CN113701678A

CN113701678A - Road surface flatness detection method based on line scanning three-dimension

Info

Publication number: CN113701678A
Application number: CN202111101390.8A
Authority: CN
Inventors: 曹民; 林红; 王新林; 卢毅; 邢旭凯; 严懿; 高超; 陈琪
Original assignee: Wuhan Optical Valley Excellence Technology Co ltd
Current assignee: Wuhan Optical Valley Excellence Technology Co ltd
Priority date: 2021-09-18
Filing date: 2021-09-18
Publication date: 2021-11-26

Abstract

The application provides a three-dimensional road surface flatness detection method based on line scanning, and relates to the technical field of road surface measurement engineering. The method comprises the following steps: acquiring original elevation data of each cross section along the width direction of a road by using a line scanning three-dimensional measuring device, and acquiring first elevation data corresponding to the original elevation data; correcting the first elevation data of each cross section respectively according to the attitude parameter corresponding to the line scanning three-dimensional measuring device, the calibration working distance, the working distance of the line scanning three-dimensional measuring device in the elevation direction and the preset number of measuring points of each cross section when the line scanning three-dimensional measuring device collects each cross section, so as to obtain the second elevation data of each cross section, and further determining the second elevation data of each longitudinal section vertical to each cross section; and determining the flatness of the road surface by using an international flatness index IRI calculation formula according to the second elevation data of each longitudinal section. This can improve the accuracy of determining the flatness of the road surface.

Description

Road surface flatness detection method based on line scanning three-dimension

Technical Field

The application relates to the technical field of pavement measurement engineering, in particular to a three-dimensional pavement evenness detection method based on line scanning.

Background

The road flatness not only affects the driving comfort of drivers and passengers, but also causes the phenomena of vehicle vibration, tire abrasion and unstable vehicle running speed, so that the determination of the road flatness is an important work of a road surface measuring project.

At present, the road surface evenness is usually evaluated by adopting an International Roughness Index (IRI), and the road surface data required for calculating the International evenness Index (IRI) can be obtained by adopting a three-dimensional laser scanning mode.

However, the road surface data obtained by the prior art has a certain deviation from the actual road surface data, and the road surface flatness condition cannot be truly reflected, so that the accuracy of determining the road surface flatness is reduced.

Disclosure of Invention

An object of the present application is to provide a three-dimensional road flatness detecting method based on line scanning, which can improve the accuracy of determining the road flatness, in view of the above disadvantages in the prior art.

In order to achieve the above purpose, the technical solutions adopted in the embodiments of the present application are as follows:

the embodiment of the application provides a three-dimensional road surface flatness detection method based on line scanning, which comprises the following steps:

acquiring original elevation data of each cross section along the width direction of a road by using a line scanning three-dimensional measuring device, and acquiring first elevation data corresponding to the original elevation data;

correcting first elevation data of each cross section respectively according to attitude parameters corresponding to the line scanning three-dimensional measuring device, a calibration working distance, a working distance of the line scanning three-dimensional measuring device in the elevation direction and the preset number of measuring points of each cross section when the line scanning three-dimensional measuring device collects each cross section, so as to obtain second elevation data of each cross section, wherein the line scanning three-dimensional measuring device comprises a line scanning three-dimensional camera, an attitude sensor and a laser;

determining second elevation data of each vertical section perpendicular to each cross section according to the second elevation data of each cross section;

and determining the flatness of the road surface by using an international flatness index IRI calculation formula according to the second elevation data of each longitudinal section.

Optionally, the determining second elevation data of each vertical section perpendicular to each cross section according to the second elevation data of each cross section includes:

calculating the position information of the required longitudinal profile along the width direction of the road by using the flatness, and determining the corresponding measuring points in each cross section required by the flatness calculation by combining the position information of each measuring point in the cross section along the width direction of the road;

forming an elevation data set by the second elevation data of the corresponding measuring points in each cross section;

and taking the second elevation data in the elevation data set as second elevation data of the same vertical section.

Optionally, the acquiring, by using a line scanning three-dimensional measurement device, original elevation data of each cross section along the road width direction to obtain first elevation data corresponding to the original elevation data includes:

and converting the original elevation data into the first elevation data according to pre-acquired calibration parameters, wherein the original elevation data are image space coordinate data, and the first elevation data are object space coordinate data.

Optionally, the correcting the first elevation data of each cross section according to the attitude parameter and the calibration working distance corresponding to the line scanning three-dimensional measurement device, the working distance of the line scanning three-dimensional measurement device in the elevation direction corresponding to each cross section acquired by the line scanning three-dimensional measurement device, and the preset number of measurement points of each cross section, to obtain the second elevation data of each cross section includes:

and respectively correcting the first elevation data of each cross section according to the calibration stage of the calibration parameters, the attitude parameter characteristics corresponding to the line scanning three-dimensional measuring device, the calibration working distance, the working distance of the line scanning three-dimensional measuring device in the elevation direction when the line scanning three-dimensional measuring device collects each cross section and the preset number of measuring points of each cross section, so as to obtain the second elevation data of each cross section.

Optionally, the correcting the first elevation data of each cross section according to the calibration stage of the calibration parameters, the attitude parameter characteristics corresponding to the line scanning three-dimensional measurement device, the calibration working distance, the working distance of the line scanning three-dimensional measurement device in the elevation direction corresponding to the line scanning three-dimensional measurement device when the line scanning three-dimensional measurement device collects each cross section, and the preset number of measurement points of each cross section to obtain the second elevation data of each cross section includes:

if the calibration stage of the calibration parameters is after the line scanning three-dimensional measuring device is installed on the measuring carrier, and the attitude parameter characteristic corresponding to the line scanning three-dimensional measuring device is the attitude angle of the line scanning three-dimensional measuring device relative to the horizontal plane, the first elevation data of each measuring point of each cross section is respectively calculated according to the formula:

correcting to obtain second elevation data of each measuring point of each cross section;

if the calibration stage of the calibration parameters is after the line scanning three-dimensional measuring device is installed on the measuring carrier, and the attitude parameter characteristic corresponding to the line scanning three-dimensional measuring device is the line scanningAnd (3) respectively calculating the first elevation data of each measuring point of each cross section according to a formula by using the offset angle of the three-dimensional measuring device relative to the installation posture of the line scanning three-dimensional measuring device:

and correcting to obtain second elevation data of each measuring point of each cross section.

