A base calibration method of a multi-station mechanical arm calibration device

Abstract

The application discloses a base calibration method of a multi-station mechanical arm calibration device, a 3D measuring device is clamped on the jth station of a multi-station base through a quick locking mechanism, and measurement points are collected on three mutually orthogonal to-be-measured planes of the 3D measuring device by using an external measuring device; a fitting plane P i is obtained through plane fitting based on the measurement points, and then the fitting plane P i is offset to obtain an offset plane P i ', the offset distance of the offset plane P i ' is the distance from the corresponding fitting plane P i to a virtual constraint point, and the virtual constraint point passes through all the offset planes P i '; station coordinate systems {D i} are established by taking the three offset planes P j ' as three planes of a coordinate system; the above steps are repeated when the 3D measuring device is installed on other stations to obtain station coordinate systems {D j} of the corresponding stations; relative pose parameters between the different station coordinate systems {D j} are calculated, and station calibration is completed. The station calibration has high precision.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of robots, in particular to a base calibration method of a multi-station robot arm calibration device. BACKGROUND

[0002] At present, the calibration and measurement of the robot arm are mostly carried out by using a laser tracker and other measuring devices. Such devices usually have a measurement accuracy of μm level, so the calibration accuracy is very high. However, such devices are usually very expensive, and in some production sites, due to the presence of guardrails outside the robot arm, an open calibration environment cannot be provided, and the line of sight is easily blocked. The robot arm needs to be disassembled and transported to an open environment for calibration, which greatly limits its application.

[0003] The prior art also exists by using a mechanical tool for calibration, for example, a robot calibration device based on multi-station measurement described in Chinese invention patent 202110278848.0. The 3D measuring device is installed on different stations for measurement, and then the measurement points obtained on different stations are all converted to the same coordinate system. However, the coordinate system conversion process needs to measure the relative pose relationship between different stations on the multi-station base in advance, and there is no mature and reliable method for this problem at present. SUMMARY

[0004] In order to solve the above technical problems, the purpose of the present application is to provide a base calibration method of a multi-station robot arm calibration device, which uses a high-precision external measuring device to calibrate the multi-station base to obtain the relative pose χ ij between different stations, and as much as possible to improve the rigidity and repeatability of the 3D measuring device and the multi-station base, so as to convert the measurement points obtained on different stations to the same coordinate system with high precision in the subsequent measurement process.

[0005] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0006] A base calibration method of a multi-station robot arm calibration device, comprising the following steps:

[0007] (1) clamp the 3D measuring device on the jth station of the multi-station base through the quick locking mechanism, and use the external measuring device to collect measurement points on three mutually orthogonal measurement planes on the 3D measuring device;

[0008] (2) based on the measurement points, obtain the fitting planes P i (i=1, 2, 3) of the three measurement planes by plane fitting, and then offset the fitting planes P i to obtain the offset planes P i '(i=1, 2, 3), and the offset planes Pi the offset distance of the fitting plane P i (i = 1, 2, 3) to the virtual constraint point, so that the virtual constraint point passes through all the offset planes P i (i = 1, 2, 3);

[0009] (3) respectively taking the three offset planes P i (i = 1, 2, 3) as the XOY, XOZ, YOZ planes of the coordinate system, establishing the work station coordinate system {D j};

[0010] (4) repeating steps (1)-(3) by installing the 3D measuring device on other work stations to obtain the work station coordinate system {D j} of the corresponding work station;

[0011] (5) calculating the relative pose parameters between different work station coordinate systems {D j} to complete the work station calibration. A base station calibration method of a multi-station mechanical arm calibration device, comprising the following steps:

[0012] (1) clamping the 3D measuring device on the jthwork station of the multi-station base through the quick locking mechanism, and collecting measurement points on three mutually orthogonal measurement planes on the 3D measuring device using an external measuring device;

[0013] (2) based on the measurement points, obtaining the fitting planes P i (i = 1, 2, 3) of the three measurement planes through plane fitting;

[0014] (3) respectively taking the three fitting planes P i (i = 1, 2, 3) as the XOY, XOZ, YOZ planes of the coordinate system, establishing the work station coordinate system {D j};

[0015] (4) repeating steps (1)-(3) by installing the 3D measuring device on other work stations to obtain the work station coordinate system {D j} of the corresponding work station;

[0016] (5) calculating the relative pose parameters between different work station coordinate systems {D j} to complete the work station calibration.

