JP6620720B2 - Road surface condition judgment system - Google Patents

Description

  The present invention relates to a road surface state determination system that determines an uneven state of a road surface.

  Conventionally, it is determined whether or not a road surface is damaged, such as a dent, by road surface property measurement using a road surface property measurement vehicle equipped with a laser scanning device and a camera. For example, in Patent Document 1, a road section in which a road surface may be damaged is detected by detecting vertical vibration generated in a vehicle, and road surface properties are measured for the extracted road section. A method for determining whether or not damage has occurred is disclosed.

Japanese Patent Laying-Open No. 2015-176540

  In patent document 1, after extracting the road section in which the road surface may be damaged using the vibration of the up-down direction, the road surface property measuring vehicle provided with the laser scanning apparatus and the camera was used about the extracted road section. Measure road surface properties. As a result, road sections in which unevenness that causes vibrations in the vehicle may exist on the road surface are extracted, and it is possible to determine whether unevenness exists on the road surface by measuring road surface properties. However, since the road surface property measurement vehicle includes a laser scanning device and a camera, the cost of the laser scanning device and the camera is required.

  The present invention has been made based on this situation, and the object of the present invention is to determine whether or not there is unevenness on the road surface without using a road surface property measuring vehicle equipped with a laser scanning device or a camera. It is to provide a road surface state determination system for determining the road surface.

  The above object is achieved by a combination of the features described in the independent claims, and the subclaims define further advantageous embodiments of the invention. Reference numerals in parentheses described in the claims indicate a correspondence relationship with specific means described in the embodiments described later as one aspect, and do not limit the technical scope of the present invention. .

  In order to achieve the above object, the present invention provides a road surface state determination system (1) for determining the state of unevenness existing on a road surface for each predetermined road section, in the vertical direction of the vehicle (10). Based on the acceleration, an acceleration acquisition unit (110) that sequentially acquires the applied acceleration, a section determination unit (113) that sequentially determines a road section where the vehicle is located, and vibration due to unevenness existing on the road surface. The vibration determination unit (212) that determines whether or not the vibration has occurred, and the vibration determination unit determine whether or not vibration has occurred in the vehicle based on the acceleration acquired in the same road section more than a predetermined number of times, An unevenness determination unit (213) that determines that there is unevenness on the road surface in the road section when the frequency at which it is determined that vibration has occurred in the vehicle is greater than or equal to a threshold value.

  According to the above configuration, when the vehicle vibrates in the vertical direction as the vehicle travels on the unevenness present on the road surface, the acceleration acquired by the acceleration acquisition unit changes. The vibration determination unit determines whether or not the vehicle is vibrated due to unevenness present on the road surface, based on the acceleration.

  However, since the range in the road width direction through which the tire passes when the vehicle travels on the road is a part of the entire road width direction, the vehicle exists on the road surface even if the road surface is uneven. There are cases where the vehicle travels on uneven surfaces and travels while avoiding uneven surfaces. For this reason, there is a possibility that the vibration determination unit may determine that no vibration has occurred even in a road section where unevenness exists on the road surface, and there is unevenness on the road surface in one determination by the vibration determination unit. It may not be possible to correctly determine whether or not

  On the other hand, when the section determination unit determines the road section where the vehicle is located, it is possible to identify the road section on which the vibration determination unit has made the determination, that is, the road section from which the acceleration used for the determination has been acquired. Therefore, it is possible to compare the results of the determination by the vibration determination unit a plurality of times whether or not vibration has occurred in the same road section.

  When the vibration determination unit determines whether or not vibration has occurred in a road section having unevenness on the road surface for a predetermined number of times or more, the determination is made when the vehicle travels on the unevenness existing on the road surface. Is expected to be included at a certain frequency. Therefore, when the frequency at which the vibration determining unit determines that vibration has occurred is equal to or greater than the threshold, the unevenness determining unit determines that there is unevenness on the road surface, so that the vibration determining unit has unevenness on the road surface. Even if it is a certain road section, the influence by determining that there is no vibration is suppressed, and it is possible to determine whether or not there is unevenness on the road surface.

It is a figure showing the outline of road surface condition judging system 1 concerning an embodiment. It is a figure which shows the structure of the vehicle equipment 100 which concerns on embodiment. It is a figure which shows the structure of the center apparatus 200 which concerns on embodiment. It is a figure which shows the determination method of the road area where the vehicle 10 is located. 3 is a flowchart showing the operation of the in-vehicle device 100. 4 is a flowchart showing the operation of the center device 200. It is the example which showed the acceleration which the acceleration acquisition part 110 acquired along the road area. It is the example which showed the acceleration which removed the offset by a gradient along the road area. This is an example in which the number of times that the vibration determination unit 212 determines vibration is shown for each road section.

