Road surface evaluation device

Abstract

To evaluate road surface profiles efficiently with good accuracy.SOLUTION: A road surface evaluation device 10 comprises: an information acquisition unit 111 that acquires position information on a plurality of vehicles, acceleration information indicating the acceleration of the plurality of vehicles, and map information including information on a prescribed road, as travel information for the plurality of vehicles; an evaluation unit 112 that calculates the stability of travel behavior of each of the plurality of vehicles on the basis of travel information acquired by the information acquisition unit 111 at the time the plurality of vehicles traveled on the prescribed road in the past, selects a vehicle group to be evaluated from among the vehicles whose stability is greater than or equal to a prescribed level, and evaluates the road surface roughness of the prescribed road on the basis of the travel information on the vehicle group acquired by the information acquisition unit 111; and an output unit 113 that outputs information regarding the road surface roughness evaluated by the evaluation unit 112 in association with information on the prescribed road acquired by the information acquisition unit 111.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a road surface evaluation device that evaluates a road surface profile that represents the uneven shape of a road surface. [Background technology]

[0002] Conventionally, one such device known in the art is one that evaluates the roughness of a road surface based on driving information, including driving acceleration, obtained from multiple vehicles traveling on the road (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 059636 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a method of acquiring driving information from multiple vehicles, such as the device described in Patent Document 1, when the number of vehicles increases, the communication capacity between the device and each vehicle increases, which may increase the load on the communication infrastructure. [Means for solving the problem]

[0005] The road surface evaluation device according to one aspect of the present invention includes a travel information acquisition unit that acquires, as travel information of a plurality of vehicles, position information of the plurality of vehicles and acceleration information indicating accelerations of the plurality of vehicles; The system includes a map information acquisition unit that acquires map information including information on a specified road; a calculation unit that calculates the stability of the driving behavior of each of a plurality of vehicles based on driving information acquired by the driving information acquisition unit when the plurality of vehicles have previously traveled along the specified road; an evaluation unit that selects a group of vehicles to be evaluated from vehicles whose stability calculated by the calculation unit is at or above a predetermined level, and evaluates the roughness of the road surface of the specified road based on the driving information of the group of vehicles acquired by the driving information acquisition unit; and an output unit that outputs information regarding the roughness of the road surface evaluated by the evaluation unit in correspondence with the information of the specified road acquired by the map information acquisition unit. Effect of the Invention

[0006] According to the present invention, a road surface profile can be evaluated efficiently and accurately. [Brief description of the drawings]

[0007] [Figure 1] 1 is a diagram showing an example of the configuration of a road surface evaluation system including a road surface evaluation device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a block diagram showing a configuration of a main part of the in-vehicle device. [Diagram 3] 1 is a block diagram showing a configuration of a main part of a road surface evaluation device according to an embodiment of the present invention. [Figure 4A] FIG. 2 is a diagram showing an example of a map of roads on which a vehicle travels. [Figure 4B] 4B is a diagram showing an example of travel information acquired by a road surface evaluation device from an in-vehicle device of a vehicle that traveled on the road in FIG. 4A. [Diagram 5] 4B is a diagram showing an example of a road surface roughness value calculated based on travel information acquired from an in-vehicle device of a vehicle traveling on the road of FIG. 4A. [Figure 6A] FIG. 4 is a diagram for explaining a method of deriving the correlation between a road surface roughness value and a lateral acceleration. [Figure 6B] FIG. 4 is a diagram for explaining a method of deriving the correlation between a road surface roughness value and a lateral acceleration. [Figure 7] FIG. 4 is a diagram showing an example of road surface profile information. [Figure 8]4 is a flowchart showing an example of processing executed by a calculation unit in FIG. 3. [Figure 9] 4 is a flowchart showing an example of processing executed by a calculation unit in FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 9. A road surface evaluation device according to an embodiment of the present invention is a device for evaluating a road surface profile of a road on which a vehicle travels. Fig. 1 is a diagram showing an example of the configuration of a road surface evaluation system including a road surface evaluation device according to this embodiment. As shown in Fig. 1, the road surface evaluation system 1 includes a road surface evaluation device 10 and an in-vehicle terminal 30. The road surface evaluation device 10 is configured by, for example, a server device. The in-vehicle terminal 30 is configured to be able to communicate with the road surface evaluation device 10 via a communication network 2.