[0017] As a preferred, the external measuring device is a articulated measuring arm, a laser tracker or a three-coordinate instrument, and the external measuring device measures through a contact probe or a laser probe or a laser scanning head.

[0018] As preferred, the multi-station base and the external measuring device are fixed on the same workbench, and n points are marked on three mutually orthogonal planes to be measured of the 3D measuring device respectively, and the external measuring device collects coordinates of the planes to be measured near the marked points.

[0019] As preferred, when the external measuring device collects n coordinate points of the planes to be measured, according to the coordinate points, plane fitting is performed by using three-dimensional measurement software to obtain fitting planes Pi (i=1, 2, 3) of the three mutually orthogonal planes to be measured of the 3D measuring device, and then the coordinate system creation command of the three-dimensional measurement software is used to establish the station coordinate system {D i (i=1, 2, 3) as the XOY, XOZ, YOZ planes of the coordinate system. j

[0020] As preferred, the three mutually orthogonal planes to be measured of the 3D measuring device are the three inner sides of the sensor fixing seat, and the plane offset command of the three-dimensional measurement software is used to offset the fitting planes Pi (i=1, 2, 3) respectively to obtain three offset planes Pi' (i=1, 2, 3), and the offset distance l offset is calculated by using the following formula: zero wherein l target is the distance from the inner side of the sensor fixing seat to the measuring surface of the probe of the displacement sensor when the probe of the displacement sensor is at zero position, and l j is the target reading of each displacement sensor when the ceramic ball is at the virtual constraint point, and d is the diameter of the ceramic ball, and then the coordinate system creation command of the three-dimensional measurement software is used to establish the station coordinate system {D i} as the XOY, XOZ, YOZ planes of the coordinate system.

[0021] As preferred, for step (5), two station coordinate systems {D j} are selected, and four points are arbitrarily taken in space, and the homogeneous coordinates of the four points in the station coordinate system {D i} are derived as the reference of the station coordinate system {D i}, and the homogeneous coordinates of the four points in the station coordinate system {D j} are derived as the reference of the station coordinate system {D j}, and T(χ ij ) is calculated based on the following formula:

[0022] ​​​​​​

[0023] Then, T(x ij ) is converted into 6D pose parameter χ i between the work station coordinate systems {D j} and {D ij}.

[0024] As preferred, the quick locking mechanism comprises a positioning assembly and a clamping assembly, the first positioning assembly and the first clamping assembly are arranged on the multi-station base, the first positioning assembly is a triangularly arranged positioning pin or positioning ball, or double positioning pins, or double positioning balls, or a V-shaped block, and the bottom of the 3D measuring device is provided with a second positioning assembly positioned with the first positioning assembly; the second positioning assembly is a triangularly arranged positioning pin or positioning ball, or double positioning pins, or double positioning balls, or a V-shaped block; and the clamping assembly is one or a combination of a clamp, a threaded fastener or a buckle.

[0025] As preferred, the 3D measuring device comprises a calibration base, a calibration connecting seat, a sensor fixing seat and a displacement sensor connected in sequence from bottom to top; the displacement measurement axis of the displacement sensor forms an angle of 0-90° with the horizontal plane, and the displacement sensor is provided with three displacement measurement axes, and the displacement measurement axes of the three displacement sensors are perpendicular to each other.

[0026] As preferred, the sensor fixing seat is provided with three mounting surfaces, and the three displacement sensors are vertically mounted on the three mounting surfaces, each mounting surface corresponds to an inner side surface, and a hard limit is arranged on the inner side surface, when the measuring head of the displacement sensor moves towards the interior of the displacement sensor, the measuring head collides with the hard limit to serve as the zero position of the displacement sensor.

[0027] The present application has the following beneficial effects due to the adoption of the above technical solutions:

[0028] By using high-precision external measuring devices, a coordinate system fixedly connected with the 3D measuring device is established, and then the relative pose χ ij between the coordinate systems fixedly connected with the 3D measuring device is used as the relative pose χ ij between different work stations, so that the multi-station base is calibrated, and then the measurement points obtained in different work stations are all accurately converted into the same coordinate system through the relative pose between different coordinate systems, thereby realizing large-range space measurement.

