CN112630751A - Calibration method of laser radar - Google Patents
Calibration method of laser radar Download PDFInfo
- Publication number
- CN112630751A CN112630751A CN201910952199.0A CN201910952199A CN112630751A CN 112630751 A CN112630751 A CN 112630751A CN 201910952199 A CN201910952199 A CN 201910952199A CN 112630751 A CN112630751 A CN 112630751A
- Authority
- CN
- China
- Prior art keywords
- group
- ground
- ground fitting
- point
- points
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 28
- 239000013598 vector Substances 0.000 claims abstract description 95
- 230000014509 gene expression Effects 0.000 claims description 9
- 150000001875 compounds Chemical class 0.000 claims description 6
- 238000001514 detection method Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 8
- 238000009434 installation Methods 0.000 description 6
- 239000000126 substance Substances 0.000 description 4
- 238000004364 calculation method Methods 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 230000008447 perception Effects 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 230000008859 change Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/497—Means for monitoring or calibrating
- G01S7/4972—Alignment of sensor
Abstract
The invention discloses a calibration method of a laser radar, which is used for a vehicle driving system and comprises the following steps: acquiring ground fitting point data of the laser radar, and calculating the position of each ground fitting point in a rectangular coordinate system according to the information of the ground fitting points; selecting a first group of ground fitting points and a second group of ground fitting points, wherein the first group of ground fitting points and the second group of ground fitting points have different included angles with the advancing direction of the vehicle, and respectively fitting a linear equation of the first group of ground fitting points and a linear equation of the second group of ground fitting points; calculating a first normal vector of a plane where the first group of ground fitting points are located and a second normal vector of a plane where the second group of ground fitting points are located according to the linear equation of the first group of ground fitting points and the linear equation of the second group of ground fitting points respectively; calculating an included angle between a first normal vector of a plane where the first group of ground fitting points are located and a second normal vector of a plane where the second group of ground fitting points are located; and analyzing the included angle to finish calibration.
Description
Technical Field
The invention relates to the technical field of laser radars, in particular to a calibration method of a laser radar.
Background
The laser radar determines the distance through the time difference and the phase difference of laser signals, measures the horizontal angle through horizontal rotation scanning or phase control scanning, and can carry out three-dimensional detection on the environment through acquiring multi-angle signals in the vertical direction. In a general laser radar attitude calibration method, a special measuring instrument is adopted to manually measure the pitch angle, the roll angle and the rotation angle of a laser radar during installation, and measurement data is written into a configuration file. The method has low calibration precision, easily causes false alarm during target detection, and can cause frequent false alarm of the target response of the automatic braking system in serious cases, thereby influencing the automatic driving experience. And the method cannot ensure the detection consistency of the batch application programs.
Disclosure of Invention
In view of this, the present invention provides a calibration method capable of automatically measuring a laser radar installation angle.
Based on the above purpose, the invention provides a calibration method of a laser radar, which is used for a vehicle driving system and comprises the following steps:
acquiring ground fitting point data of the laser radar, and calculating the position of each ground fitting point in the rectangular coordinate system according to the ground fitting point data;
selecting a first group of ground fitting points and a second group of ground fitting points, wherein the first group of ground fitting points and the second group of ground fitting points have different included angles with the advancing direction of the vehicle, and fitting a first group of linear equations and a second group of linear equations respectively;
calculating a first normal vector of a plane where the first group of ground fitting points are located and a second normal vector of a plane where the second group of ground fitting points are located according to the first group of linear equations and the second group of linear equations respectively;
calculating an included angle between the first normal vector and the second normal vector;
and analyzing the included angle to finish calibration.
In one embodiment, the first group of ground fit points comprises a first group of ground fit points and a second group of ground fit points, and the first group of ground fit points and the second group of ground fit points are symmetrically arranged; the included angle between the first grouping ground fitting point and the advancing direction of the vehicle is-15 degrees to-10 degrees, and the included angle between the second grouping ground fitting point and the advancing direction of the vehicle is 10 degrees to 15 degrees.
In one embodiment, the first set of linear equations includes a first spatially formulated linear equation and a second spatially formulated linear equation;
the expression of the first spatial linear equation is (1x-x0)/xa＝(1y-y0)/ya＝(1z-z0)/zaWherein, in the step (A),1x is variable and is a coordinate point of the first grouping ground fitting point on the x axis,1y is a variable and is a coordinate point of the ground fit point of the first packet on the y axis,1z is a variable and is a coordinate point of the first grouping ground fitting point on the z axis; x is the number of0、xa、y0、ya、z0And zaAre constants of a first space type linear equation, and a normal vector of the first space type linear equation is
The expression of the second spatial linear equation is (2x-x1)/xb＝(2y-y1)/yb＝(2z-z1)/zb(V) wherein, in the formula (V),2x is variable and is a coordinate point of the first grouping ground fitting point on the x axis,2y is a variable and is a coordinate point of the ground fit point of the first packet on the y axis,2z is a variable and is a coordinate point of the second group of ground fitting points on the z axis; x is the number of1、xb、y1、yb、z1And zbAre constants of a second spatial linear equation with a normal vector of
In one embodiment, the second set of ground fit points includes a third group of ground fit points and a fourth group of ground fit points, the third group of ground fit points and the fourth group of ground fit points being symmetrically disposed; the included angle between the fitting point of the third grouping ground and the advancing direction of the vehicle is-20 degrees to-15 degrees, and the included angle between the fitting point of the fourth grouping ground and the advancing direction of the vehicle is 15 degrees to 20 degrees.