if the calibration stage of the calibration parameters is before the line scanning three-dimensional measuring device is installed on the measuring carrier, and the attitude parameter characteristic corresponding to the line scanning three-dimensional measuring device is the attitude angle of the line scanning three-dimensional measuring device relative to the horizontal plane, the first elevation data of each measuring point of each cross section is respectively calculated according to the formula:

if the calibration stage of the calibration parameters is before the line scanning three-dimensional measuring device is installed on the measuring carrier, and the attitude parameter characteristic corresponding to the line scanning three-dimensional measuring device is the offset angle of the line scanning three-dimensional measuring device relative to the installation attitude of the line scanning three-dimensional measuring device, the first elevation data of each measuring point of each cross section is respectively calculated according to the formula:

correcting to obtain the second height of each measuring point of each cross sectionProgram data;

wherein i is 1, 2, …, N, i is the ith measuring point on the cross section, N is the number of the preset measuring points on the cross section, θ is the calibrated installation inclination angle of the line scanning three-dimensional measuring device and the horizontal plane, D is the calibrated working distance corresponding to the line scanning three-dimensional measuring device, M is the serial number corresponding to the middle measuring point of the cross section, β is the number of the middle measuring point of the cross section, N is the number of the ith measuring point on the cross section, N is the number of the preset measuring points on the cross section, θ is the calibrated installation inclination angle of the line scanning three-dimensional measuring device and the horizontal plane, M is the serial number corresponding to the middle measuring point of the cross section, and_tfor the attitude angle of the line scanning three-dimensional measuring device relative to the horizontal plane when the line scanning three-dimensional measuring device collects the cross section at the moment t, d_tCorresponding working distance of the line scanning three-dimensional measuring device relative to the horizontal plane in the elevation direction when the line scanning three-dimensional measuring device collects the cross section at the moment t, wherein A is the pixel size of the cross section along the width direction of the road, f is the lens focal length of the line scanning three-dimensional camera, and beta_gThe offset angle, z, of the corresponding line scanning three-dimensional measuring device relative to the installation posture of the line scanning three-dimensional measuring device when the line scanning three-dimensional measuring device collects the cross section at the moment t_tiFirst elevation data z 'of the ith measurement point in the cross section acquired by the line scanning three-dimensional measurement device at the time t'_tiAnd obtaining second elevation data after correcting the first elevation data of the ith measuring point.

determining at least one reference cross section from each cross section according to the filtering parameters corresponding to each cross section and the reference filtering parameters;

determining abnormal measuring points in each cross section except the reference cross section according to the reference elevation data of the reference cross section and the second elevation data of each measuring point of each cross section;

replacing the second elevation data of the abnormal measuring point with the second elevation data of the measuring point associated with the abnormal measuring point to obtain the replaced second elevation data of each measuring point of each cross section, wherein the associated measuring points comprise: measuring points within a preset distance from the abnormal measuring points;

and determining second elevation data of each vertical section perpendicular to each cross section according to the replaced second elevation data of each measuring point of each cross section.

Optionally, if the number of the line scanning three-dimensional measurement devices is greater than or equal to two, before determining second elevation data of each vertical section perpendicular to each cross section according to the second elevation data of each cross section, the method further includes:

determining a plurality of matched cross sections between adjacent line scanning three-dimensional measuring devices according to the number of the cross sections with the phase difference along the longitudinal direction of the adjacent line scanning three-dimensional measuring devices, wherein the longitudinal direction is the driving direction of a measuring carrier loaded with the line scanning three-dimensional measuring devices;

determining the measurement points of each matched cross section between the adjacent line scanning three-dimensional measuring devices on the overlapping area according to the parameters of the overlapping area pre-calibrated in the width direction of the road by the adjacent line scanning three-dimensional measuring devices and the transverse sampling interval corresponding to the adjacent line scanning three-dimensional measuring devices;

obtaining second elevation data of each measuring point on the overlapping area according to second elevation data corresponding to the measuring points with the same identification on the overlapping area;

and respectively splicing the second elevation data of each matched cross section of the adjacent line scanning three-dimensional measuring device and the second elevation data of each measuring point on the overlapped area to obtain a plurality of spliced second elevation data of the cross sections.

The beneficial effect of this application is:

the embodiment of the application provides a road surface flatness detection method based on line scanning three-dimension, which comprises the following steps: acquiring original elevation data of each cross section along the width direction of a road by using a line scanning three-dimensional measuring device, and acquiring first elevation data corresponding to the original elevation data; correcting the first elevation data of each cross section respectively according to the attitude parameter corresponding to the line scanning three-dimensional measuring device, the calibration working distance, the working distance of the line scanning three-dimensional measuring device in the elevation direction corresponding to the line scanning three-dimensional measuring device when the line scanning three-dimensional measuring device collects each cross section and the preset number of measuring points of each cross section to obtain second elevation data of each cross section; determining second elevation data of each longitudinal section perpendicular to each cross section according to the second elevation data of each cross section; and determining the flatness of the road surface by using an international flatness index IRI calculation formula according to the second elevation data of each longitudinal section.

By adopting the line scanning three-dimensional-based road surface evenness detection method provided by the embodiment of the application, when the line scanning three-dimensional camera in the line scanning three-dimensional measurement device is used for acquiring the elevation data of the cross section along the width direction of the road, the attitude parameter corresponding to the line scanning three-dimensional measurement device and the working distance in the elevation direction are acquired at the same time, and based on the attitude parameter and the working distance in the elevation direction, the first elevation data can be corrected, so that the influence caused by unstable factors (such as jitter) when the line scanning three-dimensional measurement device acquires the elevation data of the cross section can be compensated, the second elevation data acquired after the line scanning three-dimensional measurement device corrects the first elevation data can truly reflect the elevation information of the road surface, the road surface evenness condition is truly reflected, and the accuracy of determining the road surface evenness can be improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic flow chart of a three-dimensional road flatness detection method based on line scanning according to an embodiment of the present application;

fig. 2 is a schematic flow chart of another road flatness detection method based on line scanning three-dimension according to an embodiment of the present application;

fig. 3 is a schematic flowchart of another road flatness detecting method based on line scanning three-dimension according to an embodiment of the present application;

fig. 4 is a schematic flow chart of another road flatness detection method based on line scanning three-dimensional according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments.

Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

The road flatness detecting method mentioned in the present application is explained below with reference to the drawings. Fig. 2 is a schematic flow chart of a line-scanning three-dimensional-based road flatness detection method according to an embodiment of the present application. As shown in fig. 1, the method may include:

s101, acquiring original elevation data of each cross section along the width direction of the road by using a line scanning three-dimensional measuring device, and acquiring first elevation data corresponding to the original elevation data.

The line scanning three-dimensional measuring device comprises a line scanning three-dimensional camera, camera parameters of the line scanning three-dimensional camera can be set according to actual requirements, and the transverse sampling interval of the line scanning three-dimensional measuring device can be smaller than or equal to 2mm, specifically 1mm and 2 mm. After receiving a data acquisition instruction sent by the processor, the line scanning three-dimensional camera can acquire original elevation data corresponding to each measuring point on the cross section of the current position, wherein the transverse sampling interval represents the interval between adjacent measuring points.

When the line scanning three-dimensional camera performs the data acquisition action, the processor may determine whether to send a data acquisition instruction to the line scanning three-dimensional camera according to a corresponding relationship between a driving distance of a measurement carrier (e.g., a vehicle) and a set longitudinal sampling interval, where the longitudinal sampling interval is used to indicate a distance between two adjacent cross sections along the driving direction of the measurement carrier, and if the longitudinal sampling interval may be less than or equal to 5mm, specifically may be 5mm, it should be noted that the present application does not limit specific values of the transverse sampling interval and the longitudinal sampling interval.

For example, if the horizontal sampling interval is 1mm and the longitudinal sampling interval is 5mm, the measurement carrier runs on a target road section, the distance measurement unit mounted on the measurement carrier can send the running distance information to the processor in real time, if the processor judges that the distance between the previous data acquisition position and the current position is 5mm, the processor can control the line scanning three-dimensional camera to acquire data, and acquire elevation data corresponding to each measurement point on the cross section of the current position, and the interval between each measurement point is 1mm, and so on, the elevation information, namely the original elevation information, of each cross section included on the target road surface can be finally acquired. It should be noted that the original elevation data of each cross section directly acquired by the line scanning three-dimensional camera is data in an image space coordinate system, that is, the data is image space coordinate data, and the elevation data required in the calculation of the international flatness index IRI in the later stage is data in an object space coordinate system, that is, the data is object space coordinate data. For this reason, it is first necessary to convert the raw elevation data in the image-space coordinate system into elevation data in the object-space coordinate system, i.e., first elevation data.

The line scanning three-dimensional measuring device can avoid the situation that an independent measuring system is needed when the traditional road flatness is detected, and can save cost.

S102, correcting the first elevation data of each cross section respectively according to the attitude parameters corresponding to the line scanning three-dimensional measuring device, the calibration working distance, the working distance of the line scanning three-dimensional measuring device in the elevation direction corresponding to the line scanning three-dimensional measuring device when the line scanning three-dimensional measuring device collects each cross section and the preset number of measuring points of each cross section, and obtaining the second elevation data of each cross section.

The line scanning three-dimensional measuring device comprises a line scanning three-dimensional camera, an attitude sensor and a laser, and the line scanning three-dimensional camera, the attitude sensor and the laser are generally packaged in the line scanning three-dimensional measuring device, the attitude sensor can acquire attitude parameters of the line scanning three-dimensional measuring device, and the attitude parameters can be specifically attitude angles of the line scanning three-dimensional measuring device relative to a horizontal plane or offset angles of the line scanning three-dimensional measuring device relative to a self-installation attitude, which is not limited in the application. It can be seen that the line scanning three-dimensional measurement device can obtain different attitude parameters relative to different reference objects, that is, the attitude parameters of the line scanning three-dimensional measurement device have different characteristics, and the first elevation data of each cross section can be corrected by adopting a corresponding correction principle according to the attitude parameter characteristics of the line scanning three-dimensional measurement device.

The calibrated working distance of the line scanning three-dimensional measuring device is a parameter (constant) obtained before the start of the road flatness detection work in a static calibration mode, the number of measuring points of each cross section is the same, the number of the measuring points is related to the camera parameters of the line scanning three-dimensional camera, if the number of the measuring points is specifically 2048, the calibrated working distance and the number of the measuring points of the line scanning three-dimensional measuring device can be stored in a processor in advance. The processor can also acquire the working distance of the line scanning three-dimensional measuring device in the elevation direction when the line scanning three-dimensional camera acquires the cross section each time, and the processor can store the acquisition time corresponding to each cross section, the working distance of the line scanning three-dimensional measuring device in the elevation direction at each acquisition time and the attitude parameter corresponding to the line scanning three-dimensional measuring device at each acquisition time in a correlated manner.

Taking a cross section as an example, according to the above mentioned parameters, respectively using the corresponding correction principle to correct the elevation data corresponding to each measurement point on the cross section, so as to obtain second elevation data corresponding to each measurement point on the cross section, and storing the second elevation data corresponding to each measurement point in association with the cross section.

S103, determining second elevation data of each vertical section perpendicular to each cross section according to the second elevation data of each cross section.

And S104, determining the flatness of the road surface by using an international flatness index IRI calculation formula according to the second elevation data of each longitudinal section.