[0029] The three mutually orthogonal to-be-measured planes of the 3D measuring device are three inner side surfaces of the sensor fixing seat as the measurement reference surfaces, the three inner side surfaces of the sensor fixing seat are relatively rigid, and are not easy to deform under the measurement force of the contact measuring head of the external measuring device, so that the measurement precision is high; secondly, the three inner side surfaces of the sensor fixing seat are precisely machined and have good shape precision (including perpendicularity and flatness); thirdly, the three inner side surfaces of the sensor fixing seat are large enough to ensure the accuracy of plane fitting. BRIEF DESCRIPTION OF DRAWINGS

[0030] Fig. 1 A schematic diagram of a method for establishing a work coordinate system for embodiment 1 of the present application is shown in the figure.

[0031] Fig. 2 A schematic diagram of calculating a transformation matrix between different measurement coordinate systems for embodiment 1 of the present application is shown in the figure.

[0032] Fig. 3 A structural schematic diagram of embodiment 1 of the present application is shown in the figure. DETAILED DESCRIPTION

[0033] The embodiments of the present application will be described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0034] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, or can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] Embodiment 1,

[0036] As Figs. 1-3 shown, a base calibration method of a multi-station mechanical arm calibration device, comprising the following steps:

[0037] (1) The multi-station base 3 and the external measuring device 11 are fixed on the same workbench to ensure the measurement accuracy. The 3D measuring device 1 is clamped on the jth station of the multi-station base 3 through the quick locking mechanism 2. The three mutually orthogonal planes to be measured of the 3D measuring device are the three inner sides of the sensor fixing seat. An external measuring device is used to mark n points on the three mutually orthogonal planes to be measured 4 of the 3D measuring device. The external measuring device adopts a seven-degree-of-freedom articulated measuring arm. The external measuring device collects and measures points on the plane to be measured close to the marked points;

[0038] (2) As shown in Fig. 1 , three-dimensional measurement software is used to obtain the fitting planes P i (i=1, 2, 3) of the three planes to be measured based on the measurement points through plane fitting. i (i=1, 2, 3) are offset to obtain three offset planes P i '(i=1, 2, 3). The offset distance of the offset plane P i '(i=1, 2, 3) is the distance from the corresponding fitting plane P i (i=1, 2, 3) to the virtual constraint point, so that the virtual constraint point passes through all the offset planes P i '(i=1, 2, 3); the offset distance l offset of each plane is calculated using the following formula: where l zero is the distance from the inner side of the sensor fixing seat to the measuring surface of the probe of the displacement sensor when the probe of the displacement sensor is at zero position, and l target is the target reading of each displacement sensor when the ceramic ball is at the virtual constraint point, and d is the diameter of the ceramic ball.

[0039] (3) As shown in Fig. 2 , then the coordinate system creation command of the three-dimensional measurement software is used to establish the station coordinate system {D i} by taking the three offset planes P j '(i=1, 2, 3) as the XOY, XOZ and YOZ planes of the coordinate system, respectively.

[0040] (4) Repeat steps (1) to

[0041] (3) to obtain the station coordinate system {D j} of the corresponding station.

[0042] (5) The relative pose parameters between different station coordinate systems {D j} are calculated to complete the station calibration.

[0043] For step (5), select two station coordinate systems {D i} and {D j}, arbitrarily take four points in space, and derive the homogeneous coordinates of the four points in the station coordinate system {D i} and {D i} respectively based on the station coordinate system {D j}. And Then derive the homogeneous coordinates of the four points in the station coordinate system {D j} and {D ij} based on the station coordinate system {D ij}. And Calculate T(χ i ) based on the following formula, and derive the coordinates to 9 decimal places in order to improve the calculation accuracy.

[0044]

[0045] The basis for deriving the above formula is that the coordinate transformation of points in different coordinate systems can be directly realized by multiplying the transformation matrix between the coordinate systems and the homogeneous coordinates of the points, and then multiplying the inverse of the square matrix on both sides of the equation to realize the solution of the transformation matrix.

[0046] Then convert T(χ j ) into the 6D pose parameter χ ij between the station coordinate systems {D i} and {D j}.

[0047] The external measuring device is a joint measuring arm, a laser tracker or a three-coordinate instrument, and the external measuring device measures through a contact probe or a laser probe or a laser scanning head. The external measuring device of the embodiment adopts a seven-degree-of-freedom joint measuring arm, and the measurement accuracy of the contact probe or the laser probe is better than 20μm, and the measurement accuracy of the laser scanning head is better than 41μm.

[0048] The three-dimensional measurement software can adopt PolyWorks.