In one embodiment, the second set of linear equations includes a third spatially formulated linear equation and a fourth spatially formulated linear equation;
the expression of the third spatial linear equation is (3x-x2)/xc＝(3y-y2)/yc＝(3z-z2)/zc(VI) wherein, in the formula (VI),3x is variable and is a coordinate point of the third grouping ground fitting point on the x axis,3y is variable and is a coordinate point of the third grouping ground fitting point on the y axis,3z is a variable and is a coordinate point of the third grouping ground fitting point on the z axis; x is the number of2、xc、y2、yc、z2And zcAre constants of a spatial linear equation, and the normal vector of the third spatial linear equation is
The expression of the fourth spatial equation is (4x-x3)/xd＝(4y-y3)/yd＝(4z-z3)/zdWherein, in the step (A),4x is variable and is a coordinate point of the fourth group of ground fitting points on the x axis,4y is variable and is the coordinate point of the fourth group of ground fitting points on the y axis,4z is a variable and is a coordinate point of the fourth group of ground fitting points on the z axis; x is the number of3、xd、y3、yd、z3And zdAre constants of a space linear equation, and the normal vector of the fourth space linear equation is
In one embodiment, the first normal vector passes through a system of equations
So as to obtain the compound with the characteristics of,
a first normal vector of a plane where the first group of ground fitting points are located,
is the normal vector of the first spatial equation,
is a normal vector of a second space type linear equation;
the second normal vector of the plane where the second group of ground fitting points are located passes through the equation set
So as to obtain the compound with the characteristics of,
is the normal vector of the plane where the first group of ground fitting points are located,
is the normal vector of the third space-wise linear equation,
is the normal vector of the fourth space-based linear equation.
In one embodiment, the included angle is expressed as,
wherein theta is an included angle,
a first normal vector of a plane where the first group of ground fitting points are located,
and the normal vector of the plane where the second group of ground fitting points are located.
In one embodiment, the calculating the position of each ground fitting point in the rectangular coordinate system according to the information of the ground fitting points comprises:
by the formula x ═ L × cos (δ) × sin (γ)azimuth) Calculating a coordinate point of the ground fitting point on an x axis, wherein x is the coordinate point of the ground fitting point on the x axis, L is the longitudinal distance from the ground fitting point to the laser radar, cos is cosine, delta is the vertical angle between the ground fitting point and the laser radar, sin is sine, and gamma isazimuthFitting points for the ground and the horizontal angular resolution of the laser radar;
by the formula y ═ L ═ cos (δ) × (γ)azimuth) Calculating a coordinate point of the ground fitting point on a y axis, wherein y is the coordinate point of the ground fitting point on the y axis;
and calculating the coordinate point of the ground fitting point on the z axis by the formula z-L sin (delta), wherein z is the coordinate point of the ground fitting point on the z axis.
In one embodiment, the step of analyzing the included angle and completing calibration includes: and judging whether the included angle is smaller than a preset threshold value, and if so, respectively recording the coordinates of the first normal vector and the second normal vector to finish calibration.
In one embodiment, the preset threshold is 1 ° to 10 °.
From the above, the calibration method of the laser radar provided by the invention can be seen by selecting the first group of ground fitting points and the second group of ground fitting points with different included angles with the vehicle advancing direction, respectively fitting the linear equation of the corresponding first group of ground fitting points and the linear equation of the corresponding second group of ground fitting points, then calculating the first normal vector of the plane where the first group of ground fitting points are located and the second normal vector of the plane where the second group of ground fitting points are located, and completing the calibration according to the included angle between the first normal vector and the second normal vector. Therefore, automatic detection of the installation posture of the laser radar is achieved, man-hour is short without manual consumption, and consistency of laser radar detection programs can be guaranteed.
Drawings
Fig. 1 is a schematic diagram of a pitch angle ω of a lidar according to an embodiment of the invention;
FIG. 2 is a schematic diagram of a roll angle γ of a lidar according to an embodiment of the invention;
fig. 3 is a schematic view of a rotation angle α of the lidar according to an embodiment of the present invention;
FIG. 4 is a flowchart of a calibration method for a laser radar according to an embodiment of the present invention;
fig. 5 is a schematic diagram of a ground fitting point according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments and the accompanying drawings.
