Road surface condition determination system and server

Abstract

To provide a road surface state determination system and a server capable of determining a state of a road surface with high accuracy.SOLUTION: An acceleration sensor 21 built in an on-vehicle device 2 is mounted on a vehicle V and detects a vertical acceleration of the vehicle V. The on-vehicle device 2 transmits the acceleration to a server 3. The server 3 acquires a variance value of an absolute value of an acceleration that was detected during traveling a predetermined distance within a predetermined speed range for each vehicle V on the basis of the received acceleration and determines a road surface state traveled by the vehicle V on the basis of the acquired variance value.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a road surface condition determination system and a server. [Background technology]

[0002] As devices for determining whether the road surface on which a vehicle is traveling is good or bad, for example, a bad road determination device described in Patent Document 1 and a road surface condition identification device described in Patent Document 2 have been proposed. The above-mentioned bad road determination device and road surface condition identification device determine whether the road is good or bad based on the variance value of acceleration. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-63544 A [Patent Document 2] JP 2001-287634 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional bad road judgment devices and road surface condition identification devices described above had the problem that they were unable to accurately judge whether a road was bad, particularly whether the road surface had unevenness, cracks, fissures, holes, or other defects that required repair.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a road surface condition determination system and a server that can accurately determine the condition of a road surface. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the road surface condition determination system and server according to the present invention are characterized by the following [1] to [5]. [1] An acceleration sensor mounted on a vehicle to detect an acceleration in a vertical direction of the vehicle; The acceleration sensor detects Up and down a variance value acquisition unit that acquires a variance value of the absolute value of the acceleration; a determination unit that determines a road surface condition on which the vehicle has traveled based on the variance value acquired by the variance value acquisition unit, The variance value acquisition unit Up and down Each time acceleration is detected, Up and down Acceleration detection A plurality of the above-mentioned detected points between the detected point and a point a predetermined distance before the detected point. Up and down Get the variance of the absolute value of acceleration. It is a road condition judgment system. [2] In the road surface condition determination system according to the present invention, The variance value acquisition unit detects the variance value while the vehicle is traveling within a predetermined speed range for a predetermined distance or a predetermined period. Up and down Get the variance of the absolute value of acceleration. It is a road condition judgment system. [3] In the road surface condition determination system according to [1] or [2], The acceleration sensor is mounted on a plurality of the vehicles, the variance value acquisition unit acquires the variance value for each vehicle, the determining unit determines the road surface condition based on the number of the vehicles that have passed through a predetermined area or a predetermined road and for which the variance value is equal to or greater than a predetermined value; It is a road condition judgment system. [4] In the road surface condition determination system according to [3], The determination unit determines a ratio between a total number of the vehicles that have passed through the specified area or the specified road in a specified period and a number of the vehicles for which the variance value is equal to or greater than the specified value among the vehicles that have passed through the specified area or the specified road in the specified period. Is the value greater than or equal to a given value? The road surface condition is determined based on the It is a road condition judgment system. [5] Through communication with a vehicle, an acceleration sensor mounted on the vehicle detects Up and down a variance value acquisition unit that acquires a variance value of the absolute value of the acceleration; a determination unit that determines a road surface condition based on the variance value, The variance value acquisition unit Up and down Each time acceleration is detected, Up and down Acceleration detection A plurality of the above-mentioned detected points between the detected point and a point a predetermined distance before the detected point. Up and down Get the variance of the absolute value of acceleration. It is a server.

[0007] According to the road surface condition determination system and server configured as above in [1] and [5], the road surface condition is determined based on the variance of the absolute value of the vertical acceleration. This makes it possible to determine the road surface condition with high accuracy without the upward acceleration and the downward acceleration canceling each other out. According to the road surface condition determination system configured as in [2] above, the variance of the absolute values ​​of the acceleration detected while traveling within a predetermined speed fluctuation range for a predetermined distance or a predetermined period of time is obtained. This makes it possible to obtain a variance value that is not influenced by vertical acceleration caused by speed differences due to sudden braking, sudden starting, etc., and to determine the road surface condition with even greater accuracy. According to the road surface condition determination system having the configurations [3] and [4] above, the road surface condition can be determined with even greater accuracy by using acceleration sensors mounted on multiple vehicles. Effect of the Invention

[0008] According to the present invention, it is possible to provide a road surface condition determination system and a server capable of determining the road surface condition with high accuracy.

