CN102874161A - Road image collecting vehicle and road image collecting method - Google Patents

Abstract

The invention discloses a road surface image acquisition vehicle and a road surface image acquisition method. The acquisition vehicle comprises: a vehicle body, the bottom of which has a viewfinder window for shooting by a linear camera; a linear camera fixed above the viewfinder window . The method of the present invention includes: controlling the linear camera to take images of the road surface through a viewing window at the bottom of the vehicle body. In the present invention, a viewfinder window is opened at the bottom of the vehicle to collect road surface images at the bottom area of the vehicle body. Since the area at the bottom of the car body has uniform light, the captured road image has a better effect and is not affected by changes in the light of the external daylight. Compared with the way of taking road images outside the vehicle body, there is no need to use additional external strong light source devices, generator devices, etc., which reduces the power consumption, cost, and complexity of the road image acquisition system.

Description

Road surface image collection vehicle and road surface image collection method

technical field

The invention relates to image acquisition equipment, in particular to a road surface image acquisition vehicle and a road surface image acquisition method.

Background technique

Pavement surface damage is an important reference content for road maintenance evaluation and analysis, and it is also the main basis for road engineers to judge the pavement overlay. Among the four major damage indicators of pavement technical condition, surface damage is the most difficult to measure and calculate.

The method of artificial visual inspection was used in the early stage. The disadvantage of this method is that it is seriously affected by human subjective factors, low efficiency and poor reliability. At present, road condition rapid detection vehicles are used for detection of road surface damage on national and provincial trunk roads. In this inspection vehicle, road surface damage information is obtained by collecting road surface images and performing damage recognition on the road surface images in the later stage. Install the road surface image acquisition system on the road condition rapid detection vehicle. The system consists of four parts: inspection vehicle, road surface image acquisition camera, light source equipment and generator.

The current light source equipment needs to provide a strong enough light source in order to reduce the influence of the roadside image on the roadside building shadows or tree shadows to a certain extent. Since the roadside shadows appear irregularly, it is not convenient to reduce the shadow by turning on and off the light source. Impact. As a result, the captured road surface image is affected by shadows, and the shooting is unclear or blurred, which is inconvenient for subsequent post-processing of the captured road surface image.

Contents of the invention

In view of this, the present invention is to provide a road surface image collection vehicle and a road surface image collection method to solve the above-mentioned problem that the captured images are not conducive to subsequent processing.

In order to solve the above problems, the present invention provides a road surface image acquisition vehicle, comprising:

a car body, the bottom of the car body has a viewfinder window for shooting with a linear camera;

A linear camera is fixed above the viewfinder window.

Preferably, the viewing window is strip-shaped, and its extension direction is parallel to the axle of the collection vehicle, and the vehicle body does not block the downward light passing through the viewing window.

Preferably, the distance between the ground projection of the viewing window and the ground projection of its adjacent axle is no greater than 60 cm.

Preferably, the linear camera is fixed in the vehicle body through an adjustable bracket;

The adjustable bracket includes:

Bracket bottom plate, used to fix the camera bracket;

The camera bracket is vertically fixed on the bracket bottom plate, and a chute is provided on the camera bracket, and a bolt vertically moving up and down along the chute is arranged in the chute;

One end of the adapter plate is fixedly connected to the bolt on the channel of the camera bracket, and the other end is fixedly connected to the linear camera.

Preferably, the viewing window is opened on the chassis of the vehicle body, the bottom of the trunk, or the bottom plate of the bracket.

Preferably, it also includes:

On both sides of the vehicle body, a light barrier perpendicular to the ground is respectively fixed;

The light baffle is close to or intersects the extension line of the viewfinder window;

The bottom edge of the light blocking plate is parallel to the ground, and the distance between them is not less than 20cm.

Preferably, it also includes:

a light detector, used to detect the light intensity below the viewfinder window outside the vehicle body;

a controller, configured to receive the light intensity value detected by the light detector, compare it with a threshold value, and control the light baffle to extend out of the vehicle body or retract into the vehicle body through the lifting mechanism according to the comparison result; or,

The time range to which the current moment belongs is judged, and according to the judgment result, the light baffle is controlled to protrude from the vehicle body or retract into the vehicle body through the lifting mechanism.

Preferably, the lifting mechanism is a rope pulley type, an arm type or a flexible shaft type lifting mechanism.

The present invention provides a road surface image acquisition method, comprising:

The linear camera is controlled to take images of the road surface through the viewing window at the bottom of the vehicle body.

Preferably, during the process of taking road images through the viewfinder window at the bottom of the car body, it also includes:

Detecting the light intensity value below the viewfinder window outside the vehicle body;

Comparing the light intensity value with a threshold value, and controlling the light barrier to protrude from the vehicle body or retract into the vehicle body through the lifting mechanism according to the comparison result;

Or, judge the time range to which the current moment belongs, and control the light barrier to extend out of the vehicle body or retract into the vehicle body through the lifting mechanism according to the judgment result.

In the present invention, a viewfinder window is opened at the bottom of the vehicle to collect road surface images at the bottom area of the vehicle body. Since the area at the bottom of the car body has uniform light, the captured road image has a better effect and is not affected by changes in the light of the external daylight. Compared with the way of taking road images outside the vehicle body, there is no need to use additional external strong light source devices, generator devices, etc., which reduces the power consumption, cost, and complexity of the road image acquisition system.

Description of drawings

Fig. 1 is the structural diagram of the collection vehicle in the embodiment;

Fig. 2 is the structural diagram of another collecting car in the embodiment;

Fig. 3 A is the road image collected under different D1 situations in the embodiment;

Fig. 3B is a structural diagram of the adjustable bracket in the embodiment;

Fig. 4 is the structure drawing of the collecting car that light barrier has been installed in the embodiment;

Fig. 5 is a structural diagram of the light blocking plate in the embodiment.

Detailed ways

In order to clearly illustrate the solutions in the present invention, preferred embodiments are given below and detailed descriptions are given in conjunction with the accompanying drawings.

Referring to Fig. 1, an embodiment of the present invention provides a road surface image acquisition vehicle, including:

Car body 2, the bottom of the car body 2 has a viewfinder window 3 for shooting with a linear camera;

The linear camera 1 is fixed above the viewing window 3 .

In the road surface image acquisition vehicle of the present invention, since the viewfinder window is set at the bottom of the vehicle body, the external light is blocked by the vehicle body itself during the process of taking road images, and the light at the bottom of the vehicle body is even and will not be affected by roadside buildings. The shadow of the object or the influence of strong light, the captured image is clear, which is convenient for subsequent analysis and processing.

Preferably, the viewing window 3 can be set on the chassis 4, and can also be set on the bottom of the trunk of the collection vehicle.

Preferably, referring to FIG. 2 , the viewfinder window 3 is elongated, extending in a direction parallel to the axle of the collection vehicle, and the car body 2 does not block the light that passes through the viewfinder window 3 downwards, that is, viewfinder Light between window 3 and the ground.

In FIG. 2 , it is shown that the ground projection line 6 of the viewing window 3 and the ground projection line 61 of the axles of the two wheels 5 are two parallel lines, and the distance D1 between the two parallel lines is ≤ 60 cm.

Whether the viewfinder window 3 is set on the chassis 4 or at the bottom of the trunk, the viewfinder window 3 should be as close to the position of the wheel as possible, for example, the distance D1≤60cm from the projected line of the axle. The wheel 5 can block the shadow or strong light on the side of the road, and the image quality of the road surface image at the bottom of the car body taken through the viewfinder window 3 is better than that of other positions near the wheel position.

After a lot of experiments, the inventor found that the distance of D1 is not as small as possible. When it is close to zero, the effect is poor due to the influence of the axle; when it is near 40cm, the best effect is achieved; when it is close to 60cm or more than 60cm, the effect is poor.

See the comparison diagram of the two collected images in Figure 3A. Figure 3A shows the collected images of the same road surface less than ten minutes apart. The left side is the video image collected when D1=90cm, and the right side It is the image collected when D1=40cm. From the comparison images, it can be seen that the image collected on the left is unevenly illuminated, with partial shadows and overexposure, while the image collected on the right is of relatively high quality: uniform light, clear textures and cracks, which are conducive to automatic computer recognition.

When D1≤60cm, even in the case of oblique sunlight in the morning and afternoon, the light is not easy to hit the scanning line part, and it will not cause a local area of the collected image to be very bright, while the local area is very bright. The impact on the recognition result is fatal.

On the road below the viewfinder window 3 of the car body 2, the external light is blocked by the car body 2 and the tires 5, the light is uniform, and the captured image is clear. Even if sunlight shines from the rear of the car body 2, the projection line 6 of the viewfinder window 3 is either in the shadow or in the sun as a whole, and the light in the shooting area always maintains good uniformity in the lateral direction.

Preferably, referring to FIG. 3B , the linear camera 1 is fixed on the adjustable bracket shown in FIG. 3B . Adjustable stand includes:

The bracket bottom plate 10 is used to fix the camera bracket 7;

The camera bracket 7 is used to fix the linear camera 1; the camera bracket 7 is vertically fixed on the bracket bottom plate 10, and a chute is provided on the camera bracket 7, and a bolt that moves vertically up and down along the channel is arranged in the chute;

An adapter plate 11, one end is fixedly connected to the bolt on the channel of the camera bracket 7, and the other end is fixedly connected to the linear camera 1;

Preferably, one end of the adapter plate 11 fixedly connected to the linear camera 1 is also installed with a camera protective cover 8 .

Preferably, the bracket bottom plate 10 can be integrated with the chassis 4 of the vehicle body 2 or the bottom of the trunk of the vehicle body 2 .

If support base plate 10 is produced separately, viewfinder window 3 can be offered on support base plate 10 . At the bottom of the chassis 4 of the car body 2 or the trunk, the position of the adjustable bracket is installed, and the opening corresponding to the position of the viewfinder window 3 on the support base plate 10 is opened, and the size of the opening is not less than the viewfinder window 3. After the adjustable bracket is fixed, the linear camera 1 shoots the road surface image of the ground through the viewfinder window 3 .

Preferably, the viewfinder window 3 is strip-shaped, with a length not less than 40 cm and a width not less than 0.5 cm.

Through the chute on the camera bracket 7, the adapter plate 11 can move up and down, thereby driving the linear camera 1 to move up and down, and the adjustment range can be controlled within 20cm.

The plane where the linear camera 1 and the adapter board 11 are located is parallel to the support bottom plate 10 . The adjustable support is fixed on the chassis 4 of the car body 2 or the bottom of the trunk through the support base plate 10, and the plane of the fixed support base plate 10 is parallel to the ground.

Referring to the height D2 of the linear camera 1 shown in FIG. 1 , D2 is usually 85cm±10cm from the ground, and the height of the linear camera 1 from the ground can be adjusted through the chute on the camera bracket 7 .

Preferably, in the embodiment, the projection position of the viewfinder window 3 where the linear camera 1 captures the image is within a certain distance from the adjacent axle, but the light in this area is sometimes affected by sunlight. In order to overcome this problem, a light blocking plate 51 is respectively installed on both sides of the vehicle body 2 of the collection vehicle, which will be described below in conjunction with FIG. 4 .

Referring to Fig. 4, the plane of the light blocking plate 51 and the side of the car body 2 are in a plane, perpendicular to the ground, and close to or intersect the extension line of the viewfinder window 3; the extension line and the vertical line of the length direction of the viewfinder window 3 form The plane passes through the middle position of the light blocking plate 51.

The light blocking plate 51 can be installed on the side of the car body 2 using a variety of lifting mechanisms, such as using the same lifting mechanism as the electric window, such as the rope pulley type, the cross-arm type or the flexible shaft type, etc., to control the light blocking plate 51 to extend out of the car body 2 outside or retracted into the inside of the car body 2.

Preferably, a light sensor is installed near the viewfinder window 3 of the acquisition vehicle to detect the light intensity below the viewfinder window 3, and the detected light intensity value is sent to a controller, such as a single-chip microcomputer, a processor, etc., and the controller Compare the light intensity value with the threshold value, when it is greater than the threshold value, it means that the light is strong, and the light barrier 51 is controlled to extend from the vehicle body 2; when it is less than the threshold value, it indicates that the light is weak, and the light barrier 51 is controlled to retract into the vehicle body.

Of course, the corresponding length of the light blocking plate 51 is controlled precisely according to the interval to which the light intensity belongs.

Preferably, at different times, the intensity of light and the length of the shadow produced by the object are different. If no light sensor is installed, the time period when the light baffle 51 stretches out of the vehicle body or retracts into the vehicle body can also be set, for example, from 10 am to Between 16:00 in the afternoon, control the light blocking plate 51 to retract into the vehicle body; in other time periods, control the light blocking plate to extend out of the vehicle body. The bottom edge of the light-shielding plate is parallel to the ground, and when the light-shielding plate 51 stretches out to the limit position, the distance between the light-shielding plate 51 and the ground is 20cm.

Preferably, the light blocking plate 51 can also be fixed on both sides of the vehicle body 2 by using simple mechanical components. Referring to FIG.

The swivel clamp 16 is designed with a spiral ellipse. When in a loose state, the short semi-axis of the rotary clamp 16 is tangent to the clamp 15. When in a fastened state, the rotary clamp 16 is tangent to the long semi-axis position and the clamp 15.

When in use, first clamp the upper and lower clamps 15 connected to the light barrier 51 to the steel plate below the chassis of the collection vehicle, then pass the latch 13 through the small hole of the lower clamp, and finally rotate the wrench 14 down to the level . When no longer detecting within a period of time or when needing to replace the light blocking plate 51, rotate the wrench 14 upwards to the vertical position, at this moment, the steel wire on the clip is loose, and the latch 13 is taken out from the small hole of the clip below, The light blocking plate 51 can be taken out.

Preferably, the size of the light blocking plate 51 can be selected according to the situation of the vehicle body, usually 40 cm wide can be selected, and the bottom edge of the light blocking plate 51 should be no less than 20 cm from the ground. The plane passing through the viewfinder window 3 and perpendicular to the ground just passes through the middle position of the light blocking plate 51 .

Preferably, computer equipment is installed on the collection vehicle for receiving the image data collected by the linear camera 1, processing the image data, and analyzing the collected road surface image data.

The road surface image acquisition vehicle of the present invention collects road surface image data through the area under the chassis of the vehicle without additional use of external strong light source devices, generator devices, etc., which reduces the power consumption, cost and complexity of the road surface image acquisition system.

An embodiment of the present invention provides a method for collecting road images, including: controlling the linear camera to capture road images through a viewing window at the bottom of the vehicle body.

Preferably, during the process of taking road images through the viewfinder window at the bottom of the car body, it also includes:

Detecting the light intensity value below the viewfinder window outside the vehicle body;

Comparing the light intensity value with a threshold value, and controlling the light barrier to protrude from the vehicle body or retract into the vehicle body through the lifting mechanism according to the comparison result;

Or, judge the time range to which the current moment belongs, and control the light barrier to extend out of the vehicle body or retract into the vehicle body through the lifting mechanism according to the judgment result.

For the road surface image acquisition vehicle described in each embodiment of the present invention, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A road image acquisition vehicle, characterized in that, comprising: a car body, the bottom of the car body has a viewfinder window for shooting with a linear camera; A linear camera is fixed above the viewfinder window. 2. The collection vehicle according to claim 1, wherein the viewfinder window is strip-shaped, and its extension direction is parallel to the axle shaft of the collection vehicle, and the vehicle body does not block the direction passing through the viewfinder window. under the light. 3. The collection vehicle according to claim 1 or 2, characterized in that the distance between the ground projection of the viewing window and the ground projection of its adjacent axle is not greater than 60 cm. 4. The collection vehicle according to claim 1, wherein the linear camera is fixed in the vehicle body by an adjustable bracket; The adjustable bracket includes: Bracket bottom plate, used to fix the camera bracket; The camera bracket is vertically fixed on the bracket bottom plate, and a chute is provided on the camera bracket, and a bolt vertically moving up and down along the chute is arranged in the chute; One end of the adapter plate is fixedly connected to the bolt on the channel of the camera bracket, and the other end is fixedly connected to the linear camera. 5 . The collection vehicle according to claim 4 , wherein the viewing window is set on the chassis of the vehicle body, the bottom of the trunk, or the bottom plate of the bracket. 6 . 6. The collecting vehicle according to claim 1, further comprising: On both sides of the vehicle body, a light shield perpendicular to the ground is respectively fixed; The light baffle is close to or intersects the extension line of the viewfinder window; The bottom edge of the light blocking plate is parallel to the ground, and the distance between them is not less than 20cm. 7. The collecting vehicle according to claim 6, further comprising: a light detector, used to detect the light intensity below the viewfinder window outside the vehicle body; a controller, configured to receive the light intensity value detected by the light detector, compare it with a threshold value, and control the light baffle to extend out of the vehicle body or retract into the vehicle body through the lifting mechanism according to the comparison result; or, The time range to which the current moment belongs is judged, and according to the judgment result, the light baffle is controlled to protrude from the vehicle body or retract into the vehicle body through the lifting mechanism. 8. The collecting vehicle according to claim 7, characterized in that, the lifting mechanism is a sheave type, cross-arm type or flexible shaft type lifting mechanism. 9. An image acquisition method based on the acquisition vehicle according to claim 1, characterized in that, comprising: The linear camera is controlled to take images of the road surface through the viewing window at the bottom of the vehicle body. 10. An image acquisition method based on the acquisition vehicle according to claim 7, characterized in that, controlling the linear camera, and in the process of taking a road surface image through the viewfinder window at the bottom of the vehicle body, also includes: Detecting the light intensity value below the viewfinder window outside the vehicle body; Comparing the light intensity value with a threshold value, and controlling the light barrier to protrude from the vehicle body or retract into the vehicle body through the lifting mechanism according to the comparison result; Or, judge the time range to which the current moment belongs, and control the light barrier to extend out of the vehicle body or retract into the vehicle body through the lifting mechanism according to the judgment result.

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