The environmental perception system is a key system for realizing intelligent driving. The environment sensing system usually comprises a camera, a millimeter wave radar and a laser radar, and the detection precision of the laser radar is directly influenced by the precision of the installation posture of the laser radar. Therefore, the calibration of the lidar is the most important loop in the debugging of the sensing system. The calibration of the laser radar means 1) measuring the installation position of the laser radar, namely the offset on X, Y and Z coordinates relative to a perception coordinate system; 2) the attitude of the lidar, i.e., pitch angle, roll angle, and rotation angle, is measured. Fig. 1 is a schematic diagram of the pitch angle ω of the lidar. Fig. 2 is a schematic diagram of a roll angle γ of the lidar. Fig. 3 is a schematic diagram of the rotation angle α of the lidar.
The usual attitude calibration of the coordinates of the lidar is manually calibrated by the measuring instrument and the measured values are filled into a parameter file for manual updating. The inventor of the application finds that the manual measurement method has inevitable errors in long-term test work, and the situation that the errors of a plurality of vehicles are inconsistent is not favorable for ensuring the consistency of the laser radar detection program. The application analyzes the data of the laser radar point cloud, respectively fits the planes where the two groups of measuring points are located, analyzes the error of the normal vectors of the two planes, updates the parameters and automatically calibrates the laser radar.
Referring to fig. 4, an embodiment of the present invention provides a method for calibrating a laser radar, which is used for a vehicle driving system, and includes:
s100, obtaining ground fitting point data of the laser radar, and calculating the position of each ground fitting point in a rectangular coordinate system according to the ground fitting point data;
s200, selecting a first group of ground fitting points and a second group of ground fitting points, wherein the first group of ground fitting points and the second group of ground fitting points have different included angles with the advancing direction of the vehicle, and respectively fitting a first group of linear equations and a second group of linear equations;
s300, calculating a first normal vector of a plane where the first group of ground fitting points are located and a second normal vector of a plane where the second group of ground fitting points are located according to the first group of linear equations and the second group of linear equations respectively;
s400, calculating an included angle between the first normal vector and the second normal vector;
and S500, analyzing the included angle to finish calibration.
According to the calibration method of the laser radar, the first group of ground fitting points and the second group of ground fitting points which have different included angles with the advancing direction of the vehicle are selected, the corresponding first group of linear equations and the second group of linear equations are respectively fitted, then the first normal vector of the plane where the first group of ground fitting points are located and the second normal vector of the plane where the second group of ground fitting points are located are calculated, and calibration can be completed according to the included angle between the first normal vector and the second normal vector. Therefore, automatic detection of the installation posture of the laser radar is achieved, man-hour is short without manual consumption, and consistency of laser radar detection programs can be guaranteed.
Before step S100, the vehicle mounted with the laser radar is stopped on a horizontal road surface.
In step S100, the ground fitting point data refers to data of points, at the same angle, where the distance difference does not change suddenly, in the point cloud data obtained when the laser beam in the laser radar scans the flat ground, as shown in fig. 5. The ground fitting points form a plurality of elliptical areas, the origins of the ellipses are the same, and the lengths of the major axes and the minor axes of the ellipses are different. The information of each ground fitting point comprises the longitudinal distance L between the ground fitting point and the laser radar, the vertical angle delta between the ground fitting point and the laser radar, and the horizontal angle resolution gamma between the ground fitting point and the laser radarazimuth。
Wherein, calculating the position of each ground fitting point in the rectangular coordinate system according to the information of the ground fitting points comprises: and (3) calculating a coordinate point of the ground fitting point on the x axis through a formula (I), calculating a coordinate point of the ground fitting point on the y axis through a formula (II), and calculating a coordinate point of the ground fitting point on the z axis through a formula (III).
x＝L*cos(δ)*sin(γazimuth)(Ⅰ)；y＝L*cos(δ)*cos(γazimuth) (II); z ═ L × sin (δ) (iii). Wherein x is a coordinate point of the ground fitting point on the x axis; y is a coordinate point of the ground fitting point on the y axis; z is a coordinate point of the ground fitting point on the z axis, L is the longitudinal distance between the ground fitting point and the laser radar, cos is cosine, delta is the vertical angle between the ground fitting point and the laser radar, sin is sine, and gamma isazimuthFitting points to the ground with the horizontal and angular resolution of the lidar.
In step S200, the first group of ground fitting points and the second group of ground fitting points selected both include a plurality of ground fitting points, and the plurality of ground fitting points are respectively distributed on different ellipses. Optionally, the plurality of ground fit points comprises points on each ellipse. The first group of ground fitting points and the second group of ground fitting points have different included angles with the advancing direction of the vehicle so as to avoid the first group of ground fitting points and the second group of ground fitting points from being overlapped.
The first set of ground fit points includes a first group of ground fit points and a second group of ground fit points. The included angles between the first grouping ground fitting point and the second grouping ground fitting point and the advancing direction of the vehicle are different, so that the accuracy of plane simulation is improved. The first sub-group ground fit point and the second sub-group ground fit point may be symmetrically disposed. Optionally, the first group ground fitting point forms an angle θ with the vehicle forward direction1Is-15 degrees to-10 degrees, and the included angle theta between the second sub-group ground fitting point and the advancing direction of the vehicle2Is 10-15 degrees.
