Method for calibrating tool coordinate system of self-positioning device with self-positioning carrier coordinate system

Abstract

The application provides a method for calibrating a tool coordinate system of a self-positioning device and a self-positioning carrier coordinate system, comprising the following steps: fixing the front end of the self-positioning device through a tool; under the constraint of the tool, making the self-positioning device move linearly along two directions on a platform by a distance, and acquiring a first pose data set and a second pose data set output by a VIO system respectively; acquiring a rotation matrix between the tool coordinate system and the self-positioning carrier coordinate system according to the first pose data set and the second pose data set; fixing the front end vertex of a cuboid structure of the self-positioning device through the tool, making the self-positioning device transform multiple poses, and acquiring pose data output by the VIO system in the pose transformation process; and acquiring a translation matrix between the tool coordinate system and the self-positioning carrier coordinate system based on the pose data output by the VIO system in the pose transformation process, so that the technical problem of large calibration error in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of calibration between self-positioning device self-coordinate systems, and particularly relates to a calibration method for a tool coordinate system of a self-positioning device and a self-positioning carrier coordinate system. BACKGROUND

[0002] A positioning pen and similar self-positioning devices including a multi-view camera and an inertial measurement unit (IMU) cannot directly establish a connection between a tool coordinate system (such as a goose neck coordinate system of the positioning pen) used for indication thereon and a carrier coordinate system (such as an IMU coordinate system or a camera coordinate system) thereof.

[0003] In order to obtain a corresponding relationship between the tool coordinate system used for indication thereon and the carrier coordinate system thereof, the prior art directly gives the corresponding relationship by using a hardware structure size of the positioning pen. However, due to machining and installation errors of the hardware structure size, a corresponding relationship between coordinate systems obtained due to the structure size and the installation errors has a large translation, which can reach about 7 degrees. SUMMARY

[0004] The present application aims to at least solve one of the technical problems in the related art to some extent.

[0005] To this end, the present application aims to provide a calibration method for a tool coordinate system of a self-positioning device and a self-positioning carrier coordinate system, so as to improve the accuracy of calibration between the tool coordinate system of the self-positioning device and the self-positioning carrier coordinate system.

[0006] To achieve the above-mentioned purpose, the present application provides a calibration method for a tool coordinate system of a self-positioning device and a self-positioning carrier coordinate system, the self-positioning device including a body, an upper end of the body extending a goose neck structure, a top end of the goose neck structure being a cuboid structure, a front end of the cuboid structure being provided with a chamfer; a long axis and two short axes of the cuboid structure corresponding to z, x and y axes of the tool coordinate system respectively, a positive direction of the long axis being a direction in which the goose neck structure points; the self-positioning device being configured with a VIO system, and the method including:

[0007] The cuboid structure at a front end of the self-positioning device is fixed by a tool, and the tool and the self-positioning device are placed on a platform; under a constraint of the tool, the self-positioning device is linearly moved in two directions on the platform by a distance, and a first pose data set and a second pose data set output by the VIO system in the two direction movement processes are obtained;

[0008] A rotation matrix between the tool coordinate system and the self-positioning carrier coordinate system is obtained according to the first pose data set and the second pose data set;

[0009] transform multiple poses of the cuboid structure of the self-positioning device by fixing the front end vertex of the cuboid structure of the self-positioning device by a tool, and obtain pose data output by the VIO system during the pose transformation;

[0010] Based on the pose data output by the VIO system during the pose transformation, obtain a translation matrix between the tool coordinate system and the self-positioning carrier coordinate system, and obtain a calibration relationship between the tool coordinate system and the self-positioning carrier coordinate system of the self-positioning device according to the rotation matrix and the translation matrix.

[0011] The calibration method of the tool coordinate system and the self-positioning carrier coordinate system of the self-positioning device provided in the present application is that the self-positioning device moves linearly in two directions of the platform, a rotation matrix between the tool coordinate system and the self-positioning carrier coordinate system is calculated according to the pose data output by the visual inertial odometer of the self-positioning device during the linear motion; the pose is transformed under the premise of restricting the pointing direction of the front end vertex of the self-positioning device, and a translation matrix between the tool coordinate system and the self-positioning carrier coordinate system is calculated according to the pose data output by the visual inertial odometer of the self-positioning device during the pose transformation; high accuracy, easy to implement.

[0012] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0013] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, taken in conjunction with the accompanying drawings, in which:

[0014] Figure 1 A flowchart of a calibration method of a tool coordinate system and a self-positioning carrier coordinate system of a self-positioning device provided by an embodiment of the present application;

[0015] Figure 2 A schematic diagram of a positioning pen provided by an example of the present application;

[0016] Figure 3 A flowchart of a method for obtaining a rotation matrix between a tool coordinate system and a self-positioning carrier coordinate system provided by an embodiment of the present application. DETAILED DESCRIPTION

[0017] The embodiments of the present application are 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.

[0018] Term explanation:

[0019] Visual-Inertial Odometry (VIO) is an algorithm that fuses camera image information and Inertial Measurement Unit (IMU) data to estimate the pose (position and attitude) of a mobile platform in three-dimensional space.

[0020] The tool coordinate system of the self-positioning device and the calibration method of the self-positioning carrier coordinate system of the embodiment of the application are described below with reference to the accompanying drawings.

[0021] Figure 1 A flowchart of a tool coordinate system of a self-positioning device and a calibration method of a self-positioning carrier coordinate system provided by an embodiment of the application. The self-positioning device of the embodiment of the application includes a body, the upper end of the body extends a swan neck structure, the top end of the swan neck structure is a cuboid structure, the long axis and the two short axes of the cuboid structure correspond to the z axis, the x axis and the y axis of the tool coordinate system of the self-positioning device respectively, and the positive direction of the long axis is the direction in which the swan neck structure points; the self-positioning device is configured with a VIO system; as shown in the figure, the calibration method of the tool coordinate system of the self-positioning device and the self-positioning carrier coordinate system includes the following steps: Figure 1

[0022] Step S101, fix the cuboid structure at the front end of the self-positioning device by the tool, and place the tool and the self-positioning device on the platform; under the constraint of the tool, make the self-positioning device move linearly on the platform along two directions for a distance, and obtain a first pose data set and a second pose data set output by the VIO system respectively during the movement in the two directions.

[0023] It should be noted that self-positioning refers to a coordinate system that can output its own position and attitude, and the self-positioning device can output its own pose, and the carrier coordinate system of the self-positioning device can be an IMU coordinate system or a camera coordinate system, etc.

[0024] The self-positioning device is used for Figure 2 ​The shown positioning pen includes a body 1, the body 1 is configured with a circuit board, an inertial measurement unit and two cameras 2, the front end of the body 1 is configured with a display screen and a key, the inertial measurement unit, the camera 2, the display screen and the key are connected with the circuit board, the bottom end of the body 1 is provided with a handheld structure 3, the upper end of the body 1 extends out a swan neck structure 4, the top end of the swan neck structure 4 is a cuboid structure 5, the front end head of the cuboid structure 5 becomes a round head through chamfering; the tool coordinate system of the positioning pen is defined on the cuboid structure 5 at the front end of the swan neck structure of the positioning pen, the long axis and the two short axes of the cuboid structure 5 correspond to the z axis, the x axis and the y axis of the tool coordinate system respectively, and the positive direction of the long axis is the direction in which the swan neck structure points; the carrier coordinate system of the positioning pen itself is described taking the IMU coordinate system as an example. The positioning pen is configured with a VIO system, which can output the position and posture of the front end of the swan neck structure of the positioning pen relative to the IMU coordinate system at any moment, that is, output the pose representation of the IMU at the front end of the swan neck structure of the positioning pen in the global coordinate system w coordinate system of the VIO. Since the IMU coordinate system and the camera coordinate system of the positioning pen have been calibrated in advance, the attitude of the camera coordinate system can be calculated by obtaining the pose of the IMU coordinate system, and vice versa. Specifically, the VIO system running on the positioning pen can output 6 degrees of freedom pose data (i.e. the relative pose of the current pose relative to the initial pose at the start time of the odometer) at each collection time, with a frequency of about 30HZ; for example, at 100.03s, the translation p is 0, 0, 0, and the attitude is (quaternion) 0, 0, 0, 1; at 100.06s, the translation p is 0.1, 0.05, 0.002, and the attitude quaternion is 0.16, 0.01, 0.000, 0.99...; these data are calculated by the positioning pen according to the inertial measurement unit and the camera acquisition data. For example, the VIO system output result of the positioning pen at 0 time includes and , wherein, is the attitude of the positioning pen at 0 time, that is, the rotation representation of the IMU of the positioning pen in the global coordinate system w coordinate system of the VIO; is the translation of the positioning pen at 0 time, that is, the translation representation of the IMU of the positioning pen in the global coordinate system w coordinate system of the VIO.

[0025] It should be noted that the self-positioning carrier coordinate system of the positioning pen in this example is the IMU coordinate system, and the VIO system output result includes and , and the VIO system output result of the self-positioning device in this application is represented as and .

[0026] As an implementation, the self-positioning device is moved linearly along the direction of the gooseneck structure under the constraint of the tooling for a distance, and a first pose data set output by the VIO system during the movement is obtained; the self-positioning device is moved linearly along the direction of the first side of the cuboid structure under the constraint of the tooling for a distance, and a second pose data set output by the VIO system during the movement is obtained.

[0027] As an example, the cuboid structure at the front end of the gooseneck structure of the positioning pen is clamped by a rectangular support tooling provided with a rectangular groove at the top, and the tooling and the positioning pen are placed on a platform, which is an xy-direction translation platform, together. The tooling drives the positioning pen to realize linear motion in two directions on the platform. First, the positioning pen is moved linearly along the direction of the gooseneck structure (i.e., the z-axis of the tool coordinate system) under the constraint of the tooling for a distance, and a first pose data set output by the VIO system during the movement in this direction is obtained. Then, the positioning pen is moved linearly along the direction of a side of the gooseneck structure (i.e., the direction of a side of the cuboid structure, which is in the same plane as the x-axis and the z-axis and is not parallel to the z-axis) under the constraint of the tooling for a distance, and a second pose data set output by the VIO system during the movement in this direction is obtained.

[0028] One of the movement directions in this step is along the z-axis of the tool coordinate system, and the other movement direction is only required to be in the xoz plane, and does not necessarily have to be along the x-axis of the tool coordinate system. In this way, the accuracy of the odometry output by the self-positioning device is higher than that of pure movement along the x-axis of the tool coordinate system.

[0029] For example, the data acquisition frequency of the positioning pen is about 30 Hz, and a series of pose data are obtained by the VIO system of the positioning pen during linear movement in two directions, to form a pose data set , including a series of positions and a series of attitudes .

[0030] In step S102, a rotation matrix between the tool coordinate system and the self-positioning carrier coordinate system is obtained according to the first pose data set and the second pose data set.

[0031] As an implementation, the method for obtaining the rotation matrix between the tool coordinate system and the self-positioning carrier coordinate system includes:

[0032] In step S201, a direction vector representation of the z-axis of the tool coordinate system in the self-positioning carrier coordinate system is obtained based on the first pose data set .

[0033] In this embodiment, the first pose data set includes pose data of n1 position points corresponding to n1 time points, and n1 is a positive integer greater than 1.

[0034] As an implementation manner, a method for obtaining a direction vector representation of a z-axis of a tool coordinate system in a self-localization carrier coordinate system includes: dividing a first pose data set into a first position data set and a first attitude data set; transforming the first position data set into an n1x3 array, and calculating principal component direction vectors of the array through principal component analysis to obtain a direction vector representation of the principal component direction vectors in a w coordinate system ; wherein the w coordinate system is a coordinate system in which the pose data output by the VIO system is located; calculating a mean value of the first attitude data set to obtain a mean attitude; and obtaining the direction vector representation of the z-axis of the tool coordinate system in the self-localization carrier coordinate system according to the direction vector representation and the mean attitude .

[0035] As an implementation manner, a method for calculating principal component direction vectors of an array through principal component analysis includes: regarding the n1x3 array as n1 three-dimensional vectors, calculating mean values of each dimension, and subtracting the mean values of each dimension from the data of each dimension to obtain n1 three-dimensional vectors that are centralized; wherein each three-dimensional vector corresponds to three-dimensional coordinates of a point; constructing the n1 three-dimensional vectors that are centralized into a centralized data matrix, and calculating a covariance matrix of the centralized data matrix; performing eigenvalue decomposition on the covariance matrix to obtain a plurality of eigenvalues and unit eigenvectors corresponding to each eigenvalue; and regarding a unit eigenvector corresponding to a maximum eigenvalue in the plurality of eigenvalues as the principal component direction vector of the array

[0036] Therefore, the embodiment obtains the direction vector corresponding to the linear movement direction through the principal component analysis method, and improves the data accuracy.

[0037] Step S202, based on the second pose data set, obtaining a direction vector representation of a first side direction of a tool coordinate system in a self-localization carrier coordinate system .

[0038] It should be noted that the implementation manner of the present step can refer to the above-mentioned step S201 for details, and the principle is the same, which will not be described here.

[0039] Step S203, based on the direction vector representation and the direction vector representation , obtaining a direction vector representation of a y-axis of a tool coordinate system in a self-localization carrier coordinate system .

[0040] The direction vector representation is obtained through the following formula:

[0041] = ×

[0042] directional vector representation directional vector representation directional vector representation .

[0043] Step S204, according to the directional vector representation directional vector representation , the directional vector representation of the x-axis of the tool coordinate system in the self-positioning carrier coordinate system is obtained .

[0044] This step obtains the directional vector representation by the following formula:

[0045]

[0046] directional vector representation directional vector representation directional vector representation .

[0047] Step S205, according to the directional vector representation directional vector representation directional vector representation , the rotation matrix between the tool coordinate system and the self-positioning carrier coordinate system is obtained.

[0048] Thus, the rotation matrix between the tool coordinate system of the self-positioning device and the self-positioning carrier coordinate system is obtained , which is represented as follows:

[0049]

[0050] Step S103, the front end vertex of the cuboid structure of the self-positioning device is fixed by the tool, so that the self-positioning device is transformed into multiple postures, and the pose data output by the VIO system during the posture transformation is obtained.

[0051] The number of transformed postures is required to be greater than 2, and generally more than 10 postures are selected.

[0052] The tool of this step serves to constrain the front end vertex of the self-positioning device, and under this premise, the self-positioning device is transformed into a posture to obtain the pose data output by the VIO system during the posture transformation, i.e., the posture and the position at each time.

[0053] Step S104, based on the pose data output by the VIO system during the posture transformation, the translation matrix between the tool coordinate system and the self-positioning carrier coordinate system is obtained.

[0054] It can be understood that, in the process of converting the posture motion, since the front end vertex of the self-positioning device is invariant in translation in the w coordinate system output by the VIO system, the self-positioning device satisfies the following relationship during the motion:

[0055]

[0056] wherein i represents the i-th moment, represents the translation matrix between the tool coordinate system of the self-positioning device and the self-positioning carrier coordinate system, is the translation of the self-positioning device at the i-th moment, i.e., the translation representation of the self-positioning carrier coordinate system of the self-positioning device in the global coordinate system w of the VIO; is the posture of the self-positioning device at the i-th moment, i.e., the rotation representation of the self-positioning carrier coordinate system of the self-positioning device in the global coordinate system w of the VIO; represents the translation matrix between the tool coordinate system of the self-positioning device and the w coordinate system.

[0057] Therefore, for any two moments, taking the 0-th and 1-th moments as examples, the poses satisfy the following relationship:

[0058]

[0059] wherein, is the posture of the self-positioning device at the 0-th moment, is the translation of the self-positioning device at the 0-th moment, is the posture of the self-positioning device at the 1-th moment, is the translation of the self-positioning device at the 1-th moment.

[0060] Therefore, the following formula can be derived:

[0061]

[0062] wherein, represents the translation representation of the self-positioning carrier coordinate system at the 1-th moment in the 0-th moment coordinate system, and also represents the translation transformation relationship between the self-positioning carrier coordinate system at the 0-th moment and the self-positioning carrier coordinate system at the 1-th moment; represents the rotation representation of the self-positioning carrier coordinate system at the 1-th moment in the 0-th moment coordinate system, and also represents the rotation transformation relationship between the self-positioning carrier coordinate system at the 0-th moment and the self-positioning carrier coordinate system at the 1-th moment.

[0063] A plurality of sets of data are integrated, and the following formula can be obtained:

[0064]

[0065] The following definitions are made:

[0066]

[0067] Thus, the translation matrix between the tool coordinate system of the self-positioning device and the self-positioning carrier coordinate system is .

[0068] Thus, as an implementation manner, the method for obtaining the translation matrix between the tool coordinate system and the self-positioning carrier coordinate system based on the pose data output by the VIO system in the pose transformation process comprises:

[0069] Based on the pose data output by the VIO system in the pose transformation process, a plurality of sets of translation representations and rotation representations of the self-positioning carrier coordinate system at different time instants are obtained by the following formula:

[0070]

[0071]

[0072] wherein, represents the rotation representation of the self-positioning carrier coordinate system at the i-th time instant in the (i-1)-th time coordinate system, represents the translation representation of the self-positioning carrier coordinate system at the i-th time instant in the (i-1)-th time coordinate system, is the translation of the self-positioning device at the i-th time instant; is the pose of the self-positioning device at the (i-1)-th time instant, represents the inverse of

[0073] Based on the plurality of sets of translation representations and rotation representations of the self-positioning carrier coordinate system at different time instants, the matrix A and b are obtained by the following formula:

[0074]

[0075] The translation matrix between the tool coordinate system of the self-positioning device and the self-positioning carrier coordinate system is calculated according to the following formula: :

[0076]

[0077] Illustratively, continuing to take the 0,1 time instant as an example, after obtaining the position data and pose data output by the VIO system, the relative pose transformation at the 0,1 time instant can be obtained according to the following formula, as follows:

[0078]

[0079]

[0080] ​Similarly, in the process of transforming multiple poses of the self-positioning device, according to the obtained pose data output by the VIO system, multiple sets of translation and rotation representations of the self-positioning carrier coordinate system at different times are obtained, so as to obtain the matrix A and b; then according to , the translation matrix is obtained.

[0081] After obtaining the rotation matrix and the translation matrix between the tool coordinate system and the self-positioning carrier coordinate system of the self-positioning device, the rotation matrix and the translation matrix are integrated to obtain the pose transformation matrix between the tool coordinate system and the self-positioning carrier coordinate system, that is, the calibration between the tool coordinate system and the self-positioning carrier coordinate system of the self-positioning device is completed.

[0082] The calibration method for the tool coordinate system and the self-positioning carrier coordinate system of the self-positioning device according to the embodiments of the present application is that the self-positioning device moves linearly in two directions of the platform, the rotation matrix between the tool coordinate system and the self-positioning carrier coordinate system is calculated according to the pose data output by the visual inertial odometer of the self-positioning device in the linear motion process; the pose is transformed on the premise of constraining the pointing direction of the front vertex of the self-positioning device, and the translation matrix between the tool coordinate system and the self-positioning carrier coordinate system is calculated according to the pose data output by the visual inertial odometer of the self-positioning device in the pose transformation process; the accuracy is high, and the implementation is convenient; the direction vector of linear motion is obtained by combining the principal component analysis method, and the accuracy of data is further improved.

[0083] In the foregoing embodiment description, the description of the terms “one embodiment”, “some embodiments”, “example”, “specific example”, or “some examples” means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the description, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the description and the features of the different embodiments or examples without contradiction.

[0084] In addition, the terms “first”, “second” are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with “first”, “second” can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of “multiple” is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0085] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and that changes, modifications, substitutions and variations can be made by those skilled in the art without departing from the scope of the present application.

Claims

1. A method for calibrating a tool coordinate system of a self-positioning device to a self-positioning carrier coordinate system, characterized by The self-positioning device comprises a body, an upper end of the body extends a swan neck structure, a top end of the swan neck structure is a cuboid structure, a front end of the cuboid structure is provided with a chamfer; a long axis and two short axes of the cuboid structure correspond to z axis, x axis and y axis of the tool coordinate system respectively, a positive direction of the long axis is a direction in which the swan neck structure points; The self-positioning device is configured with a VIO system, and the method comprises: The cuboid structure at the front end of the self-positioning device is fixed by a tool, and the tool and the self-positioning device are placed on a platform; under the constraint of the tool, the self-positioning device is linearly moved in two directions on the platform by a distance, and first pose data set and second pose data set output by the VIO system in the moving process in the two directions are acquired; including: under the constraint of the tool, the self-positioning device is linearly moved in a direction in which the swan neck structure points by a distance, and first pose data set output by the VIO system in the moving process is acquired; under the constraint of the tool, the self-positioning device is linearly moved in a first side direction of the cuboid structure by a distance, and second pose data set output by the VIO system in the moving process is acquired; the direction in which the swan neck structure points is z axis of the tool coordinate system, and the first side direction of the cuboid structure is in xoz plane of the tool coordinate system; According to the first pose data set and the second pose data set, a rotation matrix between the tool coordinate system and the self-positioning carrier coordinate system is obtained; including: based on the first pose data set, a direction vector representation of the z-axis of the tool coordinate system in the self-positioning carrier coordinate system is obtained ; based on the second pose data set, a direction vector representation of the first side direction of the tool coordinate system in the self-positioning carrier coordinate system is obtained ; based on the direction vector representation and the direction vector representation , a direction vector representation of the y-axis of the tool coordinate system in the self-positioning carrier coordinate system is obtained ; according to the direction vector representation and the direction vector representation , a direction vector representation of the x-axis of the tool coordinate system in the self-positioning carrier coordinate system is obtained ; according to the direction vector representation , the direction vector representation and the direction vector representation , the rotation matrix between the tool coordinate system and the self-positioning carrier coordinate system is obtained; The front vertex of the cuboid structure of the self-positioning device is fixed by a tool, and the self-positioning device is transformed into multiple poses, and pose data output by the VIO system in the pose transformation process is acquired; Based on the pose data output by the VIO system in the pose transformation process, a translation matrix between the tool coordinate system and the self-positioning carrier coordinate system is acquired, and a calibration relationship between the tool coordinate system and the self-positioning carrier coordinate system of the self-positioning device is obtained according to the rotation matrix and the translation matrix.

2. The method of claim 1, wherein, The first pose data set includes pose data of n1 points corresponding to n1 time points, n1 being a positive integer greater than 1; and the direction vector representation of the z-axis of the tool coordinate system in the self-positioning carrier coordinate system is obtained based on the first pose data set ; comprising: The first pose data set is divided into first position data set and first pose data set; transforming the first position data set into an n1x3 array and calculating principal component direction vectors of the array by principal component analysis to obtain direction vector representations of the principal component direction vectors in a w coordinate system ; wherein the w coordinate system is a coordinate system in which the pose data output by the VIO system is located. The mean value of the first pose data set is calculated to obtain the mean value pose; According to the direction vector representation and the mean pose, a direction vector representation of a z-axis of a tool coordinate system in a self-localizing carrier coordinate system is obtained .

3. The method of claim 2, wherein, The principal component direction vector of the array is calculated by principal component analysis; including: The n1x3 array is taken as n1 three-dimensional vectors, the mean value of each dimension is calculated, and the data of each dimension is subtracted by the mean value of the corresponding dimension to obtain the centralized n1 three-dimensional vectors; wherein each three-dimensional vector corresponds to the three-dimensional coordinates of a point; The centralized n1 three-dimensional vectors are constructed into a centralized data matrix, and the covariance matrix of the centralized data matrix is calculated; The covariance matrix is subjected to eigenvalue decomposition to obtain multiple eigenvalues and unit eigenvectors corresponding to each eigenvalue; The unit eigenvector corresponding to the maximum eigenvalue in the multiple eigenvalues is taken as the principal component direction vector of the array.

4. The method of claim 1, wherein, Based on the pose data output by the VIO system in the pose transformation process, a translation matrix between the tool coordinate system and the self-positioning carrier coordinate system is acquired; including: Based on the pose data output by the VIO system in the pose transformation process, a translation representation and a rotation representation of the self-positioning carrier coordinate system at different time are obtained by the following formula: wherein, represents a rotation representation of the self-localizing carrier coordinate system at time i in the coordinate system at time i-1, represents a translation representation of the self-localizing carrier coordinate system at time i in the coordinate system at time i-1, is a translation of the self-localizing device at time i; is a pose of the self-localizing device at time i-1, represents the inverse of Based on the plurality of sets of translational representation and rotational representation of the self-localization carrier coordinate system at different time, the matrix A and b are obtained through the following formula: The translation matrix between the tool coordinate system of the self-localization device and the self-localization carrier coordinate system is calculated according to the following formula : 。 5. The method of claim 1, wherein, The self-localization carrier coordinate system is an IMU coordinate system, and the method further comprises: According to the calibration relationship between the tool coordinate system of the self-localization device and the self-localization carrier coordinate system and the calibration relationship between the IMU coordinate system and the camera coordinate system, the calibration relationship between the tool coordinate system of the self-localization device and the camera coordinate system is obtained.

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