<First Embodiment>
Hereinafter, a road surface condition determination system 1 as a first embodiment of the present invention will be described with reference to the drawings. Before going into the configuration and detailed description of the road surface state determination system 1, an outline of the operation of the road surface state determination system 1 will be described with reference to FIG. The road surface state determination system 1 includes an in-vehicle device 100 used in the vehicle 10 and a center device 200 used in the data center 20. As the vehicle 10, for example, a passenger car including a large passenger car such as a bus used for a route bus or a truck used in a transportation company can be used. In the present embodiment, the in-vehicle device 100 having the same configuration is mounted on each of the plurality of vehicles 10.

  The in-vehicle device 100 sequentially acquires the acceleration in the vertical direction of the vehicle 10 and transmits the acquired string of accelerations to the center device 200. When the vehicle 10 travels on the road section A1 where there is unevenness, vibration in the vertical direction occurs, and the fact that the vibration has occurred appears in the acceleration column as a temporal change in acceleration.

  The center device 200 receives the train of accelerations transmitted by the vehicle 10 and determines whether or not vibration has occurred from the change in acceleration. This determination is performed for a plurality of vehicles 10 traveling on the road section A1, and the state of unevenness on the road surface in the road section A1 is determined based on the ratio at which it is determined that vibration has occurred.

[Configuration of in-vehicle device 100]
The configuration of the in-vehicle device 100 will be described with reference to FIG. The in-vehicle device 100 includes an in-vehicle device control unit 101, an acceleration sensor 102, a GNSS receiver 103, a map database 104, and a wide area transmission unit 105.

  The in-vehicle device control unit 101 is configured mainly by a microcomputer including a CPU, a ROM, a RAM, and the like, and the CPU uses a temporary storage function of the RAM and a non-transitional tangible recording medium (non -transitory tangible storage medium) is executed as the acceleration acquisition unit 110, the vehicle speed acquisition unit 111, the position acquisition unit 112, the section determination unit 113, and the data transmission unit 114.

  The acceleration sensor 102 is a sensor that measures acceleration acting in the vertical direction of the vehicle 10. For example, the acceleration sensor 102 may be provided so that the positive direction of the detection axis of the acceleration sensor 102 is the upward direction of the vehicle 10 and the negative direction of the detection axis is the downward direction of the vehicle 10.

  The GNSS receiver 103 is a receiver used to receive a positioning signal transmitted from a positioning satellite that constitutes a GNSS (Global Navigation Satellite System) and measure the position of the GNSS receiver 103.

  The map database 104 is a database storing map data. In this embodiment, the map data stores a reference position for determining a road section, a road shape, and a positional relationship of each road section with respect to the reference position. are doing.

  The reference position is determined to be a position such as an intersection that has a road shape in which the traveling direction of the vehicle 10 is easily changed compared to surrounding roads. In this embodiment, the coordinates of the center of the intersection are stored in the map database 104 as the reference position. As another example, the coordinates of one point of the curve may be stored as the reference position.

  The road shape is map data used for map matching that corrects the current position, which is the newest point in the position locus, by comparing the position locus with the road shape on the map. In the present embodiment, the map matching is executed using the road shape only when the vehicle 10 passes around the reference position in the process of determining a road section where the vehicle 10 described later is located. Therefore, the road shape stored in the map database 104 in this embodiment may be only the road shape around the reference position.

  The road section is determined by dividing the road extending from the reference position according to the distance from the reference position. For example, for one of roads extending from an intersection having a reference position, the distance from the reference position is a range from 0 m to 20 m as a first road section, a range from 20 m to 40 m as a second section, and 40 m to 60 m. May be divided and determined as in the third section, and a section ID specifying the road section may be given. In addition, the distance in this embodiment means the movement distance in the case of moving along a road, and does not necessarily correspond with a linear distance. Specifically, since it is the movement distance when moving along a road, if all the roads moved are straight lines, it matches the straight line distance, but the moved road contains a curved part In some cases, it does not match the straight line distance.

  When the road section is determined in this way, the road section in which the vehicle 10 is located is determined by the coordinates of the reference position that the vehicle 10 has passed most recently and the road that has advanced from the reference position that has passed most recently. It can be specified by the azimuth and the distance from the reference position that has passed most recently. Therefore, in this embodiment, in order to determine the road section where the vehicle 10 is located, the coordinates of the reference position, the direction of the road extending from the intersection having the reference position, and the distance from the reference positions at both ends of the road section are determined. The section ID is stored in the map database 104 in association with each other. Thereby, the positional relationship of each road section with respect to the reference position is stored in the map database 104.

