CN117073581B

CN117073581B - Calibration method and device of line laser profilometer system and electronic equipment

Info

Publication number: CN117073581B
Application number: CN202311167443.5A
Authority: CN
Inventors: 杨军; 韩成彬; 马浩然; 张�杰; 蔡明杰; 宋启原; 邵天兰; 丁有爽
Original assignee: Mech Mind Robotics Technologies Co Ltd
Current assignee: Mech Mind Robotics Technologies Co Ltd
Priority date: 2023-09-12
Filing date: 2023-09-12
Publication date: 2024-01-26
Anticipated expiration: 2043-09-12
Also published as: CN117073581A

Abstract

The present disclosure provides a calibration method, a device and an electronic device for a line laser profiler system, where the method includes: acquiring a first coordinate obtained through a reference line laser profiler, wherein the first coordinate is a three-dimensional coordinate of the sphere center of the calibration sphere under a first coordinate system, and the first coordinate system is a coordinate system under the reference line laser profiler; for each auxiliary line laser profiler, acquiring a second coordinate obtained by the auxiliary line laser profiler, wherein the second coordinate is a three-dimensional coordinate of the sphere center of the calibration sphere under a second coordinate system, and the second coordinate system is a coordinate system under the auxiliary line laser profiler; determining a reflection parameter of the second coordinate system relative to the first coordinate system; determining conversion parameters from the second coordinate system to the first coordinate system according to the first coordinate, the second coordinate and the reflection parameters; and calibrating the line laser profiler system according to the conversion parameter and the reflection parameter, and realizing the calibration of the line laser profiler system.

Description

Calibration method and device of line laser profilometer system and electronic equipment

Technical Field

The disclosure relates to the field of sensor calibration, in particular to a calibration method, a calibration device and electronic equipment of a line laser profilometer system.

Background

In the measuring scene of the object, the line laser profiler or the object to be measured is driven to move by a motion axis. In the moving process, the line laser profiler projects laser lines to the surface of an object through a laser, brightness information reflected by the profile surface is recorded through an optical sensor, and then the geometric dimension of the object is calculated through a computer.

However, when there are a plurality of line laser profilers, there are inconsistent coordinate systems and different installation deviations for different line laser profilers, there is a need for a calibration method that can correct the installation deviations simultaneously and calibrate the measurement results of different line laser profilers to a uniform coordinate system.

Disclosure of Invention

Aspects of the present disclosure provide a calibration method, apparatus, and electronic device for a line laser profiler system to calibrate the line laser profiler system to transform three-dimensional coordinates acquired by different line laser profilers into a baseline laser profiler coordinate system.

A first aspect of an embodiment of the present disclosure provides a calibration method of a line laser profiler system, the line laser profiler system including: a plurality of line laser profilers and a motion axis, the motion axis driving movement of the line laser profilers or calibration balls, the plurality of line laser profilers comprising: the calibration method comprises the steps of:

Acquiring a first coordinate obtained through a reference line laser profiler, wherein the first coordinate is a three-dimensional coordinate of the sphere center of the calibration sphere under a first coordinate system, and the first coordinate system is a coordinate system under the reference line laser profiler;

for each auxiliary line laser profiler, acquiring a second coordinate obtained by the auxiliary line laser profiler, wherein the second coordinate is a three-dimensional coordinate of the sphere center of the calibration sphere under a second coordinate system, and the second coordinate system is a coordinate system under the auxiliary line laser profiler;

determining a reflection parameter of the second coordinate system relative to the first coordinate system;

determining conversion parameters from the second coordinate system to the first coordinate system according to the first coordinate, the second coordinate and the reflection parameters;

the line laser profiler system is calibrated based on the conversion parameters and the reflection parameters.

A second aspect of the disclosed embodiments provides a calibration device for a line laser profiler system, the line laser profiler system comprising: a plurality of line laser profilers and a motion axis, the motion axis driving movement of the line laser profilers or calibration balls, the plurality of line laser profilers comprising: a baseline laser profiler and at least one auxiliary line laser profiler, the calibration device comprising:

the calibration ball is used for calibrating the line laser profiler system;

The first acquisition module is used for acquiring a first coordinate obtained through the reference line laser profiler, wherein the first coordinate is a three-dimensional coordinate of the sphere center of the calibration sphere under a first coordinate system, and the first coordinate system is a coordinate system under the reference line laser profiler;

the second acquisition module is used for acquiring a second coordinate obtained by the auxiliary line laser profiler for each auxiliary line laser profiler, wherein the second coordinate is a three-dimensional coordinate of the spherical center of the calibration sphere under a second coordinate system, and the second coordinate system is a coordinate system under the auxiliary line laser profiler;

the first determining module is used for determining reflection parameters of the second coordinate system relative to the first coordinate system;

the second determining module is used for determining conversion parameters from the second coordinate system to the first coordinate system according to the first coordinate, the second coordinate and the reflection parameters;

and the calibration module is used for calibrating the line laser profiler system according to the conversion parameter and the reflection parameter.

A third aspect of an embodiment of the present disclosure provides an electronic device, including: a processor, a memory and a computer program stored on the memory and executable on the processor, the processor implementing the calibration method of the first aspect when executing the computer program.

A fourth aspect of the disclosed embodiments provides a computer-readable storage medium having stored therein computer-executable instructions for implementing the calibration method of the first aspect when executed by a processor.

A fifth aspect of the disclosed embodiments provides a computer program product comprising: a computer program stored in a readable storage medium, from which the computer program can be read by at least one processor of an electronic device, the at least one processor executing the computer program causing the electronic device to perform the calibration method of the first aspect.

The present disclosure provides a calibration method of a line laser profiler system, the line laser profiler system comprising: a plurality of line laser profilers and a motion axis, the motion axis driving movement of the line laser profilers or calibration balls, the plurality of line laser profilers comprising: the method comprises the steps of obtaining a first coordinate obtained through the reference line laser profiler, wherein the first coordinate is a three-dimensional coordinate of a sphere center of a calibration sphere under a first coordinate system, and the first coordinate system is a coordinate system under the reference line laser profiler; for each auxiliary line laser profiler, acquiring a second coordinate obtained by the auxiliary line laser profiler, wherein the second coordinate is a three-dimensional coordinate of the sphere center of the calibration sphere under a second coordinate system, and the second coordinate system is a coordinate system under the auxiliary line laser profiler; determining a reflection parameter of the second coordinate system relative to the first coordinate system; determining conversion parameters from the second coordinate system to the first coordinate system according to the first coordinate, the second coordinate and the reflection parameters; and calibrating the line laser profiler system according to the conversion parameter and the reflection parameter, and realizing the calibration of the line laser profiler system.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate and explain the present disclosure, and together with the description serve to explain the present disclosure. In the drawings:

fig. 1 is a schematic view of an application scenario provided in an exemplary embodiment of the present disclosure;

FIG. 2 is a flow chart of steps of a method for calibrating a line laser profiler system according to an exemplary embodiment of the present disclosure;

FIG. 3 is a schematic diagram of an installation of a line laser profiler system without reflection provided by an exemplary embodiment of the present disclosure;

FIG. 4 is a schematic illustration of an installation of another line laser profiler system without reflection provided by an exemplary embodiment of the present disclosure;

FIG. 5 is a schematic diagram of a reflective mounting of a line laser profiler system according to an exemplary embodiment of the present disclosure;

FIG. 6 is a schematic diagram of another line laser profiler system with reflection provided in accordance with an exemplary embodiment of the present disclosure;

FIG. 7 is a schematic illustration of the presence of co-planar non-collinear calibration spheres provided by exemplary embodiments of the present disclosure;

FIG. 8 is a schematic view of only one calibration sphere and planar base provided by an exemplary embodiment of the present disclosure;

FIG. 9 is a schematic illustration of a plurality of calibration spheres co-linear provided by an exemplary embodiment of the present disclosure;

FIG. 10 is a schematic view of a laser surface perpendicular to an axis of motion provided by an exemplary embodiment of the present disclosure;

FIG. 11 is a schematic view of a laser surface non-perpendicular to the axis of motion provided by an exemplary embodiment of the present disclosure;

FIG. 12 is a flowchart of steps for determining a coordinate transformation matrix and a scaling matrix provided by an exemplary embodiment of the present disclosure;

FIG. 13 is a schematic diagram of a third coordinate system and a fourth coordinate system provided by an exemplary embodiment of the present disclosure;

FIG. 14 is a block diagram of a calibration device provided in an exemplary embodiment of the present disclosure;

fig. 15 is a schematic structural diagram of an electronic device according to an exemplary embodiment of the present disclosure.