The second set of ground fit points includes a third grouping of ground fit points and a fourth grouping of ground fit points. The included angles between the first grouping ground fitting point and the second grouping ground fitting point and the advancing direction of the vehicle are different, so that the accuracy of plane simulation is improved. The third grouping ground fitting point and the fourth grouping ground fitting point are symmetrically arranged. Optionally, the third grouping ground fitting point forms an angle θ with the vehicle forward direction3Is-20 degrees to-15 degrees, and the angle theta between the fourth group of ground fitting points and the advancing direction of the vehicle4Is 15-20 degrees.
The linear equation of each group of ground fitting points can be a spatial linear equation, and the linear equation of each group of ground fitting points comprises two linear equations. The first set of linear equations includes a first spatial linear equation and a second spatial linear equation. Namely, the first grouping of ground fit points and the second grouping of ground fit points respectively correspond to the first spatial equation of straight line and the second spatial equation of straight line. The second set of linear equations includes a third spatial linear equation and a fourth spatial linear equation. The third grouping ground fit point and the fourth grouping ground fit point correspond to a third spatial equation of straight lines and a fourth spatial equation of straight lines respectively.
The first spatial equation is calculated by the formula (IV) (IV)1x-x0)/xa＝(1y-y0)/ya＝(1z-z0)/za(IV). Wherein the content of the first and second substances,1x is variable and is a coordinate point of the first grouping ground fitting point on the x axis,1y is a variable and is a coordinate point of the ground fit point of the first packet on the y axis,1z is a variable and is a coordinate point of the first grouping ground fitting point on the z axis; x is the number of0、xa、y0、ya、z0And zaAre constants of a first space type linear equation, and a normal vector of the first space type linear equation is
The second spatial linear equation is calculated by the formula (V) ((V))2x-x1)/xb＝(2y-y1)/yb＝(2z-z1)/zb(V). Wherein the content of the first and second substances,2x is variable and is a coordinate point of the first grouping ground fitting point on the x axis,2y is a variable and is a coordinate point of the ground fit point of the first packet on the y axis,2z is a variable and is a coordinate point of the second group of ground fitting points on the z axis; x is the number of1、xb、y1、yb、z1And zbAre constants of a second spatial linear equation with a normal vector of
The third space equation is calculated by the formula (VI) < CHEM >3x-x2)/xc＝(3y-y2)/yc＝(3z-z2)/zc(VI). Wherein the content of the first and second substances,3x is variable and is a coordinate point of the third grouping ground fitting point on the x axis,3y is variable and is a coordinate point of the third grouping ground fitting point on the y axis,3z is a variable and is a coordinate point of the third grouping ground fitting point on the z axis; x is the number of2、xc、y2、yc、z2And zcAll constants of a space linear equation, a third space equationThe normal vector of the linear equation is
The fourth space-wise linear equation is calculated by the formula (VII) < CHEM >4x-x3)/xd＝(4y-y3)/yd＝(4z-z3)/zd(VII). Wherein the content of the first and second substances,4x is variable and is a coordinate point of the fourth group of ground fitting points on the x axis,4y is variable and is the coordinate point of the fourth group of ground fitting points on the y axis,4z is a variable and is a coordinate point of the fourth group of ground fitting points on the z axis; x is the number of3、xd、y3、yd、z3And zdAre constants of a space linear equation, and the normal vector of the fourth space linear equation is
In step S300, a first normal vector of a plane where the first group of ground fitting points are located passes through a system of equations
So as to obtain the compound with the characteristics of,
a first normal vector of a plane where the first group of ground fitting points are located,
is the normal vector of the first spatial equation,
is the normal vector of the second space-based linear equation.
The second normal vector of the plane where the second group of ground fitting points are located passes through the equation set
So as to obtain the compound with the characteristics of,
is the normal vector of the plane where the first group of ground fitting points are located,
is the normal vector of the third space-wise linear equation,
is the normal vector of the fourth space-based linear equation.
In step S400, the included angle is calculated by formula (viii),
wherein theta is an included angle,
a first normal vector of a plane where the first group of ground fitting points are located,
and the normal vector of the plane where the second group of ground fitting points are located.
In step S500, the step of analyzing the included angle and completing calibration includes: and comparing the included angle with a preset threshold, and recording the coordinates of the first normal vector and the second normal vector when the included angle is smaller than the preset threshold, so as to finish calibration. At this time, the parameters of the first normal vector and the second normal vector, of which the included angle is smaller than the preset threshold value, are stored as the parameters of the ground normal vector. And when the included angle is larger than the preset threshold, returning to the step S200, reselecting the ground fitting points, and performing subsequent calculation until the included angle between the first normal vector of the plane where the first group of ground fitting points are located and the second normal vector of the plane where the second group of ground fitting points are located is smaller than the preset threshold.
The preset threshold value is related to the intersection where the vehicle runs, and the better the road condition is, the smaller the value is. Optionally, the preset threshold is 1 ° to 10 °.
In the method for calibrating the laser radar provided by the embodiment of the invention, when the method is implemented specifically, a vehicle carrying the laser radar is stopped on a horizontal road surface, a laser beam in the laser radar starts to scan the ground, and data of points with non-abrupt distance difference at the same angle are selected. During selection, two groups of data points with an included angle of-15 degrees to-10 degrees and an included angle of 10 degrees to 15 degrees are respectively selected to simulate a first space type linear equation and a second space type linear equation, and a first normal vector is calculated; two groups of data points with an included angle of-20 degrees to-15 degrees and an included angle of 15 degrees to 20 degrees are respectively selected to simulate a third space type linear equation and a fourth space type linear equation, and a second plane normal vector is calculated. And calculating an included angle between the first normal vector and the second normal vector, comparing whether the obtained included angle is smaller than a preset threshold value, and if the result is negative, selecting the first group of ground fitting points and the second group of ground fitting points again until the result is positive. And recording the parameters of the first normal vector and the second normal vector when the result is yes as the parameters of the ground normal vector, namely completing the calibration. The method has the advantages that the method can accurately and automatically calibrate only by the aid of laser radar point cloud without other auxiliary equipment; meanwhile, the plane is fitted through a plurality of groups of ground fitting points, so that the accuracy of plane parameters is improved; and the included angle between the normal vectors of the planes is compared with a preset threshold determined according to the road condition information, and the parameters of the normal vectors smaller than the preset threshold are recorded to realize more accurate parameter selection. The method can reduce the manual calibration of the laser radar and reduce the workload; the laser radar can be automatically calibrated, and the calibration precision is higher than that of manual calibration; the consistency of the laser radar target detection program is improved.
The embodiment of the invention also provides a calibration device of the laser radar, which comprises:
the ground fitting point coordinate calculation module is used for acquiring ground fitting point data of the laser radar and calculating the position of each ground fitting point in the rectangular coordinate system according to the information of the ground fitting points;
the linear equation fitting module is used for selecting a first group of ground fitting points and a second group of ground fitting points, wherein the first group of ground fitting points and the second group of ground fitting points have different included angles with the advancing direction of the vehicle, and respectively fitting a linear equation of the first group of ground fitting points and a linear equation of the second group of ground fitting points;
the normal vector solving module is used for calculating a first normal vector of a plane where the first group of ground fitting points are located and a second normal vector of a plane where the second group of ground fitting points are located according to a linear equation of the first group of ground fitting points and a linear equation of the second group of ground fitting points respectively;
the normal vector included angle calculation module is used for calculating the included angle between a first normal vector of the plane where the first group of ground fitting points are located and a second normal vector of the plane where the second group of ground fitting points are located;
and the analysis module is used for analyzing the included angle to finish calibration.
Optionally, the analysis module further comprises:
the judgment submodule is used for judging whether the included angle is smaller than a preset threshold value or not and outputting a judgment result;
and the parameter storage submodule is used for respectively recording the coordinates of the first normal vector and the second normal vector when the judgment result is yes, so as to finish calibration.
It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are used for distinguishing two entities with the same name but different names or different parameters, and it should be noted that "first" and "second" are merely for convenience of description and should not be construed as limitations of the embodiments of the present invention, and they are not described in any more detail in the following embodiments.
Those of ordinary skill in the art will understand that: the discussion of any embodiment above is meant to be exemplary only, and is not intended to intimate that the scope of the disclosure, including the claims, is limited to these examples; within the idea of the invention, also features in the above embodiments or in different embodiments may be combined, steps may be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.
In addition, well known power/ground connections to Integrated Circuit (IC) chips and other components may or may not be shown within the provided figures for simplicity of illustration and discussion, and so as not to obscure the invention. Furthermore, devices may be shown in block diagram form in order to avoid obscuring the invention, and also in view of the fact that specifics with respect to implementation of such block diagram devices are highly dependent upon the platform within which the present invention is to be implemented (i.e., specifics should be well within purview of one skilled in the art). Where specific details (e.g., circuits) are set forth in order to describe example embodiments of the invention, it should be apparent to one skilled in the art that the invention can be practiced without, or with variation of, these specific details. Accordingly, the description is to be regarded as illustrative instead of restrictive.
While the present invention has been described in conjunction with specific embodiments thereof, many alternatives, modifications, and variations of these embodiments will be apparent to those of ordinary skill in the art in light of the foregoing description. For example, other memory architectures (e.g., dynamic ram (dram)) may use the discussed embodiments.
The embodiments of the invention are intended to embrace all such alternatives, modifications and variances that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, substitutions, improvements and the like that may be made without departing from the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (10)
1. A calibration method of a laser radar is used for a vehicle driving system, and is characterized by comprising the following steps:
acquiring ground fitting point data of the laser radar, and calculating the position of each ground fitting point in the rectangular coordinate system according to the ground fitting point data;
selecting a first group of ground fitting points and a second group of ground fitting points, wherein the first group of ground fitting points and the second group of ground fitting points have different included angles with the advancing direction of the vehicle, and fitting a first group of linear equations and a second group of linear equations respectively;
calculating a first normal vector of a plane where the first group of ground fitting points are located and a second normal vector of a plane where the second group of ground fitting points are located according to the first group of linear equations and the second group of linear equations respectively;
calculating an included angle between the first normal vector and the second normal vector;
and analyzing the included angle to finish calibration.
2. The lidar calibration method according to claim 1, wherein the first group of ground fit points comprises a first group of ground fit points and a second group of ground fit points, and the first group of ground fit points and the second group of ground fit points are symmetrically arranged; the included angle between the first grouping ground fitting point and the advancing direction of the vehicle is-15 degrees to-10 degrees, and the included angle between the second grouping ground fitting point and the advancing direction of the vehicle is 10 degrees to 15 degrees.
3. The lidar calibration method according to claim 2, wherein the first set of linear equations comprises a first spatial linear equation and a second spatial linear equation;
the expression of the first spatial linear equation is (1x-x0)/xa＝(1y-y0)/ya＝(1z-z0)/zaWherein, in the step (A),1x is variable and is a coordinate point of the first grouping ground fitting point on the x axis,1y is a variable and is a coordinate point of the ground fit point of the first packet on the y axis,1z is a variable and is a coordinate point of the first grouping ground fitting point on the z axis; x is the number of0、xa、y0、ya、z0And zaAre constants of a first space type linear equation, and a normal vector of the first space type linear equation is
The expression of the second spatial linear equation is (2x-x1)/xb＝(2y-y1)/yb＝(2z-z1)/zb(V) wherein, in the formula (V),2x is variable and is a coordinate point of the first grouping ground fitting point on the x axis,2y is a variable and is a coordinate point of the ground fit point of the first packet on the y axis,2z is a variable and is a coordinate point of the second group of ground fitting points on the z axis; x is the number of1、xb、y1、yb、z1And zbAre constants of a second spatial linear equation with a normal vector of
4. The lidar calibration method according to claim 3, wherein the second group of ground fitting points comprises a third group of ground fitting points and a fourth group of ground fitting points, and the third group of ground fitting points and the fourth group of ground fitting points are symmetrically arranged; the included angle between the fitting point of the third grouping ground and the advancing direction of the vehicle is-20 degrees to-15 degrees, and the included angle between the fitting point of the fourth grouping ground and the advancing direction of the vehicle is 15 degrees to 20 degrees.
5. The lidar calibration method according to claim 4, wherein the second set of linear equations comprises a third spatial linear equation and a fourth spatial linear equation;
the expression of the third spatial linear equation is (3x-x2)/xc＝(3y-y2)/yc＝(3z-z2)/zc(VI) wherein, in the formula (VI),3x isThe variable is a coordinate point of the third grouping ground fitting point on the x axis,3y is variable and is a coordinate point of the third grouping ground fitting point on the y axis,3z is a variable and is a coordinate point of the third grouping ground fitting point on the z axis; x is the number of2、xc、y2、yc、z2And zcAre constants of a spatial linear equation, and the normal vector of the third spatial linear equation is
The expression of the fourth spatial equation is (4x-x3)/xd＝(4y-y3)/yd＝(4z-z3)/zdWherein, in the step (A),4x is variable and is a coordinate point of the fourth group of ground fitting points on the x axis,4y is variable and is the coordinate point of the fourth group of ground fitting points on the y axis,4z is a variable and is a coordinate point of the fourth group of ground fitting points on the z axis; x is the number of3、xd、y3、yd、z3And zdAre constants of a space linear equation, and the normal vector of the fourth space linear equation is
6. The lidar calibration method of claim 5, wherein the first normal vector passes through a system of equations
So as to obtain the compound with the characteristics of,
a first normal vector of a plane where the first group of ground fitting points are located,
is the first emptyThe normal vector of the equation of the formula,
is a normal vector of a second space type linear equation;
the second normal vector of the plane where the second group of ground fitting points are located passes through the equation set
So as to obtain the compound with the characteristics of,
is the normal vector of the plane where the first group of ground fitting points are located,
is the normal vector of the third space-wise linear equation,
is the normal vector of the fourth space-based linear equation.
7. The method for calibrating laser radar according to claim 6, wherein the included angle is expressed as,
wherein theta is an included angle,
a first normal vector of a plane where the first group of ground fitting points are located,
and the normal vector of the plane where the second group of ground fitting points are located.
8. The lidar calibration method according to claim 1, wherein the calculating the position of each ground fitting point in the rectangular coordinate system according to the information of the ground fitting points comprises:
by the formula x ═ L × cos (δ) × sin (γ)azimuth) Calculating a coordinate point of the ground fitting point on an x axis, wherein x is the coordinate point of the ground fitting point on the x axis, L is the longitudinal distance from the ground fitting point to the laser radar, cos is cosine, delta is the vertical angle between the ground fitting point and the laser radar, sin is sine, and gamma isazimuthFitting points for the ground and the horizontal angular resolution of the laser radar;
by the formula y ═ L ═ cos (δ) × (γ)azimuth) Calculating a coordinate point of the ground fitting point on a y axis, wherein y is the coordinate point of the ground fitting point on the y axis;
and calculating the coordinate point of the ground fitting point on the z axis by the formula z-L sin (delta), wherein z is the coordinate point of the ground fitting point on the z axis.
9. The lidar calibration method according to claim 1, wherein the step of analyzing the included angle and completing calibration comprises: and judging whether the included angle is smaller than a preset threshold value, and if so, respectively recording the coordinates of the first normal vector and the second normal vector to finish calibration.
10. The lidar calibration method according to claim 9, wherein the predetermined threshold is 1 ° to 10 °.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910952199.0A CN112630751A (en) | 2019-10-09 | 2019-10-09 | Calibration method of laser radar |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910952199.0A CN112630751A (en) | 2019-10-09 | 2019-10-09 | Calibration method of laser radar |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112630751A true CN112630751A (en) | 2021-04-09 |
Family
ID=75283402
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910952199.0A Pending CN112630751A (en) | 2019-10-09 | 2019-10-09 | Calibration method of laser radar |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112630751A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115615352A (en) * | 2022-09-28 | 2023-01-17 | 山东交通学院 | Calibration method and device of laser scanner and storage medium |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060061566A1 (en) * | 2004-08-18 | 2006-03-23 | Vivek Verma | Method and apparatus for performing three-dimensional computer modeling |
| CN103837869A (en) * | 2014-02-26 | 2014-06-04 | 北京工业大学 | Vector-relation-based method for calibrating single-line laser radar and CCD camera |
| US20140240162A1 (en) * | 2012-10-31 | 2014-08-28 | Board Of Regents, The University Of Texas System | Method and Apparatus for Detecting Subsurface Targets Using Data Inversion and a Temporal Transmission Line Model |
| JP2014202709A (en) * | 2013-04-09 | 2014-10-27 | スズキ株式会社 | Object detection device for vehicle |
| CN106846416A (en) * | 2017-02-06 | 2017-06-13 | 遂昌县睿鼎科技服务有限公司 | Unit beam splitting bi-eye passiveness stereo vision Accurate Reconstruction and subdivision approximating method |
| CN106885531A (en) * | 2017-04-20 | 2017-06-23 | 河北科技大学 | Wagon box based on two-dimensional laser radar describes device 3 D scanning system scaling method |
| CN108256446A (en) * | 2017-12-29 | 2018-07-06 | 百度在线网络技术（北京）有限公司 | For determining the method, apparatus of the lane line in road and equipment |
| US20190086524A1 (en) * | 2017-09-17 | 2019-03-21 | Baidu Online Network Technology (Beijing) Co., Ltd . | Parameter calibration method and apparatus of multi-line laser radar, device and readable medium |
| CN109541571A (en) * | 2018-12-29 | 2019-03-29 | 北京智行者科技有限公司 | The combined calibrating method of EPS zero bias and multi-line laser radar |
| CN109597054A (en) * | 2018-12-21 | 2019-04-09 | 宁波傲视智绘光电科技有限公司 | The scaling method of laser radar |
| CN109696663A (en) * | 2019-02-21 | 2019-04-30 | 北京大学 | A kind of vehicle-mounted three-dimensional laser radar scaling method and system |
| CN109737968A (en) * | 2019-03-07 | 2019-05-10 | 中山大学 | Indoor fusion and positioning method based on two-dimentional LiDAR and smart phone |
| US20190235062A1 (en) * | 2017-08-23 | 2019-08-01 | Tencent Technology (Shenzhen) Company Limited | Method, device, and storage medium for laser scanning device calibration |
| CN110163918A (en) * | 2019-04-24 | 2019-08-23 | 华南理工大学 | A kind of line-structured light scaling method based on projective geometry |
-
2019
- 2019-10-09 CN CN201910952199.0A patent/CN112630751A/en active Pending
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060061566A1 (en) * | 2004-08-18 | 2006-03-23 | Vivek Verma | Method and apparatus for performing three-dimensional computer modeling |
| US20140240162A1 (en) * | 2012-10-31 | 2014-08-28 | Board Of Regents, The University Of Texas System | Method and Apparatus for Detecting Subsurface Targets Using Data Inversion and a Temporal Transmission Line Model |
| JP2014202709A (en) * | 2013-04-09 | 2014-10-27 | スズキ株式会社 | Object detection device for vehicle |
| CN103837869A (en) * | 2014-02-26 | 2014-06-04 | 北京工业大学 | Vector-relation-based method for calibrating single-line laser radar and CCD camera |
| CN106846416A (en) * | 2017-02-06 | 2017-06-13 | 遂昌县睿鼎科技服务有限公司 | Unit beam splitting bi-eye passiveness stereo vision Accurate Reconstruction and subdivision approximating method |
| CN106885531A (en) * | 2017-04-20 | 2017-06-23 | 河北科技大学 | Wagon box based on two-dimensional laser radar describes device 3 D scanning system scaling method |
| US20190235062A1 (en) * | 2017-08-23 | 2019-08-01 | Tencent Technology (Shenzhen) Company Limited | Method, device, and storage medium for laser scanning device calibration |
| US20190086524A1 (en) * | 2017-09-17 | 2019-03-21 | Baidu Online Network Technology (Beijing) Co., Ltd . | Parameter calibration method and apparatus of multi-line laser radar, device and readable medium |
| CN108256446A (en) * | 2017-12-29 | 2018-07-06 | 百度在线网络技术（北京）有限公司 | For determining the method, apparatus of the lane line in road and equipment |
| CN109597054A (en) * | 2018-12-21 | 2019-04-09 | 宁波傲视智绘光电科技有限公司 | The scaling method of laser radar |
| CN109541571A (en) * | 2018-12-29 | 2019-03-29 | 北京智行者科技有限公司 | The combined calibrating method of EPS zero bias and multi-line laser radar |
| CN109696663A (en) * | 2019-02-21 | 2019-04-30 | 北京大学 | A kind of vehicle-mounted three-dimensional laser radar scaling method and system |
| CN109737968A (en) * | 2019-03-07 | 2019-05-10 | 中山大学 | Indoor fusion and positioning method based on two-dimentional LiDAR and smart phone |
| CN110163918A (en) * | 2019-04-24 | 2019-08-23 | 华南理工大学 | A kind of line-structured light scaling method based on projective geometry |
Non-Patent Citations (4)
| Title |
|---|
| HAO-TIAN ZHU 等: ""Determination of Propagation Constant of Terahertz Dielectric Ridge Waveguide "", 《IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT》, 31 December 2017 (2017-12-31), pages 2118 - 2128 * |
| MOHAMMAD AWRANGJEB 等: ""Automatic Building Footprint Extraction and Regularisation from LIDAR Point Cloud Data"", 《2014 INTERNATIONAL CONFERENCE ON DIGITAL IMAGE COMPUTING: TECHNIQUES AND APPLICATIONS (DICTA)》, 31 December 2014 (2014-12-31), pages 1 - 8 * |
| 牛路标: ""基于机载和车载LiDAR数据的建筑物三维建模方法研究"", 《中国优秀硕士论文全文数据库》, 15 November 2017 (2017-11-15) * |
| 程子阳 等: ""扫描线段特征用于三维点云地面分割"", 《光电工程》, 15 July 2019 (2019-07-15), pages 1 - 10 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115615352A (en) * | 2022-09-28 | 2023-01-17 | 山东交通学院 | Calibration method and device of laser scanner and storage medium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109001711B (en) | Multi-line laser radar calibration method | |
| CN103454619B (en) | Electrical axis optical calibration system of spaceborne microwave tracking-pointing radar and calibration method thereof | |
| CN112098964B (en) | Calibration method, device, equipment and storage medium of road-end radar | |
| CN110501712B (en) | Method, device and equipment for determining position attitude data in unmanned driving | |
| CN101587187B (en) | Method for correcting deviation of depth measuring sonar system | |
| CN108225185A (en) | A kind of vehicle-mounted scanning system calibration method | |
| CN112684432A (en) | Laser radar calibration method, device, equipment and storage medium | |
| CN113625237A (en) | Vehicle-mounted millimeter wave radar pitch angle error calibration method and device and electronic equipment | |
| CN108286946B (en) | Method and system for sensor position calibration and data splicing | |
| CN112630751A (en) | Calibration method of laser radar | |
| US8816901B2 (en) | Calibration to improve weather radar positioning determination | |
| CN113671453A (en) | Vehicle-mounted millimeter wave radar pitch angle error calibration method and device, storage medium and electronic equipment | |
| CN115200612B (en) | Method, system, computer device and readable storage medium for checking inclinometer | |
| CN113447908B (en) | GPS Beidou coordinate acquisition method and device for fixed radar detection target | |
| CN113702928B (en) | Intersection radar calibration method and equipment | |
| CN113740876B (en) | Three-dimensional laser radar light path adjusting method and device and electronic equipment | |
| CN115950450A (en) | Calibration method and device of two-dimensional Doppler velocimeter, computer equipment and medium | |
| CN114442073A (en) | Laser radar calibration method and device, vehicle and storage medium | |
| CN113256734A (en) | Vehicle-mounted sensing sensor calibration method and system and electronic equipment | |
| Le Scouarnec et al. | A positioning free calibration method for mobile laser scanning applications | |
| JP7409163B2 (en) | Stationary sensor calibration device and stationary sensor calibration method | |
| CN116026349B (en) | Method, apparatus, electronic device and medium for vehicle distance measurement | |
| CN113758515B (en) | Zero calibration method, zero calibration device, electronic equipment and computer-readable storage medium | |
| JP6884173B2 (en) | Route generator and route generation method | |
| CN114264320A (en) | Calibration method and device of guide instrument based on satellite positioning |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |