CN101319485A - Photographing measurement method for detecting highroad pavement planeness - Google Patents

Abstract

The invention provides a video measurement method for checking the flatness of road surfaces. Firstly, a measurement vehicle stops on a road surface to be measured; a camera device is fixed on one end of the inner part of the measurement vehicle, the optical axis of the camera device is in parallel to the bottom plane of the vehicle; two mark poles, the distance between which is r and the heights of which are different, are vertical to the bottom plane of the vehicle and fixed on the other end of the inner part of the measurement vehicle, top ends of the two mark poles are provided with a collaboration mark respectively; when the measurement vehicle runs on the road surface to be measured, the camera device takes images of collaboration marks at different moments while the measurement vehicle runs; the altitude of the road surface is obtained in real time by processing images and data, finally a series of altitude parameters obtained are synthesized into a vertical section profile curve of the road surface to be measured. The method adapts to the requirements of constructing and developing modern highways and meets the needs of measuring with high precision, high reliability and high automation, thereby having good application prospect in construction fields such as highways and air fields, etc.

Description

Detect the photographing measurement method of highroad pavement planeness

Technical field

The present invention relates to engineering fields such as highway construction, airfield runway, and discipline range such as digital photogrammetry, Digital Image Processing, computer vision, further be meant a kind of photographing measurement method that detects highroad pavement planeness.

Background technology

Surface evenness mainly is meant the fluctuation situation of change of the vertical section of road surface section curve that causes Vehicular vibration in the process of moving, obtains the elevation amount that the surface evenness index just need obtain the road surface.Wherein elevation refers to the deviation on sampled point relative ideal plane, generally all is to measure starting point place horizontal plane as the ideal plane.

As shown in Figure 1, ACDF is the ideal plane, and ABDE is the road surface, and ABD is the vertical section of road surface section curve, then | and BC| is an elevation.

Surface evenness is important index during road surfacing, pavement construction examination, the urban road surfaces of improvement primary stage estimated, and has directly determined the comfort level of vehicle ', the safety and the user mode on road surface.The surface evenness index can provide important information for the policymaker, the policymaker can be made for maintenance, the maintenance on road surface and overhauling etc. optimize decision-making.On the other hand, surface evenness can provide the information of pavement construction quality and the objective indicator of performance rating exactly.

In China, the detection of surface evenness is a difficult point in the pavement evaluation always, its main cause is that the research starting point of the research and development of surface evenness detector and evaluation theory is lower, cause most of smoothness measuring equipments of China's autonomous production in the past can't directly record international international roughness index IRI, do not form the Evaluation of Pavement Evenness theoretical system that a cover adapts to national conditions with fashion.Still there is suitable gap in China aspect surface evenness detection technique and the detecting instrument compared with developed countries, influenced highway in China and urban road construction quality managemant and periodically evaluation.China Ministry of Communications last century the nineties formulated planeness and detected standard, proposed to adopt general in the world international roughness index IRI in 1998.But in fact, still seldom adopt international roughness index IRI in department of basic unit.Its main cause is that the testing equipment of this respect is relatively backward, and technology is relative with the talent to be lacked; On the other hand, the planeness instrument operation of import and detection content do not meet the application request of China sometimes, and the operation interface of foreign language edition has increased the operation easier of import instrument, and the demarcation of instrument and maintenance often depend on the country of origin, use inconvenience, cost an arm and a leg.In the application of China's planeness detection technique, the planeness standard deviation is used comparatively extensively.For obtaining international roughness index IRI, planeness detects department and often the planeness standard deviation is converted to international roughness index IRI.Research Institute of Highway, Ministry of Communications once carried out correlation analysis with planeness standard deviation sigma and international roughness index IRI, and drawing international roughness index IRI can obtain by the planeness standard deviation, that is:

IRI＝σ/0.6 (1.1)

In fact, above conversion formula only is suitable on the road surface that the short wavelength is only arranged, and in the road surface has, during long wavelength's composition (when the road surface has small size fluctuating or the slope is arranged), above formula is false.In reality, most road surfaces all have small size fluctuating or the slope are arranged, and just generally are difficult for intuitively finding out.Have only very smooth road surface can adopt above conversion formula.We can say that above formula has bigger limitation on using, should not apply, just do not having other way to obtain under the situation of international roughness index IRI, use reluctantly.