[0049] The quick locking mechanism includes a positioning assembly and a clamping assembly, and the first positioning assembly and the first clamping assembly are arranged on the multi-station base. The first positioning assembly is a triangularly arranged positioning pin or positioning ball, or double positioning pins, or double positioning balls, or a V-shaped block. The bottom of the 3D measuring device is provided with a second positioning assembly positioned with the first positioning assembly. The second positioning assembly is a triangularly arranged positioning pin or positioning ball, or double positioning pins, or double positioning balls, or a V-shaped block. The clamping assembly is one or a combination of a clamp, a threaded fastener or a buckle.

[0050] The 3D measuring device 1 includes a calibration base 101, a calibration connecting base 102, a sensor fixing base 103, and a displacement sensor 104 connected in sequence from bottom to top; the displacement measuring axis of the displacement sensor forms an angle of 0 to 90° with the horizontal plane, and there are three displacement sensors, with the displacement measuring axes of the three displacement sensors being perpendicular to each other in pairs.

[0051] The sensor mounting base has three mounting surfaces, and three displacement sensors are vertically mounted on the three mounting surfaces. Each mounting surface corresponds to an inner side surface, and a hard limit is provided on the inner side surface. When the probe of the displacement sensor moves into the interior of the displacement sensor, the probe hits the hard limit and is taken as the zero position of the displacement sensor.

[0052] With a multi-station base containing 5 workstations ( Fig. 3 For example, the coordinate system of the workstation measured by this multi-station base is shown in the attached figure. Fig. 2 As shown, in order to transform the coordinates of measurement points under different workstation coordinate systems to the same coordinate system (this coordinate system is also regarded as the measurement coordinate system {D}; the multi-workstation base has 5 workstations, and in this embodiment, the workstation coordinate system of the third workstation is selected as the measurement coordinate system {D}, that is, {D3} is selected as the measurement coordinate system {D}), it is necessary to determine the relative 6D pose vector χ between {D3} and the other four workstation coordinate systems after the multi-workstation base is built. 3j (j=1,2,4,5). Calculate T(χ) according to the above formula. 3j Then convert it into 6D pose parameters χ. 3j as follows.

[0053]

[0054] Then T(χ) ij Convert to workstation coordinate system {D} i} and {D j 6D pose parameters χ between} ij The result is shown as 0 (this is an example for reference only).

[0055] Table 1. Relative 6D pose between different workstation coordinate systems and the measurement coordinate system.

[0056]

[0057] Example 2

[0058] The parts of this embodiment that are structurally identical to those in Embodiment 1 will not be described again. The differences are as follows:

[0059] A method for calibrating the base of a multi-station robotic arm calibration device includes the following steps:

[0060] (1) Clamping the 3D measuring device on the jth station of the multi-station base through the quick locking mechanism, collecting measurement points on three mutually orthogonal measurement planes of the 3D measuring device using an external measuring device;

[0061] (2) Based on the measurement points, obtaining the fitting planes P i

[0062] (i = 1, 2, 3) of the three measurement planes through plane fitting;

[0063] (3) Taking the three fitting planes P i (i = 1, 2, 3) as the XOY, XOZ, YOZ planes of the coordinate system respectively, establishing the station coordinate system {D j};

[0064] (4) Repeating steps (1)-(3) to obtain the station coordinate system {D j} of the corresponding station by installing the 3D measuring device on other stations;

[0065] (5) Calculating the relative pose parameters between different station coordinate systems {D j} to complete station calibration.

[0066] When the external measuring device collects n coordinate points on the measurement plane, according to these coordinate points, plane fitting is performed using three-dimensional measurement software to obtain the fitting planes P i (i = 1, 2, 3) of the three mutually orthogonal measurement planes of the 3D measuring device, and then the coordinate system creation command of the three-dimensional measurement software is used to take the three fitting planes P j} as the XOY, XOZ, YOZ planes of the coordinate system respectively, establishing the station coordinate system {D j}.

[0067] For step (5), two station coordinate systems {D i} and {D j} are selected, and four points are arbitrarily taken in space, and the homogeneous coordinates of the four points in the station coordinate system {D i} are derived as the reference of the station coordinate system {D i}, that is, and Then, the homogeneous coordinates of the four points in the station coordinate system {D j} are derived as the reference of the station coordinate system {D j}, that is, and and T(χ ij ) is calculated based on the following formula, and in order to improve the calculation accuracy, the coordinates are accurate to 9 decimal places.

[0068]

[0069] The basis of the above formula derivation is that the coordinate transformation of a point in different coordinate systems can be directly realized by multiplication of the transformation matrix between the coordinate systems and the homogeneous coordinates of the point, and the homogeneous coordinates of four points are used to form a square matrix, and then the inverse of the square matrix is right multiplied on both sides of the equation to realize the solution of the transformation matrix.

[0070] Then, T(x ij ) is converted into the 6D pose parameter χ i between the work station coordinate systems {D j} and {D ij}.

[0071] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and the ordinary skilled in the art can make changes, modifications, replacements, variations, delete part of the features, add features or recombine features to form technical solutions within the scope of the present application without departing from the principles and purposes of the present application. Any simple modification, equivalent change and modification made to the above embodiments according to the innovative principles of the present application still belongs to the scope of the technical solutions of the present application.

Claims

1. A base calibration method of a multi-station robot calibration device, characterized by: It comprises the following steps: (1) the 3D measuring device is clamped on the jth station of the multi-station base through the quick locking mechanism, and three mutually orthogonal measurement planes on the 3D measuring device are used to collect measurement points by using an external measuring device; (2) Based on the measurement points, the fitting planes P of the three planes to be measured are obtained by plane fitting i (i = 1, 2, 3), and then the fitting planes P i are offset to obtain offset planes P i '(i = 1, 2, 3). The offset distance of the offset planes P i '(i = 1, 2, 3) is the distance from the corresponding fitting plane P i (i = 1, 2, 3) to the virtual constraint point, so that the virtual constraint point passes through all the offset planes P i '(i = 1, 2, 3). (3) three offset planes P i (i = 1, 2, 3) as the XOY, XOZ, YOZ planes of the coordinate system, establish the station coordinate system {D j}; (4) install the 3D measuring device on other stations to repeat steps (1)-(3) to obtain the station coordinate system {D j} of the corresponding station; (5) calculate the relative pose parameters between different station coordinate systems {D j} to complete station calibration; Three mutually orthogonal planes to be measured of the 3D measuring device are three inner sides of the sensor fixing seat, a plane offset command of the three-dimensional measuring software is used to offset the fitting planes Pi (i = 1, 2, 3) respectively, three offset planes Pi' (i = 1, 2, 3) are obtained, and the offset distance l offset The following formula is used for calculation: Wherein l zero is the distance from the inner side of the sensor fixing seat to the measuring surface of the probe of the displacement sensor when the probe of the displacement sensor is at zero position, l target is the target reading of each displacement sensor when the ceramic ball is at the virtual constraint point, d is the diameter of the ceramic ball, and then a coordinate system creation command of the three-dimensional measuring software is used to take the three offset planes Pi' (i = 1, 2, 3) as the XOY, XOZ and YOZ planes of the coordinate system, and a work position coordinate system {D j} is established. For step (5), select two workstation coordinate systems {D} i } and {D j }, arbitrarily select four points in space, and define them using the workstation coordinate system {D}. i Using} as the reference, derive the coordinates of these four points in the workstation coordinate system {D}. i homogeneous coordinates in} and Then, using the workstation coordinate system {D} j Using} as the reference, derive the coordinates of these four points in the workstation coordinate system {D}. j homogeneous coordinates in} and And calculate T(χ) based on the following formula ij ), Then convert T(x ij ) into 6D pose parameter χ i} and {D j} between the coordinate system {D ij .

2. The base calibration method of the multi-station robot calibration device according to claim 1, wherein: The multi-station base and the external measuring device are fixed on the same workbench, and n points are marked on the three mutually orthogonal measurement planes of the 3D measuring device, respectively, and the external measuring device collects coordinates of the measurement planes near the marked points.

3. The base calibration method of the multi-station robot calibration device according to claim 1, wherein: The quick locking mechanism comprises a positioning assembly and a clamping assembly, the multi-station base is provided with a first positioning assembly and a first clamping assembly, the first positioning assembly is a triangularly arranged positioning pin or positioning ball, or double positioning pin, or double positioning ball, or V-shaped block, and the bottom of the 3D measuring device is provided with a second positioning assembly positioned with the first positioning assembly; the second positioning assembly is a triangularly arranged positioning pin or positioning ball, or double positioning pin, or double positioning ball, or V-shaped block; the clamping assembly is one or a combination of a clamp, a threaded fastener or a buckle.

