CN110470274B

CN110470274B - Method for measuring pavement longitudinal section curve through Doolittle decomposition

Info

Publication number: CN110470274B
Application number: CN201910809901.8A
Authority: CN
Inventors: 魏晖
Original assignee: Jiangxi University of Technology
Current assignee: Jiangxi University of Technology
Priority date: 2019-08-29
Filing date: 2019-08-29
Publication date: 2021-03-19
Anticipated expiration: 2039-08-29
Also published as: CN110470274A

Abstract

The invention disclosesA method of measuring a pavement profile curve by Doolittle decomposition comprising: collecting the starting point road surface elevation q (0) and the ending point road surface elevation q (n) and measuring the midpoint vector distance v (i) between the starting point and the ending point, wherein i is 1, … and n-1; calculating a trace by a direct trigonometric decomposition method by taking a midpoint vector distance sequence { v (i) | i ═ 1, …, n-1} as an input

The starting and ending point elevations q (0) and q (n) are substituted to calculate a road surface vertical section curve { q (i) | i ═ 1, …, n-1 }. The embodiment of the invention calculates the road surface longitudinal section curve by adopting the starting point elevation, the end point elevation and the midpoint vector distance between the starting point and the end point, avoids the low efficiency problem of a leveling instrument height measurement method and the trend problem of a road surface unevenness laser measurement method based on an inertia reference, and has the advantages of simple structure and good environmental adaptability.

Description

Method for measuring pavement longitudinal section curve through Doolittle decomposition

Technical Field

The invention relates to the technical field of highway traffic, in particular to a method for measuring a pavement longitudinal section curve through Doolittle decomposition.

Background

The height q of the road surface relative to the reference plane and the change q (I) along the road trend length I are called as the longitudinal section curve or the roughness function of the road surface. The road profile curve has numerical characteristics that affect the vehicle dynamic, the driving quality and the road dynamic load. Since the road profile curve is a random signal and cannot give a definite mathematical relation, the road unevenness is often described by statistical characteristics. The Power Spectral Density (PSD) method and the International Roughness Index (IRI) method are the main methods for evaluating the road surface roughness at present, wherein the PSD method is mostly used in the field of vehicle engineering, and the IRI method is mostly used in road engineering.

However, PSD and IRI lack the ability of local evaluation, and the road surface profile curve still needs to be measured for evaluating the local unevenness of the road surface. Common methods are leveling instrument height measurement, 3 meter ruler measurement, and laser unevenness measurement. The high-range measuring method of the level gauge has the advantages of simple measuring process, stable measuring result and low measuring speed efficiency. The 3 meter ruler measurement is faster than the level measurement, but has a small wavelength range. The laser measurement method for the road surface unevenness based on the inertial reference is high in measurement accuracy and measurement speed, but because random walk exists in dead reckoning, the trend term is difficult to avoid.

The following reference is adopted, the distance from the straight beam to the road surface can be measured through the three distance measuring sensors, the vector distance is calculated, the troubles of zero point, gain drift and vehicle-wheel-road coupling can be eliminated, and the road surface longitudinal section curve cannot be easily calculated directly due to the limitation of the structural size. If a road surface profile curve is to be obtained, a new calculation method is sought.

Disclosure of Invention

The invention provides a method for calculating a road surface longitudinal section curve according to elevation of a starting point and an end point and midpoint vector distance between the starting point and the end point, aiming at solving the technical problem of how to construct the road surface longitudinal section curve under a follow-up reference.

A method of measuring a pavement profile curve by Doolittle decomposition comprising:

collecting starting and end point elevations q (0) and q (n) and measuring midpoint vector distances v (i) between the starting and end points, wherein i is 1, … and n-1;

calculating a trace by a direct trigonometric decomposition method by taking a midpoint vector distance sequence { v (i) | i ═ 1, …, n-1} as an input

The starting and ending point elevations q (0) and q (n) are substituted to calculate a road surface vertical section curve { q (i) | i ═ 1, …, n-1 }.

Wherein the midpoint vector distance v (i) is expressed using the formula:

where v (i) is the midpoint vector distance at mileage i, and the unit m, i is 1,2, …, n-1; q (i) is the height at mileage i in m.

Wherein the mid-point vector distance v (i) is obtained by measuring the distance to the road surface by three symmetrically arranged distance measuring sensors.

The trace is calculated by a direct trigonometric decomposition method by taking a midpoint vector distance sequence { v (i) | i ═ 1, …, n-1} as input

Comprises the following steps:

calculating the coefficient u by Doolittle decomposition according to the sequence of i-1, …, n-1_i,j、l_i,jAs shown in formula (2):

calculating the intermediate value s (i) in the order of i ═ 1, …, n-1, as in formula (3):

calculating an estimate of altitude at range i in order of i-n-1, …,1

As shown in formula (4):

wherein, in the step of calculating the road surface vertical section curve { q (i) | i ═ 1, …, n-1} by substituting the starting point elevation q (0) and the ending point elevation q (n), the calculation formula for calculating the road surface vertical section curve { q (i) | i ═ 1, …, n-1} is:

the invention utilizes the elevation of the starting point and the end point and the midpoint vector distance between the starting point and the end point to calculate the longitudinal section curve of the road surface, avoids the low efficiency problem of a leveling instrument height measurement method and the trend item problem of a road surface unevenness laser measurement method based on an inertia reference, and can obtain an accurate solution through finite four arithmetic operations. The method for measuring the road surface longitudinal section curve can be used for measuring by adopting three distance measuring sensors which are symmetrically arranged on a straight beam, and the measuring device has simple structure and good environmental adaptability.