The development of China's smoothness measuring equipment mainly originates in the early eighties in last century.The municipal sector in Xi'an, Beijing, Shanghai and highway research department had begun the development of continous way smoothness measuring equipment (eight take turns instrument) respectively originally, and had begun concrete application mid-term in the eighties.Even to this day, the continous way smoothness measuring equipment still has bigger application market, but the continous way smoothness measuring equipment has its basic limitation.Because the wavelength of its detection is limited to short wavelength range (less than 1.5 meters), therefore can't obtain international roughness index IRI (IRI require to detect wavelength must greater than 30 meters).What the continous way smoothness measuring equipment can detect is the planeness standard deviation, only is short wavelength's planeness and the planeness standard deviation can reflect.Along with the raising that requires detects to planeness in China, continous way smoothness measuring equipment more and more incompatibility market is used.Another kind of response type detection type, it mainly limits to is instrument palpus periodic calibrating, and can't directly obtain international roughness index IRI.But along with the requirement to IRI of the universal use of international roughness index IRI and Ministry of Communications, the application of response type detector has also begun to be restricted.Therefore, a kind of application request, operation easier demarcation and maintaining little, instrument that meets China of market in urgent need do not rely on external direct-type roughness measurement instrument.

In recent years, with computer technology and digital image processing techniques is that the information technology of core obtains develop rapidly, the digital camera device manufacturing technology level increases substantially, and these scientific and technological progresses make the measurement that utilizes photographing measurement method to implement surface evenness become possibility.

Summary of the invention

The technical problem to be solved in the present invention is, defective at the prior art existence, a kind of photographing measurement method that detects highroad pavement planeness is proposed, it applies to the highway planeness with videographic measurment and detects, system digitalized degree height, can satisfy the needs of speedway and airfield runway requirement high accuracy, high-reliability, high automation degree detecting, thereby improve surface evenness parameter level greatly, to adapt to modern high-grade highway construction demand for development.

For achieving the above object, the technical scheme that the present invention takes is that photographing measurement method is in the car of described detection highroad pavement planeness:

A. will measure car places on the road surface to be measured, an end fixedly mounts a camera head in described measurement car car, its optical axis is parallel to the car baseplane, 2 r distances of being separated by are settled in the vertical car of other end baseplane in car, and highly different marker posts, two marker posts are only in the direction motion of vertical car baseplane; The top of marker post respectively is provided with a cooperation sign;

When b. described measurement car moves, take the image of measuring different cooperation signs constantly in the car running with described camera head on road surface to be measured;

C. handle by image and data and obtain the road surface elevation in real time;

Further, use the longitudinal section section curve on the synthetic described road surface to be measured of road surface elevation parameter that is obtained.

The method that wherein said road surface elevation parameter obtains is:

P ₁, P ₂For being installed in the cooperation sign of measuring on the car mark bar, two marker post parallel distances are fixed as r, and measuring car speed when measuring is the V meter per second, and the camera head per second can be taken the H frame, then, obtain the relative elevation measured value Δ of sampling interval s=V/H respectively by two cooperation marks by inferior pixel location _1c, Δ _2c:

Δ _c＝Δ _s-Δ _x

Wherein:

Δ _cThe depth displacement of measuring for video camera

Δ _sActual depth displacement for the road surface

Δ _xVariable quantity for reference platform

By a series of relative elevation amount Δs that record _{1c, n}, Δ _{2c, n}Obtain a series of height measurement value h _{1c, n}, h _{2c, n}:

$h_{1c,n}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{1c,i}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}({\mathrm{\Δ}}_{1s,i}-{\mathrm{\Δ}}_{1x,i})=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{1s,i}-\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{1x,i}$

$h_{2c,n}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{2c,i}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}({\mathrm{\Δ}}_{2s,i}-{\mathrm{\Δ}}_{2x,i})=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{2s,i}-\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{2x,i}$

The height measurement value that is s by above a series of sampling intervals can draw two curvilinear function f respectively ₁(S), f ₂(S);

Again at two curvilinear function f ₁(S), f ₂(S) upward get a little for the r interpolation with the spacing distance, obtaining a series of spacings is the centrifugal pump h ' of r (i.e. distance between two marker posts) _{1c, n}, h ' _{2c, n}:

$h_{1c,n}^{\′}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{1s,i}^{\′}-\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{1x,i}^{\′},$ $h_{2c,n}^{\′}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{2s,i}^{\′}-\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{2x,i}^{\′}$

${\mathrm{\Δ}}_r=h_{2c,n}^{\′}-h_{1c,n}^{\′}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{2s,i}^{\′}-\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{2x,i}^{\′}-\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{1s,i}^{\′}+\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{1x,i}^{\′}$

Because the variable quantity of reference platform is identical, has thus:

${\mathrm{\&Delta;}}_r=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2s,i}^{\&prime;}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1s,i}^{\&prime;}=h_2-{\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="A20081003178800162.png"\; state="\{\{state\}\}">h</figure-callout>}}_1$

Wherein:

h ₁For measuring the true elevation that car moves to n the first marker post position after the r distance;

h ₂For measuring the true elevation that car moves to n the second marker post position after the r distance;

So Δ _rBeing spacing is the actual depth displacement in road surface of r;

Because the road surface has the inclination angle amount to be the gradient of θ, the relative elevation Δ of cooperation mark p2 position and cooperation mark p1 position on the measurement car _RFor:

Δ _R＝r×sinθ+Δ _r×cosθ

By above-mentioned a series of spacings is the actual relative elevation difference Δ of r _{R, n}, obtaining a series of spacings is r, relatively the absolute elevation h of basic point _n:

$h_n=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{R,i}.$

As known from the above, the present invention is a kind of photographing measurement method that detects highroad pavement planeness, and the needs that it can satisfy speedway and airfield runway requirement high accuracy, high-reliability, high automation degree detecting have improved surface evenness parameter level greatly; When using the inventive method, the disposable camera of having demarcated before only needing to measure is in the camera head field range cooperation sign and gets final product, and therefore in actual use, simple to operate, the operability of measurement mechanism is good.

Description of drawings

Fig. 1 is a road surface sectional structure schematic diagram;

Fig. 2 is a photographing measurement method principle schematic of the present invention;

Fig. 3 is a cooperation mark pattern;

Wherein (a) is circular, (b) is crosshair, (c) is vertical angles;

Fig. 4 measures graph of a relation for video camera;

Fig. 5 is a discrete data matched curve schematic diagram in the inventive method;

Fig. 6 gets the discrete point schematic diagram in the inventive method in matched curve;

Fig. 7 is reference platform parameter-relation chart under the situation of inclination angle;

Fig. 8 is rut computational methods schematic diagrames.

The specific embodiment

The present invention will be further described below in conjunction with drawings and Examples.

The experimental program figure of the image measuring device that planeness detects in the car as shown in Figure 2, G ₁For being installed in the video camera of measuring tailstock portion, P ₁, P ₂For being installed in the cooperation sign of measuring on the car mark bar, two marker posts are all the time perpendicular to the automobile reference platform, and its parallel distance is fixed as r, video camera C ₁Be fixedly mounted on the reference platform of automobile, its optical axis is perpendicular to marker post.

