm, 898.82mm), P2(x, y, z) = (400.13mm, 711.93mm, 911.82mm), P3(x, y, z) = (396.63mm, 710.79mm, 920.66mm), P4(x, y, z) = (392.37mm, 706.13mm, 923.60mm), P5(x, y, z) = (387.54mm, 697.62mm, 919.35mm), P6(x, y, z) = (386.47mm, 692.17mm, 909.30mm), P7(x, y, z) = (389.67mm, 692.49mm, 898.67mm), P8(x, y, z) = (394.17mm, 697.51mm, 895.58mm).

[0089] Further, establish the receiving antenna coordinates, denoted as S TX2 .

[0090] Specifically, S TX2 is

[0091]

[0092] Further, the T-mac2 coordinates, denoted as S TM2 .

[0093] Specifically, S TM2 is

[0094]

[0095] In a possible implementation manner, the first coordinate conversion relationship is the conversion relationship of the measurement platform coordinate system relative to the laser tracker coordinate system; the second coordinate conversion relationship is the position relationship of the transmitting device coordinate system relative to the first pose measurement device coordinate system; the third coordinate conversion relationship is the position relationship of the receiving device coordinate system relative to the second pose measurement device coordinate system.

[0096] In a specific example, with the laser tracker as the reference coordinate system, the conversion relationship of the measurement platform coordinate system W relative to the laser tracker coordinate system LT is directly obtained through the SA software supporting the laser tracker, denoted as That is, the first coordinate conversion relationship.

[0097] Further, since S WThe coordinates were obtained with reference to the laser tracker's coordinate system, therefore

[0098] Specifically, for

[0099]

[0100] In a specific example, using the transmitter T-mac1 as the reference coordinate system, the positional relationship between the transmitter coordinate system TX1 and the transmitter T-mac1 TM1 is directly obtained through the SA software accompanying the laser tracker, denoted as... That is, the second coordinate transformation relationship.

[0101] Specifically, for

[0102]

[0103] In a specific example, using the receiver T-mac2 as the reference coordinate system, the positional relationship between the receiver coordinate system TX2 and the receiver T-mac2 TM2 is directly obtained using the SA software accompanying the laser tracker, denoted as... That is, the third coordinate transformation relationship.

[0104] Specifically, for

[0105]

[0106] In one possible implementation, the fourth coordinate transformation relationship is the positional relationship of the first pose measuring device coordinate system relative to the first robot default tool coordinate system; the fifth coordinate transformation relationship is the positional relationship of the second pose measuring device coordinate system relative to the second robot default tool coordinate system.

[0107] In a specific example, the relationship between the T-mac and the robot's default tool coordinates is solved using a three-dimensional pose method. like Figure 6 As shown.

[0108] In a specific example, first, set the position and orientation of the robot 1 tool coordinate system to 0; select "Set tool coordinates"; move to any three poses, and using the laser tracker coordinate system as a reference, measure the T-mac1 coordinates through the laser tracker, denoted as the first pose measurement coordinate system under the first pose. The coordinate system of the first pose measuring device in the second pose The first pose measuring device coordinate system in the third pose Simultaneously, the pose of the flange end in the robot's base coordinate system is read in three different pose states, and these poses are recorded as the coordinate system of the flange end in the first pose. Coordinate system of the end flange in the second pose Coordinate system of the end flange in the third pose

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115] In a specific example, taking the T-mac1 coordinates measured in the first pose as a reference, the transformation relationship of the second pose relative to the first pose is directly obtained through the SA software supporting the laser tracker, that is

[0116] Specifically, is

[0117]

[0118] In a specific example, taking the T-mac1 coordinates measured in the second pose as a reference, the transformation relationship of the third pose relative to the second pose is directly obtained through the SA software supporting the laser tracker, that is

[0119] Specifically, is

[0120]

[0121] In a specific example, calculate the transformation relationship of the end flange coordinates of the second pose relative to the first pose according to the following formula.

[0122]

[0123] In a specific example, calculate the transformation relationship of the end flange coordinates of the third pose relative to the second pose according to the following formula.

[0124]

[0125] Furthermore, according to the principle of the three-pose method, it can be known that

[0126]

[0127] In the formula, This refers to the positional relationship between the transmitter T-mac1 and the robot 1's default tool coordinates. E represents the positional relationship between the receiver T-mac2 and the default tool coordinates of robot 2; E is the identity matrix.

