JP6938107B1 - How to measure road surface damage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for measuring damage on a road surface capable of measuring damage on the road surface at low cost and with good accuracy. A method for measuring damage to a road surface includes a step S1 in which a reference ruler is placed on the surface of a road, a step S2 in which a reference ruler is photographed by an imaging device installed in a vehicle to obtain a reference ruler image, and a reference ruler. Step S3 that separates the ruler pixels from the image and stores them in the ruler layer, step S4 that captures the road surface with an image pickup device while traveling on the road with a vehicle, and obtains a road surface image, and a road surface image showing damage to the road surface. The extraction step S5, the step S6 for creating a composite image by superimposing the road surface image and the reference ruler image, the step S7 for setting the auxiliary line so as to surround the damage on the road surface in the composite image, and the auxiliary line and the reference. It has step S8 to calculate the magnitude of the damage based on the pixels. [Selection diagram] Fig. 1

Description

The present invention relates to a method of measuring damage to the surface of a road on which a vehicle travels.

Since the vehicle load acts directly on the road surface, which is the surface of the pavement of the road, there is a high possibility that damage will occur particularly among various parts of the road structure. From the viewpoint of preventing accidents and ensuring safe and smooth traffic, road managers carry out more detailed maintenance work than other parts by thorough daily inspections, especially on the road surface.

Damage to the road surface includes cracks, potholes, peeling and rutting. Among them, potholes are a serious factor that poses a danger to vehicle driving, and the signs of them appear as two-way cracks. Therefore, early detection of potholes and bidirectional cracks and identification of their shapes and dimensions are extremely important for ensuring safety.

Searching for road damage during routine inspections usually relies on the visual inspection of an inspector on board a police car. However, in order to avoid inconvenience to road users as much as possible, it is necessary to visually check the patrol car while keeping it running at a relatively high speed, and it is difficult to catch the damage with high accuracy. be.

Therefore, conventionally, a road inspection vehicle equipped with a line camera has been proposed for the purpose of photographing and inspecting the road surface while traveling on the road (see Patent Document 1). This road inspection vehicle is equipped with a line camera that photographs the road surface from above vertically so as to project forward from the front end of the vehicle body. The vehicle body is equipped with a control device for a line camera and a recording device for recording video data taken by the line camera. When you inspect the road using this road inspection vehicle, you can obtain an image of the road surface taken vertically from above with a line camera, so even if you drive at a relatively high speed, the road surface will be damaged or the shape of the structure etc. And dimensions can be grasped accurately.

Japanese Unexamined Patent Publication No. 2002-54911

However, the conventional road inspection vehicle is expensive because it uses a line camera and a control device that are not widely used and has a support structure that supports the line camera in front of the vehicle. Therefore, in order to introduce this road inspection vehicle for daily inspection, it is necessary to introduce a large number of expensive road inspection vehicles, which is not realistic in terms of cost. In addition, there is a problem that it takes a lot of labor to process and analyze the data collected by the road inspection vehicle.

Therefore, an object of the present invention is to provide a method for measuring road surface damage that can measure road surface damage at low cost and with good accuracy.

In order to solve the above problems, the method for measuring damage to the road surface of the present invention includes a reference ruler arranging step of arranging a reference ruler having a scale in the orthogonal direction on the surface of the road.
A reference ruler photographing process of photographing the reference ruler arranged in front of the traveling direction of the vehicle by an imaging device installed in the vehicle to obtain a reference ruler image, and
A road surface photographing process in which the road surface is photographed by the imaging device to obtain a road surface image while traveling on the road with the vehicle.
A composite image creation step of superimposing the reference ruler image and the road surface image to create a composite image, and
It is characterized by including a damage dimension detection step for detecting the damage dimension of the road surface existing in the road surface image based on the composite image.