[0009] The communication network 2 includes not only public wireless communication networks such as the Internet and mobile phone networks, but also closed communication networks established for each designated management area, such as wireless LAN, Wi-Fi (registered trademark), Bluetooth (registered trademark), etc.

[0010] The in-vehicle terminal 30 is mounted on a vehicle 20. The vehicles 20 include a plurality of vehicles 20-1, 20-2, . . . , 20-n. The vehicles 20 may be manually driven vehicles or automatically driven vehicles. The vehicles 20 may include vehicles of different models and grades.

[0011] 2 is a block diagram showing the main configuration of the in-vehicle terminal 30 according to this embodiment. The in-vehicle terminal 30 includes an electronic control unit (ECU) 31, a positioning sensor 32, an acceleration sensor 33, a steering angle sensor 34, a vehicle speed sensor 35, and a TCU (Telematic Control Unit) 36.

[0012] The positioning sensor 32 is, for example, a GPS sensor that receives a positioning signal transmitted from a GPS satellite and detects the absolute position (latitude, longitude, etc.) of the vehicle 20. The positioning sensor 32 includes not only a GPS sensor but also a sensor that performs positioning using radio waves transmitted from satellites of various countries called GNSS satellites, including quasi-zenith orbit satellites.

[0013] The acceleration sensor 33 detects acceleration in the left-right direction, i.e., lateral acceleration, of the vehicle 20. The acceleration sensor 33 may be configured to detect acceleration in the front-rear direction and acceleration in the up-down direction as well as the lateral acceleration of the vehicle 20. The steering angle sensor 34 detects the steering angle of a steering wheel (not shown) of the vehicle 20. The vehicle speed sensor 35 detects the vehicle speed of the vehicle 20.

[0014] 2, the ECU 31 includes a computer having a calculation unit 310 such as a CPU, a storage unit 320 such as a ROM, a RAM, and other peripheral circuits (not shown) such as an I / O interface. The calculation unit 310 functions as a sensor value acquisition unit 311 and a communication control unit 312 by executing a program stored in advance in the storage unit 320.

[0015] The sensor value acquisition unit 311 acquires the detection values ​​of the sensors 33-35 and the absolute position of the vehicle 20 detected by the positioning sensor 32 at a predetermined period. The communication control unit 312 transmits the information acquired by the sensor value acquisition unit 311 (hereinafter referred to as driving information) together with a vehicle ID capable of identifying the vehicle 20 to the road surface evaluation device 10 via the TCU 36 at a predetermined period.

[0016] The road surface evaluation device 10 detects the uneven shape of the road surface, that is, the roughness of the road surface (hereinafter also referred to as the road surface profile) based on the detection value of the acceleration sensor 33 of the vehicle 20 (vehicle-mounted terminal 30). Information on this detected road surface profile is output to a terminal owned by a road management company or the like, and is used as reference data when the road management company or the like considers the need for repairs, etc. In other words, the detection value of the acceleration sensor is used to evaluate the road surface profile.

[0017] 3 is a block diagram showing the configuration of the main parts of the road surface evaluation device 10 according to this embodiment. The road surface evaluation device 10 includes a computer having a calculation unit 110 such as a CPU, a storage unit 120 such as a ROM, a RAM, and other peripheral circuits (not shown) such as an I / O interface. The storage unit 120 stores map information including a road map and various information processed by the calculation unit 110.

[0018] The calculation unit 110 executes the programs stored in the storage unit 120 to function as an information acquisition unit 111 , an evaluation unit 112 , an output unit 113 , and a communication control unit 114 .

[0019] The information acquisition unit 111 receives travel information from the in-vehicle terminal 30 of each vehicle 20 traveling on a road via the communication control unit 114. The travel information includes position information indicating the position of the vehicle 20 and acceleration information indicating the acceleration of the vehicle 20. The position information includes travel time information indicating the time when the vehicle 20 traveled to that position. The travel information also includes travel speed information indicating the travel speed of the vehicle 20. The travel speed information includes a sensor value of the vehicle speed sensor 35, that is, a measured value of the travel speed of the vehicle 20. The travel information also includes steering angle information indicating the steering angle of the steering wheel of the vehicle 20. The steering angle information includes a sensor value of the steering angle sensor 34, that is, a measured value of the steering angle of the vehicle 20. The information acquisition unit 111 can identify the vehicle 20 that is the source of the travel information by the vehicle ID associated with the travel information.