  The wide area transmission unit 105 is a wireless communication apparatus that is connected to a wide area communication line via a base station and transmits data to the center apparatus 200 through the wide area communication line.

  The acceleration acquisition unit 110 sequentially acquires acceleration in the vertical direction of the vehicle 10 measured by the acceleration sensor 102.

  The vehicle speed acquisition unit 111 acquires the vehicle speed of the vehicle 10 using a vehicle speed signal output by the vehicle speed sensor 11 according to the vehicle speed of the vehicle 10. The position acquisition unit 112 performs positioning based on the positioning signal received by the GNSS receiver 103 and acquires the position of the vehicle 10 on which the in-vehicle device 100 is mounted.

  The section determination unit 113 determines a road section where the vehicle 10 is located using the vehicle speed acquired by the vehicle speed acquisition unit 111, the position acquired by the position acquisition unit 112, and the map data stored in the map database 104. Thereby, the road section in which the vehicle 10 is located at the time when the acceleration acquisition unit 110 acquires each acceleration is determined. A detailed description of the method of determining the road section in which the vehicle 10 is located will be described later with reference to FIG.

  The data transmission unit 114 sends the acceleration acquired by the acceleration acquisition unit 110 and the section ID indicating the road section where the vehicle 10 is located at the time of acquiring the acceleration determined by the section determination unit 113 to the wide-area transmission unit 105. The included acceleration data is transmitted to the center apparatus 200.

[Configuration of Center Device 200]
The configuration of the center apparatus 200 will be described with reference to FIG. The center device 200 is realized by using one or a plurality of server devices, and includes a wide area reception unit 201 and a center calculation unit 202.

  The wide-area receiving unit 201 is a communication device that can be connected to a wide-area communication line via a base station, and receives acceleration data transmitted by the wide-area transmission unit 105 via the wide-area communication line via the base station.

  The center calculation unit 202 is configured as a normal computer including a CPU, a RAM, a ROM, an I / O, a bus line that connects these configurations, and the like. The center calculation unit 202 executes a program stored in a non-transitional tangible recording medium such as a ROM while the CPU uses the temporary storage function of the RAM, thereby causing the data reception unit 210 to calculate a change amount. Operation as the unit 211, the vibration determination unit 212, and the unevenness determination unit 213 is performed.

  The data receiving unit 210 acquires acceleration data transmitted by the in-vehicle device 100 and received by the wide area receiving unit 201. The change amount calculation unit 211 uses the acceleration included in the acceleration data acquired by the data reception unit 210 and uses an acceleration change amount that is an acceleration change amount in the road section where the vehicle 10 is located at the time when the acceleration is acquired. Is calculated. In the present embodiment, the absolute value of a value obtained by subtracting the average value of the acceleration acquired in the road section where the acceleration is acquired from the acceleration included in the acceleration data acquired by the data receiving unit 210 is obtained. The value obtained by this is the acceleration change amount in the present embodiment. It is considered that the average value of acceleration in the road section approximately matches the acceleration offset caused by the road surface gradient in the road section. Therefore, by subtracting the average value of acceleration, the influence of the road surface gradient is reduced, and it becomes easy to determine the change in acceleration due to vibration.

  Based on the acceleration, the vibration determination unit 212 determines whether or not the vehicle 10 has been vibrated in the vertical direction due to the unevenness present on the road surface. For example, when the acceleration change amount calculated by the change amount calculation unit 211 is a numerical value greater than or equal to a threshold value, it may be determined that vibration has occurred due to unevenness existing on the road surface. The threshold value for determining that vibration has occurred is in accordance with the amount of acceleration change calculated by the change amount calculation unit 211 when the vehicle 10 travels on the unevenness to which it is determined that there is unevenness and the vehicle 10 generates vibration. Is set.

  In addition, about the state in which an unevenness | corrugation exists, it is good also as dividing the degree of an unevenness | corrugation into a several step. In this case, in addition to determining that vibration has occurred, the vibration determination unit 212 may determine whether the vibration generated according to the level is large or small.

  In the present embodiment, the degree of unevenness is divided into two stages, large and small, 0.2G is used as a threshold for determining whether or not unevenness is generated, and 0.3G is a threshold for determining the magnitude of vibration according to the size of the unevenness. And Specifically, when the acceleration change amount is a value of 0.2 G or more and less than 0.3 G, it is determined that vibration of vibration level 1 has occurred due to the presence of small unevenness on the road surface. Further, when the value is 0.3 G or more, it is determined that vibration at vibration level 2 has occurred due to the presence of large irregularities on the road surface.

