Road surface condition information providing system

Abstract

To provide a road surface state information provision system capable of providing road deterioration information by acquiring the same in an early stage.SOLUTION: A road surface state information provision system measures a motor current value of an electrically-driven power steering device EPS with a current sensor 34. If an increased amount from a reference motor current value corresponding to a tire rudder angle exceeds a predetermined increment threshold value, it is determined that there are ruts, and traveling information obtained by associating the determination information with information on a position of a self vehicle is transmitted to a data center DS. In the data center DS, deterioration indices of the road surfaces are produced for each position on road surfaces based on traveling information collected from a plurality of general vehicles V, V,... and road surface deterioration estimated information obtained by associating information on the deterioration indices with position information on a surface corresponding to the information is transmitted to an administrator terminal device ATE. A road administrator visually checks images displayed on the administrator terminal device ATE to determine whether or not repair at each of positions of the road surfaces is necessary.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a road surface condition information providing system. In particular, the present invention relates to an improvement for providing early information on the deterioration of a road surface.

Background Art

[0002] Conventionally, as a system for detecting the condition of a road surface, a system disclosed in Patent Document 1 is known. The system disclosed in this Patent Document 1 detects road surface conditions such as deterioration of the road surface while patrolling a patrol vehicle equipped with a camera, a G-sensor, a microphone, and a GPS unit.

[0003] Specifically, an abnormality in the paving of the road surface is detected from the road surface in a road image photographed by a camera. Also, an abnormality in the paving of the road surface is detected from the acceleration measured during driving by a G-sensor. Also, an abnormality in the paving of the road surface is detected from voice data recorded during driving on the road surface by a microphone. Then, the position where an abnormality in the paving is detected by any one or two of the detection information of the road image, acceleration, and voice data is specified, and an instruction for reinspection of this specified position is output.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since the system disclosed in Patent Document 1 identifies an abnormality by re-investigating the location where an abnormality (deterioration to the extent that repair is required) is detected after conducting a simple investigation with a patrolling vehicle, it is difficult to repeatedly perform a road surface condition detection operation (an operation to detect the degree of deterioration of the road surface) on the same road within a relatively short period of time, and there was a possibility that a delay would occur in the timing of obtaining information that there is an abnormality (pavement abnormality) on the road surface. That is, there was a possibility that a delay would occur in the timing of road repair. For this reason, the state in which an abnormality has occurred on the road surface could be left unattended for a long period of time, and there was a possibility of causing problems such as adversely affecting the ride comfort of vehicles traveling on the road surface during that period.

[0006] The present invention has been made in view of such points, and an object thereof is to realize a road surface condition information providing system capable of early obtaining and providing information on deterioration of the road surface.

Means for Solving the Problems

[0007] The solution means of the present invention for achieving the above object is premised on a road surface condition information providing system that provides information on the deterioration state of a road surface. And this road surface condition information providing system is configured to include a plurality of ordinary vehicles and an information aggregation device capable of communicating with the plurality of ordinary vehicles. Each of the ordinary vehicles includes a position detection means for detecting its own vehicle position, a measurement means for measuring the value of a parameter that changes due to a change in the contact state between the steering wheel and the road surface, and a travel information transmission unit that transmits travel information in which the information on the own vehicle position detected by the position detection means is associated with the information on the value of the parameter measured by the measurement means at the own vehicle position or road surface deterioration determination information based on the value of the parameter. Further, the information aggregation device includes an information reception unit that receives the travel information transmitted from the travel information transmission unit of each of the ordinary vehicles, a deterioration index creation unit that creates a deterioration index of the road surface state for each position of the road surface based on the plurality of travel information received by the information reception unit, a road surface deterioration estimation information creation unit that creates road surface deterioration estimation information in which the information on the deterioration index created by the deterioration index creation unit is associated with the position information of the road surface corresponding to the information, and a road surface deterioration estimation information providing unit that provides the road surface deterioration estimation information. and the parameter that changes due to the change in the contact state between the steering wheel and the road surface is the current value of the electric assist motor provided in the electric power steering device, and the measuring means is a current sensor that measures the current value It is characterized by this.

[0008] The ordinary vehicle referred to here is a vehicle different from the above-described patrol vehicle specialized in detecting the deterioration state of a road surface, and is a vehicle in which a general user is riding (for example, traveling toward a specific destination).

[0009] Due to the above-mentioned specific matters, if the road surface is deteriorated (for example, if there are ruts), when a general vehicle passes over the road surface (for example, when the steering wheel enters the rut), the value of a parameter (a parameter that changes due to the change in the contact state between the steering wheel and the road surface) changes due to the change in the contact state between the steering wheel of the vehicle and the road surface, and this is measured by the measuring means. Also, since a general vehicle detects its own vehicle position by the position detecting means, driving information (or driving information associating the information of the own vehicle position with the information of the value of the parameter measured at the own vehicle position or the road surface deterioration determination information based on the value of the parameter measured at the own vehicle position) is transmitted by the driving information transmitting unit to the information aggregating device. In the information aggregating device, a plurality of pieces of driving information are received by the information receiving unit, and based on these pieces of driving information, the deterioration index creating unit creates a deterioration index of the road surface state for each position of the road surface. Then, road surface deterioration estimation information associating the information of the deterioration index with the position information of the road surface corresponding to the information is created by the road surface deterioration estimation information creating unit. And this road surface deterioration estimation information will be provided by the road surface deterioration estimation information providing unit (for example, provided to a road manager or a road repair determination unit that determines the necessity of road repair (repair of the road surface) by receiving the road surface deterioration estimation information). By receiving the provision of this road surface deterioration estimation information, it is possible to easily determine the necessity of road repair. In this way, since the road surface deterioration estimation information created based on the driving information transmitted from each of a plurality of general vehicles is provided, compared with detecting the state of the road surface by patrolling with a dedicated patrol vehicle, it becomes possible to provide information on the deterioration of the road surface earlier. As a result, it is suppressed that a delay occurs in the timing until information on the occurrence of an abnormality on the road surface is obtained, and a delay in the timing of road repair can be avoided. Also, when the steering wheel is forcibly steered (turned) due to the influence of ruts (in the case of a situation where the steering wheel is grabbed, for example), the driver applies a steering force (holding force) to the steering wheel that counteracts the steering force of this forced steering. Therefore, in an electric power steering device, the electric assist motor operates so that the assist force of this holding force is generated, and the current value (motor current value) temporarily increases. And the greater the depth of the rut, the greater the holding force required, and accordingly the motor current value also increases. That is, there is a correlation between the depth of the rut and the motor current value. Therefore, by using the current value of the electric assist motor as the parameter and measuring the current value with a current sensor, driving information corresponding to the depth of the rut can be obtained, and an index of the deterioration of the road surface condition can be obtained with high accuracy.

[0010] In addition, when the value of the parameter exceeds a predetermined threshold value, driving information associating the information on the position of the host vehicle at which the value of the parameter was acquired with road surface deterioration determination information based on the value of the parameter is transmitted from the driving information transmission unit.

[0011] As a result, when the value of the parameter exceeds a predetermined threshold value due to the progress of road surface deterioration, the driving information is transmitted from the driving information transmission unit to the information aggregation device. Therefore, only useful information can be narrowed down as the information transmitted to the information aggregation device, and the high efficiency of information utilization and the reduction of the load on the information aggregation device can be achieved.

[0012] In addition, when the amount of change per unit time of the value of the parameter exceeds a predetermined threshold value, driving information associating the information on the position of the host vehicle at which the change amount exceeds the predetermined threshold value with road surface deterioration determination information based on the change amount is transmitted from the driving information transmission unit.

[0013] As a result, when the amount of change per unit time of the value of the parameter exceeds a predetermined threshold value due to a large change in the contact state between the steering wheel and the road surface, the driving information is transmitted from the driving information transmission unit to the information aggregation device. Therefore, also in this case, the high efficiency of information utilization and the reduction of the load on the information aggregation device can be achieved.

[0021] Another solution means of the present invention for achieving the above object is premised on a road surface condition information providing system that provides information on the deterioration state of the road surface. And this road surface condition information providing system is configured to include a plurality of general vehicles and an information aggregating device that can communicate with the plurality of general vehicles. Each of the general vehicles includes a position detecting means for detecting its own vehicle position, a measuring means for measuring the value of a parameter that changes due to a change in the contact state between the steering wheel and the road surface, and the information on the own vehicle position detected by the position detecting means and the value of the parameter measured by the measuring means at the own vehicle position or road surface deterioration determination information based on the value of the parameter. And it is provided with a running information transmitting unit that transmits running information in which they are associated. Further, the information aggregating device includes an information receiving unit that receives the running information transmitted from the running information transmitting unit of each of the general vehicles, a deterioration index creating unit that creates a deterioration index of the road surface state for each position of the road surface based on the plurality of pieces of running information received by the information receiving unit, a road surface deterioration estimation information creating unit that creates road surface deterioration estimation information in which the information on the deterioration index created by the deterioration index creating unit is associated with the position information of the road surface corresponding to the information, and a road surface deterioration estimation information providing unit that provides the road surface deterioration estimation information. The parameter that changes due to a change in the contact state between the steering wheel and the road surface is by the rotation angle of the electric assist motor provided in the electric power steering device there is The measuring means is a motor rotation angle sensor that measures the rotation angle. characterized by the following.

[0022] When the steering wheel is forced to steer due to the influence of ruts, the rotor of the electric assist motor will also be forced to rotate. And the greater the depth of the rut, the greater the rotation angle of the electric assist motor (the rotation angle forced to rotate). That is, there is a correlation between the depth of the rut and the rotation angle of the electric assist motor. Therefore, by using the rotation angle of the electric assist motor as the parameter and measuring this rotation angle with a motor rotation angle sensor, driving information corresponding to the depth of the rut can be obtained.

[0029] Another solution means of the present invention for achieving the above object is premised on a road surface condition information providing system that provides information on the deterioration state of a road surface. And this road surface condition information providing system is configured to include a plurality of general vehicles and an information aggregating device capable of communicating with the plurality of general vehicles. Each of the general vehicles includes a position detecting means for detecting its own vehicle position, a measuring means for measuring the value of a parameter that changes due to a change in the contact state between the steering wheel and the road surface, and a running information transmitting unit that transmits running information associating the information on the own vehicle position detected by the position detecting means with the information on the value of the parameter measured by the measuring means at the own vehicle position or road surface deterioration determination information based on the value of the parameter. Further, the information aggregating device includes an information receiving unit that receives the running information transmitted from the running information transmitting unit of each of the general vehicles, a deterioration index creating unit that creates a deterioration index of the road surface condition for each position of the road surface based on the plurality of pieces of running information received by the information receiving unit, a road surface deterioration estimation information creating unit that creates road surface deterioration estimation information associating the information on the deterioration index created by the deterioration index creating unit with the position information of the road surface corresponding to the information, and a road surface deterioration estimation information providing unit that provides the road surface deterioration estimation information. The parameter that changes due to a change in the contact state between the steering wheel and the road surface is The difference in the steering angles of each of the left and right steering wheels when each of the left and right steering wheels can be independently steered such that The measuring means is a steering angle sensor that measures the steering angles of each of the left and right steering wheels. it is characterized by.

[0030] When one steering wheel is forced to steer due to the influence of ruts, the steering angle of that steering wheel increases, resulting in a difference in the steering angles of the left and right steering wheels, and this difference increases as the depth of the rut increases. That is, there is a correlation between the depth of the rut and the difference in the steering angles of each steering wheel. Therefore, by using the difference in the steering angles of each steering wheel as the parameter and measuring this difference in steering angle with a steering angle sensor, driving information corresponding to the depth of the rut can be obtained.

[0031] In addition, the road surface deterioration estimation information providing unit transmits the road surface deterioration estimation information to a terminal device monitored by a road administrator.

[0032] As a result, the road administrator will receive the provision of road surface deterioration estimation information via the terminal device, and can easily determine the necessity of road repair.

[0033] In addition, the road surface deterioration estimation information providing unit transmits the road surface deterioration estimation information to a road repair determination unit that determines the necessity of road repair by machine learning through comparison between the provided road surface deterioration estimation information and teacher information of the pre-stored road surface deterioration estimation information.

[0034] According to this, it is possible to automatically determine the necessity of road repair by machine learning, reduce the burden on road administrators, and avoid a situation where the road surface deteriorates (a state where repair is necessary) due to an incorrect judgment by the road administrator and is left unattended for a long time.

Effects of the Invention

[0035] In the present invention, a deterioration index of the road surface state is created for each position of the road surface based on the driving information collected from a plurality of ordinary vehicles, and road surface deterioration estimation information is provided by associating the information of this deterioration index with the position information of the road surface corresponding to the information. For this reason, compared with a system that detects the state of the road surface by driving a dedicated patrol vehicle, it becomes possible to provide information on the deterioration of the road surface earlier. As a result, it is possible to suppress a delay in the timing until information on the occurrence of an abnormality on the road surface is obtained, and avoid a delay in the timing of road repair.

Brief Description of the Drawings

[0036]

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Embodiments for Carrying Out the Invention

[0037] Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment will be described by taking as an example the case where the road surface state information providing system according to the present invention is constructed using a rack assist type electric power steering device.

[0038] - Schematic Configuration of Road Surface State Information Providing System - FIG. 1 is a diagram showing a schematic configuration of a road surface condition information providing system 1 according to the present embodiment. As shown in this FIG. 1, the road surface condition information providing system 1 includes an electric power steering device EPS mounted on each of a plurality of vehicles V, V,... a data center (information aggregation device) DS, and an administrator terminal device ATE. The data center DS and the administrator terminal device ATE are installed, for example, in a road management organization (such as a construction bureau of a local government or a road repair contractor). And a configuration is adopted in which communication can be performed between these electric power steering devices EPS, the data center DS, and the administrator terminal device ATE using a predetermined communication network CN.

[0039] As a communication form between these electric power steering devices EPS, the data center DS, and the administrator terminal device ATE, a form of performing two-way communication through a mobile phone network having a large number of base stations, the Internet, a dedicated communication network, or the like is adopted. Note that the communication form between the electric power steering device EPS and the data center DS is a form of performing two-way communication through a mobile phone network, the Internet, a dedicated communication network, or the like. On the other hand, the communication form between the data center DS and the administrator terminal device ATE may be a form of performing two-way communication through a dedicated communication line.

[0040] Hereinafter, the electric power steering device EPS, the data center DS, and the administrator terminal device ATE will be described.

[0041] (Electric Power Steering Device) The electric power steering device EPS mounted on each vehicle V, V,... will be described. In FIG. 1, the configuration of the part related to the road surface condition information providing system 1 is shown, representing the electric power steering device EPS mounted on one vehicle V.

[0042] As shown in FIG. 1, an electric power steering apparatus EPS includes a steering mechanism (steering device) 10 for steering a left front wheel T1 (hereinafter, also referred to as a left tire in some cases), which is a steering wheel (also called a steered wheel), and a right front wheel T2 (hereinafter, also referred to as a right tire in some cases).

[0043] The steering mechanism 10 has a steering wheel 11, a steering shaft 12 connected to the steering wheel 11, and a rack bar 14.

[0044] The steering mechanism 10 converts the rotation around the axis of the steering shaft 12 interlocked with the rotation operation of the steering wheel 11 into the left - right direction stroke motion (linear motion) of the rack bar 14 by a rack - and - pinion mechanism 13. Due to the stroke motion of the rack bar 14, the left front wheel T1 and the right front wheel T2, which are the steered wheels, are steered.

[0045] The steering shaft 12 includes a main shaft 12a connecting the steering wheel 11 at the upper end, a pinion shaft 12c connected to the rack - and - pinion mechanism 13, and an intermediate shaft 12b connecting the main shaft 12a and the pinion shaft 12c via universal joints 12d, 12e.

[0046] The rack bar 14 is provided with a gear portion 14a formed near the center of the rack bar 14. The central portion of the rack bar 14 is housed in the rack housing 15. Both the left and right ends of the rack bar 14 protrude from the rack housing 15 and are connected to one end of each of the left and right tie rods 16. The other end of each of the left and right tie rods 16 is connected to a knuckle 17 provided on the left front wheel T1 and the right front wheel T2, respectively. A rack end member 18 is provided at the connection portion between the rack bar 14 and the tie rod 16. On the other hand, stopper portions 15a are formed at both ends of the rack housing 15. When the rack bar 14 strokes axially by a predetermined amount or more, the rack end member 18 and the stopper portion 15a come into contact with each other. As a result, the stroke range of the rack bar 14 is restricted.

[0047] The electric assist motor 21, which is the power source of the electric power steering apparatus EPS, is constituted by a three-phase synchronous permanent magnet motor (three-phase brushless motor). The electric assist motors 21 each include a rotor (not shown) and a stator fixed in a housing supported by the vehicle body and facing the rotor. A rotating shaft (not shown) that rotates integrally with the rotor can transmit power to the rack bar 14 via a reduction gear 19.

[0048] The steering ECU 20 that constitutes the control system of the electric power steering apparatus EPS includes, for example, a processor such as a CPU (Central Processing Unit), a ROM (Read-Only Memory) that stores a control program, a RAM (Random-Access Memory) that temporarily stores data, and input / output ports and the like.

[0049] A motor rotation angle sensor 22, a steering force sensor 23, a steering angle sensor 24, a wheel speed sensor 25, a current sensor (measurement means) 34, a G sensor 26, and a GPS module (position detection means) 27 are connected to the steering ECU 20 by signal lines.

[0050] The motor rotation angle sensor 22 is incorporated inside the electric assist motor 21 and outputs a signal representing the rotation angle of the rotor of the electric assist motor 21. This motor rotation angle sensor 22 is constituted by, for example, a resolver or a Hall sensor. Incidentally, the angular velocity and the rotational speed of the electric assist motor 21 are acquired from the signal representing the rotation angle. In addition, the electrical angle of the electric assist motor 21 is acquired from the signal representing the rotation angle.

[0051] The steering force sensor 23 is provided on the steering shaft 12 (main shaft 12a). The steering force sensor 23 detects the torsional force input to a torsion bar (not shown) interposed in the steering shaft 12 as the steering force.

[0052] The steering angle sensor 24 detects the steering angle of the steering wheel 11 and outputs a signal representing the steering angle.

[0053] The wheel speed sensor 25 detects the rotational speeds of the respective wheels T1, T2 and outputs signals representing these rotational speeds.

[0054] The current sensor 34 detects the value of the current flowing through the coil of the electric assist motor 21 (hereinafter referred to as the motor current value) and outputs a signal representing the motor current value (a parameter that changes due to a change in the contact state between the steered wheel and the road surface in the present invention).

[0055] Here, the change in the motor current value will be described. FIG. 2 is a diagram showing an example of the relationship between the tire steering angle and the motor current value. This FIG. 2 shows an example of the relationship between the tire steering angle (for example, the tire steering angle resulting from the driver rotating the steering wheel 11) and the motor current value in a relatively small range. The thin line in this FIG. 2 shows the relationship between the tire steering angle and the motor current value when the vehicle V is traveling on a flat road (a road surface without ruts or the like). In this case, as the tire steering angle increases (such as when traveling on a winding road and as the curvature of the road increases), the motor current value gradually increases so as to obtain a larger assist force (the assist force against the steering force) by the electric assist motor 21.

[0056] On the other hand, when the vehicle V is traveling on a road surface with ruts or the like (a deteriorated road surface), when the tire (steering wheel) enters the rut from the flat road, when the tire contacts the inclined surface inside the rut, or when the tire exits the rut to the flat road, a situation occurs where the tire is forcibly steered (turned) due to the influence of the rut (the so-called situation where the steering wheel is taken). At this time, the driver (for example, a driver trying to maintain straight-ahead driving) applies a steering force (hereinafter sometimes referred to as a steering holding force) to the steering wheel 11 to counteract the steering force of this forced steering. That is, steering is performed in the direction opposite to the forced steering direction. For this reason, the electric assist motor 21 operates so that an assist force for this steering holding force in the opposite direction is generated. That is, the motor current value temporarily increases so that this assist force is generated. The thick line in FIG. 2 shows an example of the change in the motor current value accompanying the generation of this assist force. In such a situation, a change in the motor current value different from the normal motor current value corresponding to the tire steering angle (the motor current value shown by the thin line in FIG. 2) appears. That is, when such a change in the motor current value appears, it can be determined that there are ruts on the road surface.

[0057] FIG. 3 is a diagram showing a state where the tire T has entered the rut WT. FIG. 4 is a diagram showing an example of the relationship between the depth of the rut WT and the motor current value. FIG. 3 shows a plurality of ruts WT with different depths, and the depth increases in the order of the solid line, the broken line, and the one-dot chain line. And, as the relationship between the depth of this rut WT and the motor current value, as shown in FIG. 4, the greater the depth of the rut WT, the greater the change in the motor current value. Also in this FIG. 4, the depth increases in the order of the solid line, the broken line, and the one-dot chain line. This is due to the fact that the greater the depth of the rut WT, the closer the inclination angle of the inclined surface inside the rut WT approaches the vertical direction. That is, the closer the inclination angle of the inclined surface inside the rut WT is to the vertical direction, the greater the steering force that is forcibly steered when the tire T is in contact with this inclined surface, and therefore, the greater the holding force that the driver applies to the steering wheel 11 in opposition to it. As a result, the greater the depth of the rut WT, the greater the change in the motor current value.

[0058] The G sensor 26 detects the vertical acceleration and the lateral acceleration generated in the vehicle and outputs the acceleration signal. Also, the sensor for detecting the behavior of the vehicle V is not limited to this, and may include a G sensor for detecting the longitudinal acceleration or a yaw rate sensor for detecting the yaw rate.

[0059] The GPS module 27 measures the position of the host vehicle by receiving a signal from a GPS satellite and outputs the host vehicle position information, which is the measurement result.

[0060] The steering ECU 20 is connected to the motor drive circuit 30 and sends a command signal to the motor drive circuit 30. The motor drive circuit 30 has a well-known configuration for performing well-known motor vector control. The motor drive circuit 30 drives the electric assist motor 21 with the electric power supplied from the in-vehicle power supply 33 based on the command signal from the steering ECU 20.

[0061] In addition, the steering ECU 20 includes an information receiving unit 28, a rut determination unit 29, and a driving information transmitting unit 20A as functional units realized by the control program. Hereinafter, an outline of the functions of these units will be described.

[0062] The information receiving unit 28 is capable of receiving information on the motor current value (the current value flowing through the coil of the electric assist motor 21) detected by the current sensor 34 and information on the position of the host vehicle measured by the GPS module 27.

[0063] The rut determination unit 29 is a functional unit that determines whether or not there is a rut WT on the road surface based on the motor current value. In the rut determination unit 29 according to the present embodiment, when the motor current value exceeds a predetermined threshold value, it is determined that there is a rut WT (the rut determination flag is turned on).

[0064] Hereinafter, the relationship between the road surface contact state of the tires during the running of the vehicle V, the forced steering force generated in the tires accordingly (the steering force generated due to the reaction force from the road surface), and the motor current value for generating the assist force of the holding steering force will be described for a plurality of patterns.

[0065] First, FIG. 5 shows the road surface contact states of the tires T1 and T2 when the vehicle V travels from the front side to the back side of the paper surface. FIG. 5(a) is a diagram showing a running state in which the left and right tires T1 and T2 enter the central portion of the rut WT, and FIG. 5(b) is a diagram showing a running state in which the left and right tires T1 and T2 are in contact with the outside of the rut WT.

[0066] In the cases shown in these figures, the tires T1 and T2 are not affected by the rut WT, and no forced steering force is generated. Therefore, no holding steering force is generated. As a result, in these cases, as shown in FIG. 6, the motor current value remains zero. In FIG. 6, the upward direction of the vertical axis represents the magnitude of the assist force for steering to the right side, and the downward direction of the vertical axis represents the magnitude of the assist force for steering to the left side.

[0067] FIG. 7 shows the road surface contact state of the tires when the vehicle V travels from the front side to the back side of the paper surface. FIG. 7(a) is a diagram showing a running state in which the left tire (left front wheel) T1 enters the central portion of the rut WT and the inner portion of the right tire (right front wheel) T2 contacts the inclined surface of the rut WT. FIG. 7(b) is a diagram showing a running state in which the outer portion of the left tire T1 and the inner portion of the right tire T2 each contact the inclined surface of the rut WT. FIG. 7(c) is a diagram showing a running state in which the outer portion of the left tire T1 contacts the inclined surface of the rut WT and the right tire T2 contacts the outside of the rut WT. FIG. 7(d) is a diagram showing a running state in which the left tire T1 enters the central portion of the rut WT and the right tire T2 contacts the outside of the rut WT.

[0068] In the states shown in FIGS. 7(a) to 7(c), since a forced steering force is generated in the direction in which at least one tire climbs the inclined surface of the rut WT, a forced steering force to the left is generated. Also, in the state shown in FIG. 7(d), since the height position of the left tire T1 is lower by the depth of the rut WT than the height position of the right tire T2, a forced steering force to the left is also generated in this case.

[0069] In the cases shown in these figures, the tires T1 and T2 are affected by the rut WT, and a forced steering force to the left is generated. The driver will turn the corrective steering wheel so as to apply a steering force to the right to counteract this forced steering force. Therefore, a motor current will be generated to generate an assist force for this steering force to the right (assist force to the right). As a result, in these cases, as shown in FIG. 8, the motor current value will change. Also, particularly in the state shown in FIG. 7(d), since a forced steering force is continuously generated during the period when the left tire T1 enters the central portion of the rut WT, a steering force to the right is also continuously generated, and an assist force for the steering force is also continuously generated. As shown in FIG. 9, the motor current value will change.

[0070] Further, FIG. 10 shows the road surface contact state of the tires when the vehicle V travels from the front side to the back side of the paper surface. FIG. 10(a) is a diagram showing a running state in which the inner part of the left tire T1 contacts the inclined surface of the rut WT and the right tire T2 enters the central part of the rut WT. FIG. 10(b) is a diagram showing a running state in which the inner part of the left tire T1 and the outer part of the right tire T2 each contact the inclined surface of the rut WT. FIG. 10(c) is a diagram showing a running state in which the left tire T1 contacts the outside of the rut WT and the outer part of the right tire T2 contacts the inclined surface of the rut WT. FIG. 10(d) is a diagram showing a running state in which the left tire T1 contacts the outside of the rut WT and the right tire T2 enters the central part of the rut WT.

[0071] Even in the states shown in FIGS. 10(a) to 10(c), since a forced steering force is generated in the direction in which at least one tire climbs up the inclined surface of the rut WT, contrary to the states shown in FIGS. 7(a) to 7(c) described above, a forced steering force to the right is generated. Further, in the state shown in FIG. 10(d), since the height position of the right tire T2 is lower by the depth of the rut WT than the height position of the left tire T1, a forced steering force to the right is also generated in this case.

[0072] In the cases shown in these figures, the tires T1 and T2 are affected by the rut WT, and a forced steering force to the right is generated. The driver will turn the corrective steering wheel so as to apply a steering force to the left to counteract this forced steering force. Therefore, a motor current will be generated to generate an assist force for this steering force to the left (assist force to the left). As a result, in these cases, as shown in FIG. 11, the motor current value will change. In particular, in the state shown in FIG. 10(d), since a forced steering force is continuously generated during the period when the right tire T2 enters the central part of the rut WT, a steering force to the left is also continuously generated, and an assist force for the steering force is also continuously generated. As shown in FIG. 12, the motor current value will change.

[0073] Furthermore, FIG. 13 shows the road surface contact states of the tires T1 and T2 when the vehicle V travels from the front side to the back side of the paper surface. FIG. 13(a) is a diagram showing a traveling state in which the inner part of the left tire T1 and the inner part of the right tire T2 are in contact with the inclined surface of the rut WT. FIG. 13(b) is a diagram showing a traveling state in which the outer part of the left tire T1 and the outer part of the right tire T2 are in contact with the inclined surface of the rut WT. FIG. 13(c) is a diagram showing a traveling state in which the inner part of the left tire T1 is in contact with the inclined surface of the rut WT and the right tire T2 is grounded on the outside of the rut WT. FIG. 13(d) is a diagram showing a traveling state in which the left tire T1 is grounded on the outside of the rut WT and the inner part of the right tire T2 is in contact with the inclined surface of the rut WT.

[0074] Even in the states shown in FIGS. 13(a) to 13(d), a forced steering force is generated in the direction in which the tire climbs up the inclined surface of the rut WT. However, in the situation shown in FIG. 13(a), a forced steering force to the right is generated in the left tire T1, while a forced steering force to the left is generated in the right tire T2. In the situation shown in FIG. 13(b), a forced steering force to the left is generated in the left tire T1, while a forced steering force to the right is generated in the right tire T2. In the situation shown in FIG. 13(c), a forced steering force to the right is generated in the left tire T1. However, since the height position of the left tire T1 is lower by the depth of the rut WT than the height position of the right tire T2, a forced steering force to the left is generated. In the situation shown in FIG. 13(d), a forced steering force to the left is generated in the right tire T2. However, since the height position of the right tire T2 is lower by the depth of the rut WT than the height position of the left tire T1, a forced steering force to the right is generated. That is, in the states shown in FIGS. 13(a) to 13(d), the forced steering force is an unstable situation, and accordingly, the steering force by the driver also becomes unstable. For this reason, the motor current value for generating the assist force with respect to the steering force also becomes unstable. As a result, in these cases, as shown in FIG. 14 for example, the motor current value changes in an unstable state.

[0075] FIG. 15 is a diagram showing an example of changes in the motor current value during the period from when the tires T1 and T2 enter the rut WT until they escape. In FIG. 15, at the timing t1 in the figure, one of the tires enters the rut WT, and accordingly, the motor current value temporarily increases. In what is shown in FIG. 15, since the motor current value is increasing so that the assist force to the right side becomes larger, for example, the state shown in FIG. 7(b) is assumed. Also, during the period from timing t2 to timing t3 in the figure, the motor current value is in an unstable state. In what is shown in FIG. 15, since the motor current value is increasing so that the assist force to the left side becomes larger during the period from timing t2 to timing t3, for example, the state shown in FIG. 13(c) is assumed. Further, at the timing t4 in the figure, one of the tires that had entered the rut WT escapes from the rut WT, and accordingly, the motor current value temporarily increases. In what is shown in FIG. 15, since the motor current value is increasing so that the assist force to the right side becomes larger at the time of this escape, for example, it is assumed that the left tire T1 has escaped from the state shown in FIG. 13(c).

[0076] As described above, the rut determination unit 29 utilizes the fact that the motor current value changes due to the presence of the rut WT, and determines that the rut WT is present (a rut WT with a predetermined depth or more is present) when the motor current value exceeds a predetermined threshold value, and transmits its determination signal (a determination signal indicating the presence of the rut WT and a signal related to the size of the rut WT) to the traveling information transmitting unit 20A.

[0077] Hereinafter, a method for determining the presence of the rut WT will be specifically described. As this determination method, the presence or absence of the rut WT is determined based on the deviation of the motor current value for obtaining the assist force by the electric assist motor 21 when the rut WT is not present (the increase in the motor current value for obtaining the assist force against the steering force).

[0078] That is, when the vehicle V is traveling straight (the steering angle of the steering wheel 11 is approximately zero), the assist force by the electric assist motor 21 is in a state where it is substantially zero and the motor current value is also substantially zero. Therefore, when the increase amount from this motor current value exceeds a predetermined increase threshold value, it is determined that the rut WT exists. As this increase threshold value, a value such as 3 A is set by experiment or simulation. This value is not limited to this.

[0079] Also, when the vehicle V is traveling on a curved road (traveling in a state where the steering wheel 11 is rotated at a predetermined steering angle), the assist force by the electric assist motor 21 is generated, and a corresponding motor current value (hereinafter referred to as the reference motor current value) is generated. Therefore, when the increase amount from this reference motor current value exceeds a predetermined increase threshold value, it is determined that the rut WT exists. In this case, information that the vehicle V is traveling on a curved road is required (it is necessary to confirm that the steering wheel 11 is rotated at a predetermined steering angle not for obtaining a steering force but for traveling on a curved road). Therefore, in the present embodiment, the bending information of the road on which the vehicle V is currently traveling is acquired from the map information stored in the navigation system mounted on the vehicle V. Further, since the reference motor current value is determined according to the tire steering angle as shown by the thin line in FIG. 2, when it is determined based on the map information that the road on which the vehicle V is traveling is a curved road, the reference motor current value is obtained from the steering angle signal currently transmitted from the steering angle sensor 24. Then, when the motor current value detected by the current sensor 34 exceeds a predetermined increase threshold value with respect to this reference motor current value, it is determined that the rut WT exists.

[0080] Further, when the motor current value is changed according to the vehicle speed when the vehicle V is traveling on a curved road (for example, when the motor current value is set higher as the vehicle speed is lower), the reference motor current value will be corrected accordingly. The relationship between this vehicle speed and the correction amount of the reference motor current value is set by experiments or simulations. In this case, when the motor current value detected by the current sensor 34 exceeds a predetermined increase threshold with respect to the corrected reference motor current value, it is determined that the rut WT exists. In this case, the vehicle speed information is calculated based on the rotation speed signals of the respective wheels T1 and T2 from the wheel speed sensor 25. Further, the vehicle speed when traveling on the road may be temporarily set from the speed limit information (restricted vehicle speed information) included in the map information stored in the navigation system mounted on the vehicle V, and the reference motor current value may be corrected according to the temporarily set vehicle speed.

[0081] The driving information transmitting unit 20A receives the determination information from the rut determination unit 29 (the road surface deterioration determination information in the present invention, which is information on the presence or absence of the rut WT and the size of the rut WT) and the information on the position of the host vehicle (the position information when it is determined by the rut determination unit 29 that the rut WT exists: the position information of the host vehicle measured by the GPS module 27), and transmits (sends) the driving information associating these information to the data center DS via the communication network CN.

[0082] (Data center) The data center DS performs information processing according to the driving information (the driving information associating the road surface deterioration determination information and the information on the position of the host vehicle) received from the driving information transmitting units 20A of the respective vehicles V, V,.... As its functional units, it includes an information receiving unit 41, a deterioration index creating unit 42, a road surface deterioration estimation information creating unit 43, and a road surface deterioration estimation information providing unit 44. The functions of these units are realized by a program stored in a computer provided in the data center DS. Hereinafter, the outlines of the functions of these units will be described.

[0083] The information receiving unit 41 receives the driving information transmitted by the driving information transmitting units 20A of each vehicle V, V,....

[0084] The deterioration index creation unit 42 creates a deterioration index of the road surface state for each position of the road surface based on a plurality of pieces of driving information received by the information receiving unit 41. In the present embodiment, as an example of the deterioration index to be displayed on the display screen of the administrator terminal device ATE, a bar graph (bar graph having a height corresponding to the degree of deterioration of the road surface) superimposed and displayed on a map is adopted, and the deterioration index creation unit 42 creates a bar graph corresponding to the degree of deterioration of the road surface. Hereinafter, the creation operation of this bar graph will be described.

[0085] Each of the plurality of pieces of driving information includes road surface position information and road surface deterioration determination information (information on the presence or absence of rut WT and the size of rut WT) at that position. The deterioration index creation unit 42 aggregates the road surface deterioration determination information at the same road surface position and obtains the average value of the degree of deterioration of the road surface at that position. For example, the average value of the increase amount of the motor current value detected by the current sensor 34 with respect to the reference motor current value is obtained, and that value is associated with the position of the road surface. Such an operation is performed for each position (road surface position). As a result, in the deterioration index creation unit 42, information on the degree of deterioration of the road surface at each road surface position is created as a deterioration index. And the size of this deterioration index (the larger the degree of deterioration of the road surface, the larger the deterioration index) is defined as the height dimension of the bar graph. The information on the deterioration index (information on the height dimension of the bar graph) associated with these road surface positions is transmitted to the road surface deterioration estimation information creation unit 43.

[0086] The road surface deterioration estimation information creation unit 43 creates road surface deterioration estimation information in which the deterioration index information received from the deterioration index creation unit 42 is associated with the road surface position information corresponding to the information. That is, each road surface position on the map is associated with the deterioration index (bar graph) corresponding to that road surface position, and image information in which the bar graph is drawn superimposed on the map is created as the road surface deterioration estimation information. This road surface deterioration estimation information is transmitted to the road surface deterioration estimation information providing unit 44.

[0087] The road surface deterioration estimation information providing unit 44 transmits the road surface deterioration estimation information (image information) received from the road surface deterioration estimation information creating unit 43 to the administrator terminal device ATE via the communication network CN or a communication line.

[0088] (Administrator terminal device) The administrator terminal device ATE provides the road surface deterioration estimation information transmitted from the road surface deterioration estimation information providing unit 44 of the data center DS to the road administrator. As its functional units, it includes an information receiving unit 51 and an information display unit 52. The functions of these units are realized by programs stored in a computer provided in the administrator terminal device ATE. Hereinafter, an outline of the functions of these units will be described.

[0089] The information receiving unit 51 receives the road surface deterioration estimation information transmitted from the road surface deterioration estimation information providing unit 44 of the data center DS.

[0090] The information display unit 52 displays the road surface deterioration estimation information (image information) received by the information receiving unit 51 on a display screen for providing it to a road administrator (not shown). This road surface deterioration estimation information is image information in which the bar graph is drawn superimposed on a map.

[0091] As the map display state displayed on the display screen by this information display unit 52, a first map display state in which a wide area (wide-angle area) is displayed and a second map display state in which a narrow area (narrow-angle area) is displayed are switchable.

[0092] FIG. 16 is a diagram showing an example of the first map display state, and FIG. 17 is a diagram showing an example of the second map display state. These map display states are switchable by an operation of the road administrator (operation of the administrator terminal device ATE). Also, when switching to the second map display state, by designating an area to be enlarged in the first map display state (the area surrounded by a circle in FIG. 16) (designating it with a pointing device or the like), it is possible to switch to the second map display state of the designated area.

[0093] In the second map display state, an image with the bar graph superimposed on the map is displayed, and at the position of the road surface where it is determined that the rut WT exists, the size of the rut WT is displayed as the height of the bar graph.

[0094] By visually observing the position and height of each bar graph in this second map display state, the road administrator recognizes the size of the rut WT at each road surface position and determines whether road repair is necessary. For example, it is determined that road repair is necessary for a road surface position where the height of the bar graph is equal to or greater than a predetermined length.

[0095] -Operation of Road Surface Condition Information Providing System- Next, the operation of the road surface condition information providing system 1 will be described. FIG. 18 is a sequence diagram showing an example of the operations of the vehicle V, the data center DS, and the administrator terminal device ATE. In FIG. 18, from the left in order, the information processing operations in the vehicle V (rut WT determination operation, travel information creation and transmission operation), the information processing operations in the data center DS (deterioration index creation operation, road surface deterioration estimation information creation and provision operation), and the operation in the administrator terminal device ATE (road surface deterioration estimation information display operation) are represented. Note that in FIG. 18, the communication between one vehicle V, the data center DS, and the administrator terminal device ATE is taken as an example, but the communication between other vehicles V, V,... and the data center DS and the administrator terminal device ATE is also performed in the same manner.

[0096] First, in the electric power steering device EPS mounted on the vehicle V, detection of the motor current value by the current sensor 34 and measurement (acquisition) of the position of the own vehicle by the GPS module 27 are performed (S1). Then, when the motor current value exceeds a predetermined threshold value (the increase amount from the reference motor current value exceeds a predetermined increase threshold value), it is determined that the rut WT exists (rut existence determination is performed: S2).

[0097] When rut existence determination is performed, travel information associating the determination information (information indicating the existence of rut WT and information on the size of rut WT) with the position information of the host vehicle is transmitted to the data center DS. At the data center DS, upon receiving the travel information from each vehicle V, V, …, these travel information are aggregated (S3), and a deterioration index of the road surface condition is created for each position of the road surface (S4). Then, road surface deterioration estimation information associating the information on this deterioration index with the position information of the road surface corresponding to the information is created (S5), and this road surface deterioration estimation information is transmitted toward the administrator terminal device ATE.

[0098] At the administrator terminal device ATE, by receiving this road surface deterioration estimation information, this road surface deterioration estimation information (image information) is displayed on the display screen (S6). That is, by switching from the first map display state described above to the second map display state, an image in which a bar graph corresponding to the degree of deterioration of the road surface (the size of rut WT) is superimposed and drawn on the map is displayed.

[0099] -Effects of the Embodiment- As described above, in this embodiment, based on the travel information collected from a plurality of general vehicles V, V, …, a deterioration index of the road surface condition is created for each position of the road surface, and road surface deterioration estimation information associating the information on this deterioration index with the position information of the road surface corresponding to the information is provided. For this reason, compared with a method of detecting the road surface condition by patrolling with a dedicated patrol vehicle, it becomes possible to provide information on the deterioration of the road surface earlier. As a result, it is possible to suppress a delay in the timing until information on the occurrence of an abnormality on the road surface is obtained, and it is possible to avoid a delay in the timing of road repair.

[0100] Further, in this embodiment, since the deterioration state of the road surface is detected based on the travel information from a plurality of general vehicles V, V, …, it is not necessary to use an expensive dedicated patrol vehicle, and the road surface condition can be detected at low cost and with high accuracy. Also, highly reliable road surface deterioration estimation information can be provided.

[0101] Also, in this embodiment, when the rut determination unit 29 determines that a rut WT exists because the motor current value exceeds a predetermined threshold value, driving information is transmitted. That is, when the motor current value exceeds the predetermined threshold value due to the progress of road surface deterioration, the driving information is transmitted toward the data center DS. Therefore, it is possible to narrow down to only useful information as the information (driving information) transmitted to the data center DS, and it is possible to improve the efficiency of information use and reduce the load on the data center DS.

[0102] (Modification example of the system) Next, a modification example of the road surface condition information providing system 1 will be described. In the above-described embodiment, the road administrator determines the necessity of road repair by visually observing the position and height of each bar graph in the second map display state. In this modification example, instead, the necessity of road repair is determined by machine learning in the data center DS. Since the configuration and operation other than the determination of the necessity of road repair are the same as those of the above-described embodiment, only the configuration and operation related to the determination of the necessity of road repair will be described here.

[0103] FIG. 19 is a diagram showing a schematic configuration of the road surface condition information providing system 1 according to this modification example. As shown in this FIG. 19, the data center DS of the road surface condition information providing system 1 according to this modification example includes, as its functional units, in addition to the above-described information receiving unit 41, deterioration index creating unit 42, road surface deterioration estimation information creating unit 43, and road surface deterioration estimation information providing unit 44, a road repair determination unit 45.

[0104] This road repair determination unit 45 receives the provision of road surface deterioration estimation information from the road surface deterioration estimation information providing unit 44, and determines the necessity of road repair by machine learning through comparison between this road surface deterioration estimation information and the teacher information of the pre-stored road surface deterioration estimation information. That is, the road surface deterioration estimation information for which it should be determined that road repair is necessary is stored as information corresponding to each position of each road surface, and using this information as teacher information, it is determined whether the road surface deterioration estimation information provided from the road surface deterioration estimation information providing unit 44 requires road repair. In this case, it is preferable that the teacher information (teacher information of road surface deterioration estimation information) is given as information considering road environment information such as road bending, speed regulation, presence of traffic signals, presence of once-stop positions, etc.

[0105] And when it is determined that road repair is necessary, determination information associating that information (information indicating that road repair is necessary) with the road surface position information is transmitted to the administrator terminal device ATE.

[0106] In the administrator terminal device ATE, the information receiving unit 51 receives this determination information, and the information display unit 52 displays the position of the road surface determined to require repair on the display screen of the administrator terminal device ATE. For example, the position of the road surface determined to require repair is presented by, for example, the position of the road surface determined to require repair blinking on the map on the display screen. The road administrator recognizes the existence of the road surface requiring repair by visually observing the display on this display screen.

[0107] According to this modification example, it is possible to automatically determine the necessity of road repair, reduce the burden on the road administrator, and avoid a situation where the road surface deteriorates (a state where repair is necessary) due to an incorrect judgment by the road administrator and is left unattended for a long time.

[0108] (Modification example of parameters) Next, a modified example of a parameter (a parameter that changes due to a change in the contact state between the steering wheel and the road surface) will be described. In the above-described embodiment and the modified example of the road surface state information providing system 1, the presence or absence of the rut WT was determined using the motor current value of the electric assist motor 21 as a parameter. Instead, it is also possible to adopt the following parameters.

[0109] First, as a parameter, the steering force as the torsional force measured by the steering force sensor 23 can be applied.

[0110] Similar to the above-described embodiment, when the driver applies a holding steering force to the steering wheel 11 to counteract the forced steering force due to the influence of the rut WT, the holding steering force becomes larger as the depth of the rut WT is greater. Therefore, by measuring this holding steering force (steering force) with the steering force sensor 23, running information corresponding to the depth of the rut WT can be obtained, and an index of deterioration of the road surface state can be obtained with high accuracy. In this case, it is necessary to confirm that the steering wheel 11 is rotated at a predetermined steering angle (a steering force is input) not for running on a winding road but for obtaining the holding steering force. Therefore, similar to the case of the above-described embodiment, it is necessary to acquire information that the road on which the vehicle V is currently running is a substantially straight road from the map information stored in the navigation system mounted on the vehicle V. That is, based on the map information, on the condition that the road on which the vehicle V is currently running is a substantially straight road, when the steering force measured by the steering force sensor 23 exceeds a predetermined threshold value, it is determined that there is a rut WT having a predetermined depth or more.

[0111] Also, as a parameter, the rotation angle of the electric assist motor 21 measured by the motor rotation angle sensor 22 can be applied.

[0112] When the tires T1 and T2 are forced to be steered due to the influence of the rut WT, the rotor of the electric assist motor 21 will also be forced to rotate. And the greater the depth of the rut WT, the greater the rotation angle (the rotation angle forced to rotate) of the electric assist motor 21. That is, there is a correlation between the depth of the rut WT and the rotation angle of the electric assist motor 21. For this reason, by using the rotation angle of the electric assist motor 21 as the parameter and measuring this rotation angle with the motor rotation angle sensor 22, driving information corresponding to the depth of the rut WT can be obtained.

[0113] Also, as the parameter, the rotation angle of the steering wheel 11 measured by the steering angle sensor (rotation angle sensor) 24 is applicable.

[0114] When the tire is forced to be steered due to the influence of the rut WT, the steering wheel 11 connected via the rack and pinion mechanism 13, the steering shaft 12, etc. will also be forced to rotate. And the greater the depth of the rut WT, the greater the rotation angle (the rotation angle forced to rotate) of the steering wheel 11. That is, there is a correlation between the depth of the rut WT and the rotation angle of the steering wheel 11. For this reason, by using the rotation angle of the steering wheel 11 as the parameter and measuring the rotation angle of the steering wheel 11 with the steering angle sensor 24, driving information corresponding to the depth of the rut WT can be obtained.

[0115] Also, as the parameter, the difference in the rotational speeds of the left and right tires T1 and T2 measured by the wheel speed sensor 25 is applicable.

[0116] When only one of the left and right tires T1 and T2 enters the rut WT, the height position of this one tire becomes lower than that of the other tire, and the tire is forced to be steered toward this one. In this case, the rotational speed of one tire becomes lower than that of the other tire. And the greater the depth of the rut WT, the greater this difference in rotational speed. That is, there is a correlation between the depth of the rut WT and the difference in the rotational speeds of the left and right tires T1 and T2 respectively. For this reason, the parameter is set as the difference in the rotational speeds of the left and right tires T1 and T2 respectively, and by measuring the rotational speeds of the left and right tires T1 and T2 respectively with the wheel speed sensors 25, running information corresponding to the depth of the rut WT can be obtained.

[0117] Also, as the parameter, the vertical acceleration and the lateral acceleration of the vehicle V measured by the G-sensor 26 are applicable.

[0118] When only one of the left and right tires T1 and T2 enters the rut WT, vertical acceleration and lateral acceleration occur in the vehicle V. Also, when both of the left and right tires T1 and T2 enter the rut WT substantially simultaneously, vertical acceleration occurs in the vehicle V. These accelerations become greater as the depth of the rut WT is greater. For this reason, the parameter is set as the vertical acceleration and the lateral acceleration of the vehicle V, and by measuring these accelerations with the G-sensor 26, running information corresponding to the depth of the rut WT can be obtained.

[0119] Also, in a vehicle V in which each of the left and right tires T1 and T2 can be steered independently, as the parameter, the difference in the steering angles of the left and right tires T1 and T2 respectively is applicable.

[0120] When one tire is forced to steer due to the influence of rut WT, the steering angle of the tire increases, resulting in a difference in the steering angles of the left and right tires T1 and T2, respectively. This difference increases as the depth of rut WT increases. That is, there is a correlation between the depth of rut WT and the difference in the steering angles of each of the tires T1 and T2. Therefore, by using the parameter as the difference in the steering angles of each of the tires T1 and T2 and measuring the difference in the steering angles with a steering angle sensor (not shown), driving information corresponding to the depth of rut WT can be obtained.

[0121] As parameters that change due to changes in the contact state between the steered wheel and the road surface, the motor current value in the above-described embodiment and the parameters cited in this modified example (steering force, rotation angle of the electric assist motor 21, rotation angle of the steering wheel 11, difference in the rotational speeds of the left and right tires T1 and T2, respectively, acceleration of the vehicle V, difference in the steering angles of the left and right tires T1 and T2, respectively) may be combined with each other to perform a rut WT determination operation. For example, when it is determined that rut WT exists in both cases in the rut WT determination operations using each of the plurality of parameters, driving information may be transmitted to the data center DS.

[0122] -Other Embodiments- Note that the present invention is not limited to the above-described embodiment and each of the modified examples, and all modifications and applications included in the scope of the claims and the scope equivalent thereto are possible.

[0123] For example, in the above-described embodiment and each of the modified examples, the case where the road surface state information providing system 1 according to the present invention is constructed using a rack assist type electric power steering device EPS has been described as an example. The present invention is not limited to this, and the road surface state information providing system 1 according to the present invention may be constructed using other types of electric power steering devices (such as column assist type or pinion assist type). Further, it is also possible to apply a steer-by-wire type steering system.

[0124] Also, in the above-described embodiment and each of the modified examples, the steering ECU 20 mounted on the vehicle V is provided with a rut determination unit 29 as a functional unit, and after determining the presence or absence of the rut WT by the rut determination unit 29, driving information is transmitted to the data center DS. The present invention is not limited to this, and driving information associating the motor current value and the information on the position of the host vehicle that has acquired the motor current value is transmitted from the driving information transmission unit 20A of the steering ECU 20 to the data center DS, and in this data center DS, the presence or absence of the rut WT may be determined from the plurality of received driving information to create a deterioration index.

[0125] Also, in the above-described embodiment and each of the modified examples, when the value of the parameter exceeds a predetermined threshold value (in the case of the above-described embodiment, when the increase amount from the reference motor current value exceeds a predetermined increase threshold value), it is determined that the rut WT is present. The present invention is not limited to this, and when the amount of change per unit time of the value of the parameter exceeds a predetermined threshold value (in the case of the above-described embodiment, when the amount of change per unit time of the motor current value exceeds a predetermined threshold value), it may be determined that the rut WT is present. In this case, since the contact state between the tires (steering wheels) T1 and T2 and the road surface changes greatly, when the amount of change per unit time of the value of the parameter exceeds a predetermined threshold value, the driving information is transmitted from the driving information transmission unit 20A to the data center DS. Therefore, also in this case, it is possible to improve the utilization efficiency of the information and reduce the load on the data center DS. For example, in the case of the change in the motor current value shown in FIG. 15 described above, when the amount of change per unit time of the value of the motor current value (the change gradient of the motor current value) during the period from the timing t1 to the timing t2 in the figure exceeds a predetermined threshold value, it is determined that the rut WT is present and the driving information is transmitted from the driving information transmission unit 20A to the data center DS.

[0126] In addition, in the above-described embodiment and each of the modified examples, the height dimension of the bar graph, which is a deterioration index, was set by aggregating the road surface deterioration determination information at the same road surface position to obtain the average value of the degree of deterioration of the road surface at that road surface position. The present invention is not limited to this. The parameters (such as motor current values) may be received from each vehicle V, V, ..., and the average value of the values obtained by dividing the peak value of the parameters (for example, the peak value of the motor current value) at the same road surface position by the tire steering angle at that road surface position may be obtained as the deterioration index. Further, the deterioration index may be set by obtaining a moving average value, a weighted moving average value, or the like of the degree of deterioration of the road surface. Further, the deterioration index is not limited to a bar graph. For example, the deterioration index may be numerically displayed on a map, or the time when road repair is required may be predicted and that time may be numerically displayed on the map.

[0127] Further, as a usage form of the road surface state information providing system 1 according to the present invention, the deterioration index created by the data center DS and the information on the day when the deterioration index was created may be associated and stored, and the secular change of the deterioration index, that is, the secular change of the deterioration state of the road surface may be aggregated. According to this, since the progress of the deterioration of the road surface can be easily grasped, the time when road repair is required can be estimated, and the preparation for road repair can be made in advance, which is effective.

[0128] As another usage mode of the road surface condition information providing system 1 according to the present invention, the number of vehicles V that have been determined by the rut determination unit 29 to have a rut WT among a plurality of vehicles V, V,... that have passed a specific road surface may be grasped. That is, by grasping the ratio of the number of vehicles V that have been determined to have a rut WT by means of a camera or the like installed on the road, the reliability of the traveling information transmitted to the data center DS can be determined. In this case, when the ratio of the number of vehicles V that have been determined to have a rut WT is high (for example, 50% or more: when the reliability of the traveling information is high), the deterioration index is created by the deterioration index creation unit 42, while when the ratio of the number of vehicles V that have been determined to have a rut WT is low (for example, less than 50%: when the reliability of the traveling information is low), processing such as not creating the deterioration index by the deterioration index creation unit 42 becomes possible. These numerical values are not limited to these.

[0129] Incidentally, the present invention can also be applied as a road surface condition information providing system 1 configured to include an autonomous vehicle. That is, it is a road surface condition information providing system 1 configured to include a vehicle equipped with an electric power steering device that automatically applies a steering force due to the presence of a rut WT.

[0130] Further, the deterioration of the road surface is not limited to that targeting the rut WT, and it is also applicable when there is a bump on the road surface.

Industrial Applicability

[0131] The present invention is applicable to a road surface condition information providing system for early providing information on the deterioration of a road surface.

Explanation of Signs

[0132] 1 Road surface condition information providing system 11 Steering wheel 20 Steering ECU 20A Traveling information transmitting unit 21 Electric assist motor 22 Motor rotation angle sensor (measurement means) 23 Steering force sensor (measurement means) 24 Steering angle sensor (rotation angle sensor, measurement means) 25 Wheel speed sensor (measurement means) 26 G sensor (acceleration sensor, measurement means) 27 GPS module (position detection means) 34 Current sensor (measurement means) 41 Information receiving unit 42 Deterioration index creation unit 43 Road surface deterioration estimation information creation unit 44 Road surface deterioration estimation information providing unit 45 Road repair determination unit DS Data center (information aggregation device) ATE Administrator terminal device V Vehicle (general vehicle) T1 Left front wheel, left side tire (steering wheel) T2 Right front wheel, right side tire (steering wheel) EPS Electric power steering device WT Rut

Claims

1. A road surface condition information providing system for providing information on the deterioration state of a road surface, comprising a plurality of general vehicles and an information aggregation device capable of communicating with the plurality of general vehicles, each of the general vehicles includes a position detection means for detecting its own vehicle position, a measurement means for measuring a value of a parameter that changes due to a change in the contact state between the steering wheel and the road surface, and a running information transmission unit for transmitting running information associating the information of the own vehicle position detected by the position detection means with the information of the value of the parameter measured by the measurement means at the own vehicle position or road surface deterioration determination information based on the value of the parameter, the information aggregation device includes an information reception unit for receiving the running information transmitted from the running information transmission unit of each general vehicle, a deterioration index creation unit for creating a deterioration index of the road surface condition for each position of the road surface based on the plurality of pieces of running information received by the information reception unit, a road surface deterioration estimation information creation unit for creating road surface deterioration estimation information associating the information of the deterioration index created by the deterioration index creation unit with the position information of the road surface corresponding to the information, and a road surface deterioration estimation information providing unit for providing the road surface deterioration estimation information, the parameter that changes due to a change in the contact state between the steering wheel and the road surface is the current value of an electric assist motor provided in an electric power steering device, the measurement means is a current sensor for measuring the current value, and the road surface condition information providing system is characterized by this.

2. A road surface condition information providing system for providing information on the deterioration state of a road surface, comprising a plurality of general vehicles and an information aggregation device capable of communicating with the plurality of general vehicles, Each of the general vehicles includes a position detection means for detecting the position of the vehicle itself, a measurement means for measuring the value of a parameter that changes due to a change in the contact state between the steering wheel and the road surface, and a travel information transmission unit that transmits travel information associating the information on the position of the vehicle itself detected by the position detection means with the information on the value of the parameter measured by the measurement means at the position of the vehicle itself or road surface deterioration determination information based on the value of the parameter. The information aggregation device includes an information reception unit that receives the travel information transmitted from the travel information transmission unit of each of the general vehicles, a deterioration index creation unit that creates a deterioration index of the road surface state for each position of the road surface based on the plurality of travel information received by the information reception unit, a road surface deterioration estimation information creation unit that creates road surface deterioration estimation information associating the information on the deterioration index created by the deterioration index creation unit with the position information of the road surface corresponding to the information, and a road surface deterioration estimation information provision unit that provides the road surface deterioration estimation information. The parameter that changes due to a change in the contact state between the steering wheel and the road surface is the rotation angle of an electric assist motor provided in an electric power steering device. The measurement means is a motor rotation angle sensor that measures the rotation angle, and is a road surface state information providing system.

3. A road surface state information providing system for providing information on the deterioration state of a road surface, It is configured to include a plurality of general vehicles and an information aggregation device capable of communicating between the plurality of general vehicles. Each of the general vehicles includes a position detection means for detecting the position of the vehicle itself, a measurement means for measuring the value of a parameter that changes due to a change in the contact state between the steering wheel and the road surface, and a travel information transmission unit that transmits travel information associating the information on the position of the vehicle itself detected by the position detection means with the information on the value of the parameter measured by the measurement means at the position of the vehicle itself or road surface deterioration determination information based on the value of the parameter. The information aggregation device includes an information receiving unit that receives the driving information transmitted from the driving information transmitting unit of each general vehicle, a deterioration index creating unit that creates a deterioration index of the road surface condition for each position of the road surface based on the plurality of driving information received by the information receiving unit, a road surface deterioration estimation information creating unit that creates road surface deterioration estimation information associating the information of the deterioration index created by the deterioration index creating unit with the position information of the road surface corresponding to the information, and a road surface deterioration estimation information providing unit that provides the road surface deterioration estimation information. The parameter that changes due to the change in the contact state between the steering wheel and the road surface is the difference in the steering angle of each of the left and right steering wheels when each of the left and right steering wheels can be independently steered. The measurement means is a steering angle sensor that measures the steering angle of each of the left and right steering wheels, and is a road surface condition information providing system.

4. In the road surface condition information providing system according to claim 1, 2, or 3, When the value of the parameter exceeds a predetermined threshold, driving information associating the information of the own vehicle position at which the value of the parameter is acquired with road surface deterioration determination information based on the value of the parameter is transmitted from the driving information transmitting unit. This is a road surface condition information providing system.

5. In the road surface condition information providing system according to claim 1, 2, or 3, When the amount of change per unit time of the value of the parameter exceeds a predetermined threshold, driving information associating the information of the own vehicle position at which the change amount exceeds the predetermined threshold with road surface deterioration determination information based on the change amount is transmitted from the driving information transmitting unit. This is a road surface condition information providing system.

6. In the road surface condition information providing system according to claim 1, 2, or 3, The road surface deterioration estimation information providing unit transmits the road surface deterioration estimation information to a terminal device monitored by a road administrator. This is a road surface condition information providing system.

7. In the road surface condition information providing system according to claim 1, 2, or 3, The road surface condition information providing system is characterized in that the road surface deterioration estimation information providing unit transmits the road surface deterioration estimation information to a road repair determination unit that determines the necessity of road repair by machine learning based on a comparison between the provided road surface deterioration estimation information and teacher information of the road surface deterioration estimation information stored in advance.

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