[0128] Furthermore, to obtain

[0129]

[0130]

[0131] Furthermore, based on the above two equations, the positional relationship between the transmitter T-mac1 and the robot 1's default tool coordinates can be obtained. This is the fourth coordinate transformation relationship. for

[0132]

[0133] In a specific example, the positional relationship between the receiver T-mac2 and the robot 2's default tool coordinates can be obtained similarly.

[0134] In a specific example, using the template support measurement platform coordinate system as a reference, the positional relationship of T-mac2 relative to the robot's default tool coordinates can be obtained, denoted as...

[0135] Furthermore, the specific data for each step of the receiving antenna process are as follows:

[0136]

[0137]

[0138]

[0139]

[0140]

[0141]

[0142]

[0143]

[0144] Furthermore, the fifth coordinate transformation relationship for

[0145]

[0146] In a possible implementation, the sixth coordinate transformation relationship is the transformation relationship of the default tool coordinate of the first robot at any pose with respect to the coordinate system of the first robot; the seventh coordinate transformation relationship is the transformation relationship of the default tool coordinate of the second robot at any pose with respect to the coordinate system of the second robot; the eighth coordinate transformation relationship is the transformation relationship of the coordinate system of the first pose measurer with respect to the coordinate system of the laser tracker; the ninth coordinate transformation relationship is the transformation relationship of the coordinate system of the second pose measurer with respect to the coordinate system of the laser tracker.

[0147] In a possible implementation, the calculating the user coordinates of the robot according to the first coordinate transformation relationship to the ninth coordinate transformation relationship and performing user coordinate calibration includes: calculating the user coordinates of the first robot according to the sixth coordinate transformation relationship, the eighth coordinate transformation relationship, the first coordinate transformation relationship and the fourth coordinate transformation relationship and performing user coordinate calibration on the first robot; calculating the user coordinates of the second robot according to the seventh coordinate transformation relationship, the ninth coordinate transformation relationship, the first coordinate transformation relationship and the fifth coordinate transformation relationship and performing user coordinate calibration on the second robot.

[0148] In a specific example, first calibrate the user coordinates of robot 1, move robot 1 to any pose (for example, any point in the three-pose method can also be selected, and the first moving point position is selected in this experiment), and directly read the transformation relationship of the default tool coordinate of robot 1 with respect to the base coordinate of robot 1, that is, the sixth coordinate transformation relationship

[0149] Specifically, For

[0150]

[0151] Furthermore, taking the laser tracker as the reference coordinate system, directly measure the transformation relationship of the T-mac1 coordinate system TM1 with respect to the laser tracker coordinate system LT through the SA software supporting the laser tracker, that is, the eighth coordinate transformation relationship

[0152] Specifically, For

[0153]

[0154] Furthermore, obtain the transformation relationship of the measurement platform coordinate system W with respect to the laser tracker coordinate system LT

[0155] Specifically, For

[0156]

[0157] Furthermore, by obtaining the transformation relationship between the transmitter T-mac1 and the robot 1's default tool coordinates...

[0158] Specifically, for

[0159]

[0160] Furthermore, the transformation relationship between the measurement platform and the robot's base coordinates is calculated using the following formula, which is the user coordinate.

[0161]

[0162] Specifically, for

[0163]

[0164] Furthermore, this data was written into the user coordinates of robot 1, thus completing the user coordinate calibration of robot 1.

[0165] In a specific example, the transformation relationship between the measurement platform and the robot's two base coordinates can be obtained similarly. This data was written into the user coordinates of robot 2, thus completing the user coordinate calibration of robot 2.

[0166] Furthermore, the transformation relationship between the measurement platform and the receiver robot's base coordinates can be obtained similarly. Write this data into the user coordinates of the receiving robot.

[0167]

[0168]

[0169]

[0170]

[0171]

[0172] In one possible implementation, calculating the tool coordinates of the robot based on the first coordinate transformation relationship to the ninth coordinate transformation relationship and calibrating the tool coordinates includes: calculating the tool coordinates of the first robot based on the fourth coordinate transformation relationship and the second coordinate transformation relationship and calibrating the tool coordinates of the first robot; calculating the tool coordinates of the second robot based on the fifth coordinate transformation relationship and the third coordinate transformation relationship and calibrating the tool coordinates of the second robot.