  The unevenness determination unit 213 determines whether or not the vibration determination unit 212 has determined whether or not the vehicle 10 has vibrated a predetermined number of times or more for the same road section, and the frequency at which it is determined that vibration has occurred is equal to or greater than a threshold value. In this case, it is determined that there is unevenness on the road surface in the road section.

  When the number of times of determination as to whether vibration has occurred is small, the result of determination as to whether vibration has occurred is likely to be biased, and the possibility that an error will occur in the determination by the unevenness determination unit 213 increases. Therefore, in order to suppress the occurrence of bias in the determination result of whether or not vibration has occurred and to suppress erroneous determination as to whether or not there is unevenness on the road surface, the predetermined number of times is It is preferable that the number of times is as large as possible. However, if the number of times exceeds a certain number, the determination accuracy is not improved so much. Therefore, the predetermined number of times may be about 50 to 200, for example.

  The threshold value of the frequency is a threshold value for discriminating between a state where unevenness exists on the road surface and a state where unevenness exists on the road surface. Therefore, between the frequency at which it is determined that vibration has occurred in the vehicle 10 when the road surface has unevenness and the frequency at which it is determined that vibration has occurred in the vehicle 10 when there is no unevenness on the road surface. It is determined to be a value of.

  Here, when the vehicle 10 travels on a road section having unevenness on the road surface, the frequency at which it is determined that vibration has occurred in the road section changes according to the spread and number of places where the unevenness exists. To do. The frequency of the determination that the vibration has occurred in the road section increases as the size of the area where the unevenness is large and the number of the areas where the unevenness exists are large.

  Therefore, the frequency threshold is set according to the degree of unevenness that should be determined to be in a state where unevenness exists. The frequency threshold is, for example, 20%.

  Moreover, when there are vibration determination times equal to or greater than the predetermined number of times described above, it is necessary to determine whether or not there is unevenness on the road surface of one road section using all vibration determination results. Absent. For example, for each road section, among the vehicles 10 traveling on the road section, the vibration determination result for 50 cars from the time when the acceleration data is transmitted to the center device 200 is close to the time when the determination is performed on the road surface. It may be determined whether or not unevenness exists. At this time, if the frequency threshold is 20% of the determined number of times, the road surface state is determined based on whether or not the vibration has occurred 10 times or more.

  Furthermore, when it is determined that there is unevenness on the road surface, the level of unevenness existing on the road surface depends on whether it is determined that vibration of vibration level 1 has occurred or whether vibration of vibration level 2 has occurred. May be estimated. For example, when the number of times it is determined that the vibration of the vibration level 2 has occurred is 10 times or more, it is determined that the road surface is in a state where rough roads, in which large unevenness is generated on the road surface, have progressed. The total number of times that the vibration level 2 vibration is determined is less than 10 and the number of vibration level 1 vibration determinations and the vibration level 2 vibration determination is 10 or more. In this case, it is determined that the road surface, which is a state in which small unevenness is generated on the road surface, starts to become rough.

[Determination method of road section where vehicle 10 is located]
A method for determining the road section in which the vehicle 10 is located will be described with reference to FIG. A road A extends from the intersection where the reference position P is located. In the road A, a section having a distance from the reference position P of 0 m to 20 m is determined in advance as a road section A1, a section of 20 m to 40 m is a road section A2, and a section of 40 m to 60 m is a road section A3.

  The section determination unit 113 performs map matching by comparing the locus of the position acquired by the position acquisition unit 112 with the road shape stored in the map database 104, and the reference is a time at which the vehicle 10 is positioned at the reference position P. Determine the time. Thereafter, the road section where the vehicle 10 is located is determined by estimating the distance between the vehicle 10 and the reference position based on the vehicle speed of the vehicle 10 acquired by the vehicle speed acquisition unit 111.

  First, a method for determining the reference time based on the position acquired by the position acquisition unit 112 will be described. Consider a case where the position acquired by the position acquisition unit 112 is a position P1 at time t1, a position P2 at time t2, and a position P3 at time t3. It is assumed that the position P1 is corrected to the position P1a, the position P2 is corrected to the position P2a, and the position P3 is corrected to the position P3a by correcting the locus of these positions by map matching. At this time, since the corrected position closest to the reference position P is the position P2a, the time t2 when the position P2 that is the position before the correction of the position P2a is acquired is determined as the reference time.