[0009] The present invention has been briefly described above. Furthermore, the details of the present invention will be further clarified by reading the following description of the embodiment of the present invention (hereinafter, referred to as "embodiment") with reference to the accompanying drawings. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a configuration diagram showing an embodiment of a road surface condition determination system according to the present embodiment. [Diagram 2] FIG. 2 is a configuration diagram of the vehicle-mounted device shown in FIG. [Diagram 3] FIG. 3 is a configuration diagram of the server shown in FIG. [Figure 4] FIG. 4 is a diagram showing the relationship between the travel distance and the detection of acceleration, for illustrating the operation of the road surface condition determination system shown in FIG. [Diagram 5] FIG. 5 is a graph showing the variance of acceleration when traveling on a road that is in good condition and does not require repairs. [Figure 6] FIG. 6 is a graph showing the variance of the absolute value of acceleration when traveling on a road that is in good condition and does not require repairs. [Figure 7] FIG. 7 is a graph showing the relationship between the variance of the absolute value of acceleration and the speed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0012] The road surface condition determination system 1 of this embodiment is a system that determines the condition of the road surface on which a plurality of vehicles V have passed by communicating with vehicle-mounted devices 2 mounted on the vehicles V.

[0013] The road surface condition determination system 1 includes an on-board device 2 mounted on a vehicle V, a server 3 capable of communicating with the on-board device 2 via an Internet communication network 10, and a terminal 4 owned by an administrator who manages the road.

[0014] 2, the in-vehicle device 2 includes an acceleration sensor 21, an input unit 22 for inputting a speed pulse from the speed sensor 11, a GPS receiving unit 23, an Internet communication unit 24, and a control unit 25. The acceleration sensor 21 detects the acceleration in the up-down direction (vertical direction) of the vehicle V, and supplies the detected acceleration to a control unit 25 described later. The speed sensor 11 inputs, for example, a speed pulse generated every time an output shaft of a transmission of the vehicle V rotates a predetermined amount to the input unit 22.

[0015] The input unit 22 supplies the input speed pulse to the control unit 25. As is well known, the GPS receiving unit 23 receives radio waves emitted from a plurality of GPS (Global Positioning System) satellites, obtains the current position, and supplies it to the control unit 25 described later. The Internet communication unit 24 is composed of a circuit, an antenna, etc. for connecting to the Internet communication network 10.

[0016] The control unit 25 is composed of a CPU (Central Processing Unit) equipped with memories such as a RAM (Random Access Memory) and a ROM (Read Only Memory), and controls the entire vehicle-mounted device 2. The CPU of the control unit 25 operates according to a program stored in the memory. The control unit 25 periodically (for example, every second) calculates the vehicle speed based on the speed pulse. The control unit 25 also periodically collects acceleration and a current position from the acceleration sensor 21 and the GPS receiver 23. The control unit 25 then transmits the collected speed, current position, and speed to the server 3.

[0017] 3, the server 3 has an Internet communication unit 31, a database (DB) 32, and a control unit 33. The Internet communication unit 31 is composed of a circuit for connecting to the Internet communication network 10, etc. The DB 32 stores the acceleration, current position, speed, etc. transmitted from each vehicle V. The control unit 33 is composed of a CPU equipped with memories such as RAM and ROM, and is responsible for the overall control of the server 3. The control unit 33 determines the condition of the road surface that the vehicle V has passed over based on the acceleration, current position, speed, etc. transmitted from each vehicle V.

[0018] Next, the operation of the road surface condition determination system 1 configured as described above will be described with reference to Fig. 4. The control unit 33 of the server 3 (hereinafter abbreviated as server 3) calculates an average value of absolute values ​​of acceleration detected for each vehicle V while it travels a predetermined distance. Assume that the acceleration detected at an arbitrary time tn is αn. The server 3 calculates an average value |αaven| of absolute values ​​of accelerations αn to αn-m detected from the point where acceleration αn was detected to a point a predetermined distance (for example, 2 km) before, as shown in the following formula (1).

[0019]

number

[0020] Next, the server 3 functions as a variance value acquisition unit, and acquires a variance value s of the absolute values ​​of the accelerations αn to αn-m detected from the point where the acceleration αn is detected to a point a predetermined distance (for example, 2 km) before the point based on the average value |αaven| as shown in the following formula (2). 2 Calculate n.

[0021]

number

[0022] The server 3 calculates the variance value s for each detected acceleration. 2 1, …, s 2 Get n, ….

[0023] The server 3 also detects a variance value s when the speed detected during the travel of the predetermined distance is outside a predetermined speed fluctuation range (for example, 2 km or more). 2 1, …, s 2 n, ... are excluded. The server 3 functions as a determination unit and calculates the variance s of the absolute value of the acceleration detected while traveling a predetermined distance within a predetermined speed fluctuation range. 2 1, …, s 2 The road surface condition is determined based on n, ...

[0024] Specifically, the server 3 divides the road into areas, for example. Possible ways of dividing the road into areas include dividing the road into predetermined distances in the length direction, dividing the road into sections between intersections, or dividing the road into areas of 10 m x 10 m.

[0025] The server 3 acquires the total number of vehicles V that have passed through each area during a predetermined period. The server 3 also acquires the number of vehicles V whose variance values ​​acquired while passing through each area during the predetermined period are equal to or greater than a predetermined value (e.g., 0.1). When the ratio between the total number of vehicles and the number of vehicles V whose variance values ​​are equal to or greater than the predetermined value is equal to or greater than a second predetermined value, the server 3 determines that the road surface in that area is in a state in which repairs are required for unevenness, cracks, fissures, holes, etc. When the server 3 determines that repairs are required, it transmits the area to the terminal 4.

[0026] In the vertical direction, there is an acceleration in the upward direction (positive) and an acceleration in the downward direction (negative). Therefore, when the average value of the acceleration, which is not an absolute value, is calculated, the acceleration in the upward direction and the acceleration in the downward direction cancel each other out, and the average value becomes smaller and the variance value becomes larger by the amount of the cancellation. In other words, since the variance value becomes large due to factors unrelated to the road surface condition, it is not possible to accurately determine the road surface condition.

[0027] According to the above-described embodiment, the road surface condition is determined based on the variance of the absolute value of the acceleration. By using the variance of the absolute value, the upward acceleration and the downward acceleration are not offset when calculating the average value. Therefore, the road surface condition can be determined with high accuracy.

[0028] Fig. 5 is a graph showing the variance of acceleration when traveling on a road with good road surface conditions that do not require repair. Fig. 6 is a graph showing the variance of the absolute value of acceleration when traveling on a road with good road surface conditions that do not require repair. As is clear from a comparison of Figs. 5 and 6, the variance of the absolute value of acceleration can be made closer to flat than the variance of acceleration that is not absolute. This also shows that the present embodiment, which determines the road surface condition based on the variance of the absolute value of acceleration, can accurately determine the road surface condition.

[0029] FIG. 7 is a graph showing the relationship between the variance of the absolute value of acceleration and the speed. As is clear from the figure, when the speed fluctuates greatly, the variance of the absolute value of acceleration also becomes large. According to the above-mentioned embodiment, the server 3 judges the road surface condition based on the variance of the absolute value of acceleration detected while traveling a predetermined distance within a predetermined speed range. Therefore, it is possible to obtain a variance value that is not influenced by vertical acceleration caused by speed differences such as sudden braking and sudden starting, and it is possible to judge the road surface condition with even greater accuracy.

[0030] According to the embodiment described above, the server 3 judges the road surface condition based on the ratio between the total number of vehicles V that have passed through the area and the number of vehicles V that have passed through the area and have a variance value equal to or greater than a predetermined value. This allows the server 3 to judge the road surface condition with even greater accuracy using the acceleration sensors 21 mounted on the multiple vehicles V.

[0031] The present invention is not limited to the above-described embodiment, and can be appropriately modified, improved, etc. In addition, the material, shape, size, number, arrangement location, etc. of each component in the above-described embodiment are arbitrary as long as the present invention can be achieved, and are not limited.

[0032] According to the embodiment described above, the server 3 obtains the variance of the absolute values ​​of the acceleration detected while the vehicle is traveling a predetermined distance, but the present invention is not limited to this. For example, the server 3 may obtain the variance of the absolute values ​​of the acceleration detected while the vehicle is traveling for a predetermined time.

[0033] According to the above-described embodiment, the vehicle-mounted device 2 transmits the detected acceleration to the server 3, and the server 3 calculates and acquires the variance of the absolute value of the acceleration, but the present invention is not limited to this. For example, the vehicle-mounted device 2 may calculate the variance of the absolute value of the acceleration and transmit it to the server 3, and the server 3 may receive the variance from the vehicle-mounted device 2 to acquire it.

[0034] According to the above-described embodiment, the server 3 determines the road surface condition based on the variance value acquired for each of the vehicles, but the present invention is not limited to this. For example, the server 3 may determine the road surface condition based on the variance value of the absolute value of the acceleration detected by one vehicle V.