[0173] In a specific example, the tool coordinates of the robot 1 transmitter are first calibrated to obtain the transformation relationship between the transmitter coordinates and the transmitter T-mac1 coordinates.

[0174] Specifically, for

[0175]

[0176] Furthermore, the transformation relationship between the transmitter T-mac1 coordinates and the robot 1's default tool coordinates is obtained through three-dimensional pose estimation.

[0177] Specifically, for

[0178]

[0179] Furthermore, the relative pose relationship between the transmitter coordinates (i.e., the new TCP point) and the default tool coordinates of robot 1 is calculated using the following formula. This refers to the tool coordinates.

[0180]

[0181] Specifically, for

[0182]

[0183] Furthermore, this data is written into the tool coordinates of the transmitting robot 1, that is, the data is written into the tool coordinate of robot 1 with the label 0, thus completing the tool coordinate calibration of robot 1.

[0184] In a specific example, the relative pose relationship between the receiver coordinates and the robot 2's default tool coordinates can be obtained similarly. The data was written into the tool coordinates of robot 2, thus completing the tool coordinate calibration of robot 2.

[0185] Furthermore, similarly, the relative pose relationship between the receiving antenna coordinates and the robot's default tool coordinates can be obtained.

[0186]

[0187]

[0188]

[0189] Furthermore, this data is written into the tool coordinates of the receiving antenna robot 2.

[0190] In one possible implementation, controlling the tool coordinates of the robot to move along a specified trajectory in the measurement platform coordinate system includes: controlling the tool coordinates of the first robot to move along a semi-circular trajectory pointing towards the center with a preset radius and a preset incident angle in the measurement platform coordinate system; controlling the tool coordinates of the second robot to move along a semi-circular trajectory pointing towards the center with a preset radius and a preset incident angle in the measurement platform coordinate system; wherein the preset radius ranges from 0 mm to 1000 mm; and the preset incident angle ranges from 0° to 45°.

[0191] In a specific example, after completing the tool coordinate calibration and user coordinate calibration of the two robots, LAN control of the two robots is adopted. The computer is connected to the control cabinets of the two robots through an Ethernet switch to form a workgroup, such as... Figure 7 As shown. Configure the IP addresses and gateways for the computer and the two robots to enable normal communication between the computer and the two robots. Write programs to control the tool coordinates of the two robots to move along specified trajectories within the established user coordinate system, such as... Figure 15 As shown.

[0192] In a specific example, such as Figures 13-14 As shown, the program is first written to select the XOZ plane in the established user coordinate system. Based on the measurement radius and measurement angle, the program controls the tool coordinates of the two robots to move along a semi-circular trajectory pointing towards the center of the circle with a radius of R and an incident angle of θ in the user coordinate system using the template support measurement platform. Assuming the measurement radius is 400mm and the incident angle is 10°, Table 1 shows the pose coordinates and deviations when the robot moves to the target position.

[0193] Table 1. Pose of target point measured by laser tracker

[0194] Serial Number x(mm) y(mm) z(mm) Radius (mm) Rx(°) Ry(°) Rz(°) Angle (°) Theoretical value -69.4593 0 393.9231 400 0 -10 0 40 Movement Posture -64.3223 -2.836 390.7621 393.335 -0.503 -8.698 -0.335 38.565 Measurement deviation Δ -5.137 2.836 3.161 6.665 0.503 -1.302 0.335 1.435

[0195] In one possible implementation, the tenth coordinate transformation relationship is the pose relationship of the first pose measuring device coordinate system relative to the measurement platform coordinate system, and the eleventh coordinate transformation relationship is the pose relationship of the second pose measuring device coordinate system relative to the measurement platform coordinate system.

[0196] In one possible implementation, calculating the robot's actual pose based on the first coordinate transformation relationship to the eleventh coordinate transformation relationship includes: calculating the actual pose of the first robot based on the second coordinate transformation relationship and the tenth coordinate transformation relationship; and calculating the actual pose of the second robot based on the eleventh coordinate transformation relationship and the third coordinate transformation relationship.