Detailed Description

For the purposes of promoting an understanding of the principles and advantages of the disclosure, reference will now be made to the drawings and specific examples thereof, together with the following description. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present disclosure. Based on the embodiments in this disclosure, all other embodiments that a person of ordinary skill in the art would obtain without making any inventive effort are within the scope of protection of this disclosure.

Referring to FIG. 1, a line laser profiler system is shown comprising: a plurality of line laser profilers and a motion axis, wherein the motion axis drives the calibration ball along the directionMoving, the line laser profiler is stationary, i.e. the line laser and the calibration sphere are relatively moving, wherein the plurality of line laser profilers comprises: a baseline laser profiler and at least one auxiliary line laser profiler. If the line laser profiler system of fig. 1 is used to collect the three-dimensional dimensions of an object, the three-dimensional dimensions collected by the auxiliary line laser profiler are the auxiliary line laser profiler coordinate system (>) The three-dimensional dimensions acquired by the reference line laser profiler are the reference line laser profiler coordinate system (+.>) Therefore, the three-dimensional coordinates of the same object acquired by different line laser profilers are not in the same coordinate system, and the three-dimensional coordinates need to be converted into a uniform coordinate system to accurately process the measurement data. Accordingly, there is a need for a calibration method that can calibrate a line laser profiler system as shown in FIG. 1.

In summary, the present disclosure provides a calibration method of a line laser profiler system, by determining a reflection parameter existing between a reference line laser profiler and an auxiliary line laser profiler, and determining a conversion parameter from the auxiliary line laser profiler to the reference line laser profiler, the line laser profiler system is calibrated according to the reflection parameter and the conversion parameter, and three-dimensional parameters acquired by the auxiliary line laser profiler can be converted into a coordinate system of the reference line laser profiler.

FIG. 2 is a flow chart of steps of a calibration method of a line laser profiler system according to an exemplary embodiment of the present disclosure, the line laser profiler system including: a plurality of line laser profilers and motion axis, motion axis drive line laser profiler or calibration ball removal, line laser profiler and calibration ball relative movement, the relative position between a plurality of line laser profilers is fixed, a plurality of line laser profilers include: the calibration method specifically comprises the following steps of:

s201, obtaining a first coordinate obtained through a reference line laser profiler.

The first coordinate is a three-dimensional coordinate of the sphere center of the first calibration sphere under a first coordinate system, and the first coordinate system is a coordinate system under a reference line laser profiler.

Specifically, in the moving process of the motion axis, three-dimensional coordinates of a plurality of circumferences of the first calibration ball under the first coordinate system are obtained through the reference line laser profiler, and then the three-dimensional coordinates of the circumferences are fitted, so that the three-dimensional coordinates of the sphere center of the first calibration ball under the first coordinate system can be obtained. Wherein the first coordinate system is as shown in FIG. 1。

S202, for each auxiliary line laser profiler, a second coordinate obtained by the auxiliary line laser profiler is acquired.

The second coordinate is a three-dimensional coordinate of the sphere center of the second calibration sphere under a second coordinate system, and the second coordinate system is a coordinate system under the auxiliary line laser profiler.

And in the moving process of the motion axis, the three-dimensional coordinates of a plurality of circumferences of the second calibration sphere under the second coordinate system are obtained through the auxiliary line laser profiler, and then the three-dimensional coordinates of the circumferences are fitted, so that the three-dimensional coordinates of the sphere center of the second calibration sphere under the second coordinate system can be obtained. Wherein the second coordinate system is as shown in FIG. 1。

In the present disclosure, the first calibration sphere may be the same calibration sphere as the second calibration sphere, or may be a different calibration sphere. In addition, the number of the first calibration balls can be one or more, and the number of the second calibration balls can be one or more.

S203, determining reflection parameters of the second coordinate system relative to the first coordinate system.

Wherein the second coordinate system and the first coordinate system have reflection parameters when no reflection existsCan be expressed as. Reflection parameter in the presence of reflection->Can be expressed as +.>。

In one embodiment, determining reflection parameters of the second coordinate system relative to the first coordinate system includes: acquiring the mounting modes of a reference line laser profiler and an auxiliary line laser profiler; and determining a reflection parameter according to the installation mode, wherein the reflection parameter indicates no reflection if the reference line laser profiler can be overlapped with the auxiliary line laser profiler through rotation, and the reflection parameter indicates reflection if the reference line laser profiler cannot be overlapped with the auxiliary line laser profiler through rotation.

When reflection exists, the normal vector of the laser surface of the reference line laser profiler is opposite to the normal vector direction of the laser surface of the auxiliary line laser profiler.

Illustratively, in the various mounting arrangements shown in fig. 3 and 4, there is no reflection. In the various mounting arrangements shown in fig. 5 and 6, there is reflection.

In another embodiment, the first calibration sphere and the second calibration sphere may be placed on a planar base, and an asymmetric two-dimensional feature pattern is attached to the planar base, to determine a reflection parameter of the second coordinate system relative to the first coordinate system, including: acquiring a first image of an asymmetric two-dimensional characteristic pattern acquired by a reference line laser profiler; acquiring a second image of the asymmetric two-dimensional characteristic pattern acquired by the auxiliary line laser profiler; and determining reflection parameters according to the position relation between the asymmetric two-dimensional characteristic pattern in the first image and the asymmetric two-dimensional characteristic pattern in the second image.

If the asymmetric two-dimensional characteristic pattern in the first image can be obtained by rotation, the asymmetric two-dimensional characteristic pattern in the second image is not reflected. If the asymmetric two-dimensional feature pattern in the first image is not rotatable to obtain the asymmetric two-dimensional feature pattern in the second image, then a reflection is determined to be present.

In yet another embodiment, determining the reflection parameters of the second coordinate system relative to the first coordinate system includes: acquiring the actual distribution relation of the first calibration ball and the second calibration ball under the preset calibration scene; determining the detection distribution relation of the first calibration ball and the second calibration ball according to the point cloud information of the first calibration ball acquired by the reference line laser profiler and the point cloud information of the second calibration ball acquired by the auxiliary line laser profiler; determining the reflection parameter according to the actual distribution relation and the detection distribution relation;

the preset calibration scene is at least one of the following:

the number of the first calibration balls is 2, the number of the second calibration balls is 2, the diameters of the first calibration balls and the second calibration balls are not completely the same, and the sphere centers are coplanar and not collinear;

the number of the first calibration balls is greater than or equal to 3, the number of the second calibration balls is greater than or equal to 3, and the diameters of the first calibration balls and the second calibration balls are not identical.

Specifically, determining the reflection parameter by determining the distribution relation of each first calibration sphere and each second calibration sphere includes: acquiring actual distribution relations of the first calibration balls and the second calibration balls, acquiring detection distribution relations of the first calibration balls and the second calibration balls through a line laser profiler system, and determining reflection parameters according to the actual distribution relations and the detection distribution relations. For example, referring to fig. 7, if the number of the first calibration balls is 2 and the number of the second calibration balls is 2, and the diameters of the first calibration balls and the second calibration balls are not identical, and the centers of the balls are coplanar and not collinear, it may be determined whether there is reflection according to the actual distribution relationship and the detected distribution relationship of fig. 7.

In the disclosure, under a preset calibration scene, the actual distribution relation and the detection distribution relation of the first calibration sphere can determine a first coordinate system, the actual distribution relation and the detection distribution relation of the second calibration sphere can determine a second coordinate system, and then reflection parameters existing between the first coordinate system and the second coordinate system can be determined. The present disclosure is not limited to how the first coordinate system and the second coordinate system are determined specifically.

S204, according to the first coordinate, the second coordinate and the reflection parameter, determining a conversion parameter from the second coordinate system to the first coordinate system.

In one embodiment, the first calibration sphere and the second calibration sphere are the same calibration sphere, and the number of the calibration spheres is greater than or equal to three, and determining the conversion parameter from the second coordinate system to the first coordinate system according to the first coordinate, the second coordinate and the reflection parameter includes:

determining the conversion parameter according to a first formula, the first formula expressed as:wherein->Indicate->First coordinates of the calibration sphere, +.>Indicate->Second coordinates of the calibration sphere, +.>Representing reflection parameters +.>Representing rotation parameters +.>Representing the translation parameters.