According to the above configuration, in the reference ruler arrangement step, a reference ruler having a scale in the orthogonal direction is arranged on the surface of the road. Subsequently, in the reference ruler photographing step, the reference ruler image arranged in front of the traveling direction of the vehicle is photographed by the imaging device installed in the vehicle to obtain a reference ruler image. Further, in the road surface photographing step, while traveling on the road with the vehicle, the road surface is photographed by the imaging device to obtain a road surface image. After that, in the composite image creation step, the reference ruler image and the road surface image are superposed to create a composite image. Based on the composite image, the damage dimension detection step detects the damage dimension of the road surface existing in the road surface image. Since both the reference ruler image and the road surface image are images taken by an image pickup device installed in the vehicle, by using a composite image formed by superimposing them, the reference ruler part of the reference ruler image and the reference ruler part of the reference ruler image can be used. The dimension of the damage can be detected without correcting or converting the damaged part of the road surface in the road surface image. Therefore, it is possible to easily and inexpensively detect the magnitude of damage to the road surface by using a generally popular image pickup device or image processing device without performing complicated image processing. As a result, road damage can be measured as a daily inspection with a vehicle with simple equipment.

In the method for measuring damage to the road surface of one embodiment, in the damage dimension detection step, an auxiliary line is set in the composite image so as to surround the damaged portion in the road surface image, and the reference ruler where the auxiliary lines intersect. The dimension of the damage is detected based on the scale of the part of the reference ruler in the image.

According to the above embodiment, in the damage dimension detection step, an auxiliary line is set in the composite image so as to surround the damaged portion in the road surface image. It is possible to read the scale near the point where this auxiliary line and the part of the reference ruler in the reference ruler image intersect, and accurately detect the dimension of damage from the value of the scale at the point where each auxiliary line intersects. ..

In the method for measuring road surface damage of one embodiment, the reference ruler is a rectangular frame-shaped body having a scale.

According to the above embodiment, by using a rectangular frame-shaped body having a scale as a reference ruler, a portion of the rectangular frame-shaped reference ruler having a scale can be formed in the reference ruler image. By locating the damaged portion of the road surface in the road surface image inside the reference ruler portion, the dimension of the damage can be easily detected.

In one embodiment, the method for measuring road surface damage is that the reference ruler is a tape having a scale and arranged in a frame shape.

According to the above embodiment, the reference ruler can be easily transported and stored by arranging the tape having the scale in a frame shape on the road surface to form the reference ruler.

In the method for measuring road surface damage of one embodiment, the reference ruler is a plate-like body having a mesh-like pattern.

According to the above embodiment, since the reference ruler is a plate-like body having a mesh-like pattern, the damage is caused based on the pattern portion of the reference ruler image that overlaps the damaged portion of the road surface image in the composite image. The dimensions can be easily detected with good accuracy.

As for the method for measuring the damage to the road surface of one embodiment, the reference ruler has a number corresponding to the scale.

According to the above embodiment, since the reference ruler describes the numbers corresponding to the scales, the damage dimension is based on the number portion of the reference ruler image that overlaps the damaged portion of the road surface image in the composite image. Can be easily detected.

In the method for measuring road surface damage of one embodiment, numbers are arranged in the pattern of the reference ruler.

According to the above embodiment, the size of the damage in the composite image can be easily detected based on the numbers arranged in the pattern of the reference ruler.

In the method for measuring damage to the road surface of one embodiment, the size of the side to be measured with the scale of the reference ruler is 3 m or more and 4 m or less in width and 1 m or more and 2 m or less in depth.

According to the above embodiment, the width of the side to be measured with the scale of the reference ruler is set to 3 m or more and 4 m or less, so that the width direction of the traveling lane of a general road is used as a reference in the composite image. It can be surrounded by a ruler. Further, by setting the depth of the side to be measured with the scale of the reference ruler to 1 m or more and 2 m or less, for example, the vehicle travels on the road at a speed of 100 km / h and the image pickup device has a frame rate of 30 fps. When the moving image of the vehicle is taken to obtain a road surface image, it is possible to form a composite image in which the road surface is continuously surrounded by a reference ruler portion in the traveling direction without a gap in the traveling direction of the vehicle. Therefore, the dimensions of damage existing on the road surface can be detected without omission.

The method for measuring road surface damage according to the embodiment is that the image pickup device is a drive recorder.

According to the above embodiment, by using the drive recorder, it is possible to measure the damage on the road surface with inexpensive equipment. Therefore, daily inspection of the road can detect damage to the road surface with good accuracy.

It is a flow chart which shows the measuring method of the road surface damage of embodiment of this invention. It is a schematic diagram which shows the state of taking a picture of a reference ruler with an image pickup device mounted on a vehicle. It is a block diagram which shows the image pickup apparatus. It is a top view which shows the reference ruler. It is a schematic diagram which shows the reference ruler image. It is a schematic diagram which shows the composite image which superposed the reference ruler image and the road surface image. It is a schematic diagram which shows the state of detecting the damage of a road surface with a composite image. It is a top view which shows the reference ruler of another embodiment. It is a top view which shows the reference ruler of another embodiment. It is a top view which shows a part of the reference ruler of another embodiment. It is a top view which shows a part of the reference ruler of another embodiment. It is a top view which shows a part of the reference ruler of another embodiment. It is a top view which shows a part of the reference ruler of another embodiment. It is a top view which shows a part of the reference ruler of another embodiment.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 is a flow chart showing a method for measuring road surface damage according to the embodiment of the present invention. The method for measuring road surface damage of the present embodiment is intended to detect damages such as cracks, potholes, peeling and rutting generated on the surface of road pavement, and to detect the dimensions of these damages. In the method for measuring damage to the road surface of the present embodiment, an image pickup device is mounted on a vehicle, the road surface is photographed by the image pickup device while traveling on the road to be inspected by the vehicle, and the road surface is based on the image obtained thereby. It discovers damage and detects the size of the damage.

In the method for measuring damage to the road surface of the present embodiment, first, a reference ruler arranging step of arranging the reference ruler on the surface of the road is performed (step S1). The above-mentioned road means a place where a vehicle can travel, and widely includes a place where a subsequent standard ruler shooting process can be performed, such as a parking lot or a work place. The shape of the reference ruler is not limited as long as it has a scale in the orthogonal direction. The scale is not limited in color, shape, etc. as long as it is a mark indicating the length. Further, the reference ruler may have a number indicating the distance corresponding to the scale.

Next, the reference ruler photographing process is performed. That is, the image pickup device installed in the vehicle photographs the reference ruler placed on the road in step S1 with the reference ruler located in front of the traveling direction of the vehicle to obtain a reference ruler image (step). S2). The image pickup apparatus generates and outputs an image of visible light input through a lens, and is preferably capable of outputting both a still image and a moving image.

Next, a ruler pixel, which is a pixel representing a portion of the reference ruler, is separated from the reference ruler image obtained in the reference ruler shooting step and stored in the ruler layer (step S3). Here, pixels other than the ruler pixels of the reference ruler image may be set to be hidden or may be deleted. Further, the reference ruler image may have a single layer, and this layer may be used as a ruler layer to store only ruler pixels.

Subsequently, while traveling on the road to be inspected by the vehicle, a road surface photographing step of photographing the road surface with the imaging device to obtain a road surface image is performed (step S4). When performing this road surface photographing step, the position and angle of the imaging device when the reference ruler is photographed in the reference ruler photographing step of step S2 are kept the same without being changed. The road surface image may be either a moving image or a still image. When a moving image is taken as a road surface image, the image pickup device may be held in the recording mode while the vehicle is traveling. On the other hand, when a still image is taken as a road surface image, the operator may observe the road surface while the vehicle is traveling and instruct the imaging device to take a picture when the road surface is found to be damaged.

Either of the reference ruler photographing step of the step S2 and the road surface photographing step of the step S4 may be performed first. Further, when photographing the reference ruler in the above-mentioned reference ruler photographing process and when photographing the road surface in the above-mentioned road surface photographing process, it is necessary to make the load capacity of the vehicle the same and to make the photographing conditions of the road surface of the imaging device the same. be. In order to make the load capacity of the vehicle the same, it is necessary that the same person is on board in the standard ruler shooting process and the road surface shooting process, and the load in the vehicle is the same.

After that, from the road surface images obtained in the road surface photographing step, a road surface image showing damage to the road surface is extracted (step S5).

Subsequently, the road surface image extracted in step S5 and the reference ruler image from which the ruler pixels are separated in step S3 are superposed to create a composite image (step S6). This composite image can be formed by superimposing a road surface image and a reference ruler image by a known image processing technique.

Then, based on the composite image, a damage dimension detection step of detecting the damage dimension of the road surface existing in the road surface image is performed. First, for the composite image, an auxiliary line is set so as to surround the damage on the road surface in the road surface image (step S7). After that, the intersection of the auxiliary line and the reference ruler part in the reference ruler image of the composite image, that is, the ruler pixel is detected, and the size of the damage is based on the relationship between this point and the scale of the reference ruler. Is calculated (step S8).

As described above, according to the method for measuring road surface damage of the present embodiment, a composite image formed by superimposing a reference ruler image and a road surface image taken by the same imaging device installed in the same vehicle is used. There is. Therefore, the dimension of damage can be detected based on the composite image without correcting or converting between the reference ruler portion of the reference ruler image and the damaged portion of the road surface in the road surface image. Therefore, it is not necessary to convert the reference ruler image or the road surface image taken from a direction inclined with respect to the road surface so that the inclination angle is the vertical direction, or to make the distances from the imaging devices uniform. Therefore, it is possible to easily and inexpensively detect the magnitude of damage to the road surface by using a commonly used image pickup device or image processing device without performing complicated image processing. As a result, the measurement of road surface damage can be performed without using a line camera as in the past, and without using a vehicle with a special structure in which the line camera is installed in the vertical direction of the road surface. It can be carried out by vehicle. As a result, relatively inexpensive equipment can be installed in many vehicles, and road surface damage can be measured by many vehicles as a daily inspection.

FIG. 2 is a schematic view showing a state in which a reference ruler is photographed by an image pickup device mounted on a vehicle in the reference ruler photographing step of step S2. In FIG. 2, 1 is a road surface which is a surface of a road, 2 is a vehicle, 3 is an imaging device, and 4 is a reference ruler. As shown in FIG. 2, in the reference ruler photographing process, the reference ruler 4 is photographed by the image pickup apparatus 3 in a state where the reference ruler 4 is arranged in front of the traveling direction of the vehicle 2 on the road surface 1 on which the vehicle 2 travels. To obtain a reference ruler image.

FIG. 3 is a block diagram showing the image pickup apparatus 3. As shown in FIG. 3, the image pickup device 3 controls the operation of the lens 6, the image pickup unit 7 that includes an image pickup element that converts the light from the lens 6 into an electric signal, and outputs image data, and the image pickup device 3. It has a control unit 8, a storage unit 9 for storing image data created by the image pickup unit 7, and a power supply unit 10 for supplying power to the image pickup device 3. It also has an input unit 11 for commanding the operation of the image pickup apparatus 3 and various settings, and a display unit 12 for displaying captured images and information on the settings and operations. The image pickup device 3 can be configured by a digital camera, a drive recorder, or the like. The image pickup device 3 composed of a digital camera, a drive recorder, or the like can be installed in the interior of the vehicle 2 as long as the road surface can be photographed from an inclined direction. The image pickup device 3 can be arranged, for example, on a ceiling surface, a rear-view mirror for checking the rear view, an upper part of a windshield, a dashboard, or the like. Therefore, unlike a conventional road inspection vehicle, it is not necessary to fix a special member on the outside of the vehicle to support the camera in the vertical direction of the road surface. Further, the image pickup device 3 has a wireless communication function, performs wireless communication with a storage device having a wireless communication function and is arranged in a vehicle or in a remote place, and transmits the captured image to the storage device for storage. You may. Further, the image pickup device 3 has a position information detection function applying GPS (Global Positioning System), detects the shooting position of the road surface by the above position information detection function, and stores the position information in association with the captured image. You may.

FIG. 4 is a plan view showing a reference ruler of the embodiment. The reference ruler 4 is formed of a rectangular frame-shaped body made of plastic, and is arranged on the road surface in the horizontally long direction when viewed from the traveling direction of the vehicle 2. The reference ruler 4 is formed so that the size of the inner side of the frame-shaped body is 3.5 m in width and 1.5 m in depth. A plurality of scales 13, 13, 13, ... Indicating the length of the inner side are provided. Here, the reference ruler 4 may be made of another material such as aluminum.

FIG. 5 is a schematic view showing a reference ruler image obtained by the image pickup apparatus 3 in the reference ruler photographing step of step S2. When the image pickup device 3 photographs the reference ruler 4 on the road surface, as shown in FIG. 5, the scale 16 which is an image of the reference ruler and is in the subsequent damage dimension detection step is located in the center of the lower part of the reference ruler image 15. As described above, the position of the reference ruler 4 on the road surface is adjusted. The position of the reference ruler 4 at the time of shooting is adjusted while checking the image displayed on the display unit 12 of the image pickup apparatus 3. The reference ruler image 15 is edited in step S3, and the pixels showing the scale 16 are separated and stored in the ruler layer. The image pickup apparatus 3 performs the road surface photographing step of step S4 while maintaining the photographing direction and the photographing range when the reference ruler image 15 is photographed.

FIG. 6 is a schematic view showing the composite image obtained in step S6. The composite image 17 is created by reading the reference ruler image 15 and the road surface image with a personal computer after performing the reference ruler photographing step and the road surface photographing step, and superimposing the reference ruler image 15 and the road surface image with image processing software. do. As shown in FIG. 6, the composite image 17 is created so that the scale 16 which is a part of the reference ruler in the reference ruler image 15 is displayed on the front side of the image against the background of the road surface image. When the road surface image is a moving image, the pixels representing the scale 16 are superimposed on all the frames constituting the moving image. In the composite image 17 created in this way, the size of the inner side of the reference ruler 4 in the width direction is 3.5 m, so that the lane portion of the road surface on which the vehicle 2 travels is inside the scale 16 in the width direction. Can be placed in. Further, the composite image 17 is the inner side of the reference ruler 4 when the moving image of the road surface image is photographed at a frame rate of 30 fps and the speed of the vehicle 2 when the road surface image is photographed is 100 km / h. Since the size of the vehicle 2 in the depth direction is 1.5 m, the road surface on which the vehicle 2 has traveled can be arranged inside the scale 16 without omission in the traveling direction. Specifically, when the speed of the vehicle 2 is 100 km / h, that is, 27.8 m / s, the image pickup device 3 acquires 30 frames per second, so that the distance traveled by the vehicle 2 between each frame is It is 0.93 m. Since the size of the inner side of the reference ruler 4 in the depth direction of the frames acquired at such intervals is 1.5 m, the road surface portion can be continuously accommodated inside the scale 16. Here, if the size of the inner side of the reference ruler 4 in the depth direction is 0.93 m or more, the road surface portion can be continuously accommodated inside the scale 16 in the traveling direction, but the road surface image is the road surface. Since the front side in the traveling direction is higher definition, the size of the inner side of the reference ruler 4 in the depth direction is preferably 1 m or more in order to measure the damage on the road surface with high accuracy. The size of the reference ruler 4 is 3 m or more and 4 m or less, and 1 m or more, depending on the width of the lane of the road on which the vehicle 2 travels, the frame rate of the image pickup device 3, and the speed of the vehicle 2 at the time of shooting. The depth can be set to 2 m or less. Further, the reference ruler 4 may be measured along the outer side. In this case, the dimensions of the outer side of the frame-shaped body are set to a width of 3 m or more and 4 m or less and a depth of 1 m or more and 2 m or less.

FIG. 7 is a schematic view showing how the magnitude of damage to the road surface is calculated using the composite image 17 in steps S7 and S8. The magnitude of road surface damage using the composite image 17 is calculated by the personal computer and image processing software that created the composite image 17. Here, the magnitude of damage to the road surface may be calculated by software different from the image processing software that created the composite image 17, or a device capable of image processing such as another personal computer.

The magnitude of damage to the road surface can be calculated by the same image processing software after creating the composite image 17 with the image processing software. First, from the composite image 17 created in step S6, an image showing damage is selected. In the composite image 17, two width direction auxiliary lines 19 and 19 parallel to the width direction side of the scale 16 and two depth direction auxiliary lines 20 and 20 substantially parallel to the depth direction side of the scale 16 are set. do. Next, these two width direction auxiliary lines 19 and 19 and two depth direction auxiliary lines 20 and 20 surround the damaged part 18, which is a damaged part of the road surface image. After that, the angles of the depth direction auxiliary lines 20 and 20 are adjusted based on the scale of the scale 16 at which the depth direction auxiliary lines 20 intersect. Specifically, while maintaining the state where the depth direction auxiliary line 20 is in contact with the damaged portion 18, the scale at the position where the depth direction auxiliary line 20 and the lateral portion on the front side of the scale 16 intersect, and the depth direction auxiliary line 20 The inclination angle of the depth direction auxiliary line 20 is adjusted so that the scale at the position where the lateral portion on the back side of the scale 16 intersects shows the same value. In this way, the damaged portion 18 is surrounded by the two width direction auxiliary lines 19 and 19 and the two depth direction auxiliary lines 20 and 20, and then the dimension of the damaged portion 18 is calculated based on the scale of the scale 16. Here, when the damaged portion 18 is a crack, the length of the damaged portion 18 is calculated. Based on the dimensions of the damaged portion 18 measured in this way, the repair method to be performed for the damage corresponding to the damaged portion 18, the type and amount of the material required for the repair can be specified, and the damage repair plan can be performed. ..

When calculating the magnitude of road surface damage based on the composite image 17, the location of the damage may be specified. The location of the damage based on the composite image 17 can be specified based on the information about the road included in the road surface image in the composite image 17. The road surface image shows signs and kilometer posts installed around the road traveled by vehicle 2, and the location of the signs and kilometer posts should be specified based on the information written on these signs and kilometer posts. Can be done. Since the distance between the sign or kilometer post whose installation position has been specified and the damage in the road surface image can be specified using the scale 16, the position of the damage can be specified.

As described above, in the method for measuring the damage to the road surface of the present embodiment, the image pickup device 3 is mounted on the vehicle 2 traveling on the road to be inspected, the reference ruler 4 is photographed by the image pickup device 3, and the road to be inspected. The size of the damage is measured using a composite image 17 formed by superimposing a reference ruler image 15 obtained by photographing the road surface and taking a picture of the reference ruler 4 and a road surface image obtained by photographing the road surface. It is something to do. Therefore, the general-purpose imaging device 3 can be retrofitted to the vehicle 2 used for general inspection to take a picture, and the taken image can be edited with general-purpose image processing software to cause damage. The size can be measured. Therefore, the road surface damage measuring method of the present embodiment does not require an expensive inspection vehicle equipped with a special device and structure or a special image editing device, so that the road surface damage can be measured inexpensively and easily. be able to. As a result, the image pickup device 3 can be mounted on many vehicles 2 used for daily inspection, and damage to the road surface can be measured as daily inspection.

In the above embodiment, the reference ruler 3 formed of a rectangular frame is used, but a reference ruler having another shape may be used. FIG. 8 is a plan view showing a reference ruler of another embodiment. The reference ruler 21 is created by combining a surveying tape 22 having a scale printed in the length direction. The reference ruler 21 is created by arranging four surveying tapes 22, 22, 22, 22 on the road surface in a rectangular shape, and is photographed by the image pickup device 3 of the vehicle 2 to obtain a reference ruler image. Since the surveying tape 22 can be wound up to be compact when not in use, the reference ruler 21 can be easily handled. Further, by using the surveying tape 22 used for the survey, it is not necessary to prepare a dedicated reference ruler, so that the cost can be reduced. Here, the surveying tape 22 may be a disposable type having an adhesive coated on the back surface.

FIG. 9 is a plan view showing a reference ruler of another embodiment. The reference ruler 24 is formed by arranging a plurality of joint mats 25, 25, 25, ... In a frame shape. The joint mat 25 is formed of a square sheet and is provided with a concavo-convex joint on the outer edge. The joints are fitted to each other to connect the adjacent joint mats 25. The dimensions of one side of the joint mat 25 are specified in advance, and a reference line 26 and a scale 27 that form a rectangular shape when connected to each other are marked. When not in use, the reference ruler 24 can be made compact by separating the joint mats 25 from each other, so that the reference ruler 24 can be easily handled.

FIG. 10 is a plan view showing a part of the reference ruler of another embodiment. The reference ruler 30 is formed of a horizontally long rectangular plate-like body, and a mesh pattern 31 is described on the surface thereof. The mesh pattern 31 is formed by a plurality of straight lines that are arranged at equal intervals in the horizontal direction and the vertical direction and are orthogonal to each other, and each straight line has a predetermined distance from each other and functions as a scale. By using the reference ruler 30 having the mesh pattern 31, the magnitude of damage on the road surface can be calculated without setting an auxiliary line in the damage dimension detection step. Further, even if the image captured by the image pickup device 3 is distorted due to the lens, the damage in the road surface image is calculated along the mesh pattern 31 in the reference ruler image, so that the damage size can be determined with a relatively small error. Can be detected.

FIG. 11 is a plan view showing a part of the reference ruler of another embodiment. The reference ruler 33 is formed of a horizontally long rectangular plate-like body, and has a checkered pattern on its surface. The checkered pattern is formed by arranging two square portions 34 and 35 of different colors so that the same colors are not adjacent to each other. The square portions 34, 35 constituting the checkered pattern have the same side length and the length is specified in advance, and functions as a scale. By using the reference ruler 33 having a checkered pattern, the magnitude of damage on the road surface can be calculated without setting an auxiliary line in the damage dimension detection step. Further, since the adjacent square portions 34 and 35 have different colors, the size of the damaged portion on the road surface can be easily grasped in the damage dimension detection step.

FIG. 12 is a plan view showing a part of the reference ruler of another embodiment. The reference ruler 36 is formed of a horizontally long rectangular plate-like body, and has a grid pattern formed in two different colors on the surface thereof. In this grid pattern, a mesh pattern 37 formed by vertically and horizontally spaced lines at right angles to each other and the smallest square area separated by the mesh pattern 37 are provided every other in the vertical and horizontal directions. It is formed by a square portion 38 colored in a square portion 38 and a grid portion 39 other than the square portion 38, which is colored in another color and forms a grid by bands orthogonal to the vertical direction and the horizontal direction. .. One side of the smallest square separated by the mesh pattern 37 has a predetermined length and functions as a scale. By using the reference ruler 36 having a grid pattern, the magnitude of damage on the road surface can be calculated without setting an auxiliary line in the damage dimension detection step. Further, since the square portion 38 and the grid portion 39 have different colors, the size of the damaged portion of the road surface can be easily grasped in the damage dimension detection step.

FIG. 13 is a plan view showing a part of the reference ruler of another embodiment. The reference ruler 40 is formed of a horizontally long rectangular plate-like body, and is separated by a mesh pattern 41 formed on the surface by a plurality of straight lines intersecting at right angles in the horizontal direction and the vertical direction and functioning as a scale, and a mesh pattern 41. A plurality of numbers 42 continuously described in the horizontal and vertical directions in the smallest square area, and parallel to the direction in which the numbers 42 are arranged in the smallest square area separated by the mesh pattern 41. A plurality of arranged marks 43 are described. Numbers 42 are described from 1 to 10 repeatedly in the horizontal direction and the vertical direction in the square area of the mesh pattern 41. The number 42 1 is described at a position common to both the vertical direction and the horizontal direction. The mark 43 is a point described in the center of the square area of the mesh pattern 41, and is continuously described in the horizontal direction and the vertical direction from the square area in which the number 42 10 is described. Units consisting of 100 square areas surrounded by these numbers 42 and marks 43 are arranged vertically and horizontally. These units are colored so that adjacent units have different colors to form a checkerboard pattern. By using this reference ruler 40, the magnitude of damage on the road surface can be calculated without setting an auxiliary line in the damage dimension detection step. Further, since the numbers 42 and the mark 43 and the adjacent units are colored in different colors, the size of the damaged portion of the road surface can be easily grasped in the damage dimension detection step.

FIG. 14 is a plan view showing a part of the reference ruler of another embodiment. The reference ruler 45 is formed of a horizontally long rectangular plate-like body, and has a mesh pattern 46 similar to that described in the reference ruler 40 of FIG. 13 and numbers 47 and marks 48 on the surface thereof. In the reference ruler 45 of the present embodiment, the numbers 47 are described in the diagonal direction in addition to the horizontal direction and the vertical direction of the square region constituting the mesh pattern 46. One of the numbers 47 written in the oblique direction is arranged at a position common to one of the numbers 47 in the horizontal direction and the vertical direction. As a result, the numbers 47 described in the oblique direction are arranged so as to be inclined at 45 ° with respect to the arrangement direction of the numbers 47 in the horizontal direction and the vertical direction. By using this reference ruler 45, the magnitude of damage on the road surface can be calculated without setting an auxiliary line in the damage dimension detection step. Further, the numbers 47 and the mark 48 make it possible to easily grasp the size of the damaged portion of the road surface in the damage dimension detection step.

The present invention is not limited to the embodiments described above, and many modifications can be made by those who have ordinary knowledge in the art within the technical idea of the present invention.

1 Road surface 2 Vehicle 3 Imaging device 4,21,24,30,33,36,40,45 Reference ruler 6 Lens 7 Imaging unit 8 Control unit 9 Storage unit 10 Power supply unit 13,27 Scale 15 Reference ruler image 16 Scale 17 Composite Image 18 Damaged part 19 Width direction auxiliary line 20 Depth direction auxiliary line 22 Surveying tape 25 Joint mat 31,37,41 Mesh pattern 34,35,38 Square part 39 Lattice part 42,47 Number 43,48 Mark

Claims (8)

A reference ruler placement process in which a reference ruler with orthogonal scales is placed on the surface of the road,
A reference ruler photographing process of photographing the reference ruler arranged in front of the traveling direction of the vehicle by an imaging device installed in the vehicle to obtain a reference ruler image, and
A road surface photographing process in which the road surface is photographed by the imaging device to obtain a plurality of road surface images while the vehicle is traveling on the road.
A composite image creation step of superimposing the reference ruler image and the road surface image to create a composite image, and
A damage dimension detection step for detecting the damage dimension of the road surface existing in the road surface image based on the composite image is provided .
In the damage dimension detection step, an auxiliary line is set in the composite image so as to surround the damaged part in the road surface image, and based on the scale of the part of the reference ruler in the reference ruler image where the auxiliary lines intersect. , A method for measuring road surface damage, which comprises detecting the dimensions of the damage. In the method for measuring road surface damage according to claim 1,
The reference ruler is a method for measuring damage to a road surface, which is a rectangular frame-shaped body having a scale. In the method for measuring road surface damage according to claim 1,
The reference ruler is a method for measuring damage to a road surface, which is a tape having a scale and arranged in a frame shape. In the method for measuring road surface damage according to claim 1,
The reference ruler is a method for measuring damage to a road surface, which is a plate-like body having a mesh-like pattern. In the method for measuring road surface damage according to claims 1, 3 and 4,
The reference ruler is a method for measuring road surface damage, characterized in that numbers corresponding to the scales are described. In the method for measuring road surface damage according to claim 4,
A method for measuring road surface damage, characterized in that numbers are arranged in the pattern of the reference ruler. In the method for measuring road surface damage according to claim 1,
A method for measuring road surface damage, characterized in that the size of the side to be measured with the scale of the reference ruler is 3 m or more and 4 m or less in width and 1 m or more and 2 m or less in depth. In the method for measuring road surface damage according to claim 1,
The image pickup apparatus is a drive recorder, and is a method for measuring damage to a road surface.

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