[0197] In a possible implementation, the pose deviation compensation based on the deviation between the actual pose and the theoretical pose of the robot includes: generating a new target pose according to the deviation between the actual pose and the theoretical pose of the first robot, and controlling the movement of the tool coordinate of the first robot in the measurement platform coordinate system to perform the pose deviation compensation of the first robot; generating a new target pose according to the deviation between the actual pose and the theoretical pose of the second robot, and controlling the movement of the tool coordinate of the second robot in the measurement platform coordinate system to perform the pose deviation compensation of the second robot.

[0198] In a specific example, as Figure 8 shown, theoretically, the tool coordinate point of the robot (i.e., the new TCP point) has moved to the target pose in the user coordinate system. However, due to the imperfect calibration method, there is an error between the actual pose of the new TCP and the set target pose. Real-time compensation is used to reduce this error and improve the control accuracy of the actual pose.

[0199] In a specific example, taking the transmitting robot 1 as an example, the specific steps of real-time compensation are as follows: The robot moves to the target point; taking the laser tracker coordinate system as a reference, use the laser tracker to measure the transmitting end T-mac1, that is, S TM1 ; directly obtain the pose relationship between the T-mac1 coordinate system and the measurement platform coordinate system through the SA software supporting the laser tracker, that is, the tenth coordinate transformation relationship Obtain the position relationship of the transmitting end relative to the T-mac1 coordinate system of the transmitting end Calculate the relative pose relationship of the transmitting end coordinate relative to the measurement platform coordinate system (i.e., the user coordinate system) according to the following formula

[0200]

[0201] Furthermore, calculate the deviation between the theoretical pose and the actual pose of each point; generate a new target pose according to the deviation; control the movement of the tool coordinate of the robot in the user coordinate system to perform pose deviation compensation; after the movement is completed, repeat the steps of measurement and control until the pose deviation meets the requirements.

[0202] In a specific example, the robot moves to the target position, uses the laser tracker to measure and calculate the deviation between the theoretical pose and the actual pose of each point, and performs pose deviation compensation according to the deviation. Repeat the compensation process until the deviation meets the positioning requirements. Table 2 shows the pose and compensation of the target point measured by the laser tracker.

[0203] Table 2 Pose and Compensation of Target Point Measured by Laser Tracker

[0204]

[0205]

[0206] The above steps completed the calibration of the dual-robot spatial measurement system. Using the measurement platform as a reference and the transceiver as control points, the tool coordinates and user coordinates of the two robots were calibrated, and motion control and real-time compensation were achieved. This calibration method can be extended to the calibration of multi-robot spatial measurement systems.

[0207] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0208] It should also be noted that in the description of this invention, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0209] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A pose calibration method for a multi-robot space measurement system, characterized by, The method includes Establish the coordinate system of the measurement platform; Establish the coordinate system of the transmitting device, the coordinate system of the first attitude measuring device, the coordinate system of the receiving device, and the coordinate system of the second attitude measuring device; Establish the coordinate system of the laser tracker and obtain the first coordinate transformation relationship, the second coordinate transformation relationship, and the third coordinate transformation relationship; Establish the first robot coordinate system and the second robot coordinate system, obtain the default tool coordinates of the first robot and the second robot, and calculate the fourth coordinate transformation relationship and the fifth coordinate transformation relationship; Obtain the sixth, seventh, eighth, and ninth coordinate transformation relationships; calculate the robot's user coordinates based on the first to the ninth coordinate transformation relationships and perform user coordinate calibration. Calculate the robot's tool coordinates based on the first coordinate transformation relationship to the ninth coordinate transformation relationship and perform tool coordinate calibration; The tool coordinates of the robot are controlled to move along a specified trajectory in the coordinate system of the measurement platform. Obtain the tenth coordinate transformation relationship and the eleventh coordinate transformation relationship, calculate the actual pose of the robot based on the first coordinate transformation relationship to the eleventh coordinate transformation relationship, and perform pose deviation compensation based on the deviation between the actual pose of the robot and the theoretical pose of the robot.

2. The pose calibration method for a multi-robot spatial measurement system according to claim 1, characterized in that, The first coordinate transformation relationship is the transformation relationship between the coordinate system of the measurement platform and the coordinate system of the laser tracker; The second coordinate transformation relationship is the positional relationship between the coordinate system of the launching device and the coordinate system of the first pose measuring device; The third coordinate transformation relationship is the positional relationship between the receiving device coordinate system and the second pose measuring device coordinate system.