The photographing measurement method detailed step comprises in the car of the described detection highroad pavement planeness of present embodiment:

A. measuring car T is carriage shown in Figure 2.To measure car and place on the road surface R to be measured, the hard-wired high-speed camera C of an end in described measurement car car ₁Optical axis is parallel to the car baseplane, and the vertical car of other end baseplane is separated by r apart from settling 2 highly different marker posts in car, and the top of bar respectively is provided with a cooperation mark P ₁, P ₂, to move in vertical car baseplane direction, the difference in height of two bars is unlikely to make in measuring process two cooperation signs to block mutually to two marker posts only;

When b. described measurement car moves on road surface R to be measured, with described camera head C ₁Take and measure different cooperation mark P constantly in the car running ₁, P ₂Image;

C. handle by image and data and obtain the road surface elevation in real time;

D uses the road surface elevation parameter that is obtained to synthesize the longitudinal section section curve on described road surface to be measured at last.

Wherein the cooperation sign can be circular as shown in Figure 3, also can be diagonal form, or crosshair, or other figure of discerning easily arbitrarily.

The adjustment camera head makes the cooperation sign be positioned at the central authorities of visual field before measuring beginning, adjust the size of visual field, guarantee in whole measuring process, the cooperation mark is not deviate from the visual field, and that the visual field also is unlikely to is excessive, and determines the amount of exercise of two cooperation marks in image and actual momental relation at this moment, promptly according to the priori of the cooperation sign of line segment length, region area in the visual field, the publish picture factor of proportionality of picture of real-time calibration is used for the calculating of final road surface geometric parameter.In the measuring process, because the cooperation sign is connected on the marker post of measuring car, this marker post is along with measuring the car advanced in unison, but it moves up and down and is not subjected to measure the constraint of car, so the side-play amount of the cooperation sign that camera head records is actually displacement poor of the variable quantity of road surface elevation and reference platform.Supposing to measure car speed when measuring is the V meter per second, and the video camera per second can be taken the H frame, by inferior pixel location, can obtain the relative elevation measured value Δ that a series of sampling intervals are s=V/H respectively by two cooperation marks _1c, Δ _2c, see Fig. 4, as can be known:

Δ _c＝Δ _s-Δ _x

Wherein:

Δ _cThe depth displacement of measuring for video camera

Δ _sActual depth displacement for the road surface

Δ _xVariable quantity for reference platform

By a series of relative elevation amount Δs that record _{1c, n}, Δ _{2c, n}, can obtain a series of height measurement value h _{1c, n}, h _{2c, n}:

$h_{1c,n}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1c,i}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}({\mathrm{\&Delta;}}_{1s,i}-{\mathrm{\&Delta;}}_{1x,i})=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1s,i}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1x,i}$

$h_{2c,n}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2c,i}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}({\mathrm{\&Delta;}}_{2s,i}-{\mathrm{\&Delta;}}_{2x,i})=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2s,i}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2x,i}$

The height measurement value that is s by above a series of sampling intervals can draw two curvilinear function f respectively ₁(S), f ₂(S), as shown in Figure 5.Wherein sampling interval s is the distance of measuring in the every two field picture of camera head.

Get a little for the r interpolation with the spacing distance on two curvilinear functions that obtained, can obtain a series of spacings thus is the centrifugal pump h ' of r (i.e. distance between two marker posts) again _{1c, n}, h ' _{2c, n}, as shown in Figure 6.

$h_{1c,n}^{\&prime;}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1s,i}^{\&prime;}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1x,i}^{\&prime;},$ $h_{2c,n}^{\&prime;}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2s,i}^{\&prime;}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2x,i}^{\&prime;}$

Can obtain:

${\mathrm{\&Delta;}}_r=h_{2c,n}^{\&prime;}-h_{1c,n}^{\&prime;}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2s,i}^{\&prime;}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2x,i}^{\&prime;}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1s,i}^{\&prime;}+\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1x,i}^{\&prime;}$

Pairing at synchronization two cooperation marks is that same camera position is the reference platform of synchronization, so:

Δ′ _1x，i＝Δ′ _2x，i

Have thus:

${\mathrm{\&Delta;}}_r=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2s,i}^{\&prime;}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1s,i}^{\&prime;}=h_2-{\mathrm{<figure-callout\; id="1"\; label="h"\; filenames="A20081003178800162.png"\; state="\{\{state\}\}">h</figure-callout>}}_1$

Wherein:

h ₁For measuring the true elevation that car moves to n the first marker post position after the r distance

h ₂For measuring the true elevation that car moves to n the second marker post position after the r distance

So Δ _rBeing spacing is the actual depth displacement in road surface of r

By a series of spacings is the actual relative elevation difference Δ of r _{R, n}, can obtain a series of spacings is r, relatively the absolute elevation h of basic point _n:

$h_n=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{r,i}$

More than finding the solution at the hypothesis reference platform of absolute elevation do not carried out Δ so when having the inclination angle _rBe meant and consider the height value of removing the reference platform inclination angle.When the measurement car travels measurement on acclive road surface, need to add an inclination angle amount θ, the θ angle can record by the gyroscope on the measurement car.See that Fig. 7 is as showing.

As can be known after having considered inclination angle [theta], the relative elevation Δ of cooperation mark p2 position and cooperation mark p1 position _R, be between two marker posts apart from r and consider to remove the elevation difference DELTA at reference platform inclination angle _rProjection in the vertical-horizontal direction:

Δ _R＝r×sinθ+Δ _r×cosθ

By a series of spacings is the actual relative elevation difference Δ of r _{R, n}, can obtain a series of spacings is r, relatively the absolute elevation h of basic point _n:

$h_n=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{R,i}$

By this a series of absolute elevation h _nCan obtain the longitudinal profile curve on road surface.

If laterally settle such marker post, according to the aforementioned calculation method, then can obtain the longitudinal profile curve more than 5 or 5, the elevation amount h more than 5 or 5 that records by synchronization more than 5 groups or 5 groups ₁, h ₂, h ₃, h ₄, h ₅Deng the horizontal section curve that can obtain the road surface, be example with 5 group mark bars, as shown in Figure 8, the rut formula that obtains the road surface is as follows:

Revolver rut: RUT=((h ₁+ h ₃)-2h ₂)/2

Right wheel rut: RUT=((h ₃+ h ₅)-2h ₄)/2

Because measuring camera head is fixed on the reference platform, in measuring process, reference platform is that the fluctuating with the road surface rises and falls, and therefore how cancellation car body self vertical displacement just becomes the key issue of this class detection technique.Method is that imagination one in device on car body is not made the benchmark the move both vertically carrier as camera with car body the most intuitively, as early stage inertial reference.Modern detecting then adopts calculate to revise the acceleration that inertial reference is promptly used acceleration transducer measuring basis platform, obtains the vertical displacement Z of car body through quadratic integral, and Z is added among the elevation actual measured value W, then can obtain road surface height value H, promptly

H＝Z+W

Yet theory analysis and experiment operation all show, this correction not only because acceleration transducer also angle is changed responsive, as turning, pitching etc., to demarcate synchronously simultaneously very difficult, because of rather than desirable method.For this reason, the present invention has designed pairing and has done the vibrations that the method for mark mutual deviation is eliminated camera head, eliminates fluctuating and vibrations the influence to measure of reference platform with the road surface with this.

By adopting various existing digit image processing techniques, can detect accurately and network for location picture point position.For example, sub-pix framing technology is exactly one of image processing method of a kind of advanced person, uses it to make target location accuracy in the image be higher than the physical resolution of image.The present invention can adopt following sub-pixel positioning technology:

1, uses adaptive template correlation filtering method

Basic thought is to make the adjustable template of parameter, to each coarse positioning point, at first determines to answer the parameter of modeling plate, select only template, with selected template coarse positioning point and neighborhood point thereof are carried out related operation,, determine the maximal correlation position with gained index of correlation fitting surface.

2, adaptive threshold gravity model appoach

For some target, can extract target area by multiple image process method with certain area, and consider the gray distribution features of target, adopt the grey scale centre of gravity method, in the target area be with the gray scale weights obtain the target area grey scale centre of gravity as the target location, adopt the Gaussian distribution template of band adaptive threshold that the feature target is carried out track and localization simultaneously.

3, gray-scale map fitting process

For some target, also can select suitable analytic surface for use directly according to the feature of target image, gray-scale map is carried out surface fitting, obtain the extreme value place of analytic surface again, thereby realize the sub-pixel precision location of target.

4, carry out the automatic identification of the appointed area or the whole audience according to gray feature

As shown in Figure 3, the vertical angles sign image has certain feature, be all bright or dark and average gray difference is little as diagonal zones, adjacent angle zone one bright one is dark and average gray difference is big, 4 angular domains separately average gray and the average gray in whole zone have than big-difference, the average gray of center is close with the average gray in whole zone, in the same angular domain between pixel gray difference little, the sign outer rim has ellipse or sub-elliptical to exist, and has two step edges that intersect at the center to exist.Make full use of these features, can realize high-precision identification and location reliably.

Implement the present invention, can adopt with camera head and personal computer (or dsp processor) and gyroscope is the hardware device of core, low to the hardware-dependent degree, digitized degree and automaticity height, can adopt computer to the view data that camera head obtains store, duplicate, transmission and automation handle.

The selection of camera head and installation: digital camera device speed is fast, convenient storage, is easy to realize digitlization, the automation of post processing, therefore adopts digital camera device more suitable than the simulation camera head.On bad road conditions, be attended by the high vibration existence in the running owing to measure car.For guaranteeing the normal operating conditions of camera head, correctly obtain cooperation mark image, camera head need be fixed on and measure on the car.

Processor selection design scheme: in the detection of surface evenness parameter, can adopt PC computer or dsp processor, as image storage, data processing equipment.Because dsp processor speed is fast, easy and simple to handle, therefore be more suitable for being used in the actual device.Selected at camera head, can be according to the interface scheme design dsp processor of camera head.

Described measurement car can be special-purpose pavement detection car.

Detect and draw vertical section of road surface section elevation (curve) with said method, directly calculate international roughness index IRI and the accurate difference of smooth scale σ by software then; In work progress such as paving, pavement asphalt parameters such as planeness can be sent to construction machinery, for the isoparametric real-time control of work progress surface evenness provides foundation.

Claims (8)

1, a kind of photographing measurement method that detects highroad pavement planeness is characterized in that, comprises the steps:

A. will measure car places on the road surface to be measured, an end fixedly mounts a camera head in described measurement car car, its optical axis is parallel to the car baseplane, 2 r distances of being separated by are settled in the vertical car of other end baseplane in car, and highly different marker posts, two marker posts are only in the direction motion of vertical car baseplane; The top of marker post respectively is provided with a cooperation sign;

When b. described measurement car moves, take the image of measuring different cooperation signs constantly in the car running with described camera head on road surface to be measured;

C. handle by image and data and obtain the road surface elevation in real time.

2, according to the photographing measurement method of the described detection highroad pavement planeness of claim 1, it is characterized in that, by the longitudinal section section curve on the synthetic described road surface to be measured of the road surface elevation parameter that is obtained.