Wherein, each cross section is perpendicular to the road surface and along the direction of road width, and each vertical section is perpendicular to the road surface and along the direction of road length, can see that each cross section is perpendicular to each vertical section each other. The relationship between the second elevation data of the cross section and the second elevation data of the longitudinal section is explained in a matrix description manner as follows. Each cross section is taken as a row of the matrix, each longitudinal section is a column of the matrix, elements in each row of the matrix are second elevation data corresponding to each measuring point on each cross section, and it can be seen that the elements in each column of the matrix are the elevation data corresponding to each measuring point on each cross section in the same column, that is, the second elevation data corresponding to the measuring points at the same road width position on each cross section can be combined into the second elevation data of the same longitudinal section, and finally, each longitudinal section corresponding to the target road surface can be constructed, and can be numbered for each longitudinal section, such as longitudinal section 1 and longitudinal section 2.

Illustratively, according to the position information of the target vertical section, namely the road width position information, which is selected in advance and is required for calculating the international flatness index IRI, the target vertical section, such as the target vertical section 1 and the target vertical section 2, is determined from each vertical section corresponding to the target road surface, and according to the second elevation data of the target vertical section 1 and the second elevation data of the target vertical section 2, the international flatness index IRI is determined according to the international flatness index IRI calculation formula, namely the flatness of the target road surface can be determined. It should be noted that, the specific form of the international flatness index IRI calculation formula may refer to the relevant description, and will not be described here.

In summary, in the three-dimensional road surface evenness detection method based on line scanning provided by the application, when the line scanning three-dimensional camera in the line scanning three-dimensional measurement device is used for acquiring the elevation data of the cross section along the width direction of the road, the attitude parameter corresponding to the line scanning three-dimensional measurement device and the working distance in the elevation direction are acquired at the same time, and based on the attitude parameter and the working distance in the elevation direction, the first elevation data can be corrected, so that the influence caused by unstable factors (such as measurement carrier jitter) when the line scanning three-dimensional measurement device acquires the elevation data of the cross section can be compensated, and the second elevation data acquired after the line scanning three-dimensional measurement device corrects the first elevation data can truly reflect the elevation information of the road surface, so that the actual road surface evenness condition can be reflected, and the accuracy of determining the road surface evenness can be improved.

Fig. 2 is a schematic flow chart of another road flatness detection method based on line scanning three-dimensional provided in the embodiment of the present application. Optionally, the determining second elevation data of each vertical section perpendicular to each cross section according to the second elevation data of each cross section as shown in fig. 3 includes:

s201, calculating the position information of the required longitudinal profile along the width direction of the road by using the flatness, and determining the corresponding measuring points in each cross section required by flatness calculation by combining the position information of each measuring point in the cross section along the width direction of the road.

In an implementable embodiment, before determining the longitudinal profile corresponding to the flatness of the road surface, i.e. the target longitudinal section, the position information of the desired measuring point in the cross section in the road width direction can be determined first from the position information of the longitudinal profile in the road width direction.

For example, assuming that the position information of the longitudinal profile corresponding to the flatness of the road surface includes 1100mm and 2700mm in the road width direction, it is necessary to determine the measurement points of which the position information is 1100mm and the measurement points of which the position information is 2700mm in each cross section in the road width direction.

And S202, forming an elevation data set by the second elevation data of the corresponding measuring points in each cross section.

And S203, taking the second elevation data in the elevation data set as second elevation data of the same vertical section.

The second elevation data of each measuring point in each cross section corresponds to position information, the position information comprises an abscissa and an ordinate, the direction of the abscissa is the width direction of the road, the ordinate is the length direction of the road, and the second elevation data of the corresponding measuring point in each cross section with the same abscissa value can be combined into the second elevation data of the same vertical section.

Continuing with the above example, assuming that each cross section of the target road surface includes 2048 measurement points, the target road surface may include 2048 longitudinal sections, specifically, if the position information of the longitudinal profile corresponding to the calculated flatness of the road surface includes 1100mm and 2700mm along the road width direction, the measurement points with abscissa values of 1100mm in each cross section may be combined into one elevation data set, that is, the longitudinal section corresponding to the position information of 1100mm is obtained, and similarly, the measurement points with abscissa values of 2700mm in each cross section may be combined into one elevation data set, that is, the longitudinal section corresponding to the position information of 2700mm is obtained. After the vertical sections are obtained, each vertical section identifier (such as position information or a number on the road width) and the second elevation data corresponding to each vertical section can be stored in an associated manner.

Optionally, the acquiring, by using a line scanning three-dimensional measurement device, original elevation data of each cross section along the road width direction to obtain first elevation data corresponding to the original elevation data includes: the method comprises the steps of converting original elevation data into first elevation data according to pre-acquired calibration parameters, wherein the original elevation data are image space data, and the first elevation data are object space data.

The conversion relation between the image coordinate system and the object coordinate system can be represented by the calibration parameters, and the data (image coordinate data) acquired in the image coordinate system can be converted into the object coordinate system by combining the calibration parameters to obtain the object coordinate data. The calibration parameters are acquired when the line scanning three-dimensional measuring device is calibrated, the calibration parameters can be stored in a processor in advance, the processor can directly convert the calibration parameters into first elevation data according to the pre-stored calibration parameters after acquiring the original elevation data of one cross section, or sequentially convert the original elevation data of each cross section into the first elevation data after acquiring all the cross sections on the target road section, and the specific acquisition process of the calibration parameters can refer to related contents and is not described here.

Optionally, the correcting the first elevation data of each cross section according to the attitude parameter corresponding to the line scanning three-dimensional measurement device, the calibration working distance, the working distance of the line scanning three-dimensional measurement device in the elevation direction corresponding to each cross section acquired by the line scanning three-dimensional measurement device, and the preset number of measurement points of each cross section to obtain the second elevation data of each cross section includes: correcting the first elevation data of each cross section respectively according to a calibration stage of calibration parameters, attitude parameter characteristics corresponding to the line scanning three-dimensional measuring device, a calibration working distance, working distances of the line scanning three-dimensional measuring device in the elevation direction respectively corresponding to the line scanning three-dimensional measuring device when the line scanning three-dimensional measuring device collects each cross section and the number of preset measuring points of each cross section to obtain second elevation data of each cross section.