In addition, the first formula may also be expressed as。

Illustratively, a first coordinate Second coordinates->. Wherein the rotation parameter is determined according to a first formula when the first and second coordinates of at least 3 centers of sphere are known>And translation parameter->。

In another embodiment, the first calibration balls and the second calibration balls are the same calibration balls, the number of the calibration balls is one, the first calibration balls are arranged on the plane base, as shown in fig. 8, the plane base can be in any shape with a flat surface, only one calibration ball is used, the calibration balls are the first calibration balls and the second calibration balls, and the reference line laser profiler and the auxiliary line laser profiler acquire three-dimensional point cloud for the calibration balls.

Determining conversion parameters from the second coordinate system to the first coordinate system based on the first coordinate, the second coordinate and the reflection parameters, comprising: acquiring first point cloud information of a plane where a calibration sphere is located, which is obtained through a reference line laser profiler, and fitting according to the first point cloud information to obtain a first normal vector of the plane; acquiring a first direction vector of a motion axis under a first coordinate system;determining a first rotation matrix from the first normal vector and the first direction vector, the first rotation matrix expressed as:the method comprises the steps of carrying out a first treatment on the surface of the Wherein (1)>Representing a first direction vector- >，/>Representing a first normal vector, ">The method comprises the steps of carrying out a first treatment on the surface of the Acquiring second point cloud information of a plane where a calibration sphere is located, which is obtained through an auxiliary line laser profiler, and fitting according to the second point cloud information to obtain a second normal vector of the plane; acquiring a second direction vector of a motion axis under a second coordinate system; determining a second rotation matrix from the second normal vector and the second direction vector, the second rotation matrix being expressed as: />The method comprises the steps of carrying out a first treatment on the surface of the Wherein (1)>Representing a second direction vector, ">，Representing a second normal vector, ">The method comprises the steps of carrying out a first treatment on the surface of the Determining a rotation parameter according to the first rotation matrix, the second rotation matrix and the reflection parameter, wherein the rotation parameter is expressed as: />Wherein->Representing the reflection parameter; and determining the difference value between the first coordinate and the second coordinate as a translation parameter.

The plane where the calibration ball is located can be a plane base.

In the context of the present disclosure of the present invention,、/>、/>andin "/">"means cross-multiplication. Further, use->Representing a first motion coordinate system under a reference line laser profiler, a first rotation matrix +.>Representing a rotation matrix of the first coordinate system to the first motion coordinate system. Similarly, use->Representing a second motion coordinate system under the auxiliary line laser profiler, a second rotation matrix +.>Representing a rotation matrix of the second coordinate system to the second motion coordinate system.

Further, the rotation parameter may also be expressed as:or->. Exemplary, the translation parameter is expressed as +.>。

In yet another embodiment, the number of the first calibration balls is greater than or equal to 2, the number of the second calibration balls is greater than or equal to 2, the connecting line between the center of each first calibration ball and the center of each second calibration ball is a straight line, and the straight line is coplanar with and not parallel to the motion axis, referring to fig. 9, wherein the first calibration balls and the second calibration balls may be the same or different.

Determining conversion parameters from the second coordinate system to the first coordinate system based on the first coordinate, the second coordinate and the reflection parameters, comprising: determining a third direction vector of the connecting line and a first direction vector of the motion axis under a first coordinate system; determining a third rotation matrix from the third direction vector and the first direction vector, the third rotation matrix being expressed as:wherein->，/>Representing a third direction vector, ">Representing a first direction vector +.>，The method comprises the steps of carrying out a first treatment on the surface of the Determining a fourth direction vector of the connecting line and a second direction vector of the motion axis in the second coordinate system; determining a fourth rotation matrix from the fourth direction vector and the second direction vector, the fourth rotation matrix being expressed as:wherein->，/>Representing a fourth direction vector, " >Representing a second direction vector, ">，/>The method comprises the steps of carrying out a first treatment on the surface of the Determining a rotation parameter according to the third rotation matrix, the fourth rotation matrix and the reflection parameter, wherein the rotation parameter is expressed as: />Wherein->Representing the reflection parameter; determining a third coordinate based on the first coordinate and the third rotation matrix, the third coordinate being denoted +.>Wherein->Indicate->First coordinates of the first calibration balls; determining first centroid coordinates according to third coordinates of the plurality of first calibration balls, wherein the first centroid coordinates are expressed as:wherein->Representing the number of first calibration balls; determining a fourth coordinate based on the second coordinate and the fourth rotation matrix, the fourth coordinate being denoted +.>Wherein->Indicate->Second coordinates of the second calibration balls; determining a second centroid coordinate according to fourth coordinates of the plurality of second calibration balls, wherein the second centroid coordinate is expressed as: />Wherein->Representing the number of second calibration balls; determining a translation parameter according to the first centroid coordinate and the second centroid coordinate, wherein the translation parameter is expressed as: />Wherein->The actual distance between the center of mass of each first calibration sphere and the center of mass of each second calibration sphere is represented.

Wherein the first direction vector of the movement axis is a vector of the movement direction of the movement axis in the first coordinate system, and the second direction vector of the movement axis is a vector of the movement direction of the movement axis in the second coordinate system.

S205, calibrating the line laser profiler system according to the conversion parameter and the reflection parameter.

In the embodiment of the present disclosure, referring to fig. 10, if the laser surface of each line laser profiler (reference line laser profiler or auxiliary line laser profiler) is aligned with the moving direction of the movement axisPerpendicular, the conversion parameters and reflection parameters can be used directly to scale the line laser profiler system.

Further, referring to fig. 11, if the moving direction of the moving axis isAnd if the line laser profiler is not perpendicular to the laser surface, calibrating the line laser profiler to obtain a coordinate conversion matrix and a scaling matrix of each line laser profiler, and further, calibrating the line laser profiler system according to conversion parameters and reflection parameters, wherein the line laser profiler system comprises: acquiring a corresponding coordinate transformation matrix and a scaling matrix for each line laser profiler; and calibrating the line laser profiler according to the coordinate transformation matrix, the scaling matrix, the transformation parameters and the reflection parameters.

Specifically, referring to fig. 12, the method of determining the coordinate transformation matrix and the scaling matrix for each line laser profiler includes the steps of:

and S1201, acquiring third point cloud information acquired by the line laser profiler.

The line fitting, the circle fitting and the ellipse fitting mentioned below in the present disclosure may be performed by using an existing fitting tool, and the present disclosure is not limited to the fitting tool.

Wherein the third point cloud information includes: calibrating three-dimensional coordinates of circumferences of a plurality of section circles of the ball under a third coordinate system, wherein the third coordinate system is a coordinate system of a system formed by a line laser profiler and a motion axis; wherein, referring to figures 11 and 13,representing a third coordinate system, ">Representing the fourth coordinate system, ">Representing the laser plane; />The (first vertical axis) represents the movement direction of the movement axis, namely the movement direction of the line laser profiler, and the laser surface formed by a plurality of laser lines emitted by the line laser profiler is also along +.>And (3) moving in the direction. />(second vertical axis) and->Axes (horizontal axis) and->The axis (vertical axis) is vertical.

In the present disclosure, for a reference line laser profiler, the fourth coordinate system is the first coordinate system of the reference line laser profiler, and for an auxiliary line laser profiler, the fourth coordinate system is the second coordinate system of the auxiliary line laser profiler.

In the method, a line laser profiler and a calibration ball relatively move, and the line laser profiler acquires point cloud information of the spherical surface of the calibration ball in the moving process.

Further, the third point cloud information is the three-dimensional coordinates of circumferences of a plurality of section circles of the calibration sphere under a third coordinate system;

In the embodiment of the disclosure, the line laser profiler acquires the point cloud information of the circumference of the cross-section circle, and then fits the third point cloud information of the circumference of the cross-section circle, so that the point cloud information of the center of the cross-section circle, namely the fifth coordinate of the center of the circle, can be obtained.

S1202, determining a fifth coordinate of the center of the cross-section circle under a third coordinate system according to the third point cloud information.

The fifth coordinate is a three-dimensional coordinate of the center of a cross-section circle of the calibration sphere under a third coordinate system, a horizontal axis and a vertical axis of the third coordinate system are used for representing a laser surface emitted by the line laser profiler, and a first vertical axis of the third coordinate system represents the moving direction of a moving axis.

Further, referring to (2) in fig. 11, the online laser profiler followsDuring the movement, the laser surface is also along +.>And moving, wherein the laser surface intersects with circumferences of a plurality of cross-section circles of the calibration sphere, so that third point cloud information of the circumferences under a third coordinate system can be acquired, and a fifth coordinate of the center of the cross-section circle under the third coordinate system can be obtained by fitting according to the third point cloud information.

