Information provision device

Abstract

To enable an occurrence status of visibility disturbance to be accurately assessed with a simple configuration.SOLUTION: An information provision device 10 comprises: information acquisition section 111 which acquires positional information of a vehicle traveling within a predetermined region, operation information indicating either an operation state or a stopped state of a predetermined device operated during snowfall or when snow has accumulated, map information including road information, and weather information for the predetermined region; a prediction section 112 which generates visibility disturbance information indicating an occurrence status of visibility disturbance to a driver of a vehicle traveling in the predetermined region based on the operation information when the weather information indicates that snowfall or strong wind after snowfall has occurred within a first predetermined period from a certain time in the past to the present time and when an average travel speed in the predetermined region calculated based on the positional information acquired by the information acquisition section 111 is lower than the average travel speed in the predetermined region during a second predetermined period earlier than the first predetermined period; and an output section 113 which outputs the visibility disturbance information generated by the prediction section 112 in association with the road information.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an information providing device that provides information regarding the occurrence of visibility impairment. [Background technology]

[0002] A known example of this type of device is one that is equipped with a flying snow particle counter that measures the particle size and number of flying snow particles on a vehicle and calculates the visibility at the vehicle's traveling position based on the measurement values of the flying snow particle counter (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-44977 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the configuration described in Patent Document 1, it is necessary to run a dedicated vehicle equipped with a flying snow particle counter every time a measurement is made, making it difficult to efficiently grasp the occurrence of visibility impairments. [Means for solving the problem]

[0005] An information providing device according to one aspect of the present invention comprises: a driving information acquisition unit that acquires driving information including position information of a vehicle traveling within a specified area and operation information indicating the operation state or stop state of a specified device that is activated during snowfall or snow accumulation; a map information acquisition unit that acquires map information including road information; a weather information acquisition unit that acquires weather information for the specified area; a generation unit that, when the weather information indicates that snowfall or strong winds after snowfall occurred within a first specified period from a specified point in the past to the present, calculates an average driving speed of the vehicle within the specified area based on the position information acquired by the driving information acquisition unit; and, when the calculated average driving speed is lower than the average driving speed of the vehicle within the specified area during a second specified period that is earlier than the first specified period, generates visibility impairment information indicating the occurrence of visibility impairment for the driver of the vehicle traveling within the specified area based on the operation information; and an output unit that outputs the visibility impairment information generated by the generation unit in association with road information. [Effects of the Invention]

[0006] According to the present invention, the occurrence of visibility impairment can be grasped with high accuracy using a simple configuration. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing an example of the configuration of an information providing system including an information providing device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing the configuration of a main part of the in-vehicle device. [Figure 3] 1 is a block diagram showing a configuration of a main part of an information providing device according to an embodiment of the present invention; [Figure 4] FIG. 10 is a diagram showing an example of display of visibility impairment information. [Figure 5A] 4 is a flowchart showing an example of processing executed by the calculation unit of FIG. 3. [Figure 5B] 10 is a flowchart showing another example of the processing executed by the calculation unit of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 5B. An information providing device according to an embodiment of the present invention is a device for providing information regarding the occurrence of visibility impairment on a road on which a vehicle is traveling. Fig. 1 is a diagram showing an example of the configuration of an information providing system including an information providing device according to this embodiment. As shown in Fig. 1, the information providing system 1 includes an information providing device 10 and an in-vehicle device 30. The information providing device 10 is configured as a server device. The in-vehicle device 30 is configured to be able to communicate with the information providing device 10 via a communication network 2.

[0009] The communication network 2 includes not only public wireless communication networks such as the Internet network 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 device 30 is mounted on a vehicle 20. The vehicle 20 includes a plurality of vehicles 20-1, 20-2, ..., 20-n. The vehicle 20 may be a manually driven vehicle or an automatically driven vehicle. The vehicle 20 may also include vehicles of different models and grades.

[0011] 2 is a block diagram showing the configuration of the main parts of the in-vehicle device 30 according to this embodiment. The in-vehicle device 30 includes an electronic control unit (ECU) 31, a positioning unit 32, a wiper switch 33, a headlight switch 34, a turn signal switch 35, a hazard warning light switch 36, an anti-skid device 37, and a TCU (Telematic Control Unit) 38.

[0012] The positioning unit (GNSS unit) 32 is, for example, a GPS sensor that receives positioning signals transmitted from GPS satellites and detects the absolute position (latitude, longitude, etc.) of the vehicle 20. The positioning unit 32 includes not only GPS sensors but also sensors that perform positioning using radio waves transmitted from satellites of various countries called GNSS satellites, including quasi-zenith orbit satellites. The wiper switch 33 is a switch for switching on and off wipers (window wipers, not shown) installed on the windshield and rear windshield of the vehicle 20. When the wiper switch 33 is on (operated), the wipers operate, and when it is off (stopped), the wipers stop.

[0013] The headlight switch 34 is a switch for switching on / off the headlights (not shown) attached to predetermined positions (front) of the vehicle 20. When the headlight switch 34 is in the on state, the headlights are turned on, and when the headlight switch 34 is in the off state, the headlights are turned off. The turn signal switch 35 is a switch for switching on / off the turn signals (not shown) attached to predetermined positions (both the left and right sides of the front and the left and right sides of the rear) of the vehicle 20. When the turn signal switch 35 is in the on state, either the left or right turn signal flashes depending on the input operation to the turn signal switch 35, and when it is in the off state, both the left and right turn signals are turned off. The hazard flasher switch 36 is a switch for causing the left and right turn signals to function as hazard flashers. When the hazard flasher switch 36 is in the on state, the left and right turn signals flash, and when it is in the off state, both the left and right turn signals are turned off.

[0014] The anti-skid device 37 has a driving actuator that suppresses skidding of the vehicle 20. The anti-skid device 37 is activated when it detects that the vehicle 20 is understeered or oversteered when the vehicle 20 is turning, for example.

[0015] The TCU (Telematic Control Unit) 40 is an ECU that performs wireless communication with external devices such as the information providing device 10 via the communication network 2. The TCU 38 may be configured as a part of the ECU 31.

[0016] 2, the ECU 31 includes a computer having a calculation unit 310 such as a CPU, a storage unit 320 such as a ROM and a RAM, and other peripheral circuits (not shown) such as an I / O interface. The calculation unit 310 executes programs stored in advance in the storage unit 320, thereby functioning as a sensor value acquisition unit 311, a signal detection unit 312, and a communication control unit 313.

[0017] The sensor value acquisition unit 311 acquires information (absolute position of the vehicle 20) detected by the positioning unit 32 at a predetermined cycle. The signal detection unit 312 detects on / off signals output from the switches 33 to 36 and the anti-skid device 37. Specifically, the signal detection unit 312 detects signals output from the switches 33 to 36 indicating whether the switch is in an on or off state. The signal detection unit 312 also detects a signal output from the anti-skid device 37 indicating whether the anti-skid device 37 is in an on or off state.

[0018] The communication control unit 313 transmits travel information including position information indicating the sensor value (absolute position of the vehicle 20) of the positioning unit 32 acquired by the sensor value acquisition unit 311 to the information providing device 10 via the TCU 38 at predetermined intervals. Furthermore, the communication control unit 313 generates operation information indicating the on / off state of each of the switches 33 to 36 and the anti-skid device 37 based on the on / off signals detected by the signal detection unit 312, and includes the generated operation information in the travel information transmitted to the information providing device 10. Note that the travel information may include, in addition to the operation information, transmission date and time information indicating the date and time when the travel information was transmitted and detection date and time information indicating the date and time when the on / off signal was detected. Furthermore, the travel information may include a vehicle ID (vehicle identification information) that can identify the vehicle 20.

[0019] 3 is a block diagram showing the configuration of the main parts of the information providing device 10 according to this embodiment. The information providing device 10 includes a computer having a calculation unit 11 such as a CPU, a storage unit 12 such as a ROM and a RAM, and other peripheral circuits (not shown) such as an I / O interface. The storage unit 12 stores map information including a road map (hereinafter referred to as a road map) and various information processed by the calculation unit 11.

[0020] The calculation unit 11 executes the programs stored in the storage unit 12 to function as an information acquisition unit 111 , a prediction unit 112 , an output unit 113 , and a communication control unit 114 .

[0021] The information acquisition unit 111 acquires driving information. More specifically, the information acquisition unit 111 receives driving information from the in-vehicle devices 30 of each of multiple vehicles 20 (20-1, 20-2, . . . , 20-n) traveling on a road via the communication control unit 114. When the driving information includes a vehicle ID, the information acquisition unit 111 can identify the vehicle 20 that transmitted the driving information based on the vehicle ID. The information acquisition unit 111 stores the driving information received from the multiple vehicles 20 (in-vehicle devices 30) in the storage unit 12. When the communication control unit 114 receives an instruction to output visibility impairment information, the information acquisition unit 111 identifies vehicles 20 whose current driving positions are included in a designated area, i.e., vehicles 20 traveling within the designated area, based on the driving information received from each vehicle 20. The designated area can be set by the user, and the instruction to output visibility impairment information includes information indicating the designated area. It is possible to set multiple designated areas. For example, in Fig. 4 described later, cities A, B, C, and D may be set as the designated area. An instruction to output visibility impairment information is transmitted from a terminal of a road management company or the like. The visibility impairment information will be described later with reference to Fig. 4.