Drawings

FIG. 1 is a flow chart of a method for measuring a road surface profile curve by Doolittle decomposition in an embodiment of the present invention;

fig. 2 is a schematic view of measuring starting and ending road surface elevations q (0), q (n) of a road surface longitudinal section curve in the embodiment of the invention, wherein 1 is a ruler, 2 is a leveling instrument, and 3 is a road surface longitudinal section;

fig. 3 is a point vector distance sequence { v (i) | i ═ 1, …, n-1} in the longitudinal section of the road surface in the embodiment of the present invention;

fig. 4 is a road surface profile curve in the embodiment of the present invention, in which 1 is an actual road surface profile curve and 2 is a measured road surface profile.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

These and other aspects of embodiments of the invention will be apparent with reference to the following description and attached drawings. In the description and drawings, particular embodiments of the invention have been disclosed in detail as being indicative of some of the ways in which the principles of the embodiments of the invention may be practiced, but it is understood that the scope of the embodiments of the invention is not limited correspondingly. On the contrary, the embodiments of the invention include all changes, modifications and equivalents coming within the spirit and terms of the claims appended hereto.

Referring to fig. 1, a method for measuring a road surface profile curve through Doolittle decomposition according to an embodiment of the present invention is applied to the measurement of the road surface profile curve, which is directly applied to the measurement of the road surface unevenness. The method for measuring the road surface longitudinal section curve comprises the steps of S1-S3.

In step S1, start and end point elevations q (0), q (n) are collected, and midpoint vector distances v (i) between the start and end points are measured, i being 1, …, n-1.

In order to ensure the accuracy and the detection efficiency of the measurement of the longitudinal section curve of the road surface, the sectional measurement can be carried out on the road surface to be detected in the embodiment. In this embodiment, the height of the starting point and the end point of the road surface to be detected with a preset length are collected by a height measurement method of a level meter, and q (0) and q (n) are counted, as shown in fig. 2, q (0) is 214.278m, and q (n) is 220.373 m. Specifically, the preset length may be set in consideration of the measurement accuracy and the measurement efficiency, for example, 100 m. From the starting point, the midpoint vector distance is collected at equal intervals to the end point, so as to obtain a midpoint vector distance sequence { v (i) | i ═ 1, …, n-1}, as shown in fig. 3. The spacing can be considered in combination with the measurement resolution and the measurement device dimensions, for example 1 m. The midpoint vector distance of the pavement longitudinal section can be acquired through distance measuring sensors symmetrically arranged on a 2m rigid straight beam.

Step S2 is to calculate a trace by direct triangulation using the midpoint vector sequence { v (i) | i ═ 1, …, n-1} as input

Under the condition of known elevation of starting and ending points, the key point for measuring the longitudinal section curve of the road surface is to determine the longitudinal section curve trace between the starting and ending points. The midpoint vector distance is a second-order difference between the midpoint elevation and the front and rear point elevations, and can continuously describe the road surface unevenness change relationship, as shown in fig. 4. The midpoint vector distance { v (i) | i ═ 1, …, n-1} can be plotted against the curve trace

Is described as a pair

Wherein the coefficient matrix a may be defined by equation (1).

Can be solved according to a direct trigonometric decomposition method

The process is as follows: as shown in equation (1), the coefficient u is calculated in the order of i ═ 1, …, n-1_i,j、l_i,j(ii) a Calculating an intermediate value s (i) according to formula (3) in the order of i ═ 1, …, n-1; as shown in equation (4), the height estimate at mileage i is calculated in the order of i-n-1, …,1

In step S3, start and end point elevations q (0) and q (n) are substituted to calculate a road surface vertical section curve { q (i) | i ═ 1, …, n-1}, as shown in equation (5).

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A method of measuring a pavement profile curve by Doolittle decomposition comprising:

Substituting the starting point elevation q (0) and the ending point elevation q (n) to calculate a road surface vertical section curve { q (i) | i ═ 1, …, n-1 };

wherein the midpoint vector distance v (i) is expressed using the formula:

where v (i) is the midpoint vector distance at mileage i, i ═ 1,2, …, n-1; q (i) is the altitude at mileage i;

Comprises the following steps:

calculating the coefficient u by Doolittle decomposition according to the sequence of i-1, …, n-1_i,j、l_i,jThe calculation formula is as follows:

calculating the intermediate value s (i) according to the sequence of i-1, … and n-1, wherein the calculation formula is as follows:

calculating an estimate of altitude at range i in order of i-n-1, …,1

The calculation formula is as follows:

substituting the starting point elevation q (0) and the ending point elevation q (n) into a step of calculating a road surface vertical section curve { q (i) | i ═ 1, …, n-1}, wherein the formula for calculating the road surface vertical section curve { q (i) | i ═ 1, …, n-1} is as follows:

2. the method for measuring a road surface profile decomposed by Doolittle as claimed in claim 1, wherein the mid-point vector distance v (i) is obtained by measuring distances to the road surface by three distance measuring sensors symmetrically arranged.