In the embodiment of the disclosure, the fifth coordinate of the circle centers of a plurality of section circles of the calibration ball can be determined in the moving process of the line laser profiler.

S1203, a coordinate conversion matrix of the fifth coordinate to the sixth coordinate is determined.

Specifically, determining the coordinate conversion matrix of the fifth coordinate to the sixth coordinate includes: determining a calibration equation; determining a first intermediate equation according to the calibration equation; from the first intermediate equation, determineAnd->Is a value of (2); according to->And->Is used to determine the coordinate transformation matrix.

Wherein, the calibration equation is:the method comprises the steps of carrying out a first treatment on the surface of the Wherein (1)>Representing the fifth coordinate, ++>Representing the sixth coordinate, ++>Represents the angle between the first longitudinal axis and the second longitudinal axis, < >>The angle between the projection of the first longitudinal axis on the laser surface and the horizontal axis is shown.

Wherein the first intermediate equation is。

In the disclosed embodiment, referring to FIG. 2, the line laser profiler measures at each location during movementThe intersection line of the plane (laser surface) and the calibration sphere is still circular (i.e. the circumferences of a plurality of cross-section circles of the calibration sphere) due to the rotational symmetry of the calibration sphere, and the connection line of the centers of all cross-section circles is perpendicular to the laser plane, i.e. parallel to +.>A shaft (second longitudinal axis).

Further, it can be recorded in a third coordinate system) The center coordinates of the lower cross-section circle are +.>The method comprises the steps of carrying out a first treatment on the surface of the In the fourth coordinate system (+)>) The lower circle center coordinate is >. Wherein the line connecting the centers of all cross-sectional circles is parallel to +.>An axis, therefore, can be obtained +.A.of each cross-sectional circle with the movement of the line laser profiler>The values are the same for each cross-sectional circleThe values are identical. Based on this, the calibration equation is rewritten to obtain a first intermediate equation.

In an alternative embodiment, the determination is based on a first intermediate equationAnd->Comprises: determining a second intermediate equation according to the first intermediate equation, wherein the second intermediate equation is: />The method comprises the steps of carrying out a first treatment on the surface of the For->And->Performing linear fitting to obtain a first slope for +.>And->Performing linear fitting to obtain a second slope; determining a slope equation according to the second intermediate equation, the first slope and the second slope, wherein the slope equation is as follows: />Wherein->A first slope is indicated and a second slope is indicated,representing a second slope; determining +.>And->Is a value of (2).

Specifically, the first intermediate equation is eliminatedA second intermediate equation is obtained. From the second intermediate equation, one can get +.>And->Is a linear relationship of +.>And->Is to ∈>Performing straight line fitting to obtain a first slope +.>For->The second slope is +.>. Then there is a slope equation: The method comprises the steps of carrying out a first treatment on the surface of the And then get->Wherein, due to fitting, get +.>And->According to the above formula +.>And->Is a value of (2).

In another alternative embodiment, the determination is based on a first intermediate equationAnd->Comprises: under the condition that the first intermediate equation is determined to be a three-dimensional linear equation, determining a direction vector of the first intermediate equation, wherein the direction vector is expressed as:the method comprises the steps of carrying out a first treatment on the surface of the Fitting a normalized direction vector of the three-dimensional straight line, the normalized direction vector being expressed as: />The method comprises the steps of carrying out a first treatment on the surface of the Determining +.>And->The linear relationship is expressed as +.>Wherein->Is constant.

Specifically, the first intermediate equationConsidered as a three-dimensional straight line equation, the direction vector of the three-dimensional straight line equation is +.>Fitting the normalized direction vector of the three-dimensional straight line to +.>. Wherein the normalized direction vector->And (4) direction vector->There is a linear relationship，/>Is constant, then get->Solving the equation can be obtained>Due toAre all determined and can then obtain +.>And->Is a value of (2).

Wherein the coordinate transformation matrix is expressed as。

In this step, to determineAnd->The values of (2) are substituted into the matrix->And obtaining the coordinate transformation matrix.

S1204, determining a scaling matrix.

Specifically, determining the scaling matrix includes: determining a first radius of the cross-section circle according to the third point cloud information; determining a second longitudinal axis coordinate according to the third point cloud information and the coordinate conversion matrix; fitting a target ellipse according to the second longitudinal axis coordinate and the first radius to obtain a first ellipse half axis of the target ellipse along the laser surface direction and a second ellipse half axis along the second longitudinal axis direction; and determining a scaling matrix of the line laser profiler according to the first elliptic half axis and the second elliptic half axis.

The first radius of the cross-section circle can be obtained by fitting according to the third point cloud information of the cross-section circle. In the present disclosure, a first radius of each cross-sectional circle may be determined.

The second vertical axis coordinate is the vertical axis coordinate of the cross-section circle under the fourth coordinate system.

For example, if the third point cloud information includes a plurality of three-dimensional coordinates, the three-dimensional coordinates of the third point cloud information may be expressed as. Can be according to->Calculating to obtain three-dimensional coordinates of the cross-section circle (circumference and circle center) in the fourth coordinate system>Wherein ∈10 is determined>Is the second vertical axis coordinate. In embodiments of the present disclosure, a plurality of second longitudinal axis coordinates may be obtained.

In the present disclosure, if the measured profile of the line laser profiler and/or the encoder encoding interval is accurate, the fitting results are circular according to the second longitudinal axis coordinates and the first radius. If the measured contour of the line laser profiler and/or the coding interval of the encoder are inaccurate, the ellipse is obtained by fitting according to the second longitudinal axis coordinate and the first radius, namely the target ellipse.

The method comprises the step of fitting a target ellipse by using a plurality of second longitudinal axis coordinates corresponding to circumferences of a plurality of cross-section circles, second longitudinal axis coordinates of circle centers and a first radius.

Further, the half axis of the target ellipse along the laser plane direction is determined as a first ellipse half axis, and the half axis of the target ellipse along the second longitudinal axis direction is determined as a second ellipse half axis.

Referring to FIG. 2, after the third point cloud information of each cross-sectional circle is acquired, a target ellipse can be obtained by fitting, and a first ellipse half axis of the target ellipseAlong the laser plane direction, a first elliptic half-axis +.>Parallel to the laser plane and perpendicular to the second elliptical half axis. Second oval half axle->Along a second longitudinal axis.

In an alternative embodiment, if the actual radius of the calibration sphere is known, determining a scaling matrix for the line laser profiler based on the first elliptical half-axis and the second elliptical half-axis, comprising: acquiring the actual radius of the calibration sphere; determining the ratio of the actual radius to a first elliptic half axis as a first scaling factor of the line laser profiler system in the direction parallel to the laser surface; determining the ratio of the actual radius to a second elliptical half axis as a second scaling factor of the line laser profiler system in a second longitudinal axis direction; a scaling matrix is determined from the first scaling factor and the second scaling factor.

Specifically, if the actual radius isThe first elliptic half axis is +.>The second elliptic half axis is +.>First and second scaling factor tablesThe method is shown as follows: />Wherein->Representing a first scaling factor, ">Representing a second scaling factor.

In another alternative embodiment, if the actual radius of the calibration sphere is unknown, determining the scaling factor of the line laser profiler system based on the first elliptical half-axis and the second elliptical half-axis includes: determining a value 1 as a first scaling factor of the line laser profiler system in the radial direction of the calibration sphere; determining the ratio of the first elliptic half axis to the second elliptic half axis as a second scaling factor of the line laser profiler system in the direction of a second longitudinal axis; a scaling matrix is determined from the first scaling factor and the second scaling factor.

Specifically, if the radius of the calibration sphere is unknown, the laser surface fitting diameter may be used to correct scaling of the vertical axis, where the first scaling factor and the second scaling factor are expressed as:. Further, the scaling matrix is denoted +.>。

In one embodiment, the scaling matrix and the coordinate transformation matrix are determined as the final scaling matrix and coordinate transformation matrix of the line laser profiler.

In another embodiment, if a plurality of coordinate transformation matrices are obtained according to a plurality of calibration balls, determining an initial coordinate transformation matrix; wherein the initial coordinate transformation matrix is one of a plurality of coordinate transformation matrices, or the value in the initial coordinate transformation matrix is the average value of the values of at least part of the coordinate transformation matrices in the plurality of coordinate transformation matrices, and the beta value is the average value of the values of at least part of the coordinate transformation matrices in the plurality of coordinate transformation matrices; if a plurality of scaling matrixes are obtained according to a plurality of calibration balls, determining an initial scaling matrix; wherein the initial scaling matrix is one of a plurality of scaling matrices or is an average value of at least part of the plurality of scaling matrices; the line laser profiler system is calibrated according to the initial scaling matrix and the initial coordinate transformation matrix. The initial scaling matrix and the initial coordinate transformation matrix are determined as the final scaling matrix and coordinate transformation matrix of the line laser profiler.

In the present disclosure, if there are a plurality of calibration balls, the processing in the above manner may be performed on each calibration ball, and a coordinate transformation matrix and a scaling matrix may be obtained for each calibration ball. For example, there are three calibration balls #、/>And->) Wherein the calibration ball->Corresponding coordinate transformation matrix->Scaling matrix->The method comprises the steps of carrying out a first treatment on the surface of the Marking ball->Corresponding coordinate transformation matrix->Scaling matrix->The method comprises the steps of carrying out a first treatment on the surface of the Marking ball->Corresponding coordinate transformation matrix->Scaling matrix->. The initial coordinate transformation matrix may be a coordinate transformation matrix +.>Coordinate transformation matrix->And coordinate transformation matrix->For example, the initial coordinate transfer matrix may be the smallest coordinate transfer matrix +.>。

Or alternatively、/>、. Wherein ∈10 is obtained>、/>. Furthermore, the initial coordinate transformation matrix is obtained as +.>。

In the present disclosure, if the number of calibration balls and the distance between the calibration balls in the line laser profile system are determined according to the length of the object in the actual measurement scene, if a longer object needs to be measured, the number of calibration balls needs to be greater, and the distance between the calibration balls is greater.

In yet another alternative embodiment, when the number of calibration balls is greater than or equal to 2, the method further includes: adjusting an initial coordinate transformation matrix according to a preset cost function to obtain a target coordinate transformation matrix; adjusting an initial scaling matrix according to a preset cost function to obtain a target scaling matrix; then the target scaling matrix and the target coordinate transformation matrix are determined as the final scaling matrix and the coordinate transformation matrix of the line laser profiler

In an embodiment of the present disclosure, the matrix is transformed in determining the initial coordinatesAnd an initial scaling matrix->After that, the matrix can be transformed according to the initial coordinates +.>And an initial scaling matrix->Correcting the three-dimensional point cloud information on the surface of the calibration sphere, which is acquired by the linear laser profiler, to obtain corrected three-dimensional point cloud information, and then fitting the spherical center coordinates and the radius of the corresponding calibration sphere by using the corrected three-dimensional point cloud information. And then the spherical center coordinates and the radius of each calibration sphere can be obtained.

In an alternative embodiment, when the number of calibration balls is 2, the preset cost function is:；

wherein,the +.o representing the first calibration sphere>Three-dimensional coordinates of the spherical points in a third coordinate system, wherein,，/>is a positive integer; />Is the three-dimensional coordinate of the sphere center of the first calibration sphere under the fourth coordinate system, +.>The actual radius of the first calibration sphere;

the +.o representing the second calibration sphere>Three-dimensional coordinates of the spherical point in a third coordinate system, wherein,，/>is a positive integer; />Is the three-dimensional coordinate of the sphere center of the second calibration sphere under the fourth coordinate system, +.>For the actual radius of the second calibration sphere, +.>Is a constant coefficient>For the actual centre of sphere distance between the first calibration sphere and the second calibration sphere +. >Representing an initial coordinate transformation matrix,/>Representing the initial scaling matrix.

Wherein,for the spherical constraint of the calibration sphere +.>For the constraint of the center distance of the calibration ball, +.>Weight for adjusting the centre of gravity constraint relative to the sphere constraint, +.>The value of (2) can be predetermined according to the length of the center of sphere, the diameter of the calibration sphere and the number of points of the three-dimensional point cloud.

In the embodiment of the disclosure, the initial coordinate transformation matrix is adjusted by adopting a preset cost functionAnd an initial scaling matrix->Let the cost function value->Get the minimum +.>For the target coordinate transformation matrix, < > for>Scaling the matrix for the target.

In another alternative embodiment, if the number of balls is greater than or equal to 3, the preset cost function is:the method comprises the steps of carrying out a first treatment on the surface of the Wherein (1)>Indicate->The->Three-dimensional coordinates of the individual sphere points in a third coordinate system, wherein +.>，/>Is a positive integer>，/>Is a positive integer. />Is->Three-dimensional coordinates of the sphere centers of the calibration spheres under a calibration sphere coordinate system are +.>Is->The actual radius of each calibration sphere; />Representing an initial coordinate transformation matrix,/>Representing an initial scaling matrix +.>Rotation matrix representing the fourth coordinate system to the calibration sphere coordinate system,/>And representing a translation matrix from the fourth coordinate system to the calibration sphere coordinate system.

In embodiments of the present disclosure, if a ballWhen the number of (2) is greater than or equal to 3, the calibration sphere coordinate system may be predetermined according to the marker design. Using an initial coordinate transformation matrixInitial scaling matrixCorrecting the collected spherical point cloud under the third coordinate system to obtain a spherical point cloud under the fourth coordinate system; performing spherical fitting by using the corrected spherical point cloud to obtain spherical center coordinates; and calculating the rotational moment and the translation vector from the fourth coordinate system to the calibration spherical coordinate system by using the spherical center coordinate under the fourth coordinate system obtained by fitting and the spherical center coordinate under the known calibration spherical coordinate system through the existing rigid body transformation estimation algorithm. The present disclosure is not limited to rigid body transformation estimation algorithms.

If the number of balls is greater than or equal to 3, the initial coordinate transformation matrix can be adjusted by adopting the preset cost functionAnd an initial scaling matrix->Let the cost function value->Get the minimum +.>For the target coordinate transformation matrix, < > for>Scaling the matrix for the target.

If the number of the balls is greater than or equal to 3, the calibration ball coordinate system and the fourth coordinate system may have reflection, if the reflection exists, a reflection matrix is determined, and the reflection matrix is added in a preset cost function. The preset cost function may be expressed as: Wherein->Representing the reflection matrix.

In the embodiment of the application, if the target coordinate transformation matrix is obtainedAnd a target scaling matrix->And calibrating the line laser profile system by adopting a target coordinate transformation matrix and a target scaling matrix.

Further, in the using process of the line laser contour system, three-dimensional point cloud information of the object is acquired by adopting the line laser contour systemCalculating actual three-dimensional point cloud information +.>The method specifically comprises the following steps:，/>，。

in the present disclosure, the coordinate transformation matrix and scaling matrix of each line laser profiler may be determined first, then the reflection parameters of the auxiliary line laser profiler and the reference line laser are determined, and finally the transformation parameters of the auxiliary line laser profiler to the reference line laser are determined; the line laser profiler system is then scaled using the coordinate transformation matrix and scaling matrix, reflection parameters, and transformation parameters.

Further, the number of the first calibration balls is greater than or equal to 2, the first calibration balls and the second calibration balls are the same calibration balls, and the calibration line laser profiler comprises: adjusting the coordinate transformation matrix, the scaling matrix and the transformation matrix by adopting a target cost function to obtain a target coordinate transformation matrix, a target scaling matrix and a target transformation matrix; and calibrating the line laser profiler according to the target coordinate transformation matrix, the target scaling matrix, the target transformation matrix and the reflection parameters.

In one embodiment, the objective cost function is expressed as:

；

wherein,coordinate transformation matrix corresponding to the reference line laser profiler>Scaling matrix corresponding to the reference line laser profiler, < ->Represents the +.o. of baseline laser profilometer acquisition>First calibration sphere +.>Three-dimensional coordinates of the individual surface points, +.>Representing the first coordinate, ++>Representing rotation parameters +.>Coordinate transformation matrix corresponding to auxiliary line laser profiler>Representing the corresponding shrinkage of the auxiliary line laser profilerMatrix of placement->Representing +.>The +.o of the second calibration sphere>Three-dimensional coordinates of the individual surface points +.>First calibration sphere and +.>The second calibration balls are the same calibration ball, < >>Is->The sphere radius of the first calibration sphere is indicative of the translation parameter.

In another embodiment, the objective cost function is expressed as:

wherein,coordinate transformation matrix corresponding to the reference line laser profiler>Scaling matrix corresponding to the reference line laser profiler, < ->Represents the +.o. of baseline laser profilometer acquisition>First calibration sphere +.>Three-dimensional coordinates of the individual surface points, +.>Indicate->The coordinates of the sphere center of the individual sphere under a calibrated sphere coordinate system,/- >Rotation parameters representing the first coordinate system to the calibrated spherical coordinate system>Translation parameters representing the first coordinate system to the calibrated spherical coordinate system>Representing rotation parameters +.>Scaling matrix corresponding to auxiliary line laser profiler is represented, < ->Represents the coordinate transformation matrix corresponding to the auxiliary line laser profiler,represents the +.f. of auxiliary line laser profiler acquisition>The +.o of the second calibration sphere>Three-dimensional coordinates of the individual surface points, +.>Representing translation parameters->Indicate->Coordinates of the second calibration sphere on the sphere center coordinate system, < >>Indicate->Radius of the second calibration sphere.

In an embodiment of the present disclosure, the calibration sphere coordinate system is predetermined. Rotation parameters from the first coordinate system to the calibration sphere coordinate systemAnd the translation parameter of the first coordinate system to the calibration sphere coordinate system +.>The method comprises the steps of determining by using an existing rigid body transformation estimation algorithm according to spherical center coordinates in a first coordinate system, spherical center coordinates in a predetermined calibration spherical coordinate system and the determined reflection parameters.

Further, after the calibration of the on-line laser profiler system, the on-line laser profiler system may be used to correct the three-dimensional coordinates of the obtained object, where the three-dimensional coordinates of the object collected by the reference line laser profiler are expressed as Coordinate conversion matrix corresponding to reference line laser profiler>And scaling matrix->The corrected three-dimensional coordinates are. The three-dimensional coordinates of the object acquired by the auxiliary line laser profiler are expressed as +.>Auxiliary line laserCoordinate transformation matrix corresponding to profiler>And scaling matrix->Rotation parameters of auxiliary line laser profiler to reference line laser profiler +.>Translation parameter->And the reflection parameters of auxiliary line laser profiler and reference line laser profiler +.>The corrected three-dimensional coordinates are +.>。

In summary, the present disclosure achieves accurate calibration of a line laser profiler system by taking into account a plurality of influencing factors of the line laser profiler system.

Referring to fig. 14, for a block diagram of a calibration device 140 of a line laser profiler system provided by the present disclosure, the line laser profiler system includes: a plurality of line laser profilers and a motion axis, the motion axis driving movement of the line laser profilers or calibration balls, the plurality of line laser profilers comprising: the calibration device 140 specifically includes:

the calibration ball is used for calibrating the line laser profiler system;

the first obtaining module 141 is configured to obtain a first coordinate obtained by the reference line laser profiler, where the first coordinate is a three-dimensional coordinate of a center of a calibration sphere under a first coordinate system, and the first coordinate system is a coordinate system under the reference line laser profiler;

The second obtaining module 142 is configured to obtain, for each auxiliary line laser profiler, a second coordinate obtained by the auxiliary line laser profiler, where the second coordinate is a three-dimensional coordinate of a center of a sphere of the calibration sphere under a second coordinate system, and the second coordinate system is a coordinate system under the auxiliary line laser profiler;

a first determining module 143, configured to determine a reflection parameter of the second coordinate system relative to the first coordinate system;

a second determining module 144, configured to determine a conversion parameter from the second coordinate system to the first coordinate system according to the first coordinate, the second coordinate and the reflection parameter;

a calibration module 145 for calibrating the line laser profiler system based on the conversion parameters and the reflection parameters.

In an alternative embodiment, the first determining module 143 is specifically configured to obtain an installation manner of the reference line laser profiler and the auxiliary line laser profiler; and determining a reflection parameter according to the installation mode, wherein the reflection parameter indicates no reflection if the reference line laser profiler can be overlapped with the auxiliary line laser profiler through rotation, and the reflection parameter indicates reflection if the reference line laser profiler cannot be overlapped with the auxiliary line laser profiler through rotation.

In an alternative embodiment, the first calibration sphere and the second calibration sphere are placed on a planar base, and an asymmetric two-dimensional feature pattern is attached to the planar base, and the first determining module 143 is specifically configured to: acquiring a first image of an asymmetric two-dimensional characteristic pattern acquired by a reference line laser profiler; acquiring a second image of the asymmetric two-dimensional characteristic pattern acquired by the auxiliary line laser profiler; and determining reflection parameters according to the position relation between the asymmetric two-dimensional characteristic pattern in the first image and the asymmetric two-dimensional characteristic pattern in the second image.

In an alternative embodiment, the first determining module 143 is specifically configured to obtain, in a preset calibration scenario, an actual distribution relationship between the first calibration sphere and the second calibration sphere; determining the detection distribution relation of the first calibration ball and the second calibration ball according to the point cloud information of the first calibration ball acquired by the reference line laser profiler and the point cloud information of the second calibration ball acquired by the auxiliary line laser profiler; determining reflection parameters according to the actual distribution relation and the detection distribution relation;

the preset calibration scene is at least one of the following:

In an alternative embodiment, the conversion parameters include: the number of calibration balls is greater than or equal to three, and the second determining module 144 is specifically configured to determine the conversion parameter according to a first formula, where the first formula is expressed as:，/>indicate->First coordinates of the calibration sphere, +.>Indicate->Second coordinates of the calibration sphere, +.>Representing reflection parameters +.>Representing rotation parameters +.>Representing the translation parameters.

In an alternative embodiment, the number of calibration balls is one, and the second determining module 144 is specifically configured to: acquiring first point cloud information of a plane where a calibration sphere is located, which is obtained through a reference line laser profiler, and fitting according to the first point cloud information to obtain a first normal vector of the plane; acquiring a first direction vector of a motion axis under a first coordinate system;

determining a first rotation matrix from the first normal vector and the first direction vector, the first rotation matrix expressed as:the method comprises the steps of carrying out a first treatment on the surface of the Wherein (1)>Representing a first direction vector->，/>Representing a first normal vector, " >The method comprises the steps of carrying out a first treatment on the surface of the Acquiring second point cloud information of a plane where a calibration sphere is located, which is obtained through an auxiliary line laser profiler, and fitting according to the second point cloud information to obtain a second normal vector of the plane; acquiring a second direction vector of a motion axis under a second coordinate system; determining a second rotation matrix from the second normal vector and the second direction vector, the second rotation matrix being expressed as: />The method comprises the steps of carrying out a first treatment on the surface of the Wherein (1)>A second direction vector is represented as such,，/>representing a second normal vector, ">The method comprises the steps of carrying out a first treatment on the surface of the Determining a rotation parameter according to the first rotation matrix, the second rotation matrix and the reflection parameter, wherein the rotation parameter is expressed as:/>wherein->Representing the reflection parameter; and determining the difference value between the first coordinate and the second coordinate as a translation parameter.

In an alternative embodiment, the number of the first calibration balls is greater than or equal to 2, the number of the second calibration balls is greater than or equal to 2, the connecting line between the center of each first calibration ball and the center of each second calibration ball is a straight line, and the straight line is coplanar with and not parallel to the motion axis, and the second determining module 144 is specifically configured to: determining a third direction vector of the connecting line and a first direction vector of the motion axis under a first coordinate system; determining a third rotation matrix from the third direction vector and the first direction vector, the third rotation matrix being expressed as: Wherein->，/>Representing a third direction vector, ">Representing a first direction vector->，/>The method comprises the steps of carrying out a first treatment on the surface of the Determining a fourth direction vector of the connecting line and a second direction vector of the motion axis in the second coordinate system; determining a fourth rotation matrix from the fourth direction vector and the second direction vector, the fourth rotation matrix being expressed as: />Wherein->，/>Representing a fourth direction vector, ">Representing a second direction vector, ">，/>The method comprises the steps of carrying out a first treatment on the surface of the Determining a rotation parameter according to the third rotation matrix, the fourth rotation matrix and the reflection parameter, wherein the rotation parameter is expressed as: />Wherein->Representing the reflection parameter; determining a third coordinate based on the first coordinate and the third rotation matrix, the third coordinate being denoted +.>Wherein->Indicate->First coordinates of the first calibration balls; determining first centroid coordinates according to third coordinates of the plurality of first calibration balls, wherein the first centroid coordinates are expressed as:wherein->Representing the number of first calibration balls; determining a fourth coordinate based on the second coordinate and the fourth rotation matrix, the fourth coordinate being denoted +.>Wherein->Indicate->Second coordinates of the second calibration balls; determining a second centroid coordinate according to fourth coordinates of the plurality of second calibration balls, wherein the second centroid coordinate is expressed as: / >Wherein->Representing the number of second calibration balls; determining a translation parameter according to the first centroid coordinate and the second centroid coordinate, wherein the translation parameter is expressed as: />Wherein->The actual distance between the center of mass of each first calibration sphere and the center of mass of each second calibration sphere is represented.

In an alternative embodiment, calibration module 145 is specifically configured to: acquiring a corresponding coordinate transformation matrix and a scaling matrix for each line laser profiler; and calibrating the line laser profiler according to the coordinate transformation matrix, the scaling matrix, the transformation parameters and the reflection parameters.

In an alternative embodiment, the number of calibration balls is greater than or equal to 2, and the calibration module 145 is specifically configured to, when calibrating the line laser profiler according to the coordinate transformation matrix, the scaling matrix, the transformation parameter, and the reflection parameter: adjusting the coordinate transformation matrix, the scaling matrix and the transformation matrix by adopting a target cost function to obtain a target coordinate transformation matrix, a target scaling matrix and a target transformation matrix; and calibrating the line laser profiler according to the target coordinate transformation matrix, the target scaling matrix, the target transformation matrix and the reflection parameters.

In an alternative embodiment, the objective cost function is expressed as:；

wherein, Coordinate transformation matrix corresponding to the reference line laser profiler>Scaling matrix corresponding to the reference line laser profiler, < ->Represents the +.o. of baseline laser profilometer acquisition>First calibration sphere +.>Three-dimensional coordinates of the individual surface points, +.>Representing the first coordinate, ++>Representing rotation parameters +.>Coordinate transformation matrix corresponding to auxiliary line laser profiler>Scaling matrix corresponding to auxiliary line laser profiler is represented, < ->Representing +.>The +.o of the second calibration sphere>Three-dimensional coordinates of the individual surface points +.>First calibration sphere and +.>The second calibration balls are the same calibration ball, < >>Is->Sphere radius of the first calibration sphere, +.>To represent translation parameters.

In an alternative embodiment, the objective cost function is expressed as:

wherein,coordinate transformation matrix corresponding to the reference line laser profiler>Scaling matrix corresponding to the reference line laser profiler, < ->Represents the +.o. of baseline laser profilometer acquisition>First calibration sphere +.>Three-dimensional coordinates of the individual surface points, +.>Indicate->The coordinates of the sphere center of the individual sphere under a calibrated sphere coordinate system,/->Rotation parameters representing the first coordinate system to the calibrated spherical coordinate system >Translation parameters representing the first coordinate system to the calibrated spherical coordinate system>The rotation parameter is indicated as such,scaling matrix corresponding to auxiliary line laser profiler is represented, < ->Coordinate transformation matrix corresponding to auxiliary line laser profiler>Represents the +.f. of auxiliary line laser profiler acquisition>The +.o of the second calibration sphere>Three-dimensional coordinates of the individual surface points, +.>Representing translation parameters->Indicate->Coordinates of the second calibration sphere on the sphere center coordinate system, < >>Indicate->Radius of the second calibration sphere.

The calibration device provided by the disclosure can realize the calibration method, and specific reference is made to the above, and details are not repeated here.

In addition, in some of the above embodiments and the flows in the drawings, a plurality of operations appearing in a particular order are included, but it should be clearly understood that the operations may be performed out of order or performed in parallel in the order in which they appear herein, merely for distinguishing between the various operations, and the sequence number itself does not represent any order of execution. In addition, the flows may include more or fewer operations, and the operations may be performed sequentially or in parallel. It should be noted that, herein, "second", "first", etc. are used to distinguish different messages, devices, modules, etc., and do not represent a sequence, nor do they limit that "second" and "first" are different types.

Fig. 15 is a schematic structural diagram of an electronic device according to an exemplary embodiment of the present disclosure. As shown in fig. 15, the electronic device 150 includes: a processor 151, and a memory 152 communicatively coupled to the processor 151, the memory 152 storing computer-executable instructions.

The specific functions and the technical effects that can be achieved by the calibration method provided by any of the method embodiments are not described herein.

The disclosed embodiments also provide a computer-readable storage medium having stored therein computer-executable instructions that, when executed by a processor, are configured to implement any of the methods described above.

The disclosed embodiments also provide a computer program product comprising: a computer program stored in a readable storage medium, from which the computer program can be read by at least one processor of an electronic device, the at least one processor executing the computer program causing the electronic device to perform any one of the methods described above.

In the several embodiments provided in the present disclosure, it should be understood that the disclosed systems and methods may be implemented in other ways. For example, the system embodiments described above are merely illustrative, e.g., the division of elements is merely a logical functional division, and there may be additional divisions of actual implementation, e.g., multiple elements or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be through some interface, system or unit indirect coupling or communication connection, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present disclosure may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in hardware plus software functional units.

The integrated units implemented in the form of software functional units described above may be stored in a computer readable storage medium. The software functional unit is stored in a storage medium, and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor (processor) to perform part of the steps of the methods of the various embodiments of the disclosure. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

It will be clearly understood by those skilled in the art that, for convenience and brevity, only the above-mentioned division of the functional modules is illustrated, and in practical applications, the above-mentioned functional allocation may be performed by different functional modules according to needs, i.e. the internal structure of the system is divided into different functional modules to perform all or part of the above functions. The specific working process of the above system may refer to the corresponding process in the foregoing method embodiment, which is not described herein.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This disclosure is intended to cover any adaptations, uses, or adaptations of the disclosure following the general principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It is to be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the foregoing and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A method of calibrating a line laser profiler system, the line laser profiler system comprising: the line laser profiler comprises a plurality of line laser profilers and a motion shaft, wherein the motion shaft drives the line laser profiler or a calibration ball to move, and the line laser profilers comprise: a baseline laser profiler and at least one auxiliary line laser profiler, the calibration method comprising:

acquiring a first coordinate obtained through the reference line laser profiler, wherein the first coordinate is a three-dimensional coordinate of the sphere center of the calibration sphere under a first coordinate system, and the first coordinate system is a coordinate system under the reference line laser profiler;

determining a reflection parameter of a second coordinate system relative to a first coordinate system, the reflection parameter representing a reflection relationship of the second coordinate system with the first coordinate system, the reflection relationship comprising: the method comprises the steps of providing a reference line laser profiler, wherein the reference line laser profiler has a laser surface normal vector and an auxiliary line laser profiler laser surface normal vector direction when the reference line laser profiler has the reflection or not;

Determining a conversion parameter from the second coordinate system to the first coordinate system according to the first coordinate, the second coordinate and the reflection parameter;

calibrating the line laser profiler system based on the conversion parameter and the reflection parameter.

2. The method of calibrating according to claim 1, wherein said determining reflection parameters of the second coordinate system relative to the first coordinate system comprises:

acquiring the mounting modes of the reference line laser profiler and the auxiliary line laser profiler;

determining the reflection parameter according to the installation mode; and if the reference line laser profiler can not be overlapped with the auxiliary line laser profiler through rotation, the reflection parameter indicates no reflection, and if the reference line laser profiler can not be overlapped with the auxiliary line laser profiler through rotation, the reflection parameter indicates reflection.

3. The method of calibrating according to claim 1, wherein said determining reflection parameters of the second coordinate system relative to the first coordinate system comprises:

acquiring a first image of an asymmetric two-dimensional characteristic pattern acquired by the reference line laser profiler;

acquiring a second image of the asymmetric two-dimensional characteristic pattern acquired by the auxiliary line laser profiler;

And determining the reflection parameter according to the position relation between the asymmetric two-dimensional characteristic pattern in the first image and the asymmetric two-dimensional characteristic pattern in the second image.

4. The calibration method of claim 1, wherein the calibration sphere comprises a first calibration sphere and a second calibration sphere, the first calibration sphere being a calibration sphere under the baseline laser profiler and the second calibration sphere being a calibration sphere under an auxiliary line laser profiler, the determining reflection parameters of the second coordinate system relative to the first coordinate system comprising:

acquiring the actual distribution relation of the first calibration ball and the second calibration ball under a preset calibration scene;

determining the detection distribution relation of the first calibration ball and the second calibration ball according to the point cloud information of the first calibration ball acquired by the reference line laser profiler and the point cloud information of the second calibration ball acquired by the auxiliary line laser profiler;

determining the reflection parameter according to the actual distribution relation and the detection distribution relation;

the preset calibration scene is at least one of the following:

the number of the first calibration balls is 2, the number of the second calibration balls is 2, the diameters of the first calibration balls and the second calibration balls are not identical, the centers of the balls are coplanar and are not collinear, and at least one ball is not collinear with other balls;

5. The calibration method according to claim 1, wherein the conversion parameters include: and determining conversion parameters from the second coordinate system to the first coordinate system according to the first coordinate, the second coordinate and the reflection parameters, wherein the conversion parameters comprise:

determining a conversion parameter according to a first formula, wherein the first formulaThe formula is:，/>indicate->First coordinates of the calibration sphere, +.>Indicate->Second coordinates of the calibration sphere, +.>Which is indicative of the reflection parameter in question,representing the rotation parameter->Representing the translation parameter.

6. The calibration method according to claim 1, wherein the conversion parameters include: and determining a conversion parameter from the second coordinate system to the first coordinate system according to the first coordinate, the second coordinate and the reflection parameter, wherein the conversion parameter comprises the following components:

Acquiring first point cloud information of a plane where the calibration ball is located, which is obtained through the reference line laser profiler, and fitting according to the first point cloud information to obtain a first normal vector of the plane;

acquiring a first direction vector of the motion axis under the first coordinate system;

according to the first normal vector and the first direction vectorDetermining a first rotation matrix, the first rotation matrix being expressed as:the method comprises the steps of carrying out a first treatment on the surface of the Wherein (1)>Representing a first direction vector->，/>Representing a first normal vector, ">；

Acquiring second point cloud information of a plane where the calibration ball is located, which is obtained through the auxiliary line laser profiler, and fitting according to the second point cloud information to obtain a second normal vector of the plane;

acquiring a second direction vector of the motion axis under the second coordinate system;

determining a second rotation matrix from the second normal vector and the second direction vector, the second rotation matrix being expressed as:the method comprises the steps of carrying out a first treatment on the surface of the Wherein (1)>Representing a second direction vector, ">，/>Representing a second normal vector, ">；

Determining the rotation parameters according to the first rotation matrix, the second rotation matrix and the reflection parameters, wherein the rotation parameters are expressed as follows: Wherein, said->Representing the reflection parameter;

and determining the difference value between the first coordinate and the second coordinate as the translation parameter.

7. The calibration method according to claim 1, wherein the conversion parameters include: the rotation parameter and the translation parameter, the calibration ball includes first calibration ball and second calibration ball, first calibration ball is the calibration ball under the benchmark laser profiler, the second calibration ball is the calibration ball under the auxiliary line laser profiler, first calibration ball quantity is greater than or equal to 2, the second calibration ball quantity is greater than or equal to 2, the connecting line of the sphere center of each first calibration ball and the sphere center of each second calibration ball is the straight line, the straight line is coplanar and nonparallel with the motion axis, according to first coordinate, second coordinate and reflection parameter, confirm the conversion parameter of second coordinate system to first coordinate system includes:

determining a third direction vector of the connecting line and a first direction vector of the movement axis in the first coordinate system;

determining a third rotation matrix from the third direction vector and the first direction vector, the third rotation matrix being expressed as: Wherein->，/>Representing the third direction vector, +.>Representing the first direction vector, +.>，/>；

Determining a fourth direction vector of the connecting line and a second direction vector of the movement axis in the second coordinate system;

determining a fourth rotation matrix from the fourth direction vector and the second direction vector, the fourth rotation matrix being expressed as:wherein->，/>Representing the fourth direction vector, +.>Representing the second direction vector, +.>，/>；

Determining the rotation parameters according to the third rotation matrix, the fourth rotation matrix and the reflection parameters, wherein the rotation parameters are expressed as follows:wherein, said->Representing the reflection parameter;

determining a third coordinate from the first coordinate and the third rotation matrix, the third coordinate expressed asWherein->Indicate->First coordinates of the first calibration balls;

determining first centroid coordinates according to third coordinates of the plurality of first calibration balls, wherein the first centroid coordinates are expressed as:wherein->Representing the number of first calibration balls;

determining a fourth coordinate from the second coordinate and the fourth rotation matrix, the fourth coordinate expressed asWherein- >Indicate->Second coordinates of the second calibration balls;

determining second centroid coordinates according to fourth coordinates of the plurality of second calibration balls, wherein the second centroid coordinates are expressed as:wherein->Representing the number of second calibration balls;

determining the translation parameter according to the first centroid coordinate and the second centroid coordinate, wherein the translation parameter is expressed as:wherein->The actual distance between the center of mass of each first calibration sphere and the center of mass of each second calibration sphere is represented.

8. The calibration method according to any one of claims 1 to 7, characterized in that the calibrating the line laser profiler system according to the conversion parameter and the reflection parameter comprises:

acquiring a corresponding coordinate transformation matrix and a scaling matrix for each line laser profiler;

and calibrating the line laser profiler according to the coordinate transformation matrix, the scaling matrix, the transformation parameters and the reflection parameters.

9. The method of calibrating according to claim 8, wherein the number of calibration balls is greater than or equal to 2, the calibrating the line laser profiler according to the coordinate transformation matrix, the scaling matrix, the transformation parameters, and the reflection parameters, comprising:

Adjusting the coordinate transformation matrix, the scaling matrix and the transformation matrix by adopting a target cost function to obtain a target coordinate transformation matrix, a target scaling matrix and a target transformation matrix;

and calibrating the line laser profiler according to the target coordinate transformation matrix, the target scaling matrix, the target transformation matrix and the reflection parameters.

10. The calibration method according to claim 9, characterized in that the objective cost function is expressed as:；

wherein the saidRepresenting a coordinate transformation matrix corresponding to the reference line laser profiler, the +.>Representing a scaling matrix corresponding to the baseline laser profiler, the +.>Representing the +.f. of the baseline laser profiler acquisition>First calibration sphere +.>Three-dimensional coordinates of the individual surface points, said +.>Representing said first coordinate, said ++>Representing a rotation parameter, saidRepresenting a coordinate transformation matrix corresponding to the auxiliary line laser profiler, the +.>Representing a scaling matrix corresponding to the auxiliary line laser profiler,>representing the +.f. representing the acquisition of the auxiliary line laser profiler>The +.o of the second calibration sphere>Three-dimensional coordinates of the individual surface points, said +.>First calibration sphere and said +. >The second calibration balls are the same calibration ball, theIs->The sphere radius of the first calibration sphere, said +.>To represent translation parameters.

11. The calibration method according to claim 9, characterized in that the objective cost function is expressed as:wherein said->Representing a coordinate transformation matrix corresponding to the reference line laser profiler, the +.>Representing a scaling matrix corresponding to the baseline laser profiler, the +.>Representing the +.f. of the baseline laser profiler acquisition>First calibration sphere +.>Three-dimensional coordinates of the individual surface points, said +.>Indicate->The spherical center coordinates of each sphere under a calibrated spherical coordinate system are as followsRepresenting the rotation parameters of said first coordinate system to said calibrated spherical coordinate system, said +.>Representing a translation parameter of said first coordinate system to said calibrated spherical coordinate system, said +.>Representing said rotation parameter, said +.>Representing a scaling matrix corresponding to the auxiliary line laser profiler, said +.>Representing a coordinate transformation matrix corresponding to the auxiliary line laser profiler, theRepresenting the first ∈of the auxiliary line laser profiler acquisition>The +.o of the second calibration sphere>Three-dimensional coordinates of the individual surface points, said +.>Representing said translation parameter, said ++ >Indicate->The coordinates of the second calibration sphere on the sphere center coordinate system, said +.>Indicate->Radius of the second calibration sphere.

12. A calibration device for a line laser profiler system, the line laser profiler system comprising: the line laser profiler comprises a plurality of line laser profilers and a motion shaft, wherein the motion shaft drives the line laser profiler or a calibration ball to move, and the line laser profilers comprise: a baseline laser profiler and at least one auxiliary line laser profiler, the calibration device comprising:

the calibration ball is used for calibrating the line laser profiler system;

the second acquisition module is used for acquiring a second coordinate obtained by the auxiliary line laser profiler for each auxiliary line laser profiler, wherein the second coordinate is a three-dimensional coordinate of the sphere center of the calibration sphere under a second coordinate system, and the second coordinate system is a coordinate system under the auxiliary line laser profiler;

A first determining module, configured to determine a reflection parameter of a second coordinate system relative to a first coordinate system, where the reflection parameter represents a reflection relationship between the second coordinate system and the first coordinate system, and the reflection relationship includes: the method comprises the steps of providing a reference line laser profiler, wherein the reference line laser profiler has a laser surface normal vector and an auxiliary line laser profiler laser surface normal vector direction when the reference line laser profiler has the reflection or not;

13. An electronic device, comprising: processor, memory and computer program stored on the memory and executable on the processor, the processor executing the computer program implementing the calibration method according to any one of claims 1 to 11.

14. A computer readable storage medium, characterized in that the computer readable storage medium has stored therein computer executable instructions for implementing the calibration method according to any of claims 1 to 11 when executed by a processor.