[0022] Furthermore, the information acquisition unit 111 reads map information from the storage unit 12 and acquires a road map included in the map information. More specifically, when an output instruction for visibility impairment information is received from the communication control unit 114, the information acquisition unit 111 reads a road map including the specified area from the storage unit 12. Furthermore, the information acquisition unit 111 acquires information about the weather in the specified area (hereinafter referred to as weather information) via the communication control unit 114 from an external server (not shown) that distributes weather information (hereinafter referred to as weather information server).

[0023] When the weather information acquired by the information acquisition unit 111 indicates that snowfall or strong winds after snowfall (e.g., winds with a wind speed of 10 m / s or more) occurred within a specified time period from the current time, i.e., within a specified period from a time point before the current time until the current time, the prediction unit 112 predicts the occurrence of visibility impairment for the driver of the vehicle 20 traveling within the specified area. The specified time period can be set by the user, and information indicating the specified time period is included in the output instruction for visibility impairment information. Note that the specified time period may be a predetermined time period. Furthermore, strong winds after snowfall include not only cases where snowfall and strong winds occurred in sequence within the specified period, but also cases where snowfall occurred in a period prior to the specified period and strong winds occurred within the specified period.

[0024] Here, prediction of the occurrence of visibility impairment will be explained. When snowflakes or strong winds after snowfall cause flying snow particles to fly ahead of vehicle 20, the maximum distance that the driver of vehicle 20 can visually confirm (visibility) becomes shorter, resulting in so-called visibility impairment. When the driver of vehicle 20 has difficulty seeing surrounding objects such as vehicles ahead, lane markings, and median strips due to visibility impairment, he or she will slow down vehicle 20 to improve visibility and to avoid approaching or coming into contact with these objects. In this way, when visibility becomes impaired by a certain distance (e.g., 200 m) or less, the traveling speed of vehicle 20 decreases compared to when visibility impairment does not occur. The shorter the visibility, the slower the traveling speed of vehicle 20.

[0025] Furthermore, when visibility is impaired due to snowfall or strong winds after snowfall, the driver of the vehicle 20 activates the wipers to wipe away flying snow particles adhering to the windshield (windshield) and turns on the headlights to improve forward visibility. When visibility becomes even shorter (for example, below 50 m), the driver of the vehicle 20 activates the turn signal to move the vehicle 20 to a safe space on the shoulder of the road, or activates the hazard warning lights to notify surrounding vehicles that the vehicle 20 is slowing down or stopping due to travel difficulties. As such, when visibility is impaired, changes occur in the driver's driving behavior, and the behavior of the vehicle 20 changes accordingly. Therefore, when weather information indicates that snowfall or strong winds after snowfall have occurred within a specified time from the present time, the prediction unit 112 predicts whether or not visibility will be impaired based on the behavior of the vehicle 20 indicated by the travel information as follows.

[0026] When the weather information indicates that snowfall or strong winds after snowfall occurred within the designated period, the prediction unit 112 calculates the current average traveling speed of the vehicle 20 traveling within the designated area based on the change in the position of the vehicle 20 within the designated area indicated by the position information included in the traveling information acquired by the information acquisition unit 111. The average traveling speed is calculated for each road section of a predetermined length, and the predetermined length is set to the maximum length of visibility that may cause visibility impairment (for example, 200 m) or a value greater than this. When there are multiple vehicles 20 traveling within the designated area, the average traveling speed of the multiple vehicles 20 (more specifically, the average value of the average traveling speeds of each vehicle 20) is calculated. Similarly, the prediction unit 112 also calculates the average traveling speed of the vehicle 20 traveling within the designated area during a predetermined period in the past (hereinafter referred to as the comparison period). The comparison period is a period in which there was at least no snowfall or strong winds after snowfall. The prediction unit 112 determines the comparison period from a period in which there is no snowfall (such as summer). The prediction unit 112 may acquire weather information for the specified region, for example, weather information for several months, from a weather information server, identify a period during which there was no snowfall or strong winds after snowfall based on the acquired weather information, and determine that period as the comparison period. The prediction unit 112 may also determine the comparison period based on an instruction from a user. That is, the instruction to output visibility impairment information may include information specifying the comparison period.

[0027] The prediction unit 112 compares the current average driving speed with the average driving speed for the comparison period, calculated for each road section of a predetermined length. When there is a road section where the current average driving speed is lower than the average driving speed for the comparison period, the prediction unit 112 predicts whether or not the driver of the vehicle 20 traveling on that road section is experiencing impaired visibility based on the driving information acquired by the information acquisition unit 111, specifically, the operation information included in the driving information corresponding to that road section. More specifically, when the operation information indicates the operating state of at least one of the switches 33 to 36 and the anti-skid device 37, the prediction unit 112 predicts that the driver of the vehicle 20 traveling on that road section is experiencing impaired visibility.

[0028] The prediction unit 112 further predicts the level of visibility impairment in addition to the occurrence of visibility impairment. When visibility falls below 200 m, drivers experience visibility impairment, causing the traveling speed of each vehicle traveling on the road to decrease. At this time, the following trends are observed in the traveling of each vehicle depending on the length of visibility. When visibility is between 200 and 100 m, the traveling speed of each vehicle is not significantly different from the traveling speed of surrounding vehicles, such as the vehicle ahead, the vehicle behind, and vehicles traveling in adjacent lanes in the same direction (hereinafter referred to as adjacent vehicles), maintaining a stable traffic flow. When visibility falls below 100 m, the traveling speed of each vehicle drops sharply and the difference in traveling speed between vehicles increases. Furthermore, since the drivers of each vehicle begin to drive with the vehicle ahead as their target, multiple vehicles often travel in a line. When visibility falls below 50 m, it becomes difficult for the drivers of each vehicle to control the traveling speed of the vehicle 20 by operating only the accelerator pedal, and they begin to operate the brake pedal as well. As a result, the traveling speed of each vehicle further decreases. In addition, the difference in speed between the vehicles becomes even greater.

[0029] The prediction unit 112 predicts the level of visibility impairment in a road section where visibility impairment is predicted to occur (hereinafter referred to as a failure section) based on the above-mentioned driving tendency when visibility impairment occurs. Specifically, when the speed reduction amount in the failure section (= average driving speed during the comparison period - current average driving speed) is less than a threshold value Th_a1, the prediction unit 112 predicts the level of visibility impairment in the failure section to be "low" (visibility: 200 to 100 m). Note that the prediction unit 112 may predict the level of visibility impairment to be "low" when the difference in the driving speeds of the vehicles 20 in the failure section, more specifically, the variance in the average driving speeds of the vehicles 20 (hereinafter referred to as speed variance), is less than a threshold value Th_b1. The speed variance is expressed by statistical values such as variance and standard deviation. Furthermore, when the speed reduction amount in the faulty section is less than the threshold Th_a1 and the speed dispersion is less than the threshold Th_b1, the predictor 112 may predict that the level of visibility impairment in the faulty section is "low."

[0030] When the amount of speed reduction in the faulty section is equal to or greater than a threshold Th_a1 and less than a threshold Th_a2 (>Th_a1), the predictor 112 predicts that the level of visibility impairment in the faulty section will be "medium" (visibility: 100 to 50 m). Note that the predictor 112 may predict that the level of visibility impairment in the faulty section will be "medium" when the speed variance in the faulty section is equal to or greater than a threshold Th_b1 and less than a threshold Th_b2 (>Th_b1). Furthermore, the predictor 112 may predict that the level of visibility impairment in the faulty section will be "medium" when the amount of speed reduction in the faulty section is equal to or greater than a threshold Th_a1 and less than a threshold Th_a2, and the speed variance is equal to or greater than a threshold Th_b1 and less than a threshold Th_b2.

[0031] When the speed reduction amount in the faulty section is equal to or greater than a threshold Th_a2, the prediction unit 112 predicts the level of visibility impairment in the faulty section as "high" (visibility: less than 50 m). The prediction unit 112 may also predict the level of visibility impairment in the faulty section as "high" when the speed variance in the faulty section is equal to or greater than a threshold Th_b2. Furthermore, the prediction unit 112 may also predict the level of visibility impairment as "high" when the frequency of brake pedal operation of each vehicle 20 in the faulty section, specifically, the number of times an operation amount equal to or greater than a predetermined amount, is equal to or greater than a threshold Th_c. When the on-board device 30 of the vehicle 20 includes a brake pedal stroke sensor (not shown) that converts the brake pedal operation amount into an electrical signal, the sensor value acquisition unit 311 acquires information detected by the brake pedal stroke sensor (hereinafter referred to as brake operation information). The communication control unit 313 includes the brake operation information in the traveling information transmitted to the information providing device 10. The prediction unit 112 calculates the frequency of brake pedal operation based on the brake operation information included in the travel information and compares it with a threshold value Th_c. When there are multiple vehicles 20 traveling within the designated area, the prediction unit 112 calculates the average value of the brake pedal operation frequencies of each vehicle 20 and compares it with the threshold value Th_c. The method of calculating the brake pedal operation frequency is not limited to this, and the brake pedal operation frequency may be calculated based on information detected by a sensor other than the brake pedal stroke sensor. The above threshold values Th_a1, Th_a2, Th_b1, Th_b2, and Th_c are determined based on past observation results, travel simulation results, etc., and stored in the storage unit 12.

[0032] The prediction unit 112 generates visibility impairment information in which the presence or absence of visibility impairment and the predicted level of visibility impairment are associated with the road map acquired by the information acquisition unit 111. The output unit 113 outputs the visibility impairment information generated by the prediction unit 112.

[0033] The communication control unit 114 controls a communication unit (not shown) to transmit and receive data to and from external devices, etc. Specifically, the communication control unit 114 acquires weather information, map information, etc., periodically or at any timing from various servers connected to the communication network 2. The communication control unit 114 stores the information acquired from the various servers in the storage unit 12. The communication control unit 114 also transmits and receives data (such as driving information) to and from the in-vehicle device 30 of the vehicle 20 via the communication network 2. Furthermore, the communication control unit 114 transmits and receives data to and from terminals of users (hereinafter referred to as user terminals) such as road management companies. More specifically, the communication control unit 114 receives an output instruction for visibility impairment information transmitted from the user terminal via the communication network 2. When the output unit 113 outputs the visibility impairment information in response to the output instruction, the communication control unit 114 transmits the visibility impairment information to the user terminal that transmitted the output instruction via the communication network 2. When the visibility impairment information is information that can be displayed on a display device such as a display, the user can check the occurrence of visibility impairment in the specified area by operating the user terminal to display the visibility impairment information on a display that the user terminal has or is connected to the user terminal.

[0034] FIG. 4 is a diagram showing an example of the visibility impairment information output by the output unit 113. FIG. 4 shows an example of the visibility impairment information when the user sets City A, City B, City C, and City D as the specified area. In the example of FIG. 4, the road section AR1 where the visibility is predicted to be less than 50 m is indicated by a solid-line frame, road sections AR3 and AR5 where the visibility is predicted to be 100 to 50 m are indicated by dashed-dotted-line frames, and road sections AR2 and AR4 where the visibility is predicted to be 200 to 100 m are indicated by dashed-line frames. The other road sections are road sections where the visibility is predicted to be greater than 200 m and the visibility is good. This allows the user to recognize road sections where visibility impairment is occurring and the level of visibility impairment in those road sections. Note that road sections filled in black indicate road sections where vehicle 20 has never traveled and where the occurrence of visibility impairment cannot be predicted because no vehicle 20 travel information is available.

[0035] 5A and 5B are flowcharts showing an example of processing executed in accordance with a predetermined program by the calculation unit 11 (CPU) of the information providing device 10. The processing shown in the flowcharts of Fig. 5A and 5B is repeated at predetermined intervals while the information providing device 10 is running.

[0036] 5A shows a flowchart of the reception process of travel information. First, in step S11, it is determined whether travel information has been received from the in-vehicle device 30 of the vehicle 20. If the result in step S11 is negative, the process ends. If the result in step S11 is positive, the travel information received in step S11 is stored in the memory unit 12 in step S12.

[0037] FIG. 5B shows a flowchart illustrating the output process of visibility impairment information. First, in step S21, it is determined whether an instruction to output visibility impairment information has been input (received). If the result in step S21 is negative, the process is terminated. If the result in step S21 is positive, in step S22, map information is read from the memory unit 12, and a road map is acquired from the map information. At this time, a road map including the designated area is acquired based on the output instruction received in step S21. Next, in step S23, weather information is acquired from the weather information server. At this time, weather information for the designated area corresponding to the period from a past point in time specified time before the present to the present time (designated period) is acquired based on the output instruction received in step S21. In step S24, travel information of vehicles 20 whose current travel position indicated by the position information is included in the designated area, i.e., vehicles 20 traveling within the designated area, is acquired. At this time, travel information corresponding to the comparison period of vehicles 20 traveling within the designated area is also acquired from the memory unit 12. In step S25, the occurrence status of visibility impairment for the driver of vehicle 20 traveling in the specified area is predicted based on the road map acquired in step S22, the weather information acquired in step S23, and the driving information acquired in step S24. More specifically, the presence or absence of visibility impairment and the level of visibility impairment are predicted for each road section of a predetermined length. In step S26, visibility impairment information including the prediction result of step S25 is generated, and the generated visibility impairment information is output. The visibility impairment information is output via communication network 2 to the user terminal that sent the output instruction for the visibility impairment information and to a predetermined output destination terminal.

[0038] According to the embodiment of the present invention, the following advantageous effects can be achieved. (1) The information providing device 10 includes an information acquisition unit 111 that acquires driving information including position information of a vehicle 20 traveling within a predetermined area (designated area) and operation information indicating the operating state or stopped state of a predetermined device that is activated when snow falls or snow accumulates, map information including road information, and weather information for the predetermined area, a prediction unit 112 that, when the weather information indicates that snowfall or strong winds after snowfall occurred within a first predetermined period (designated period) from a predetermined time point in the past to the present, calculates an average driving speed of the vehicle 20 within the predetermined area based on the position information acquired by the information acquisition unit 111, and, when the calculated average driving speed is lower than the average driving speed of the vehicle 20 within the predetermined area during a second predetermined period (comparison period) that is earlier than the first predetermined period, generates visibility impairment information indicating the occurrence of visibility impairment for the driver of the vehicle 20 traveling within the predetermined area based on the operation information, and an output unit 113 that outputs the visibility impairment information generated by the prediction unit 112 in association with road information. When the weather information indicates that snowfall or strong winds after snowfall occurred within a first predetermined period, the prediction unit 112 calculates the average traveling speed of the vehicle 20 within a predetermined area based on the transition of the traveling position of the vehicle 20 indicated by the position information acquired by the information acquisition unit 111. When the calculated average traveling speed is lower than the average traveling speed of the vehicle within the predetermined area during a comparison period and the operation information indicates the operation state of a predetermined device, the prediction unit 112 generates visibility impairment information indicating that the driver of the vehicle 20 traveling within the predetermined area is experiencing visibility impairment. This allows accurate information regarding the occurrence of visibility impairment to be provided to users, such as road management companies, with a simple configuration. Furthermore, based on the information provided in this manner, users can quickly take measures such as prohibiting vehicles from passing through the road section where visibility impairment is occurring or notifying the driver of the occurrence of visibility impairment. As a result, traffic safety can be improved. Furthermore, because the average traveling speed of the vehicle 20 is calculated based on the transition of the traveling position of the vehicle 20, visibility impairment information can be generated even if the traveling information of the vehicle 20 does not include a detection value from a vehicle speed sensor (not shown). This reduces the amount of data communication with the vehicle 20 (on-board device 30).

[0039] (2) The predetermined devices include at least one of a headlight, a wiper, a turn signal, an emergency flasher, and an anti-skid device, thereby improving the accuracy of predicting whether or not visibility impairment will occur.

[0040] The above embodiment can be modified in various ways. Modifications are described below. In the above embodiment, the information acquisition unit 111, which serves as a travel information acquisition unit, acquires travel information including location information of the vehicle 20 traveling within a predetermined area and operation information indicating the operation state or stop state of a predetermined device that is activated during snowfall or snow accumulation. However, when information indicating the date and time when snow was removed from a road by a snowplow or the like (hereinafter referred to as snow removal information) is provided from an external server or the like, the information acquisition unit 111 may also serve as a snow removal information acquisition unit and acquire the snow removal information via the communication control unit 114. The prediction unit 112 may then identify the most recent date and time when snow was removed in the predetermined area based on the snow removal information acquired by the information acquisition unit 111, and determine the period from the most recent date and time to the present time as the first predetermined period. This allows the occurrence of visibility impairment to be predicted based on the weather after snow removal, thereby providing the user with a more accurate prediction result.

[0041] In the above embodiment, the prediction unit 112 predicts the occurrence of a visibility impairment when the weather information acquired by the information acquisition unit 111 as a weather information acquisition unit indicates that snowfall or strong winds after snowfall occurred in a predetermined area within a first predetermined period. However, the prediction unit 112 may predict the occurrence of a visibility impairment when other conditions are met. When the temperature on a road after snowfall is low and the wind speed is equal to or greater than a predetermined value, snow accumulated on the road or roadside is blown up by the wind, making it more likely that a ground blizzard will occur at or above the driver's eye level. In other words, visibility impairment is more likely to occur. In consideration of this, the prediction unit 112 may predict the occurrence of a visibility impairment when the weather information indicates that strong winds after snowfall occurred in a predetermined area within a first predetermined period and that the average temperature (or current temperature) in the predetermined area during the first predetermined period is equal to or lower than a predetermined temperature. Furthermore, when the height of the ground or snow banks beside the road is equal to or higher than the driver's eye level, even if the wind speed is not very high, flying snow particles that crawl along the snow surface may cause a ground blizzard to occur at approximately the driver's eye level. Taking this into consideration, the prediction unit 112 may predict the occurrence of visibility impairment regardless of the presence or absence of strong winds after snowfall when the height of the ground on the right or left side of the road along which the vehicle 20 is traveling is equal to or greater than a predetermined height. In this case, the communication control unit 313 includes, in the travel information transmitted to the information providing device 10, a camera image acquired by an on-board camera (not shown) that is provided at a predetermined position in front of the vehicle 20 and captures an image of the space ahead of the vehicle 20. The prediction unit 112 detects the height of the ground on the roadside ahead of the vehicle 20 based on the camera image included in the travel information. Ground blizzards may also be caused by large vehicles such as trucks (vehicles having a predetermined size or a predetermined weight or more) kicking up snow that has accumulated on the road surface. Taking this into consideration, the prediction unit 112 determines the type of vehicle 20 traveling within the designated area based on the vehicle identification information included in the traveling information acquired by the information acquisition unit 111, calculates the proportion of large vehicles to all vehicles traveling within the designated area, and when this proportion is equal to or greater than a predetermined proportion, may predict the occurrence of visibility impairment regardless of whether there is strong wind after snowfall.

[0042] In the above embodiment, the information acquisition unit 111, which functions as a travel information acquisition unit, acquires travel information of the vehicle 20 traveling within the designated area. However, for large vehicles such as trucks, where the driver's line of sight is high, the driver is less susceptible to visibility impairment even when a ground blizzard occurs. Therefore, the information acquisition unit 111 may acquire travel information of vehicles 20 whose vehicle height is equal to or less than a predetermined value so that the travel information of large vehicles that are less susceptible to visibility impairment is not used to predict visibility impairment. Specifically, the travel information acquisition unit may determine the vehicle type or class of each vehicle 20 traveling within the designated area based on vehicle identification information included in the travel information, and acquire travel information of vehicles 20 whose vehicle height, as determined from the vehicle type or class, is equal to or less than a predetermined value. In this way, by predicting the occurrence of visibility impairment for vehicles that are more susceptible to visibility impairment, prediction accuracy can be improved. Note that when the travel information includes information indicating the vehicle height of the vehicle 20 instead of or in addition to the vehicle identification information, the travel information of vehicles 20 whose vehicle height is equal to or less than a predetermined value may be acquired based on that information.

[0043] In the above embodiment, when the activation state of at least one of the switches 33 to 36 and the anti-skid device 37 is indicated in a road section where the current average traveling speed of the vehicle 20 is lower than the average traveling speed for the comparison period, the prediction unit 112 as a generating unit generates visibility impairment information indicating that the driver of the vehicle 20 traveling on the road section is experiencing visibility impairment. However, the configuration of the generating unit is not limited to this. When visibility impairment occurs, the driver of the vehicle 20 may perform driving operations with a forward-leaning posture to search for a target that can be distinguished from snow in the space ahead of the vehicle 20. In consideration of this, when the forward-leaning posture of the driver of the vehicle 20 is detected in a road section where the current average traveling speed of the vehicle 20 is lower than the average traveling speed for the comparison period, the generating unit may generate visibility impairment information indicating that the driver of the vehicle 20 traveling on the road section is experiencing visibility impairment. That is, the generating unit may generate visibility impairment information using information indicating the driving posture of the driver of the vehicle 20 (hereinafter referred to as posture information) instead of the operation information. In this case, the communication control unit 313 includes information (hereinafter referred to as posture information) detected by a seating posture sensor (not shown) provided in the driver's seat of the vehicle 20 in the driving information transmitted to the information providing device 10. The generation unit detects the forward leaning posture of the driver of the vehicle 20 based on the posture information included in the driving information. The generation unit may generate visibility impairment information using the posture information together with the operation information.