The calibration parameters are obtained when the line scanning three-dimensional measuring device is calibrated, and the calibration of the line scanning three-dimensional measuring device can be divided into two stages, wherein one stage is to calibrate the line scanning three-dimensional measuring device before the line scanning three-dimensional measuring device is installed on a measuring carrier, the calibration parameters obtained at the stage cannot eliminate the calibration installation inclination angle between the line scanning three-dimensional measuring device and the horizontal plane when the original elevation data are converted into the first elevation data, and the other stage is to calibrate the line scanning three-dimensional measuring device after the line scanning three-dimensional measuring device is installed on the measuring carrier, and the calibration installation inclination angle between the line scanning three-dimensional measuring device and the horizontal plane can be eliminated when the original elevation data are converted into the first elevation data; the attitude parameter characteristics corresponding to the line scanning three-dimensional measuring device can also be divided into two cases, when a line scanning three-dimensional camera in the line scanning three-dimensional measuring device acquires each cross section, the attitude sensor acquires the attitude angle of the line scanning three-dimensional measuring device relative to a horizontal plane, at the moment, the attitude angle of the line scanning three-dimensional measuring device is the included angle between the line scanning three-dimensional measuring device and the horizontal plane, when the line scanning three-dimensional camera acquires each cross section, the attitude sensor acquires the attitude angle of the line scanning three-dimensional measuring device relative to the installation inclination angle of the line scanning three-dimensional measuring device, and the angle of the attitude angle can be called as an offset angle.

The calibration stage of the calibration parameters and the posture parameter characteristics corresponding to the line scanning three-dimensional measuring device are combined with each other, different correction principles can be correspondingly provided, and the first elevation data of each cross section can be respectively corrected according to the actual calibration stage and the posture parameter characteristics matching the corresponding correction principles, so that the second elevation data of each cross section can be obtained.

Optionally, the correcting the first elevation data of each cross section according to the calibration stage of the calibration parameters, the attitude parameter characteristics corresponding to the line scanning three-dimensional measurement device, the calibration working distance, the working distance of the line scanning three-dimensional measurement device in the elevation direction corresponding to each cross section acquired by the line scanning three-dimensional measurement device, and the preset number of measurement points of each cross section to obtain the second elevation data of each cross section includes: if the calibration stage of the calibration parameters is that the on-line scanning three-dimensional measuring device is installed behind the measuring carrier, and the attitude parameter characteristic corresponding to the on-line scanning three-dimensional measuring device is the attitude angle of the on-line scanning three-dimensional measuring device relative to the horizontal plane, the first elevation data of each measuring point of each cross section is respectively calculated according to the formula:

correcting to obtain second elevation data of each measuring point of each cross section; if the calibration stage of the calibration parameters is that the on-line scanning three-dimensional measuring device is arranged behind the measuring carrier, and the on-line scanningThe attitude parameter characteristic corresponding to the three-dimensional scanning measuring device is the offset angle of the line scanning three-dimensional measuring device relative to the installation attitude of the line scanning three-dimensional measuring device, and the first elevation data of each measuring point of each cross section is respectively calculated according to the formula:

Wherein, in the calibration stage of the calibration parameters, after the on-line scanning three-dimensional measurement device is mounted on the measurement carrier, and the attitude parameter characteristic corresponding to the on-line scanning three-dimensional measurement device is the attitude angle of the on-line scanning three-dimensional measurement device relative to the horizontal plane, then according to the calibration mounting inclination angle of the on-line scanning three-dimensional measurement device and the horizontal plane, the calibration working distance, the preset number of measurement points of each cross section, the attitude angle of the on-line scanning three-dimensional measurement device relative to the horizontal plane when the on-line scanning three-dimensional camera collects each cross section, and the working distance of the on-line scanning three-dimensional measurement device in the elevation direction, the first elevation data of each measurement point of each cross section can be corrected by using the following first correction principle:

wherein i is the ith measuring point on the cross section, N is the number of the preset measuring points (such as 2048) on the cross section, theta is the calibrated installation inclination angle of the line scanning three-dimensional measuring device and the horizontal plane, D is the calibrated working distance of the line scanning three-dimensional measuring device and the horizontal plane, M is the serial number (such as 1024) corresponding to the middle measuring point of the cross section, and beta_tFor the attitude angle of the line scanning three-dimensional measuring device relative to the horizontal plane when the line scanning three-dimensional measuring device collects the cross section at the moment t, d_tWhen the cross section of the line scanning three-dimensional measuring device is acquired at the moment t, the working distance of the line scanning three-dimensional measuring device relative to the horizontal plane in the height direction is correspondingly acquired, wherein A is the pixel size of the cross section along the width direction of the road (such as 0)0055mm), f is the focal length of the lens of the line scanning three-dimensional camera (e.g. 12mm), z_tiFirst elevation data, z ', of the ith measurement point in the cross section acquired at time t for the line scan three-dimensional measurement'_tiAnd obtaining second elevation data after correcting the first elevation data of the ith measuring point.

According to the first correction principle, the first elevation data corresponding to each measuring point on the cross section acquired at the time t can be corrected to obtain the second elevation data corresponding to each measuring point on the cross section, it should be noted that the same cross section corresponds to the same beta_tAnd d_t. In the manner described above, the first elevation data for each cross-section may be rectified to second elevation data, and each cross-section may be stored in association with the second elevation data for the corresponding measurement point.

Wherein, in the calibration stage of the calibration parameter, after the line scanning three-dimensional measurement device is installed on the measurement carrier, and the posture parameter characteristic corresponding to the line scanning three-dimensional measurement device is the offset angle of the line scanning three-dimensional measurement device relative to the installation posture of the line scanning three-dimensional measurement device, the first elevation data of each measurement point of each cross section can be corrected by adopting the following second correction principle according to the calibration working distance between the line scanning three-dimensional measurement device and the horizontal plane, the preset number of measurement points of each cross section, and the offset angle of the line scanning three-dimensional measurement device relative to the installation posture of the line scanning three-dimensional measurement device when the line scanning three-dimensional measurement device collects each cross section, and the working distance of the line scanning three-dimensional measurement device in the elevation direction, and the second correction principle is as follows:

wherein, beta_gFor the offset angle of the corresponding line scanning three-dimensional measuring device relative to the installation posture of the line scanning three-dimensional measuring device when the line scanning three-dimensional measuring device collects the cross section at the time t, the other parameter meanings can refer to the above description.