4. The base calibration method of the multi-station robot calibration device according to claim 1, wherein: The 3D measuring device comprises a calibration base, a calibration connecting seat, a sensor fixing seat and a displacement sensor connected in sequence from bottom to top; the displacement measurement axis of the displacement sensor forms an angle of 0-90° with the horizontal plane, the displacement sensor is provided with three, and the displacement measurement axes of the three displacement sensors are perpendicular to each other.

5. The base calibration method of the multi-station robot calibration device according to claim 4, characterized in that: The sensor fixing seat is provided with three mounting surfaces, the three displacement sensors are vertically mounted on the three mounting surfaces, each mounting surface corresponds to an inner side surface, and a hard limit is arranged on the inner side surface, when the measuring head of the displacement sensor moves towards the interior of the displacement sensor, the measuring head collides with the hard limit to serve as the zero position of the displacement sensor.

6. A base calibration method of a multi-station robot calibration device, characterized in that: It comprises the following steps: (1) the 3D measuring device is clamped on the jth station of the multi-station base through the quick locking mechanism, and three mutually orthogonal measurement planes on the 3D measuring device are used to collect measurement points by using an external measuring device; (2) Based on the measurement points, the fitting planes P of the three planes to be measured are obtained by plane fitting i (i = 1, 2, 3); (3) three fitting planes P i (i = 1, 2, 3) are taken as the XOY, XOZ, YOZ planes of the coordinate system, respectively, to establish the station coordinate system {D j}; (4) install the 3D measuring device on other stations to repeat steps (1)-(3) to obtain the station coordinate system {D j} of the corresponding station; (5) calculate the relative pose parameters between different workstation coordinate systems {D j} to complete workstation calibration; When the external measuring device collects n coordinate points of the plane to be measured, according to the coordinate points, a plane fitting is performed by using a three-dimensional measuring software to obtain three mutually orthogonal fitting planes Pi (i = 1, 2, 3) of the three planes to be measured of the 3D measuring device, and then a coordinate system creation command of the three-dimensional measuring software is used to respectively take the three fitting planes P i (i = 1, 2, 3) as the XOY, XOZ and YOZ planes of the coordinate system to establish the station coordinate system {D j}. For step (5), select two workstation coordinate systems {D} i } and {D j }, arbitrarily select four points in space, and define them using the workstation coordinate system {D}. i Using} as the reference, derive the coordinates of these four points in the workstation coordinate system {D}. i homogeneous coordinates in} and Then, using the workstation coordinate system {D} j Using} as the reference, derive the coordinates of these four points in the workstation coordinate system {D}. j homogeneous coordinates in} and And calculate T(χ) based on the following formula ij ), Then convert T(x ij ) into 6D pose parameter χ i ) between work coordinate system {D j} and {D ij}.

7. The base calibration method of a multi-station robotic arm calibration device according to claim 6, wherein: The multi-station base and the external measuring device are fixed on the same workbench, and n points are marked on the three mutually orthogonal measurement planes of the 3D measuring device, respectively, and the external measuring device collects coordinates of the measurement planes near the marked points.

8. The base calibration method of the multi-station robot calibration device according to claim 6, wherein: The quick locking mechanism comprises a positioning assembly and a clamping assembly, the multi-station base is provided with a first positioning assembly and a first clamping assembly, the first positioning assembly is a triangularly arranged positioning pin or positioning ball, or double positioning pin, or double positioning ball, or V-shaped block, and the bottom of the 3D measuring device is provided with a second positioning assembly positioned with the first positioning assembly; the second positioning assembly is a triangularly arranged positioning pin or positioning ball, or double positioning pin, or double positioning ball, or V-shaped block; the clamping assembly is one or a combination of a clamp, a threaded fastener or a buckle.

9. The base calibration method of the multi-station robotic arm calibration device according to claim 6, wherein: The 3D measuring device comprises a calibration base, a calibration connecting seat, a sensor fixing seat and a displacement sensor connected in sequence from bottom to top; the displacement measurement axis of the displacement sensor forms an angle of 0-90° with the horizontal plane, the displacement sensor is provided with three, and the displacement measurement axes of the three displacement sensors are perpendicular to each other.

10. The base calibration method of the multi-station robotic arm calibration device according to claim 9, wherein: The sensor fixing base is provided with three installation surfaces, three displacement sensors are vertically installed on the three installation surfaces, each installation surface corresponds to an inner side surface respectively, and a hard limit is arranged on the inner side surface, when the measuring head of the displacement sensor moves towards the interior of the displacement sensor, the measuring head hits the hard limit, and the hard limit serves as the zero position of the displacement sensor.

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