[0020] The information acquisition unit 111 stores the travel information received from the multiple vehicles 20 (vehicle-mounted terminals 30) in chronological order in the storage unit 120. Hereinafter, the travel information stored in chronological order in the storage unit 120 is referred to as time-series travel information. In addition, the information acquisition unit 111 acquires map information including information on the roads on which the vehicles 20 travel from the storage unit 120.

[0021] The evaluation unit 112 evaluates the amount of unevenness (depth or height) of the road surface, that is, the road surface roughness, based on the travel information of the multiple vehicles 20 acquired within a predetermined period by the information acquisition unit 111. More specifically, the evaluation unit 112 calculates a road surface roughness value indicating the degree of roughness of the road surface, based on the lateral acceleration of the multiple vehicles 20 acquired within a predetermined period by the information acquisition unit 111. The road surface roughness value is, for example, a value expressed by IRI (International Roughness Index), which is an international index. Hereinafter, the road surface roughness value may be simply referred to as a roughness value.

[0022] FIG. 4A is a diagram showing an example of a map of a road on which a vehicle 20 travels. FIG. 4A shows a predetermined range (latitude Y to Z of national highway X) to be evaluated for road surface roughness. In FIG. 4A, the upward direction corresponds to the north direction, and the rightward direction corresponds to the east direction. A predetermined road to be evaluated for road surface roughness (hereinafter referred to as the evaluation target road) can be specified by a user such as a road management company. More specifically, the evaluation target road is specified by transmitting information capable of identifying the evaluation target road, such as the name and position of the evaluation target road, from a terminal owned by the road management company or the like to the road surface evaluation device 10. When the evaluation target road has multiple lanes on one side, the user may be able to specify the lanes to be evaluated for road surface roughness.

[0023] Fig. 4B is a diagram showing an example of time-series travel information acquired by the road surface evaluation device 10 from the in-vehicle terminal 30 of the vehicle 20 traveling in the predetermined range (latitude Y to Z on national highway X) in Fig. 4A. The horizontal axis in the diagram represents the position (latitude) of the vehicle 20 in the traveling direction along the travel lane, and the vertical axis represents the lateral acceleration of the vehicle 20. Characteristics D1, D2, ..., Dn represent the time-series travel information of the vehicles 20-1, 20-2, ..., 20-n, respectively.

[0024] Increasing the sampling period can improve the accuracy of the road surface roughness value calculated by the evaluation unit 112, making it possible to accurately evaluate the road surface profile. However, increasing the sampling period of the travel information (for example, 100 Hz) increases the processing load of the in-vehicle terminal 30. Furthermore, there is a risk of straining the bandwidth of the communication network 2 because the amount of data of the travel information transmitted to the road surface evaluation device 10 increases. Taking this into consideration, the evaluation unit 112 synthesizes the travel information of a first period (for example, 1 Hz) transmitted from n vehicles 20 to generate synthetic travel information of a second period (1×n Hz), and calculates the road surface roughness value based on the synthetic travel information. Here, the generation of the synthetic travel information will be described with reference to FIG. 5.

[0025] FIG. 5 is a diagram showing an example of composite travel information generated based on travel information acquired from the vehicle-mounted terminals 30 of a plurality of vehicles 20 traveling on the road shown in FIG. 4A. The composite travel information is information obtained by combining the acceleration information of each vehicle 20 based on the position information of each vehicle 20. The composite travel information shown in FIG. 5 is obtained by superimposing the values ​​of the vertical axis (lateral acceleration) of each vehicle 20 shown in FIG. 4B based on the horizontal axis (latitude). Since the vehicle speeds of each vehicle 20 and the points at which each vehicle 20 starts sampling are different from one another, even if the sampling period of the travel information of each vehicle 20 is the same, the timing at which the travel information is sampled is considered to be different for each vehicle 20. Therefore, by combining the travel information of 1 Hz sampled in n vehicles 20 as described above, travel information equivalent to 1×n Hz is obtained. The evaluation unit 112 evaluates the roughness of the road surface on which each vehicle 20 is traveling based on the composite travel information obtained in this manner.

[0026] In general, the greater the amount of unevenness on the road surface, the greater the lateral acceleration of the vehicle 20, and there is a predetermined correlation between the road surface roughness value and the lateral acceleration. The evaluation unit 112 uses information indicating this correlation (hereinafter referred to as correlation data) to calculate the road surface roughness value corresponding to the vehicle position on the road from the lateral acceleration.

[0027] First, the evaluation unit 112 performs machine learning using previously measured road surface roughness values ​​and lateral acceleration as teacher data, and derives the correlation between the road surface roughness value and the lateral acceleration. FIG. 6A and FIG. 6B are diagrams for explaining the teacher data of the road surface roughness value and the lateral acceleration, respectively. The vehicle V1 shown in FIG. 6A is a dedicated vehicle equipped with a measuring device MA for measuring road surface roughness. The measuring device MA measures the road surface roughness value of the road RD when the vehicle V1 is traveling on a predetermined road (measurement course, etc.) RD. The characteristic P1 in FIG. 6A indicates the road surface roughness value measured at this time, that is, the road surface roughness value used as teacher data.

[0028] Fig. 6B shows a state in which the vehicle 20 in Fig. 1 travels on the same road RD as in Fig. 6A. A characteristic P2 in Fig. 6B shows the lateral acceleration detected by the acceleration sensor 33 provided on the vehicle 20 while the vehicle 20 is traveling on a predetermined road RD, that is, the lateral acceleration used as teacher data.

[0029] The teacher data of the road surface roughness value and the lateral acceleration may be stored in the memory unit 120 of the road surface evaluation device 10, or may be stored in an external storage device. The evaluation unit 112 performs machine learning using the teacher data of the road surface roughness value and the lateral acceleration read from the memory unit 120 or the external storage device, and derives the correlation between the road surface roughness value and the lateral acceleration. Note that the machine learning may be performed by adding the traveling speed, the longitudinal acceleration, and the steering angle as the teacher data.

[0030] The evaluation unit 112 calculates the road surface roughness value of the road to be evaluated based on the correlation between the calculated road surface roughness value and the lateral acceleration, and on the combined travel information corresponding to the road to be evaluated.

[0031] The output unit 113 outputs the roughness information of the road surface evaluated by the evaluation unit 112, that is, the road surface roughness value, in association with the road information acquired by the information acquisition unit 111. The information output at this time is called road surface profile information. FIG. 7 is a diagram showing an example of road surface profile information. The characteristic P10 in the diagram represents the road surface roughness value calculated based on the combined travel information shown in FIG. 5. The horizontal axis represents the position (latitude) in the traveling direction along the travel lane of the vehicle 20, and the vertical axis represents the road surface roughness value. When the output unit 113 receives an output instruction of the road surface profile from a terminal of a road management company or the like via the communication network 2, it outputs the road surface profile information to the terminal that sent the output instruction or the terminal of a predetermined output destination. The output instruction of the road surface profile may be input to the road surface evaluation device 10 via an operation unit (not shown) of the road surface evaluation device 10. The road surface profile information is information that can be displayed on a display device such as a display, and a user (e.g., a road management company) can check the road surface profile by displaying the road surface profile information on a display of the user's terminal.

[0032] Incidentally, when calculating the road surface roughness value based on the driving information of a plurality of vehicles 20 as described above, as the number of vehicles 20 increases, the amount of data of the driving information transmitted to the road surface evaluation device 10 increases, which may strain the bandwidth of the communication network 2. On the other hand, the plurality of vehicles 20 may include vehicles that frequently repeat lane changes, sudden acceleration / deceleration, and sudden steering while driving. If the road surface roughness value is calculated including the driving information of vehicles 20 whose behavior while driving (hereinafter referred to as driving behavior) is unstable in this way, there is a risk that the road surface roughness cannot be evaluated accurately. Therefore, in order to address such a problem, the evaluation unit 112 evaluates the road surface roughness as follows.

[0033] First, the evaluation unit 112 reads out from the memory unit 120 the driving information acquired by the information acquisition unit 111 when the vehicle 20 previously traveled on the road to be evaluated, and calculates the stability of the driving behavior of the vehicle 20 (hereinafter simply referred to as stability) based on the driving information.

[0034] When calculating the stability, the evaluation unit 112 calculates a higher stability for a vehicle 20 having a smaller change in the traveling speed of the vehicle 20 based on the traveling speed information included in the traveling information of the vehicle 20. Note that the evaluation unit 112 may calculate the traveling speed of the vehicle 20 based on the time transition of the position information of the vehicle 20, and use the calculated traveling speed in calculating the stability.

[0035] Furthermore, the evaluation unit 112 determines whether or not the vehicle has changed lanes based on steering angle information included in the travel information of the vehicle 20, and calculates a higher stability for a vehicle that has changed lanes less frequently. The evaluation unit 112 may calculate a steering angle of the vehicle 20 based on a time transition of the position information of the vehicle 20, and use the steering angle to calculate the stability.

[0036] Furthermore, the evaluation unit 112 calculates a higher stability for a vehicle 20 with a smaller number of sudden operations based on the acceleration information of the vehicle 20. More specifically, the evaluation unit 112 generates sudden operation information indicating the presence or absence of a sudden operation of the vehicle 20 based on the acceleration information included in the travel information of the vehicle 20. The sudden operation includes any one of sudden acceleration, sudden deceleration, and sudden steering.

[0037] Furthermore, the evaluation unit 112 calculates the driving time of the vehicle 20 during the congestion occurrence time period based on the congestion information of the specified road and the position information of the vehicle 20, specifically, the driving time included in the position information, and calculates a higher stability for a vehicle with a shorter driving time.

[0038] The evaluation unit 112 selects a vehicle group to be evaluated from among the vehicles 20 whose stability calculated by the evaluation unit 112 is equal to or higher than a predetermined level. When the output unit 113 receives an instruction to output a road surface profile, the evaluation unit 112 reads out the travel information of the vehicle group to be evaluated from the travel information stored in the storage unit 120. The evaluation unit 112 evaluates the roughness of the road surface of the road to be evaluated based on the travel information of the vehicle group. More specifically, the evaluation unit 112 calculates a road surface roughness value based on the lateral acceleration of the vehicle group.

[0039] 8 is a flowchart showing an example of processing executed by the calculation unit 110 (CPU) of the road surface evaluation device 10 according to a predetermined program. The processing shown in this flowchart is repeated at a predetermined cycle when a road to be evaluated is specified by a user. First, in step S11, a command is transmitted to the traveling vehicle 20 via the communication control unit 114 to request the transmission of traveling information. Note that, when traveling information is transmitted periodically or intermittently from the in-vehicle terminal 30 of the vehicle 20, the processing of step S11 may be skipped.

[0040] In step S12, it is determined whether or not the travel information transmitted from the in-vehicle terminal 30 of the vehicle 20 in response to the command in step S11 has been received. If the result in step S12 is negative, the process is terminated. If the result in step S12 is positive, in step S13, the travel information received in step S12 is stored in the storage unit 120 together with the vehicle ID associated with the travel information. In step S14, it is determined whether or not sufficient travel information for calculating the stability has been accumulated in the storage unit 120. Specifically, based on the position information included in the travel information and the vehicle ID associated with the travel information, it is determined whether or not a predetermined number of vehicles 20 or more have traveled on the evaluation target road. If the result in step S14 is negative, the process is terminated. If the result in step S14 is positive, the stability of the travel behavior of each vehicle is calculated based on the travel information of each vehicle 20. In step S16, it is determined whether or not there is a vehicle whose stability is equal to or higher than a predetermined level. If the result in step S16 is positive, in step S17, the vehicle 20 whose stability is equal to or higher than a predetermined level is determined as the evaluation target vehicle. At this time, when there are a plurality of vehicles 20 whose stability is equal to or higher than a predetermined level, each vehicle 20 is determined to be an evaluation target vehicle.

[0041] 9 is a flowchart showing an example of processing executed in accordance with a predetermined program by the calculation unit 110 (CPU) of the road surface evaluation device 10. The processing shown in this flowchart is repeated at a predetermined cycle after the evaluation target vehicle is determined in step S17 in FIG.

[0042] First, in step S21, a command is sent to the vehicle 20 to be evaluated via the communication control unit 114 to request the transmission of travel information. In step S22, it is determined whether or not the travel information transmitted from the in-vehicle terminal 30 of the vehicle 20 to be evaluated in response to the command in step S21 has been received. If the result in step S22 is negative, the process is terminated. If the result in step S22 is positive, in step S23, the travel information received in step S22 is stored in the storage unit 120 together with the vehicle ID associated with the travel information. Note that, if the travel information is transmitted periodically or intermittently from the in-vehicle terminal 30 of the vehicle 20, the process of step S21 may be skipped. In this case, it is determined whether or not the source of the travel information is the vehicle to be evaluated based on the vehicle ID associated with the travel information received in step S22. If the source of the travel information is the vehicle to be evaluated, the travel information is stored in the storage unit 120 together with the vehicle ID.

[0043] In step S24, it is determined whether an instruction to output a road surface profile has been input (received). If the result in step S24 is negative, the process is terminated. If the result in step S24 is positive, in step S25, map information is read from memory unit 120, and road information included in the map information is acquired. In step S26, driving information of vehicle 20 to be evaluated is acquired from memory unit 120. More specifically, of the driving information of vehicle 20 to be evaluated, driving information in which the position of vehicle 20 indicated by the position information included in the driving information is on the road to be evaluated, i.e., driving information corresponding to the road to be evaluated, is read from memory unit 120.

[0044] In step S27, composite travel information is generated based on the travel information read from storage unit 120 in step S26, and the roughness of the road surface is evaluated based on the composite travel information. Next, in step S28, information in which the roughness information (roughness value) of the road surface evaluated in step S27 is associated with the road information acquired in step S25, i.e., road surface profile information, is generated and output.

[0045] According to the embodiment of the present invention, the following advantageous effects can be obtained. (1) The road surface evaluation device 10 includes an information acquisition unit 111 that acquires, as driving information of the multiple vehicles 20, position information of the multiple vehicles 20, acceleration information indicating the acceleration of the multiple vehicles 20, and map information including road information; an evaluation unit 112 that calculates the stability of the driving behavior of each of the multiple vehicles 20 based on the driving information acquired by the information acquisition unit 111 when the multiple vehicles 20 have previously traveled on a predetermined road, selects a group of vehicles to be evaluated from among the vehicles 20 whose stability is equal to or higher than a predetermined level, and evaluates the roughness of the road surface of the predetermined road based on the driving information of the group of vehicles acquired by the information acquisition unit 111; and an output unit 113 that outputs information on the roughness of the road surface evaluated by the evaluation unit 112 in association with the information on the road acquired by the information acquisition unit 111. As a result, even when the number of vehicles 20 increases, it is no longer necessary to acquire driving information from vehicles 20 other than the vehicles to be evaluated, thereby enabling efficient evaluation of the road surface roughness. In addition, the processing load of the device and the load on the communication infrastructure between the device and the vehicles can be reduced.

[0046] (2) The information acquisition unit 111 acquires, as travel information, measured values ​​of the travel speeds of the multiple vehicles 20 transmitted from the multiple vehicles 20. The evaluation unit 112 calculates a higher stability corresponding to a vehicle with a smaller amount of change in travel speed based on the travel speeds of the multiple vehicles 20 calculated from the time transition of the position information of the multiple vehicles 20 or the measured values ​​of the travel speeds of the multiple vehicles 20. This allows the road surface roughness value to be calculated based on the travel information of the vehicles 20 with less fluctuation in travel speed, making it possible to more accurately evaluate the road surface roughness.

[0047] (3) The information acquisition unit 111 acquires lane change information indicating whether or not each of the multiple vehicles 20 has changed lanes as driving information, based on the time transition of the position information of each of the multiple vehicles 20 or the measured values ​​of the steering angle sensors of the multiple vehicles 20. The evaluation unit 112 calculates a higher stability for a vehicle 20 that has changed lanes less frequently, based on the lane change information. This allows the road surface roughness value to be calculated based on the driving information of the vehicles 20 that continue to travel on the same lane, and as a result, even if the road has multiple lanes on one side and the road surface conditions differ for each lane, the road surface roughness of the road can be evaluated with high accuracy.

[0048] (4) The evaluation unit 112 further generates sudden operation information indicating the presence or absence of sudden operations for each of the multiple vehicles 20 based on the acceleration information of each of the multiple vehicles 20 included in the travel information acquired by the information acquisition unit 111. Based on the generated sudden operation information, the evaluation unit 112 calculates a higher stability for a vehicle 20 that has fewer sudden operations. The sudden operation includes any one of sudden acceleration, sudden deceleration, and sudden steering. This allows the road surface roughness value to be calculated based on the travel information transmitted from a vehicle 20 that has fewer sudden operations, making it possible to more accurately evaluate the road surface roughness.

[0049] The above embodiment can be modified in various ways. Modifications will be described below.

[0050] When the road on which the vehicle 20 is traveling is congested, for example, when the traveling speed of the vehicle 20 becomes equal to or lower than a certain speed, the lateral acceleration caused by the unevenness of the road surface may not show the above-mentioned correlation. Therefore, even if the road roughness value is calculated from the lateral acceleration of such a vehicle 20, an accurate road roughness value may not be obtained. Therefore, the evaluation unit 112 may calculate the traveling time of the vehicle 20 in the traffic jam occurrence time zone based on the traffic jam information of the predetermined road and the position information of the vehicle 20, specifically, the traveling time included in the position information, and may calculate a higher stability for a vehicle with a shorter traveling time. In this case, the information acquisition unit 111 as a traffic jam information acquisition unit acquires traffic jam information indicating the traffic jam occurrence time zone on the predetermined road from an external information distribution server (not shown) that distributes road traffic information via the communication control unit 114. In addition, the information acquisition unit 111 as a traveling information acquisition unit acquires traveling time information included in the position information of each of the multiple vehicles 20. Note that the traveling information acquisition unit may acquire information indicating the acquisition time of each of the multiple vehicles 20 as the traveling time information. The evaluation unit 112 calculates the driving time of each of the vehicles 20 during the traffic jam time period based on the traffic congestion information and the driving time information, and calculates a higher stability for the vehicle 20 with a shorter driving time. By determining the vehicle to be evaluated based on the stability calculated in this manner, the road surface roughness can be evaluated with even greater accuracy.

[0051] In the above embodiment, the evaluation unit 112 as a calculation unit calculates the stability to be high based on the driving information of the vehicle 20, and determines the vehicle 20 whose stability is equal to or higher than a predetermined level as the vehicle to be evaluated. However, when there are a certain number or more of vehicles 20 whose stability is equal to or higher than a certain level, the vehicle with a higher stability may be preferentially determined as the vehicle to be evaluated so that the number of vehicles to be evaluated does not exceed the certain number.

[0052] Also, in the above embodiment, the evaluation unit 112 as a generation unit generates the sudden operation information indicating the presence or absence of a sudden operation of the vehicle 20, based on the acceleration information included in the traveling information of the vehicle 20. However, the generation unit may generate the sudden operation information based on the traveling speed information or the steering angle information included in the traveling information of the vehicle 20, in addition to or instead of the acceleration information.

[0053] In the above embodiment, a command (hereinafter, referred to as a transmission request command) for requesting the vehicle 20 to transmit the driving information is sent in the process of FIG. 8 and FIG. 9 (S11, S21). However, a command (hereinafter, referred to as a driving request command) for requesting driving on the evaluation target road may be sent to the vehicle 20 together with the transmission request command. The driving request command includes information for identifying the evaluation target road, and the vehicle 20 (the in-vehicle terminal 30) that receives the driving request command outputs information (display information or audio information) that prompts the occupant of the vehicle 20 to drive on the evaluation target road based on the information to a display (not shown) or a speaker (not shown) provided in the vehicle cabin. Also, an incentive (reward) may be given to the occupant of the vehicle 20 that has driven on the evaluation target road in response to the driving request command. The incentive is, for example, a coupon that can be used as part of the price when the user purchases a product or receives the provision of a service at a store or the like. Also, a higher incentive may be given to the vehicle 20 that has driven on the evaluation target road in response to the driving request command, the more stable the vehicle's driving behavior is. Furthermore, the driving request command may include information requesting the occupant of the vehicle 20 to upload construction information. For example, the occupant of the vehicle 20 who recognizes a road construction section while the vehicle 20 is driving on the road to be evaluated may perform a predetermined operation on an operation unit (not shown) provided in the vehicle cabin, thereby uploading information indicating the road construction section to the road surface evaluation device 10. In this case, when the in-vehicle terminal 30 (the calculation unit 310) detects the predetermined operation, it transmits information indicating that the current driving position of the vehicle 20 is a road construction section to the road surface evaluation device 10 as part of the driving information. An incentive may further be given to the occupant who uploads the construction information.

[0054] In the above embodiment, the information acquisition unit 111 as a travel information acquisition unit receives travel information transmitted from the in-vehicle terminal 30 of the vehicle 20 and stores the received travel information in the storage unit 120. However, the travel information transmitted from the in-vehicle terminal 30 of the vehicle 20 may be stored in an external storage device. For example, the travel information transmitted from the in-vehicle terminal 30 of the vehicle 20 may be transmitted to an external server (not shown) having a storage function and stored in a storage device (not shown) of the external server. In this way, the external server may function as a travel information acquisition unit, and the evaluation unit 112 may read out the travel information of a plurality of vehicles 20 acquired within a predetermined period by the external server as a travel information acquisition unit from the storage device and use it for evaluating the road surface roughness.