[0044] Furthermore, in the above embodiment, the output unit 113 outputs the visibility impairment information to the user terminal. However, when the information providing device 10 is equipped with an output device such as a display, the output unit may output the visibility impairment information to the output device. Furthermore, in the above embodiment, the prediction unit 112 as a generation unit generates, as visibility impairment information, information (FIG. 4) in which the prediction result of the visibility impairment occurrence state is associated with the road map acquired by the information acquisition unit 111 as a map information acquisition unit. However, as long as the user can recognize the visibility impairment occurrence state in a predetermined area, the visibility impairment information may be generated in a manner different from that of FIG. 4. Furthermore, while FIG. 4 shows an example in which an administrative district (such as a city, town, or village) is set as the designated area, a road section (such as road section AR1 in FIG. 4) may also be set as the designated area. Furthermore, the designated area may also be set based on information such as latitude, longitude, and road name. Furthermore, in the above embodiment, an example has been shown in which the communication control unit 114 receives an output instruction for visibility impairment information transmitted from a terminal of a road management company or the like, but the output instruction for visibility impairment information may be transmitted from the on-board device 30 of the vehicle 20 or a communication terminal possessed by the driver of the vehicle 20. In other words, the user terminal is not limited to a terminal of a road management company or the like, but may also be a communication terminal possessed by the on-board device 30 of the vehicle 20 or the driver of the vehicle 20.

[0045] The above description is merely an example, and the present invention is not limited to the above-described embodiment and modifications, as long as the features of the present invention are not impaired. One or more of the above-described embodiment and modifications can be arbitrarily combined, and modifications can also be combined with each other. [Explanation of symbols]

[0046] 10 Information providing device, 20, 20-1 to 20-n Vehicle, 30 In-vehicle device, 11 Calculation unit, 111 Information acquisition unit, 112 Prediction unit, 113 Output unit, 114 Communication control unit, 12 Storage unit

Claims

1. a driving information acquisition unit that acquires driving information including position information of a vehicle driving within a predetermined area and operation information indicating an operation state or a stop state of a predetermined device that is operated when snow is falling or accumulated; a map information acquisition unit that acquires map information including road information; a weather information acquisition unit that acquires weather information for the predetermined area; a generating unit that, when the weather information indicates that snowfall or strong winds after snowfall have occurred within a first predetermined period from a predetermined time point in the past to the present, calculates an average traveling speed of the vehicle within the predetermined area based on the position information acquired by the traveling information acquiring unit, and, when the calculated average traveling speed is lower than an average traveling speed of the vehicle within the predetermined area during a second predetermined period that is earlier than the first predetermined period, generates visibility impairment information that indicates the occurrence of visibility impairment for a driver of the vehicle traveling within the predetermined area based on the operation information; an output unit that outputs the visibility impairment information generated by the generation unit in association with information about the road.

2. 2. The information providing device according to claim 1, The information providing device is characterized in that the predetermined device includes at least one of a headlight, a wiper, a turn signal, an emergency flasher, and an anti-skid device.

3. 3. The information providing device according to claim 1, The generation unit calculates the average driving speed of the vehicle within the specified area based on the change in the vehicle's driving position indicated by the position information acquired by the driving information acquisition unit when the weather information indicates that snowfall or strong winds after snowfall occurred within the first specified period, and generates the visibility impairment information indicating that the driver has experienced visibility impairment when the calculated average driving speed is lower than the average driving speed of the vehicle within the specified area for the second specified period and the operation information indicates the operation state of the specified device.

4. 3. The information providing device according to claim 1, a snow removal information acquisition unit that acquires snow removal information indicating the date and time when snow was removed from the road; The information providing device is characterized in that the generation unit identifies the most recent date and time when snow removal was performed in the specified area based on the snow removal information acquired by the snow removal information acquisition unit, and determines the period from the most recent date and time to the present time as the first specified period.

5. 3. The information providing device according to claim 1, The travel information further includes vehicle identification information that can identify the vehicle height of the vehicle, The information providing device is characterized in that the driving information acquisition unit acquires the driving information of vehicles that are driving within the specified area and have a vehicle height greater than or equal to a specified value, based on the vehicle identification information.

6. 3. The information providing device according to claim 1, The driving information further includes posture information indicating a driving posture of the driver of the vehicle, When the weather information indicates that there has been snowfall or strong winds after snowfall within the first specified period, the generation unit calculates the average driving speed of the vehicle within the specified area based on the change in the vehicle's driving position indicated by the position information acquired by the driving information acquisition unit, and when the calculated average driving speed is lower than the average driving speed of the vehicle within the specified area for the second specified period and the driver's forward leaning posture is detected by the posture information acquired by the driving information acquisition unit, generates the visibility impairment information indicating that the driver has a visibility impairment.

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