According to photographing measurement method in the car of the described detection highroad pavement planeness of claim 1, it is characterized in that 3, the method that described road surface elevation parameter obtains is:

P ₁, P ₂For being installed in the cooperation sign of measuring on the car mark bar, two marker post parallel distances are fixed as r, and measuring car speed when measuring is the V meter per second, and the camera head per second can be taken the H frame, locate two cooperation marks by inferior pixel, obtain the relative elevation measured value Δ of sampling interval s=V/H respectively _1c, Δ _2c:

Δ _c＝Δ _s-Δ _x

Wherein:

Δ _cThe depth displacement of measuring for camera head

Δ _sActual depth displacement for the road surface

Δ _xVariable quantity for reference platform

By a series of relative elevation amount Δs that record _{1c, n}, Δ _{2c, n}Obtain a series of height measurement value h _{1c, n}, h _{2c, n}:

$h_{1c,n}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1c,i}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}({\mathrm{\&Delta;}}_{1s,i}-{\mathrm{\&Delta;}}_{1x,i})=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1s,i}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1x,i}$

$h_{2c,n}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2c,i}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}({\mathrm{\&Delta;}}_{2s,i}-{\mathrm{\&Delta;}}_{2x,i})=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2s,i}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2x,i}$

The height measurement value that is s by above a series of sampling intervals can draw two curvilinear function f respectively ₁(S), f ₂(S);

Again from two curvilinear function f ₁(S), f ₂(S) upward get a little for the r interpolation with the spacing distance, obtaining a series of spacings is the centrifugal pump h ' of r (i.e. distance between two marker posts) _{1c, n}, h ' _{2c, n}:

$h_{1c,n}^{\&prime;}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1s,i}^{\&prime;}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1x,i}^{\&prime;},$ $h_{2c,n}^{\&prime;}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2s,i}^{\&prime;}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2x,i}^{\&prime;}$

${\mathrm{\&Delta;}}_r=h_{2c,n}^{\&prime;}-h_{1c,n}^{\&prime;}=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2s,i}^{\&prime;}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2x,i}^{\&prime;}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1s,i}^{\&prime;}+\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1x,i}^{\&prime;}$

Because the variable quantity of reference platform is identical, has thus:

${\mathrm{\&Delta;}}_r=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{2s,i}^{\&prime;}-\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{1s,i}^{\&prime;}=h_2-h_1$

Wherein:

h ₁For measuring the true elevation that car moves to n the first marker post position after the r distance;

h ₂For measuring the true elevation that car moves to n the second marker post position after the r distance;

So Δ _rBeing spacing is the actual depth displacement in road surface of r;

Because the road surface has the inclination angle amount to be the gradient of θ, the relative elevation Δ of cooperation mark p2 position and cooperation mark p1 position on the measurement car _RFor:

Δ _R＝r×sinθ+Δ _r×cosθ

By above-mentioned a series of spacings is the actual relative elevation difference Δ of r _{R, n}, obtaining a series of spacings is r, relatively the absolute elevation h of basic point _n:

$h_n=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{\mathrm{\&Delta;}}_{R,i}.$

According to the photographing measurement method of the described detection highroad pavement planeness of claim 1, it is characterized in that 4, described camera head is the high-speed figure video camera.

According to the photographing measurement method of the described detection highroad pavement planeness of claim 1, it is characterized in that 5, described cooperation is masked as circle, crosshair or vertical angles shape.

6, according to the photographing measurement method of the described detection highroad pavement planeness of claim 1, it is characterized in that, adopt sub-pix framing technology to carry out described image and handle the cooperation mark position in the positioning image.

7, according to the photographing measurement method of the described detection highroad pavement planeness of claim 1, it is characterized in that, according to the priori of the cooperation sign of line segment length, region area in the visual field, the publish picture factor of proportionality of picture of real-time calibration is used for the calculating of final road surface geometric parameter.

8, according to the photographing measurement method of the described detection highroad pavement planeness of claim 1, it is characterized in that, be horizontally arranged with marker post more than 5 pairs on the described measurement car, by the cooperation sign that is fixed on the described marker post is measured, can obtain the horizontal section curve on road surface, record the rut degree of depth on road surface.

Images