Patent Application
20250225875
The present disclosure relates to a notification system.
Japanese Unexamined Patent Application Publication No. 2020-87884 (Patent Document 1) describes a street light system that includes a plurality of street lights installed along roads on which vehicles travel and can be lit in a plurality of light colors including at least one warning color, each having a sound sensor that collects sound from the surroundings and generates collected sound data, an acoustic signal processing unit that receives the collected sound data and detects a target sound indicating an emergency vehicle and its source position based on the collected sound data, and generates emergency vehicle route data that indicates the current position and traveling direction of the emergency vehicle, and a light color control unit that generates a warning color lighting signal that instructs to light up at least one street light installed on the traveling path of the emergency vehicle in a warning color based on the emergency vehicle route data.
In a specific aspect, the present disclosure can provide a notification system capable of performing notification of road markings or the like to traveling vehicles at appropriate timing according to road situation.
A notification system according to one aspect of the present disclosure is (a) a notification system configured to include a plurality of road lights installed along a road which are directly connected to mutually communicate with each other, (b) where each of the plurality of road lights includes:
According to the above configuration, there is provided a notification system capable of performing notification of road markings or the like to traveling vehicles at appropriate timing according to road situation.
The notification system 100 according to the present embodiment is configured to include a plurality of road lights arranged on a side of the road, and when a pedestrian 102 who crosses the road (refer to as a “crosser” hereinafter in this specification) is present and when a running vehicle 103 and 104 are present on the road, road marking images 105 and 106 are drawn on the road surface visible to the passengers (e.g., drivers) of the running vehicles 103 and 104. By drawing such road marking images 105 and 106, it is possible to alert the passengers of the running vehicles 103 and 104 to the presence of the pedestrian 102, and also to alert the pedestrian 102 to the presence of the vehicles 103 and 104.
The road lights A1 to A9 are directly connected to mutually communicate with each other without going through the management server 10. Specifically, each of the road lights A1 to A9 are associated with each other as one group, and are connected so that they can communicate with each other within this group. And, data from one road light can be sent to all the other road lights and can be shared within the group.
Each road light A1 to A9 is assigned an individual identification number to identify itself, and its installation location (latitude and longitude) is also assigned.
As shown in
The management server 10 is connected to each of the road lights A1 to A9 so that they can communicate one-to-one. Communication between the management server 10 and each of the road lights A1 to A9 is configured to occur only when necessary in order to reduce the amount of communication data. Specifically, when any of the road lights A1 to A9 determines through its own self-diagnosis function that a malfunction has occurred, such as an inability to perform autonomous control, the road light with the malfunction sends data including malfunction information to the management server 10. In such a case, the management server 10 takes over control of the road light with the malfunction.
Further, the management server 10 communicates with each of the road lights A1-A9 when a system update or other such needs arise. Further, when necessary, the management server 10 can also request each of the road lights A1-A9 to transmit data indicating their operating status, image data generated by the cameras equipped in each of the road lights A1-A9, and other data communicated between the road lights A1-A9, and acquire those data.
The camera 21 is connected to the autonomous control unit 22, and photographs a predetermined range of the road corresponding to the location of the road light A1 and outputs its image data to the autonomous control unit 22.
The autonomous control unit 22 has an image processing unit 31 that detects the presence or absence of objects such as pedestrians and vehicles, as well as their respective traveling directions and speeds, by performing predetermined image processing on the image data (video data) output from the camera 21, and has a signal generating unit 32 that generates a signal indicating that the objects have been detected according to the detection result of the objects by the image processing unit 31 and outputs the data to a signal transmitting unit 33 of the communication unit 26. This autonomous control unit 22 can be realized by executing a predetermined operating program in a computer system such as that shown in
The road light illumination unit 23 is connected to the autonomous control unit 22, and is controlled by the autonomous control unit 22 to turn on in order to illuminate the road during specific time of the day, such as at night. The notification control unit 24 is connected to the autonomous control unit 22, and controls the operation of the notification unit 25 based on a signal generated by the signal generating unit 32 of the autonomous control unit 22, causing a predetermined road marking image to be drawn on the road. Further, the notification control unit 24 is connected to the signal receiving unit 34 of the communication unit 26, and controls the operation of the notification unit 25 based on signal data indicating the detection state of an object transmitted from the other road lights A2 to A9 and received by the signal receiving unit 34, causing a predetermined road marking image to be drawn on the road.
The notification unit 25 is connected to the notification control unit 24, and its operation is controlled by the notification control unit 24 to draw a predetermined road marking image on the road. The road marking image by the notification unit 25 can be set to various types such as letters, symbols, and icons. Further, the notification by the notification unit 25 is not limited to a road marking image, but may be a side surface warning light, or may be a direct notification to vehicles near the road light A1 via dedicated narrow-band communication or other communication. The following mainly describes road marking images as an example.
The communication unit 26 is connected to the autonomous control unit 22 and is used for data communication between the road light A1 and the other road lights A2 to A9. The communication unit has a signal transmitting unit 33 that transmits signal data generated by the signal generating unit 32 to each communication units 26 of the other road lights A2 to A9, and a signal receiving unit 34 that receives signal data transmitted from the communication units 26 of the other road lights A2 to A9. The communication unit 26 is also connected to the notification control unit 24, and the signal data received by the signal receiving unit 34 is also sent to the notification control unit 24.
Here, in the present embodiment, the signal generating unit 32 of the autonomous control unit 22 and the signal transmitting unit 33 of the communication unit 26 form a “first signal processing unit” and a “second signal processing unit”, and the notification control unit 24, the notification unit 25, and the signal receiving unit 34 of the communication unit 26 form a “notification execution unit”.
The CPU 201 performs information processing by reading and executing a program 207 stored in the storage device 204. The ROM 202 stores basic control programs and the like necessary for the operation of the CPU 201. The RAM 203 temporarily stores data necessary for the information processing of the CPU 201. The storage device 204 is a large-capacity storage device for storing data, and is comprised of a hard disk drive, solid state drive, or the like. The communication device 205 performs processing related to data communication with other external devices. The input/output unit 206 is an interface for connection to external devices, and in the present embodiment, is used for connection to the camera 21, the road light illumination unit 23, etc.
As shown in the figure, for example, assume that, based on the installation position of the road light A1, there is a vehicle 103 traveling to the right in the lane at the back side of a center line 132, there is a vehicle 104 traveling to the left in the figure at the front side of the center line 132, and there is a pedestrian 102 attempting to cross from the front side to the back side of the center line 132. At this time, the image processing unit 31 of the autonomous control unit 22 detects the direction of travel and speed of movement for each of vehicles 103, 104 by image processing.
Further, the image processing unit 31 detects the direction of travel and speed of movement of the pedestrian 102 who is crossing the road by image processing. Then the image processing unit 31 detects the pedestrian 102 as a crosser when the pedestrian 102 is moving in the direction of crossing the road. Here, note that regardless of the direction of travel of the pedestrian 102, when the pedestrian 102 is present within the photographing range, the unit may uniformly detect the pedestrian 102 as a crosser.
The signal generating unit 32 of the autonomous control unit 22 generates a vehicle detection signal indicating the presence of a vehicle 103 or vehicle 104, and generates a crosser detection signal indicating the presence of a pedestrian 102 who is a crosser, based on the detection results by the image processing unit 31. The data for these vehicle detection signals and crosser detection signals are each transmitted to the necessary road lights among the other road lights A2 to A9. The method for determining the necessary road lights will be described below.
Let “D” be the distance between adjacent road lights as described above (refer to
Here, α is a value for correcting the legal speed V2 in accordance with the actual road situation, and for example, can be set to a value equivalent to the difference between an actual vehicle average travel speed obtained by observing the target road within a certain period of time and the legal speed V2.
In the above calculation formula, (L/V1) is a term that calculates an estimate of the time required for the pedestrian 102 who is a crosser to cross the road (crossing time). By multiplying this crossing time by the term (V2+a), an estimated distance traveled by each vehicle during the crossing time can be obtained. By dividing this estimated travel distance by the distance D between the road lights, it is possible to obtain an estimate of how many road lights correspond to the estimated distance traveled by each vehicle. Furthermore, “+1” is added to allow for a margin in the number of road lights, and this number may be set to 2 or more depending on the situation. Based on the number of road lights obtained by this calculation formula, crosser detection signal data is transmitted to the nearby road lights on both sides. For example, if the number of road lights determined for the road light A5 is two, crosser detection signal data is transmitted to the road lights A3, A4, A6, and A7, two on each side of the road light A5.
Following is a concrete numerical example and a calculation example of the number of road lights based on the numerical example. Let the road width L be 7 (m), the moving speed V1 of the pedestrian 102 who is a crosser be 1.3 (m/s), the legal speed V2 be 50 (km/h), i.e. 14 (m/s), the correction value a be 0 (m/s), and the distance D between the road lights be 30 (m). Then, the number of calculated road lights based on the above calculation formula becomes 3.5, which can be rounded up to 4. In this case, by using one road light as a reference, crosser detection signal data is sent to four road lights on each side of the referenced road light.
Further, regardless of the presence or absence of a pedestrian 102, when vehicles 103, 104 are present, based on the estimated stopping distance F predicted from the vehicle speeds (traveling speeds) of these vehicles, the number of road lights that becomes the target for transmitting a vehicle detection signal can be determined as follows. Here, note that the estimated stopping distance F refers to the distance that is estimated to be required for a vehicle to stop, and may be determined based on the legal speed V2. Further, the estimated stopping distance F may also be set variably depending on the weather, such as when it is raining.
As an example, if the estimated stopping distance F on a dry road surface when the traveling speed is 50 (km/h) is 24.5 (m) and the distance D between road lights is 30 (m), the number of road lights according to the above calculation formula becomes 1.81, which can be rounded up to 2. In this case, based on one road light, vehicle detection signal data is transmitted to two road lights which exist in the direction of travel of the vehicle. For example, if only vehicle 103 is detected at the road light A5 and the vehicle is traveling in the direction toward the road light A6, vehicle detection signal data is transmitted to the road light A6 and the next road light A7.
The autonomous control unit 22 of the road light A1 performs a self-diagnosis to determine whether autonomous control is possible, and when autonomous control is not possible (step S11; NO), the process transitions to a fail-safe control mode (step S12). The fail-safe control mode is a mode in which alternative control is performed by the management server 10.
When autonomous control is possible (step S11; YES), the image processing unit 31 of the autonomous control unit 22 performs image processing based on the image data obtained by the camera 21, and when the lanes are distinguishable (step S13; YES), the process proceeds to detection of a crosser and a traveling vehicle. Here, the phrase “the lanes are distinguishable” refers to a situation where the lanes can be detected, not a situation where the lanes are hidden by snowfall or other factors and cannot be detected by image processing. The process when the lanes are not distinguishable (steps S25, S26) will be described later.
When a pedestrian who is a crosser is present within the photographing range (step S14; YES), the image processing unit 31 detects the crossing direction of the crosser and detects the crossing time of the crosser based on the road width L and the crosser's movement speed V1 (step S15). Further, the signal generating unit 32 calculates the number of road lights to which a crosser detection signal is to be transmitted based on the above calculation formula (step S16).
The signal generating unit 32 generates a crosser detection signal and transmits data of the crosser detection signal to the other road lights which were determined based on the number of road lights calculated in step S16 (step S17).
On the other hand, when there is no pedestrian crossing the road (step S14; NO), the image processing unit 31 does not perform steps S15 to S17, and proceeds to the following process. Specifically, when there exists a traveling vehicle within the photographing range (step S18; YES), the image processing unit 31 detects the vehicle's direction of travel and detects the vehicle speed (step S19). The vehicle speed can be calculated, for example, based on the amount of change in the vehicle's position and the elapsed time from a certain time to the next time.
Next, the signal generating unit 32 calculates the number of road lights to which a vehicle detection signal is to be transmitted using the above calculation formula based on the estimated stopping distance predicted from the calculated vehicle speed (step S20).
The signal generating unit 32 generates a vehicle detection signal and transmits the data of the vehicle detection signal to the other road lights which were determined based on the number of road lights calculated in step S20 (step S21). Here, when no vehicle is present (step S18; NO), the process proceeds to step S22 without performing steps S19 to S21.
When data of the vehicle detection signal transmitted from the other road light is received by the signal receiving unit 34 of the communication unit 26 (step S22; YES), and data of the crosser detection signal transmitted from the other road light is received by the signal receiving unit 34 of the communication unit 26 (step S23; YES), the notification control unit 24 controls the notification unit 25 to form a predetermined road marking image on the road surface. As a result, the road marking image is formed on the road surface (step S24). Thereafter, the process returns to step S11, and the subsequent processes are repeated.
Here, when the data of the vehicle detection signal transmitted from the other road light is not received (step S22; NO), or the data of the crosser detection signal transmitted from the other road light is not received (step S23; NO), the notification control unit 24 does not control to cause the formation of the road marking image. In this case as well, the process returns to step S11, and the subsequent processes are repeated.
Further, in the above-described step S13, when the lanes cannot be identified (step S13; NO), the image processing unit 31 reads out road data that has been prepared in advance and stored in a memory (not shown) (step S25), and based on this road data, synthesizes the area information such as lanes or the like with the image data obtained by the camera 21 (step S26). The road data referred to here is assumed to be extracted from the image data photographed by the camera 21 of each of the road light A1, etc. and stored in memory, when the road lights A1 to A9 are initially installed. By using such road data, it is possible to execute each process from step S14 onward, even when the lanes cannot be detected due to snowfall or the like. As shown in the figure, after the process of step S26 is completed, the process proceeds to step S14.
As shown in
Further, the road light A4 detects the other vehicle 103 in lane B, and therefore transmits a vehicle detection signal to the road lights A5-A7 which exists in the direction of travel of vehicle 103 according to the vehicle's speed. Further, the road light A9 detects vehicle 104 in lane C, and therefore transmits a vehicle detection signal to the road lights A6-A8 which exists in the direction of travel of vehicle 104 according to the vehicle's speed. In the figure, a state of having a vehicle detection signal is indicated by a circle.
Thus, since each of the road lights A1, A2, A4 to A8 receives a vehicle detection signal for lane B and/or lane C but does not receive a crosser detection signal, each of the road lights does not perform any operation to form a road marking image on the road surface. Further, since the road light A3 does not receive either a vehicle detection signal or a crosser detection signal, the road light does not perform any operation to form a road marking image on the road surface. Therefore, in this example, none of the road lights A1 to A9 form a road marking image.
As shown in
Further, since the road light A1 detects one vehicle 103 in lane B, depending on the vehicle's speed, the road light A1 transmits a vehicle detection signal related to lane B (B-lane vehicle detection signal) to the road lights A2 to A5 which exist in the direction of travel of the vehicle 103.
Further, since the road light A6 detects the other vehicle 103 in lane B, depending on the vehicle's speed, the road light A6 transmits a vehicle detection signal related to lane B (B-lane vehicle detection signal) to the road lights A7-A9 which exist in the direction of travel of the vehicle 103.
Further, since the road light A7 detects the vehicle 104 in lane C, depending on the vehicle's speed, the road light A7 transmits a vehicle detection signal related to lane C (C-lane crosser detection signal) to the road lights A4 to A6 which exist in the direction of travel of the vehicle 104.