3. The pose calibration method for a multi-robot spatial measurement system according to claim 2, characterized in that, The fourth coordinate transformation relationship is the positional relationship between the first pose measuring device coordinate system and the first robot default tool coordinate system; The fifth coordinate transformation relationship is the positional relationship between the second pose measuring device coordinate system and the second robot default tool coordinate system.

4. The pose calibration method for a multi-robot spatial measurement system according to claim 3, characterized in that, The sixth coordinate transformation relationship is the transformation relationship between the first robot's default tool coordinates and the first robot coordinate system under any pose; The seventh coordinate transformation relationship is the transformation relationship between the default tool coordinates of the second robot and the coordinate system of the second robot under any pose; The eighth coordinate transformation relationship is the transformation relationship between the first pose measuring device coordinate system and the laser tracker coordinate system; The ninth coordinate transformation relationship is the transformation relationship between the second pose measuring device coordinate system and the laser tracker coordinate system.

5. The pose calibration method for a multi-robot spatial measurement system according to claim 4, characterized in that, The step of calculating the robot's user coordinates based on the first coordinate transformation relationship to the ninth coordinate transformation relationship and performing user coordinate calibration includes... The user coordinates of the first robot are calculated and the user coordinates of the first robot are calibrated based on the sixth coordinate transformation relationship, the eighth coordinate transformation relationship, the first coordinate transformation relationship and the fourth coordinate transformation relationship. The user coordinates of the second robot are calculated and calibrated based on the seventh coordinate transformation relationship, the ninth coordinate transformation relationship, the first coordinate transformation relationship, and the fifth coordinate transformation relationship.

6. The pose calibration method for a multi-robot spatial measurement system according to claim 5, characterized in that, The step of calculating the robot's tool coordinates based on the first coordinate transformation relationship to the ninth coordinate transformation relationship and performing tool coordinate calibration includes... Calculate the tool coordinates of the first robot based on the fourth coordinate transformation relationship and the second coordinate transformation relationship, and then calibrate the tool coordinates of the first robot. The tool coordinates of the second robot are calculated and calibrated based on the fifth coordinate transformation relationship and the third coordinate transformation relationship.

7. The pose calibration method for a multi-robot spatial measurement system according to claim 6, characterized in that, The tenth coordinate transformation relationship is the pose relationship between the first pose measuring device coordinate system and the measuring platform coordinate system. The eleventh coordinate transformation relationship is the pose relationship between the second pose measuring device coordinate system and the measuring platform coordinate system.

8. The pose calibration method for a multi-robot spatial measurement system according to claim 7, characterized in that, The step of calculating the robot's actual pose based on the first coordinate transformation relationship to the eleventh coordinate transformation relationship includes... The actual pose of the first robot is calculated based on the second coordinate transformation relationship and the tenth coordinate transformation relationship; The actual pose of the second robot is calculated based on the eleventh coordinate transformation relationship and the third coordinate transformation relationship.

9. The pose calibration method for a multi-robot spatial measurement system according to claim 8, characterized in that, The posture deviation compensation based on the deviation between the robot's actual posture and its theoretical posture includes... A new target pose is generated based on the deviation between the actual pose and the theoretical pose of the first robot, and the tool coordinate motion of the first robot is controlled in the coordinate system of the measurement platform to compensate for the pose deviation of the first robot. A new target pose is generated based on the deviation between the actual pose and the theoretical pose of the second robot, and the tool coordinate motion of the second robot is controlled in the coordinate system of the measurement platform to compensate for the pose deviation of the second robot.

10. The pose calibration method for a multi-robot spatial measurement system according to claim 9, characterized in that, The tool coordinates of the controlled robot move along a specified trajectory in the coordinate system of the measurement platform, including... The tool coordinates of the first robot are controlled to move in a semi-circular trajectory pointing towards the center of the circle within the coordinate system of the measurement platform with a preset radius and a preset incident angle; The tool coordinates of the second robot are controlled to move in a semi-circular trajectory pointing towards the center of the circle within the coordinate system of the measurement platform with a preset radius and a preset incident angle; in The preset radius ranges from 0 mm to 1000 mm; the preset incident angle ranges from 0° to 45°.

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