According to the second correction principle, the cross section acquired at the moment t can be measuredCorrecting the first elevation data corresponding to the measuring points to obtain second elevation data corresponding to each measuring point of the cross section, wherein the same cross section corresponds to the same beta_gAnd d_t. In the manner described above, the first elevation data for each cross-section may be rectified to second elevation data, and each cross-section may be stored in association with the second elevation data for the corresponding measurement point.

It should be noted that, in the calibration stage of the calibration parameter, when the attitude parameter is the offset angle detected by the attitude sensor (the line scanning three-dimensional measuring device) relative to the installation attitude of the line scanning three-dimensional measuring device after the line scanning three-dimensional measuring device is installed on the measuring carrier, the attitude parameter (β) is_g) Wherein the calibration installation inclination angle (theta) of the line scanning three-dimensional measuring device and the horizontal plane is included, when the first elevation data is corrected, the calibration installation inclination angle (theta) of the line scanning three-dimensional measuring device and the horizontal plane is not introduced, and the attitude parameter (beta) is directly utilized_g) The first elevation data is converted to second elevation data.

Optionally, the correcting the first elevation data of each cross section according to the calibration stage of the calibration parameters, the attitude parameter characteristics corresponding to the line scanning three-dimensional measurement device, the calibration working distance, the working distance of the line scanning three-dimensional measurement device in the elevation direction corresponding to each cross section acquired by the line scanning three-dimensional measurement device, and the preset number of measurement points of each cross section to obtain the second elevation data of each cross section includes: if the calibration stage of the calibration parameters is that the on-line scanning three-dimensional measuring device is installed before the measuring carrier, and the attitude parameter characteristic corresponding to the on-line scanning three-dimensional measuring device is the attitude angle of the on-line scanning three-dimensional measuring device relative to the horizontal plane, the first elevation data of each measuring point of each cross section is respectively calculated according to the formula:

correcting to obtain second elevation data of each measuring point of each cross section; if the calibration stage of the calibration parameters is that the on-line scanning three-dimensional measuring device is arranged in front of the measuring carrier, and the on-line scanning three-dimensional measuring device is arranged on the measuring carrierThe attitude parameter characteristic corresponding to the scanning three-dimensional measuring device is the offset angle of the line scanning three-dimensional measuring device relative to the installation attitude of the line scanning three-dimensional measuring device, and the first elevation data of each measuring point of each cross section is respectively calculated according to the formula:

Wherein, if the calibration stage of the calibration parameter is that the on-line scanning three-dimensional measuring device is installed before the measurement carrier, and the attitude parameter characteristic corresponding to the on-line scanning three-dimensional measuring device is the attitude angle of the on-line scanning three-dimensional measuring device relative to the horizontal plane, then according to the calibration working distance of the on-line scanning three-dimensional measuring device and the horizontal plane, the preset number of the measuring points of each cross section, and the attitude angle of the on-line scanning three-dimensional measuring device relative to the horizontal plane corresponding to each cross section acquired by the on-line scanning three-dimensional measuring device, and the working distance of the on-line scanning three-dimensional measuring device in the elevation direction, the first elevation data of each measuring point of each cross section can be corrected by using the above-mentioned second correction principle, and it should be noted that, at this time, β in the second correction principle is used to correct the first elevation data of each measuring point_gBeta can be used for acquiring the attitude angle of the corresponding line scanning three-dimensional measuring device relative to the horizontal plane when the line scanning three-dimensional measuring device acquires the cross section at the moment t_tIt is indicated that reference is made to the above description for further content.

Wherein, if the calibration stage of the calibration parameter is before the on-line scanning three-dimensional measuring device is installed on the measuring carrier, and the attitude parameter characteristic corresponding to the on-line scanning three-dimensional measuring device is the offset angle of the on-line scanning three-dimensional measuring device relative to the installation attitude of the on-line scanning three-dimensional measuring device, then according to the calibration installation inclination angle of the on-line scanning three-dimensional measuring device and the horizontal plane, the calibration working distance, the preset number of measuring points of each cross section, the offset angle of the on-line scanning three-dimensional measuring device relative to the installation attitude of the on-line scanning three-dimensional measuring device when the on-line scanning three-dimensional measuring device collects each cross section, and the working distance of the on-line scanning three-dimensional measuring device in the elevation direction, the first three-dimensional measuring device can be adoptedThe correction principle corrects the first elevation data of each measurement point of each cross section, and it should be noted that β in the first correction principle is_tBeta can be used for the offset angle of the corresponding line scanning three-dimensional measuring device relative to the installation posture of the line scanning three-dimensional measuring device when the line scanning three-dimensional measuring device collects the cross section at the moment t_gIt is shown that the other contents can be described with reference to the corresponding parts.

It should be noted that, in the calibration stage of the calibration parameter, before the line scanning three-dimensional measurement device is mounted on the measurement carrier, the attitude parameter is an attitude angle of the attitude sensor (line scanning three-dimensional measurement device) relative to the horizontal plane, and the attitude angle (β) is_t) Wherein the calibration installation inclination angle (theta) of the line scanning three-dimensional measuring device and the horizontal plane is included, when the first elevation data is corrected, the calibration installation inclination angle (theta) of the line scanning three-dimensional measuring device and the horizontal plane is not introduced, and the attitude angle (beta) is directly utilized_t) The first elevation data is converted to second elevation data.

It can be understood that, in the running process of the measurement carrier, because the running speed of the measurement carrier is unstable, the line scanning three-dimensional measurement device has different measurement postures at different moments, the measurement posture influence of the line scanning three-dimensional measurement device can be corrected by correcting the posture angle detected by the posture sensor corresponding to each cross section and the working distance of the line scanning three-dimensional measurement device in the elevation direction through the line scanning three-dimensional camera, and the correction can be performed by matching the corresponding correction principle according to the calibration stage of the calibration parameters and the posture parameter characteristics corresponding to the line scanning three-dimensional measurement device, so that the accuracy of determining the road elevation data can be improved.