[0055] Also, in the above embodiment, the output unit 113 is configured to output the road surface profile information to the user's terminal, but the output unit may output the road surface profile information to the storage unit 120 so that the road surface profile information is mapped to the map information stored in the storage unit 120. In other words, the output unit may have any configuration as long as it outputs the road surface profile information.

[0056] In the above embodiment, the information acquisition unit 111 as a map information acquisition unit acquires map information including information on roads on which the vehicle 20 travels from the storage unit 120. However, the map information acquisition unit may acquire map information including information on roads on which the vehicle 20 travels from an external server device or the like.

[0057] Furthermore, in the above embodiment, an example was shown in which the road surface roughness value was expressed by the IRI, but the road surface roughness value may be expressed by another index. For example, when the road surface roughness value acquired as the teacher data is expressed by an index other than the IRI, the evaluation unit 112 may calculate the road surface roughness value expressed by that index.

[0058] The above description is merely an example, and the present invention is not limited to the above-mentioned embodiment and modifications, as long as the features of the present invention are not impaired. One or more of the above-mentioned embodiment and modifications can be arbitrarily combined, and modifications can also be combined with each other. [Explanation of symbols]

[0059] 10 Road surface evaluation device, 20, 20-1 to 20-n Vehicles, 30 Vehicle-mounted terminal, 110 Calculation unit, 111 Information acquisition unit, 112 Evaluation unit, 113 Output unit, 120 Storage unit

Claims

1. A travel information acquisition unit that acquires, as travel information of a plurality of vehicles, position information of the plurality of vehicles and acceleration information indicating accelerations of the plurality of vehicles; a map information acquisition unit for acquiring map information including information on a predetermined road; a calculation unit that calculates a stability of a driving behavior of each of the plurality of vehicles based on the driving information acquired by the driving information acquisition unit when the plurality of vehicles have previously traveled on the predetermined road; an evaluation unit that selects a group of vehicles to be evaluated from among the vehicles whose stability calculated by the calculation unit is equal to or higher than a predetermined level, and evaluates the roughness of the road surface of the predetermined road based on the traveling information of the group of vehicles acquired by the traveling information acquisition unit; and an output unit that outputs information regarding the roughness of the road surface evaluated by the evaluation unit in correspondence with information regarding the specified road acquired by the map information acquisition unit.

2. The road surface evaluation device according to claim 1, The travel information acquisition unit acquires, as the travel information, measured values ​​of the travel speeds of the plurality of vehicles transmitted from the plurality of vehicles; The road surface evaluation device is characterized in that the calculation unit calculates the stability corresponding to a vehicle to be higher for a vehicle with a smaller change in driving speed based on the driving speed of the multiple vehicles calculated from the temporal progression of the position information of the multiple vehicles, or based on the measured values ​​of the driving speed of the multiple vehicles.

3. The road surface evaluation device according to claim 1, the travel information acquisition unit acquires, as the travel information, lane change information indicating whether or not each of the plurality of vehicles has changed lanes based on a time transition of the position information of each of the plurality of vehicles or measurement values ​​of steering angle sensors of the plurality of vehicles; The road surface evaluation device is characterized in that the calculation unit calculates the stability to be higher for a vehicle that changes lanes less frequently based on the lane change information.

4. The road surface evaluation device according to claim 1, A generating unit that generates sudden operation information indicating the presence or absence of a sudden operation of each of the plurality of vehicles based on the acceleration information of each of the plurality of vehicles included in the traveling information acquired by the traveling information acquiring unit, The calculation unit calculates the stability to be higher for a vehicle having a smaller number of abrupt operations based on the abrupt operation information generated by the generation unit, The road surface evaluation device, wherein the sudden operation includes any one of sudden acceleration, sudden deceleration, and sudden steering.

5. The road surface evaluation device according to claim 1, A traffic congestion information acquisition unit that acquires traffic congestion information indicating a traffic congestion time period on the predetermined road, The position information of the plurality of vehicles includes positions of the plurality of vehicles and times when the plurality of vehicles traveled through the positions, the travel information acquisition unit acquires, as travel time information, the time included in the position information of each of the plurality of vehicles or an acquisition time of the travel information of each of the plurality of vehicles; The road surface evaluation device is characterized in that the calculation unit calculates the driving time of each of the multiple vehicles during the congestion occurrence time period based on the congestion information and the driving time information, and calculates the stability to be higher for vehicles with shorter driving times.

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