At this time, since the road light A1 does not receive a vehicle detection signal nor a crosser detection signal related to lane B and/or lane C, the road light does not perform operation of forming a road marking image on the road surface. Since the road lights A2 to A5 receive a crosser detection signal related to lane B (B-lane crosser detection signal) and a vehicle detection signal related to lane B (B-lane vehicle detection signal), the road lights form road marking images 106 on the road surface of lane B as shown in
According to the above embodiment, each of the grouped road lights autonomously detects vehicles and crossers, and transmits and receives vehicle detection signal data and crosser detection signal data corresponding to the detection results directly within the group without going through the server 10, and the road light that has acquired both the vehicle detection signal and the crosser detection signal forms a road marking image for each lane. Thereby, this suppresses unnecessary alert being called out, and can alert (notify) the passengers of each vehicle and crossers by using road markings or the like at an appropriate timing according to the road situation.
Further, since only the road light whose number and position corresponding to the moving speed of the crosser and each vehicle forms a road marking image, more than necessary road marking images are not formed. As a result, less necessary alert to the passengers of each vehicle and pedestrians surrounding the road is suppressed.
Further, since data is transmitted and received directly between the road lights without going through a host device such as the server 10, communication delay is reduced, and the vehicle detection signal and the crosser detection signal data can be transmitted and received more quickly. Therefore, this makes it possible to control with finer time resolution, and a notification system with superior responsiveness can be constructed.
Here, the present disclosure is not limited to the content of the embodiment described above, and can be implemented with various modifications within the scope of the gist of the present disclosure. For example, in the above-described embodiment, a pedestrian is shown as an example of a crosser, but a rider of a bicycle or the like may also be treated as a crosser.
Further, when each road light detects a crosser and also detects a vehicle, rather than forming a road marking image directly below its own road light, the road marking image may be formed at a position shifted to the left or right in the direction of travel of the vehicle. This can avoid overlapping of a pedestrian who is a crosser with the road marking image, which makes the road marking image easier to visualize.
Further, the color tone and image type of the road marking image may be changed between daytime and night time. For example, it is conceivable to form a road marking image in a color tone that is not easily obscured by sunlight during daytime (e.g., a strong red color tone, as sunlight is close to white), and a road marking image in a color tone that is not easily obscured by other lighting during night time (e.g., any color tone different from the other lighting may suffice, if the other lighting is a yellowish color, a white color tone or a strong red color tone or the like may suffice).
Further, the illumination state of each road light may be changed when forming a road marking image. For example, it is conceivable to increase the brightness of the road marking image more than that of the illumination light by the road light illumination unit 23 when forming the road marking image.
Further, when a pedestrian who is a crosser is crossing the road diagonally, the crossing distance can be predicted from its direction of travel, and the time required for the movement can be calculated based on the predicted crossing distance, and then the number of road lights that are targets for transmitting a crosser detection signal may be calculated.
Further, the vehicles to be detected are not limited to four-wheeled vehicles in the above-described embodiment, and may include various vehicles such as two-wheeled vehicles.
Further, in the above-described embodiment, the road width L has been treated as a known value, but it may also be obtained from the image data photographed by a camera or obtained by a distance sensor. In such a case, values such as road width and travel speed may be treated as absolute values (actual values), or as relative values based on the number of pixels in the image data, frame rate, etc.
Furthermore, as referred to in the above-described embodiment, road data may be obtained in advance and stored in memory in case lanes cannot be detected due to snowfall or the like. Specifically, in reference to two-dimensional information of image data obtained from the camera of a road light, lane information, vehicle travel direction, number of lanes, road width (road side strip width, lane width, center line width, median strip width) or the like may be stored in memory as coordinate values. For example, as shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-039515 | Mar 2022 | JP | national |
This application is a U.S. National Stage Application under 35 U.S.C § 371 of International Patent Application No. PCT/JP2023/008138 filed Mar. 3, 2023, which claims the benefit of priority under 35 U.S. C. § 119 to Japanese Patent Application No. 2022-039515 filed Mar. 14, 2022, the disclosures of all of which are hereby incorporated by reference in their entireties.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2023/008138 | 3/3/2023 | WO |