Fig. 3 is a schematic flow chart of another road flatness detection method based on line scanning three-dimension according to an embodiment of the present application. As shown in fig. 3, optionally, the determining second elevation data of each vertical section perpendicular to each cross section according to the second elevation data of each cross section includes:

s301, determining at least one reference cross section from each cross section according to the filtering parameters corresponding to each cross section and the reference filtering parameters.

Each cross section corresponds to a filtering parameter, the filtering parameter may specifically be a filtering radius, the reference filtering parameter data refers to a corresponding filtering radius (for example, the radius r is 10mm) of the median filtering, a cross section with the filtering radius as the reference filtering radius or a cross section with a filtering radius different from the reference filtering radius within a preset range may be selected from each cross section, and the cross section is used as the reference cross section.

S302, according to the reference elevation data of the reference cross section and the second elevation data of each measuring point of each cross section, determining abnormal measuring points in each cross section except the reference cross section.

Specifically, the second elevation data corresponding to each measurement point in the reference cross section may be averaged, and the average second elevation data may be used as the reference elevation data of the reference cross section.

And comparing the reference elevation data with second elevation data corresponding to each measuring point in each cross section except the reference cross section, and taking the measuring point corresponding to the elevation data with the difference exceeding the elevation threshold value with the reference elevation data as an abnormal measuring point.

And S303, replacing the second elevation data of the abnormal measuring points by using the second elevation data of the measuring points related to the abnormal measuring points to obtain the replaced second elevation data of each measuring point of each cross section.

And S304, determining second elevation data of each vertical section perpendicular to each cross section according to the replaced second elevation data of each measuring point of each cross section.

Wherein the associated measurement points comprise: the measurement points within the preset distance may include measurement points adjacent to the abnormal measurement point, measurement points on the same cross section as the abnormal measurement point, and measurement points on a cross section adjacent to the abnormal measurement point. For example, the second elevation data corresponding to the abnormal measuring point may be replaced by an average value of the second elevation data corresponding to each measuring point within the preset distance, so as to obtain the replaced second elevation data of each measuring point of each cross section.

And the replaced second elevation data of the measurement points corresponding to the same road width position on each cross section can be combined into second elevation data of the same longitudinal section, and finally each longitudinal section corresponding to the target road surface can be constructed.

It can be seen that areas such as deceleration strips, oscillation marked lines, highway and railway level crossing, pavement crack areas and the like can be detected by adopting the mode, and second elevation data corresponding to the measuring points in the areas can not be used as data for evaluating the pavement evenness, so that the accuracy of evaluating the pavement evenness can be improved.

Fig. 4 is a schematic flow chart of another road flatness detection method based on line scanning three-dimension according to an embodiment of the present application. As shown in fig. 4, optionally, before determining the second elevation data of each vertical section perpendicular to each cross section according to the second elevation data of each cross section if the number of the line scanning three-dimensional measurement devices is greater than or equal to two, the method further includes:

s401, determining a plurality of matched cross sections between adjacent line scanning three-dimensional measuring devices according to the number of the cross sections with the phase difference along the longitudinal direction of the adjacent line scanning three-dimensional measuring devices.

The longitudinal direction is the driving direction of a measuring carrier loaded with the line scanning three-dimensional measuring device, and when the road surface is wide, a plurality of line scanning three-dimensional measuring devices can be installed on the same testing carrier. Taking 2 line-scanning three-dimensional measuring devices (line-scanning three-dimensional measuring device 1, line-scanning three-dimensional measuring device 2) as an example, according to a preset longitudinal sampling interval (e.g. 5mm) and a measuring interval (e.g. 5cm) of the line-scanning three-dimensional measuring device 1 and the line-scanning three-dimensional measuring device 2 along the longitudinal direction, the number of cross sections (e.g. 10) of the line-scanning three-dimensional measuring device 1 and the line-scanning three-dimensional measuring device 2 which are different in the longitudinal direction can be calculated, and further, the relationship between each cross section corresponding to the line-scanning three-dimensional measuring device 1 and the cross section corresponding to the line-scanning three-dimensional measuring device 2 can be determined, when the number of cross sections of the line-scanning three-dimensional measuring device 1 and the line-scanning three-dimensional measuring device 2 which are different in the longitudinal direction is 10, and before the line-scanning three-dimensional measuring device 1 along the longitudinal direction, it can be seen that when the line scanning three-dimensional camera on the line scanning three-dimensional measuring device 1 acquires the 10 th cross section, the vertical coordinate of the 1 st cross section acquired by the line scanning three-dimensional measuring device 2 is consistent, and the two cross sections can be taken as matched cross sections, and the matched cross sections between the line scanning three-dimensional measuring device 1 and the line scanning three-dimensional measuring device 2 can be determined by referring to the manner described above.

S402, determining the measuring points of the matched cross sections between the adjacent line scanning three-dimensional measuring devices on the overlapped area according to the parameters of the overlapped area pre-calibrated in the width direction of the road by the adjacent line scanning three-dimensional measuring devices and the corresponding transverse sampling interval of the adjacent line scanning three-dimensional measuring devices.

Continuing with the above example, the parameters of the overlapping area of the line scanning three-dimensional measuring device 1 and the line scanning three-dimensional measuring device 2 along the width direction of the road are obtained in advance, for example, the parameter of the overlapping area is 350mm, that is, the overlapping area is 350mm between two matched cross sections. According to the transverse sampling interval and the parameters of the overlapping area, the number of the measuring points on each cross section in the overlapping area can be calculated, and if the transverse sampling interval is 1mm, the number of the measuring points on the overlapping area is 350, namely, 350 measuring points on two matched cross sections are in the overlapping area respectively.

And S403, obtaining second elevation data of each measuring point on the overlapping area according to the second elevation data corresponding to the measuring points with the same identification on the overlapping area.

Each measuring point in the cross section corresponding to each of the line scanning three-dimensional measuring devices 1 and 2 has a position mark, that is, the position information of the measuring point corresponding to the road surface, and the position information of each measuring point includes the position in the road width direction and the position in the driving direction, so that the second elevation data corresponding to the measuring points having the same position information (mark) in the overlapping area can be averaged, and the average result is used as the second elevation data of each measuring point.

S404, splicing the second elevation data of the cross section matched with the adjacent line scanning three-dimensional measuring devices and the second elevation data of the measuring points on the overlapped area respectively to obtain a plurality of spliced second elevation data of the cross section.

In which, a pair of cross sections (cross section 11, cross section 12) matching the line scanning three-dimensional measuring device 1 and the line scanning three-dimensional measuring device 2, for example, after obtaining elevation data of each measuring point in the overlapping area, the cross section 11 and the cross section 12 can be spliced to form a complete cross section. Specifically, the second elevation data for each measurement point on the cross section 11 and the second elevation data for each measurement point on the cross section 12 may be concatenated. In an embodiment where one of the cross sections is taken as the main cross section, the measurement points of the main cross section may be retained in the overlap area, the measurement points of the other cross section in the overlap area may be deleted, and the average result may be used as the second elevation data of the measurement points of the main cross section in the overlap area, so that the second elevation data of the measurement points of the cross sections 11 and 12 after the splicing may be obtained, and referring to the above description, a plurality of complete cross sections between the measuring apparatus 1 and the measuring apparatus 2 may be finally obtained.

It should be noted that, the matched cross sections can be spliced from left to right in sequence along the width direction of the road, or the matched cross sections can be spliced from right to left in sequence, which is not limited in the present application.

It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A road flatness detection method based on line scanning three-dimension is characterized by comprising the following steps:

2. The method according to claim 1, wherein determining second elevation data for each vertical section perpendicular to each cross section from the second elevation data for each cross section comprises:

3. The method according to claim 1, wherein the acquiring, by using the line scanning three-dimensional measuring device, raw elevation data of each cross section along the width direction of the road and first elevation data corresponding to the raw elevation data comprises:

4. The method according to claim 3, wherein the correcting the first elevation data of each cross section according to the attitude parameter, the calibration working distance, the working distance of the line scanning three-dimensional measurement device in the elevation direction and the preset number of measurement points of each cross section when the line scanning three-dimensional measurement device acquires each cross section respectively comprises:

5. The method according to claim 4, wherein the correcting the first elevation data of each cross section according to the calibration stage of the calibration parameters, the attitude parameter characteristics corresponding to the line scanning three-dimensional measurement device, the calibration working distance, the working distance in the elevation direction of the line scanning three-dimensional measurement device corresponding to each cross section acquired by the line scanning three-dimensional measurement device and the preset number of measurement points of each cross section to obtain the second elevation data of each cross section comprises:

correcting to obtain second elevation data of each measuring point of each cross section；

If the calibration stage of the calibration parameters is after the line scanning three-dimensional measuring device is installed on the measuring carrier, and the attitude parameter characteristic corresponding to the line scanning three-dimensional measuring device is the offset angle of the line scanning three-dimensional measuring device relative to the installation attitude of the line scanning three-dimensional measuring device, the first elevation data of each measuring point of each cross section is respectively calculated according to the formula:

6. The method according to claim 4, wherein the correcting the first elevation data of each cross section according to the calibration stage of the calibration parameters, the attitude parameter characteristics corresponding to the line scanning three-dimensional measurement device, the calibration working distance, the working distance in the elevation direction of the line scanning three-dimensional measurement device corresponding to each cross section acquired by the line scanning three-dimensional measurement device and the preset number of measurement points of each cross section to obtain the second elevation data of each cross section comprises:

wherein i is 1, 2, …, N, i is the ith measuring point on the cross section, N is the number of the preset measuring points on the cross section, θ is the calibrated installation inclination angle of the line scanning three-dimensional measuring device and the horizontal plane, D is the calibrated working distance corresponding to the line scanning three-dimensional measuring device, M is the serial number corresponding to the middle measuring point of the cross section, β is the number of the middle measuring point of the cross section, N is the number of the ith measuring point on the cross section, N is the number of the preset measuring points on the cross section, θ is the calibrated installation inclination angle of the line scanning three-dimensional measuring device and the horizontal plane, M is the serial number corresponding to the middle measuring point of the cross section, and_tcorresponding line scanning three when the line scanning three-dimensional measuring device collects the cross section at the moment tMeasuring the attitude angle of the device relative to said horizontal plane, d_tCorresponding working distance of the line scanning three-dimensional measuring device relative to the horizontal plane in the elevation direction when the line scanning three-dimensional measuring device collects the cross section at the moment t, wherein A is the pixel size of the cross section along the width direction of the road, f is the lens focal length of the line scanning three-dimensional camera, and beta_gThe offset angle, z, of the corresponding line scanning three-dimensional measuring device relative to the installation posture of the line scanning three-dimensional measuring device when the line scanning three-dimensional measuring device collects the cross section at the moment t_tiFirst elevation data z 'of the ith measurement point in the cross section acquired by the line scanning three-dimensional measurement device at the time t'_tiAnd obtaining second elevation data after correcting the first elevation data of the ith measuring point.

7. A method according to any one of claims 1 to 6 wherein determining second elevation data for each longitudinal section perpendicular to each cross-sectional plane from the second elevation data for each cross-sectional plane comprises:

determining abnormal measuring points in each cross section outside the reference cross section according to the reference elevation data of the reference cross section and the second elevation data of each measuring point of each cross section;

replacing the second elevation data of the abnormal measuring point with the second elevation data of the measuring point associated with the abnormal measuring point to obtain the replaced second elevation data of each measuring point of each cross section, wherein the associated measuring points comprise: normal measuring points within a preset distance from the abnormal measuring points;

8. The method according to any one of claims 1-6, wherein if the number of the line-scan three-dimensional measurement devices is two or more, before determining the second elevation data of each of the vertical sections perpendicular to each of the cross sections from the second elevation data of each of the cross sections, the method further comprises: