Road damage detection system

Abstract

To provide a road damage detection system that enables detection of a road damage condition over a wide range and with high accuracy.SOLUTION: A road damage detection system acquires road surface information using a LiDAR 22 and a laser scanning device 23 mounted on each of a plurality of connected vehicles 2, 2, ...; the road damage detection system determines that road surface information in which a degree of damage to a road exceeds a threshold is road surface information that should be sent to a system server 3; and the road damage detection system associates the road surface information with the positional information from which the road surface information is acquired and transmits the associated information to the system server 3. In the system server 3, a damaged point map is formed that identifies a road damaged point, and the damaged point map information is sent to a road manager terminal 5. As a result, this makes it possible to comprehensively detect a damaged condition of the road with high accuracy.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a road damage detection system. [Background technology]

[0002] Conventionally, a system that detects road damage using a traveling vehicle has been known. Patent Document 1 discloses that a vehicle is equipped with an infrared camera, a visible light camera, etc., and detects road damage based on images captured by the cameras while the vehicle is traveling, and also adds location information to the collected detection information and stores it in a storage device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-242293 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional road damage detection systems may be affected by factors that change road surface conditions, such as nighttime, rain, dust, fallen leaves, and puddles. Therefore, they may not be able to accurately detect road damage in situations where it is difficult to recognize the road damage. While it is also possible to detect road damage using fluctuations in vehicle rotation speed or vibrations, this may result in insufficient detection accuracy. Furthermore, conventional road damage detection systems detect road damage using only a single vehicle, which can lead to misjudgment of road damage depending on the road surface conditions at the time of measurement. Furthermore, when other vehicles are parked on the road, the system may not be able to detect damage to the road around the parking position of the vehicle.

[0005] The present invention has been made in consideration of the above points, and its purpose is to provide a road damage detection system that makes it possible to detect the state of road damage over a wide range (comprehensively) with high accuracy. [Means for solving the problem]

[0006] The solution of the present invention to achieve the above object is based on a road damage detection system that detects road damage based on road surface information scanned by vehicles. The road damage detection system includes a plurality of connected vehicles equipped with road surface information acquisition means that acquires the road surface information, a control unit provided in each of the connected vehicles, and a server that manages information transmitted from each of the connected vehicles, wherein the control unit includes a road surface condition determination unit that determines whether the road surface information acquired by the road surface information acquisition means is road surface information that should be transmitted to the server, and a road surface information transmission unit that transmits the road surface information to the server in association with location information from which the road surface information was acquired, and the server includes a damage point map creation unit that analyzes road surface conditions based on the plurality of road surface information received from each of the connected vehicles to create a damage point map that identifies road damage points, and a map transmission unit that transmits information of the damage point map to a map display device used by a road administrator.

[0007] In this case, the form in which road surface information is transmitted from each connected vehicle to the server may be such that information associating detailed data on the road damage state with location information is transmitted to the server, or such that information excluding detailed data on the road damage state and associating location information is transmitted to the server, and then detailed data on the road damage state is transmitted to the server upon request.

[0008] According to this specification, road surface information is acquired by road surface information acquisition means installed in each of the multiple connected vehicles. Road surface information to be sent to the server, such as roads with severe damage, is associated with the location information where the road surface information was acquired and sent to the server. The server then analyzes the road surface conditions based on the road surface information received from the multiple connected vehicles to create a damage point map that identifies road damage points, and transmits the damage point map information to a map display device used by the road administrator. This allows the road administrator to grasp the locations of road damage and the state of road damage by viewing the damage point map displayed on the map display device. Because road damage can be detected by multiple connected vehicles in this way, road surface information for the same location is transmitted to the server from multiple connected vehicles, making it possible to accurately detect road damage while minimizing the impact of changes in road surface conditions. Furthermore, even if the connected vehicle is unable to acquire road surface information due to the presence of other vehicles parked on the street, when the same or another connected vehicle passes that point at another time (when there are no other vehicles parked on the street), the road surface information acquisition means can acquire information about the road surface at that point. This makes it possible to comprehensively detect the state of road damage with high accuracy. [Effects of the Invention]

[0009] In this invention, road surface information acquired by road surface information acquisition means installed in each of a plurality of connected vehicles is transmitted to a server, and the server creates a damage point map identifying road damage points, and transmits the damage point map information to a map display device used by a road administrator, thereby enabling comprehensive detection of road damage conditions with high accuracy. [Brief explanation of the drawings]

[0010] [Figure 1]1 is a diagram showing a schematic configuration of a road damage detection system according to an embodiment; [Figure 2] FIG. 10 is a diagram showing an example of a damage location map displayed on a display screen of a road administrator terminal. [Figure 3] FIG. 10 is a sequence diagram for explaining an information transmission and reception operation according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a damage location map created by the road damage detection system according to the present invention will be provided by displaying it on the display screen of a road administrator terminal (for example, a personal computer). However, the present invention is not limited to this, and the damage location map may also be displayed on the display screen of a terminal (for example, a smartphone) carried by the road administrator.

[0012] FIG. 1 is a diagram showing a schematic configuration of a road damage detection system 1 according to this embodiment. As shown in FIG. 1, the road damage detection system 1 includes a plurality of connected vehicles 2, 2, ... and a system server 3. The system is configured to enable communication between these connected vehicles 2, 2, ... and the system server 3 using a predetermined communication network 4. The system server 3 is also capable of sending and receiving information with a road administrator terminal (map display device) 5. The communication between the system server 3 and the road administrator terminal 5 may be wired or wireless. Information may also be sent and received between the system server 3 and the road administrator terminal 5 via the communication network 4.

[0013] The following describes the connected vehicles 2, 2, ... that make up the road damage detection system 1. The configuration of the parts related to the road damage detection system 1 is the same for each of the connected vehicles 2, 2, ... shown in Figure 1. Figure 1 shows the configuration of the parts related to the road damage detection system 1, using one connected vehicle 2 (a connected vehicle that is the source of road surface information) as a representative.

[0014] The connected vehicle 2 is equipped with a GPS (Global Positioning System) module 21, a LiDAR (Light Detection and Ranging) 22, a laser scanning device 23, a DCM (Data Communication Module) 24, and a vehicle ECU (control unit) 25. These devices are interconnected via an in-vehicle network such as a CAN so as to be able to communicate with each other.

[0015] The GPS module 21 receives GPS signals transmitted from three or more (preferably four or more) satellites above the connected vehicle 2 and determines the position of the connected vehicle (host vehicle) 2. The position information of the connected vehicle 2 determined by this GPS module 21 is transmitted to the vehicle ECU 25 via CAN communication.

[0016] The LiDAR 22 is an active sensor that uses light to detect objects around the connected vehicle 2, and detects objects by emitting detection light around the connected vehicle 2 and receiving light reflected by objects around the connected vehicle 2. In this embodiment, the LiDAR 22 is used as a means for acquiring information for detecting road damage (road surface information acquisition means), and therefore the light output range includes the road surface in front of or behind the connected vehicle 2. The road surface information acquired by this LiDAR 22 is transmitted to the vehicle ECU 25 via CAN communication. At this time, the acquired road surface information and position information from which the information was acquired (position information of the connected vehicle 2 measured by the GPS module 21) are associated with each other.

[0017] The laser scanning device 23 is a sensor that performs scanning by irradiating the surrounding area with laser light from the connected vehicle 2 and detecting the reflected light with a sensor. It detects the presence of an object by irradiating laser light (e.g., a near-infrared laser beam) in front of (or behind) the connected vehicle and detecting the reflected light from the object with a photodiode, which is a light-receiving element. In this embodiment, the laser scanning device 23 is also used as a means for acquiring information for detecting road damage (road surface information acquisition means), and therefore the output range of the laser light includes the road surface in front of or behind the connected vehicle 2. The road surface information acquired by this laser scanning device 23 is transmitted to the vehicle ECU 25 via CAN communication. At this time, the acquired road surface information and the position information from which the information was acquired (position information of the connected vehicle 2 measured by the GPS module 21) are associated with each other.

[0018] The means for acquiring information for detecting road damage is not limited to the LiDAR 22 or laser scanning device 23 described above, and instead of or in addition to these, an on-board camera (e.g., a CCD camera, etc.) or millimeter wave radar may be installed.

[0019] The DCM (road surface information transmitter) 24 is a communication device that communicates with the system server 3 via the communication network 4 (for example, a mobile phone network having many base stations, the Internet network, a dedicated communication network, etc.).

[0020] The vehicle ECU 25 includes a processor such as a CPU (Central Processing Unit), a ROM (Read-Only Memory) that stores a control program, a RAM (Random-Access Memory) that temporarily stores data, an input / output port, etc. The vehicle ECU 25 includes a road surface information input unit 25a, a road surface condition determination unit 25b, and a road surface information output unit 25c as functional units realized by the control program.

[0021] The road surface information input unit 25a receives road surface information (image information, etc.) acquired by the LiDAR 22 or laser scanning device 23 mounted on the connected vehicle 2, as well as the location information of the connected vehicle 2 at the time the road surface information was acquired, via CAN communication.

[0022] The road surface condition determination unit 25b associates (links) the road surface information received by the road surface information input unit 25a with the location information of the connected vehicle 2 at the time the road surface information was acquired, and determines whether the road surface information should be transmitted to the system server 3 as road surface information. Specifically, the road surface condition determination unit 25b determines the degree of road damage, and if the damage exceeds a preset threshold, determines that the road surface information should be transmitted to the system server 3. Note that types of road damage are expected to include holes (potholes), cracks, ruts, etc., and the presence or absence of these is determined by performing well-known image analysis on the acquired road surface information. Specifically, if a pothole is detected with a diameter exceeding 30 cm, if cracks are detected with a crack rate exceeding 40%, or if ruts are detected with a depth exceeding 40 mm, the road needs prompt repair, and therefore the road surface information is determined to be road surface information that should be transmitted to the system server 3. The aforementioned values ​​are not limited to these and can be set arbitrarily. The road surface information to be transmitted to the system server 3 is not limited to information on roads that require early repair, but may also include information on roads that may require repair in the future. For example, if a pothole is detected and its diameter is greater than 15 cm but less than 30 cm, if a crack is detected and its crack rate is greater than 20% but less than 40%, or if a rut is detected and its rutting depth is greater than 20 cm but less than 40 mm, the road surface information may be determined to be road surface information to be transmitted to the system server 3. In this case, road surface information that requires early repair and road surface information that may require repair in the future are distinguished and transmitted to the system server 3, respectively.

[0023] The road surface information output unit 25c associates the road surface information determined by the road surface condition determination unit 25b to be transmitted to the system server 3 with the acquired position information and outputs the road surface information to the DCM 24. Then, when the DCM 24 receives this road surface information (road surface information associated with the position information), the DCM 24 transmits the information to the system server 3 via the communication network 4.

[0024] The system server 3 includes, as its functional units, a road surface information receiving unit 31, a road surface information collecting unit 32, a road surface information analyzing unit 33, a damage point map creating unit 34, and a map transmitting unit 35.

[0025] The road surface information receiving unit 31 receives the road surface information transmitted by the DCM 24 via the communication network 4.

[0026] The road surface information compilation unit 32 accumulates the road surface information received by the road surface information receiving unit 31. The system server 3 receives road surface information for each point transmitted from each connected vehicle 2, 2, ..., and the road surface information compilation unit 32 stores this road surface information in a storage device within the system server 3. Of the road surface information stored in this storage device, road surface information for points where road repairs have already been completed is erased when the road repairs are completed. This road surface information may be erased by an input operation by the road administrator (an input operation that indicates that road repairs have been completed), or may be erased according to the road surface information from a traveling connected vehicle 2 when the connected vehicle 2 recognizes that road repairs have been completed.

[0027] The road surface information analysis unit 33 reads out the road surface information stored in the storage device by the road surface information aggregation unit 32 and analyzes each piece of road surface information to generate information for creating a damage location map, which will be described later. For example, if the road surface information indicates that the diameter of a pothole at a certain point exceeds a threshold, the road surface information analysis unit 33 references other road surface information at that point (e.g., road surface information at that point acquired by another connected vehicle 2) and analyzes whether the pothole diameter also exceeds the threshold in that road surface information. This analysis process is performed sequentially for each point that is the subject of the road surface information, and the type and size of damage at each point are statistically managed. For example, if 80% or more of the road surface information at the same point indicates that the pothole diameter exceeds the threshold, it is determined that a pothole whose diameter exceeds the threshold exists at that point.

[0028] The damage point map creation unit 34 reads information such as the type and magnitude of damage at each point managed by the analysis in the road surface information analysis unit 33, and generates a map (damage point map) that displays the damage points on a map. In this damage point map, the locations of roads where damage has occurred are associated with the types of damage at those locations and are displayed on the map.

[0029] The map transmission unit 35 transmits information about the damage point map created by the damage point map creation unit 34 to the road administrator terminal 5. As a result, the damage point map is displayed on the display screen of the road administrator terminal 5. FIG. 2 shows an example of the damage point map displayed on the display screen 51 of the road administrator terminal 5 in this manner. The damage point map on the display screen 51 shown in FIG. 2 shows that there is one location where there is a pothole whose diameter exceeds a threshold, one location where there is a crack whose crack rate exceeds a threshold, and one location where there is a rut whose rutting exceeds a threshold. The display screen 51 of the road administrator terminal 5 is configured, for example, as a touch panel liquid crystal display.

[0030] The timing for sending information about the damage point map to the road administrator terminal 5 may be when the road administrator operates the road administrator terminal 5 to request the display of the damage point map, or when a new damage point map is generated in the damage point map creation unit 34 (when the damage point map is updated).

[0031] Next, we will explain the operation of the road damage detection system 1. Fig. 3 is a sequence diagram showing an example of the operation of each of the connected vehicle 2, system server 3, and road administrator terminal 5. From the left, Fig. 3 shows the information processing operation in the connected vehicle 2, the information processing operation in the system server 3, and the display operation in the road administrator terminal 5. Note that Fig. 3 gives an example of communication between one connected vehicle 2 and the system server 3, but communication also takes place between the other connected vehicles 2, 2, ... and the system server 3 in the same way.

[0032] First, road surface information is acquired from the LiDAR 22 or the laser scanning device 23 mounted on the connected vehicle 2 (S1). Then, a determination is made as to whether or not the road surface information should be transmitted to the system server 3 as road surface information (road surface condition determination) (S2). Then, the road surface information to be transmitted to the system server 3 (information on roads whose degree of damage exceeds a threshold) is output to the DCM 24 in association with the location information from which the road surface information was acquired. Then, this road surface information (road surface information associated with the location information) is transmitted from the DCM 24 to the system server 3.

[0033] The system server 3 collects the received road surface information (S3), and when a certain amount of road surface information has been collected, analyzes the road surface information (S4), and creates a damage point map (S5). Then, the information on this damage point map is transmitted to the road administrator terminal 5.

[0034] Based on the received information on the damage point map, the road administrator terminal 5 displays the damage point map on the display screen 51. This allows the road administrator to understand the points where the road is damaged and the state of the road damage by looking at the damage point map displayed on the display screen 51.

[0035] As described above, in this embodiment, road surface information acquired by the LiDAR 22 and laser scanning device 23 mounted on each of the multiple connected vehicles 2, 2, ... is transmitted to the system server 3, and the system server 3 creates a damage point map that identifies road damage points, and transmits information about the damage point map to the road administrator terminal 5. This makes it possible to comprehensively detect the damage state of the road with high accuracy.

[0036] -Variations- Next, a modified example will be described. In the above-described embodiment, the road surface information transmitted from the connected vehicle 2 to the system server 3 is information in which detailed data on the state of road damage (such as the magnitude of damage, such as potholes, cracks, ruts, etc.) is associated with location information.

[0037] In this modified example, instead, first, road surface information excluding detailed data on the damage state (for example, information only indicating the presence of damage) and information associating it with location information are transmitted to the system server 3. The system server 3 then analyzes the received road surface information, classifies the damage information, and creates image request information limited to only the necessary information, which is then transmitted to the connected vehicles 2, 2, ... For example, a signal requesting information only on potholes with a diameter of more than 30 cm is transmitted to the connected vehicles 2, 2, ... Then, the connected vehicles 2 that receive this image request information acquire road surface information only when they pass a point corresponding to the image request information, and transmit this road surface information to the system server 3. At this time, a limit is set on the number of times road surface information (for example, image information) is transmitted at each point.

[0038] This makes it possible to reduce false detection of road damage conditions, as image request information is created through analysis by the system server 3 and only specific road surface information is sent to the system server 3. In addition, by setting a limit on the number of times road surface information is sent at each point, operation can be carried out at low cost.

[0039] -Other embodiments- The present invention is not limited to the above-described embodiments, and all modifications and applications within the scope of the claims and equivalents thereto are possible.

[0040] For example, while the above embodiments have exemplified the LiDAR 22, the laser scanning device 23, the on-board camera, and the millimeter-wave radar as road surface information acquisition means, road surface information may be acquired by other means. For example, road surface information may be acquired from the vibration frequencies of shock absorbers or coil springs that support each wheel of the connected vehicle 2, from vehicle acceleration detected by acceleration sensors disposed in various parts of the connected vehicle 2, or from changes in the volume or frequency characteristics of sounds generated in front of or behind the connected vehicle 2. [Industrial Applicability]

[0041] The present invention is applicable to a road damage detection system that detects road damage conditions using multiple traveling connected vehicles. [Explanation of symbols]

[0042] 1. Road damage detection system 2. Connected vehicles 22...LiDAR (road surface information acquisition means) 23...Laser scanning device (road surface information acquisition means) 24...DCM (road surface information transmission unit) 25... Vehicle ECU (control unit) 25b... Road surface condition determination unit 3... System server (server) 34...Damage location map creation unit 35...Map transmission unit 5...Road administrator terminal (map display device)

Claims

[Claim 1] A road damage detection system that detects road damage based on information about a road surface scanned by a vehicle, comprising: a plurality of connected vehicles equipped with road surface information acquisition means for acquiring information about the road surface; a control unit provided in each of the connected vehicles; a server that manages information transmitted from each of the connected vehicles; The control unit a road surface condition determination unit that determines whether the road surface information acquired by the road surface information acquisition means is road surface information that should be transmitted to the server; a road surface information transmitting unit that transmits the road surface information to the server in association with location information where the road surface information has been acquired, The server a damage point map creation unit that creates a damage point map that identifies road damage points by analyzing road surface conditions based on the multiple pieces of road surface information received from each of the connected vehicles; a map transmitting unit that transmits information about the damage location map to a map display device used by a road administrator.

Images