  Next, a method for determining the road section in which the vehicle 10 is located by estimating the distance between the vehicle 10 and the reference position based on the vehicle speed of the vehicle 10 acquired by the vehicle speed acquisition unit 111 will be described. By multiplying the vehicle speed of the vehicle 10 acquired by the vehicle speed acquisition unit 111 by the cycle in which the vehicle speed acquisition unit 111 acquires the vehicle speed, the travel distance of the vehicle 10 for each cycle in which the vehicle speed is acquired can be calculated. By summing the calculated travel distances after the reference time, the distance between the reference position and the vehicle 10 can be estimated, and the road section where the vehicle 10 is located can be determined.

  In order to simplify the description, an example will be described in which the vehicle speed acquisition unit 111 acquires the vehicle speed as a 1-second cycle. When the vehicle speed acquired by the vehicle speed acquisition unit 111 at the time t2 determined as the reference time is 10 m / s, the distance between the vehicle 10 and the reference position P is estimated to be 10 m after 1 second from the time t2. . Therefore, the road section in which the vehicle 10 is located 1 second after the time t2 can be determined to be the road section A1. When the vehicle speed acquired by the vehicle speed acquisition unit 111 after 1 second of time t2 is 15 m / s, it is estimated that the distance between the vehicle 10 and the reference position P is 25 m after 2 seconds of time t2. Therefore, the road section where the vehicle 10 is located 2 seconds after the time t2 can be determined to be the road section A2.

[Operation of in-vehicle device 100]
The operation of the in-vehicle device 100 will be described along the flowchart of FIG. When the ignition switch of the vehicle 10 is turned on, the in-vehicle device control unit 101 periodically executes the process shown in FIG. 5 from S1. The period to be executed may be a period of 100 milliseconds, for example.

  In S <b> 1, the acceleration applied by the acceleration sensor 102 in the vertical direction of the vehicle 10 is acquired. S <b> 1 is processing as the acceleration acquisition unit 110. In S <b> 2, the vehicle speed of the vehicle 10 is acquired using the vehicle speed signal output from the vehicle speed sensor 11. S <b> 2 is a process performed by the vehicle speed acquisition unit 111.

  In S3, it is determined whether or not a period for positioning the position of the vehicle 10 based on the positioning signal has elapsed. The positioning cycle may be a 1 second cycle, for example. If it is determined that the time has elapsed, the process proceeds to S4. If it is determined that the time has not elapsed, the process proceeds to S7. In S4, positioning is performed based on the positioning signal received by the GNSS receiver 103, and the position of the vehicle 10 is acquired. S4 is processing as the position acquisition unit 112.

  In S <b> 5, it is determined whether the vehicle 10 has passed near any of the reference positions stored in the map database 104. This determination is a process of determining whether or not the acquired locus of the position around the reference position is long enough to collate with the road shape around the reference position. For example, what is necessary is just to judge that it passed the vicinity of the reference position, when it is thought that it moved about 10 m-30 m through the reference position. In the present embodiment, the position acquired by the positioning one time before the positioning in the immediately preceding S4 process is within 10 m from a certain reference position P stored in the map database 104, and by the positioning in the immediately preceding S4 process. When the acquired position is not within 10 m from the reference position P, it is determined that the vicinity of the reference position P has been passed. When it is determined that the vicinity of the reference position has been passed, the process proceeds to S6, and when it is determined that it has not passed, the process proceeds to S7.

  In S <b> 6, the locus of the position acquired in the process of S <b> 4 is corrected by map matching that matches the road shape stored in the map database 104. As a result, the reference time, which is the time when the vehicle 10 is located at the reference position, and the direction in which the vehicle 10 that has passed the reference position is traveling with respect to the traveling direction, that is, the vehicle 10 is traveling. The direction extending from the intersection having the reference position of the road is determined.

  In S7, the distance between the vehicle 10 and the reference position is calculated using the vehicle speed acquired in the process of S2 after the reference time determined in the latest process of S6. In the process of S8, the coordinates of the latest reference position determined to have passed in the determination of S5 in the map database 104, the road extending direction determined in the latest process of S6, and the calculation in the process of S7 immediately before are calculated. The section ID stored in association with the distance between the vehicle 10 and the reference position is determined as the section ID indicating the road section where the vehicle 10 is located. The processes of S3, S5, S6, and S7 are processes as a road section determination unit.

  In S9, it is determined whether or not the transmission period of acceleration data has elapsed. If the transmission cycle has not elapsed, the processing shown in FIG. 5 is terminated. If it is determined that the transmission cycle has elapsed, the process proceeds to S10, and after the acceleration data including the acceleration acquired in S1 and the section ID determined in S8 is transmitted, the process illustrated in FIG.

  In the present embodiment, when it is determined that the vehicle 10 has passed the reference position, a reference time that is a time when the vehicle 10 is located at the reference position is determined. That is, since the reference time is determined retroactively, the road section at the time when the acceleration is acquired may not be determined near the reference position. In addition, since it is not necessary to immediately determine the unevenness state of the road surface, there is no need to immediately transmit the acquired acceleration to the center device 200. Therefore, the measured acceleration is accumulated without sequentially being transmitted, and the transmission cycle in the process of S9 and the transmission in the process of S10 are performed so that only the acceleration in which the road section at the acquired time is determined is transmitted to the center device 200. Determine the range of acceleration to be performed.

  For example, the transmission cycle in the process of S9 is a 1 minute period, and in the process of S10, the acceleration acquired from 1 minute 20 seconds to 20 seconds ago and the road section at the time when those accelerations are acquired are used as acceleration data. What is necessary is just to transmit to the center apparatus 200. In the present embodiment, the road section in which the vehicle 10 is located cannot be determined until the vehicle 10 passes around the reference position. Therefore, since the acceleration acquired before the vehicle 10 passes around the reference position cannot determine the road section where the vehicle 10 is located at the acquired time, the acceleration is transmitted to the center device 200 in the process of S10. do not do. S9 and S10 are processing as the data transmission unit 114.

[Operation of center device 200]
The operation of the center apparatus 200 will be described with reference to the flowchart of FIG. The center calculation unit 202 periodically executes the processing illustrated in FIG. 6 in order from S11. What is necessary is just to make the period to perform once per week-one month, for example.

  In S11, the acceleration data received by the wide-area receiving unit 201 after executing the process of S11 last time is acquired. S11 is processing as the data receiving unit 210. In S12, an acceleration change amount that is an acceleration change amount is calculated. Specifically, for each acceleration included in the acceleration data acquired in S11, an absolute value of a value obtained by subtracting the average value of acceleration in the road section where the acceleration is acquired is obtained. Thereby, the change amount from the average value of the acceleration in the road section is calculated as the acceleration change amount. S <b> 12 is processing as the change amount calculation unit 211.

  In S13, it is determined whether there is a road section where the number of times the vehicle 10 has traveled is equal to or greater than a predetermined number. In the present embodiment, it is determined whether there is a road section in which the vehicle 10 has traveled 50 times or more. If it is determined that there is a road section where the number of travels is 50 times or more, the process proceeds to S14. If it is determined that there is no road section where the number of travels is 50 times or more, the process shown in FIG. .

  In S14, it is determined whether or not there is unevenness on the road surface after the most recent processing of S13 among the road sections determined that the number of times of traveling in the most recent processing of S13 is 50 or more. For one of the road sections that are not, the acceleration change amount calculated using the acceleration acquired in the last 50 runs is acquired. The processing of S13 and S14 avoids determining the road surface unevenness state with a small number of determinations as to whether or not vibration has occurred, and suppresses the possibility of erroneously determining the road surface unevenness state. Process.

  In S15, the number of times it is determined that vibrations of vibration level 1 and vibration level 2 have occurred is obtained for the acceleration change amount acquired in S14. The process of S15 is a process as the vibration determination unit 212.

  In S16, it is determined whether or not the total number of times determined to have generated vibrations of vibration level 1 and vibration level 2 obtained in S15 is 10 or more. If it is 10 times or more, the process proceeds to S17, and if it is less than 10, the process proceeds to S18.

  In S17, it is determined whether or not the number of times the vibration of the vibration level 2 that is obtained in the process of S15 has occurred is 10 times or more. If it is 10 times or more, the process proceeds to S20, and if it is less than 10, the process proceeds to S19.

  In the process of S18, it is determined that the road surface of the road section from which the acceleration change amount is acquired in the process of S14 is a normal road surface state in which the degree of unevenness of the road surface is small and it is not determined that the unevenness exists. In the process of S19, it is determined that the road surface of the road section from which the acceleration change amount is acquired in the process of S14 is in a rough start state in which a small unevenness is present on the road surface. In the process of S20, it is determined that the road surface of the road section from which the acceleration change amount is acquired in the process of S14 is a progressed rough state in which large unevenness is present on the road surface.

  In S21, whether or not all the road sections in which it has been determined that the vehicle 10 has traveled 50 times or more in the most recent processing in S13 has unevenness on the road surface by the processing in S14 to S20. Judge whether or not. If it is determined that all the sections have been determined, the process shown in FIG. 6 is terminated. If it is determined that there is a section in which the determination has not been performed, the process returns to S14. The processes of S13 and S14, and S16 to S21 are processes as the unevenness determination unit 213.

[Examples of acceleration, acceleration change, and number of vibrations]
An example of acceleration acquired by the acceleration acquisition unit 110 when a certain vehicle 10 travels on a road is shown in FIG. The vertical axis indicates acceleration, and the horizontal axis indicates distance, and the influence of offset due to the road gradient is included in the acceleration.

  FIG. 8 shows acceleration values obtained by correcting the offset due to the road gradient by subtracting the average acceleration value for each road section from the acceleration shown in FIG. Compared with FIG. 7, the influence of the offset due to the road gradient is reduced, and it is easy to determine the change in acceleration due to vibration. In this embodiment, the absolute value of this value is used as the acceleration change amount.

  FIG. 9 shows an example in which the acceleration change amount is acquired for 50 runs of the vehicle 10 and the number of times of vibration for each road section is obtained. The vertical axis represents the total number of vibrations at vibration level 1 and vibration level 2, and the horizontal axis represents distance. In addition, in this figure, the frequency | count of the vibration of each road area when the length of each road area is set to 100 m and a road area is determined is shown.

[Summary of Embodiment]
As described above, according to the embodiment described above, when the vehicle 10 vibrates in the vertical direction due to the unevenness present on the road surface, the acceleration acquired by the acceleration acquisition unit 110 changes. When the acceleration change amount calculated by the change amount calculation unit 211 increases and becomes equal to or greater than the threshold value due to a change in acceleration, the vibration determination unit 212 determines that the vehicle is vibrated due to unevenness present on the road surface.

  On the other hand, the section determination unit 113 determines the road section in which the vehicle 10 is located, thereby acquiring the road section in which the vibration determination unit 212 performs the determination, that is, the acceleration used for calculating the acceleration change amount used in the determination. It becomes possible to specify a road section. Therefore, the unevenness determination unit 213 can compare the results determined by the vibration determination unit 212 a plurality of times for the same road section. When the vibration determination unit 212 performs determination for a road section having unevenness on the road surface more than a predetermined number of times, the determination about the case where the vehicle 10 travels on the unevenness existing on the road surface is included at a certain frequency. It is expected that

  Accordingly, when the frequency at which the vibration determination unit 212 determines that vibration has occurred is equal to or greater than the threshold, the unevenness determination unit 213 determines that there is unevenness on the road surface, so that the road surface has unevenness. Nevertheless, it is possible to determine whether or not there is unevenness on the road surface by suppressing the influence of the vehicle 10 traveling while avoiding unevenness and causing no vibration.

  In addition, when the section determination unit 113 determines the road section in which the vehicle 10 is located, map matching is performed using the position of the vehicle 10 acquired by the position acquisition unit 112 only when the vehicle 10 is positioned around the reference position. Is going. Therefore, even if an error occurs in the position acquired by the position acquisition unit 112 when the position of the vehicle 10 is not around the reference position, the road section determined by the section determination unit 113 is not affected by the error. In addition, when the position of the vehicle 10 is not around the reference position, it is possible to lengthen the cycle in which the position acquisition unit 112 acquires the position, or to temporarily stop the acquisition.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, The following modification is also contained in the technical scope of this invention, Furthermore, the summary other than the following is also included. Various modifications can be made without departing from the scope. In the following description, elements having the same reference numerals as those used so far are the same as the elements having the same reference numerals in the previous embodiments unless otherwise specified. Further, when only a part of the configuration is described, the above-described embodiment can be applied to the other parts of the configuration.

<Modification 1>
In the embodiment, the road section is divided every 20 m, but the length of the road section is not limited to this. For example, it may be divided every 10 m or every 100 m, or the length may be different for each road section.

<Modification 2>
In the embodiment, the number of times to determine whether vibration has occurred in the vehicle 10 is constant. However, the number of times to determine whether vibration has occurred in the vehicle 10 may be variable. For example, it may be determined whether or not vibration has occurred in the vehicle 10 with respect to the acceleration change amount calculated using the acceleration acquired in the period from the time of determination to one week before.

<Modification 3>
In the embodiment, the absolute value of the value obtained by subtracting the average value of the acceleration in the road section from which the acceleration is acquired is used as the acceleration change amount. However, the value used as the acceleration change amount is not limited to this.

  For example, an absolute value of a value obtained by subtracting a moving average of acceleration in a predetermined period determined based on a time at which the acceleration is acquired from a certain acceleration may be used as the acceleration change amount. Specifically, it is considered that the moving average of the acceleration acquired by the acceleration acquisition unit 110 for one minute immediately before acquiring a certain acceleration also roughly matches the offset due to the road surface gradient. Therefore, an absolute value of a value obtained by subtracting a moving average of acceleration for one minute immediately before the acceleration is acquired from a certain acceleration may be used as the acceleration change amount.

  As another example, an absolute value of a value obtained by subtracting the acceleration acquired immediately before by the acceleration acquisition unit 110, that is, a difference from the immediately preceding acceleration may be used as the acceleration change amount. At this time, it is considered that the offset obtained by the gradient of the road surface is added to the acceleration acquired immediately before. Therefore, also in this case, the influence of the road surface gradient is reduced, and it becomes easy to determine the change in acceleration due to vibration.

<Modification 4>
In the embodiment, the vibration determination unit 212 uses the acceleration change amount calculated by the change amount calculation unit 211 to determine whether vibration has occurred due to unevenness present on the road surface. However, the parameters used when determining whether or not vibration has occurred are not limited to this.

  For example, when determining a road section in which the road surface inclination is small and the offset due to the road surface inclination is small with respect to the acceleration change caused by the vibration, the acceleration acquired by the acceleration acquisition unit 110 is used without calculating the acceleration change amount. Thus, it may be determined whether or not vibration has occurred in the vehicle 10. Specifically, when the absolute value of the acceleration is equal to or greater than the threshold value, it may be determined that the vehicle 10 has vibrated due to the unevenness present on the road surface. The threshold value in this case is set according to the acceleration acquired by the acceleration acquisition unit 110 when the vehicle 10 travels on the unevenness that should be determined to be uneven, and vibrations occur. In addition, what is necessary is just to determine beforehand the road area determined using an acceleration using the inclination of the road surface acquired by surveying etc. FIG.

<Modification 5>
In the embodiment, the section determination unit 113 determines the reference time using the locus of the position corrected by the map matching, and determines the road section where the vehicle 10 is located using the distance obtained based on the vehicle speed after the reference time. I was going to decide. However, the method for determining the road section is not limited to this. For example, the position acquired by the position acquisition unit 112 may be used without performing map matching. In this case, the road section may be determined by applying the position acquired by the position acquisition unit 112 to the correspondence between the position determined in advance and the road section.

1: Road surface condition determination system 10: Vehicle 11: Vehicle speed sensor 20: Data center 100: In-vehicle device 101: In-vehicle device control unit 102: Acceleration sensor 103: GNSS receiver 104: Map database 105: Wide area transmission unit 110: Acceleration acquisition unit 111: Vehicle speed acquisition unit 112: Position acquisition unit 113: Section determination unit 114: Data transmission unit 200: Center device 201: Wide area reception unit 202: Center calculation unit 210: Data reception unit 211: Change amount calculation unit 212: Vibration determination unit 213: Concavity and convexity determination unit

Claims (3)

A road surface condition determination system (1) for determining the state of unevenness existing on a road surface for each predetermined road section,
An acceleration acquisition unit (110) for sequentially acquiring acceleration applied in the vertical direction of the vehicle (10);
A section determining unit (113) for sequentially determining the road section where the vehicle is located;
A vibration determination unit (212) for determining whether vibration due to unevenness existing on a road surface has occurred in the vehicle based on the acceleration;
The frequency at which the vibration determination unit determines whether vibration has occurred in the vehicle a predetermined number of times or more based on the acceleration acquired in the same road section, and the frequency at which it is determined that vibration has occurred in the vehicle is a threshold value. When it is above, a road surface state determination system provided with the unevenness | corrugation determination part (213) which determines with the said road surface being the state where the unevenness | corrugation exists in the said road area. In claim 1,
The road surface condition determination system is
A change amount calculation that calculates an absolute value of a value obtained by subtracting the moving average of the acceleration acquired by the acceleration acquisition unit during a predetermined period determined based on the time when the acceleration is acquired from the acceleration as an acceleration change amount Part (211),
When the acceleration change amount is greater than or equal to a threshold value, the vibration determination unit is caused by unevenness existing on the road surface of the vehicle in the road section where the acceleration used to calculate the acceleration change amount is acquired. A road surface condition determination system that determines that vibration has occurred. In claim 1 or 2,
The road section is determined in advance according to a distance from a reference position that is a position serving as a reference of the road section,
The road surface condition determination system is
A position acquisition unit (112) for acquiring the position of the vehicle;
A vehicle speed acquisition unit (111) for sequentially acquiring the vehicle speed of the vehicle,
The section determining unit determines a reference time at which the vehicle is positioned at the reference position by performing map matching in which a locus of the position acquired by the position acquisition unit is compared with a road on a map, and the reference The distance between the reference position and the vehicle is determined based on the vehicle speed acquired by the vehicle speed acquisition unit after the time, and the distance between the determined reference position and the vehicle is determined from a predetermined distance from the reference position. A road surface condition determination system that determines the road section by applying the relationship to the road section.

Images