[0035] According to the embodiment described above, the server 3 judges the road surface condition based on the ratio between the total number of vehicles that have passed through the area and the number of vehicles V for which a variance value equal to or greater than a predetermined value has been acquired, but this is not limited to the above. For example, the server 3 may judge that the road surface condition requires repair when the number of vehicles V for which a variance value equal to or greater than a predetermined value has been acquired is equal to or greater than a predetermined number.

[0036] Here, the features of the embodiments of the road surface condition determination system and server according to the present invention described above will be briefly summarized and listed in the following [1] to [5]. [1] an acceleration sensor (21) mounted on a vehicle (V) for detecting an acceleration in a vertical direction of the vehicle (V); a variance value acquisition unit (33) that acquires a variance value of the absolute value of the acceleration detected by the acceleration sensor (21); and a determination unit (33) that determines a road surface condition on which the vehicle (V) has traveled based on the variance value acquired by the variance value acquisition unit (33). Road condition judgment system (1). [2] In the road surface condition determination system (1) according to [1], The variance value acquisition unit (33) acquires a variance value of the absolute value of the acceleration detected while the vehicle is traveling within a predetermined speed range for a predetermined distance or a predetermined period of time. Road condition judgment system (1). [3] In the road surface condition determination system (1) according to [1] or [2], The acceleration sensor (21) is mounted on a plurality of the vehicles (V), the variance value acquisition unit (33) acquires the variance value for each of the vehicles (V); the determining unit (33) determines the road surface condition based on the number of the vehicles that have passed through a predetermined area or a predetermined road and for which the variance value is equal to or greater than a predetermined value. Road condition judgment system (1). [4] In the road surface condition determination system (1) according to [3], the determination unit (33) determines the road surface condition based on a ratio between a total number of the vehicles that have passed through the specified area or the specified road and a number of the vehicles that have passed through the specified area or the specified road and for which the variance value is equal to or greater than the specified value. Road condition judgment system (1). [5] a variance value acquisition unit (33) that acquires a variance value of an absolute value of acceleration detected by an acceleration sensor (21) mounted on a vehicle (V) through communication with the vehicle (V); A determination unit (33) that determines a road surface condition based on the variance value. Server(3). [Explanation of symbols]

[0037] 1 Road condition judgment system 3 Server 21 Acceleration sensor 33 Control unit (variance value acquisition unit, determination unit) V Vehicle

Claims

1. An acceleration sensor mounted on a vehicle to detect an acceleration in a vertical direction of the vehicle; a variance value acquisition unit that acquires a variance value of the absolute value of the acceleration in the vertical direction detected by the acceleration sensor; a determination unit that determines a road surface condition on which the vehicle has traveled based on the variance value acquired by the variance value acquisition unit, the variance value acquisition unit acquires a variance value of absolute values ​​of a plurality of accelerations in the vertical direction detected between a point where the acceleration in the vertical direction is detected and a point a predetermined distance before the point where the acceleration in the vertical direction is detected, each time the acceleration in the vertical direction is detected. Road condition determination system.

2. The road surface condition determination system according to claim 1, the variance value acquisition unit acquires a variance value of the absolute value of the vertical acceleration detected while the vehicle is traveling within a predetermined speed range for a predetermined distance or a predetermined period of time; Road condition determination system.

3. 3. The road surface condition determination system according to claim 1, The acceleration sensor is mounted on a plurality of the vehicles, the variance value acquisition unit acquires the variance value for each vehicle, the determining unit determines the road surface condition based on the number of the vehicles that have passed through a predetermined area or a predetermined road and for which the variance value is equal to or greater than a predetermined value; Road condition determination system.

4. The road surface condition determination system according to claim 3, the determination unit determines the road surface condition based on whether a ratio of a total number of the vehicles that have passed through the specified area or the specified road in a specified period to a number of the vehicles that have passed through the specified area or the specified road in the specified period for which the variance value is equal to or greater than the specified value is equal to or greater than a specified value. Road condition determination system.

5. a variance value acquisition unit that acquires a variance value of an absolute value of an acceleration in a vertical direction detected by an acceleration sensor mounted on the vehicle through communication with the vehicle; a determination unit that determines a road surface condition based on the variance value, the variance value acquisition unit acquires a variance value of absolute values ​​of a plurality of accelerations in the vertical direction detected between a point where the acceleration in the vertical direction is detected and a point a predetermined distance before the point where the acceleration in the vertical direction is detected, each time the acceleration in the vertical direction is detected. server.

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