JP7585867B2 - Traffic information system and method for providing traffic information - Google Patents

Description

This disclosure relates to a traffic information system and a method for providing traffic information using DSRC.

Technology has been disclosed in the past that provides traffic information to vehicles so that the vehicles can take desired actions to prevent traffic accidents (see, for example, Patent Document 1).

In Patent Document 1, a higher-level device generates traffic information for all lanes, and an information provision determination device transmits the traffic information using radio waves that propagate over a wide area from an information-provision DSRC roadside device, and the vehicle receives this traffic information. Also, a light sensor transmits lane information using light waves that propagate only over a narrow area, and the vehicle receives this lane information. The vehicle then extracts traffic information for the driving lane indicated by the lane information, controls the output of a warning message from the vehicle's car navigation system, and prompts the driver to slow down or change lanes. Furthermore, an evaluation device collects and evaluates vehicle driving log data via a log-collection DSRC roadside device, and controls the provision of information from the information provision determination device.

JP 2012-212445 A

In Patent Document 1, the vehicle collects driving log data when it receives light waves as a trigger, transmits the driving log data collected by the vehicle to a base station using a DSRC roadside unit for log collection, processes the driving log data in an evaluation device on the base station side to update traffic information, and provides the updated traffic information to other vehicles from the DSRC roadside unit for information provision. In other words, the driving log data collected by the vehicle is transmitted to the base station, which causes a delay in the information, resulting in a problem of delays in providing traffic information to vehicles.

This disclosure has been made to solve the above problems, and aims to provide a traffic information system and a traffic information providing method that reduce delays in providing traffic information.

The traffic information system according to the present disclosure includes a first DSRC base station that detects radio waves emitted by a DSRC in-vehicle device mounted on a vehicle traveling on a road, and a radar base station that is communicatively connected to the first DSRC base station via a network, and that, when notified via the network that the first DSRC base station has detected radio waves, measures the position and speed of a vehicle equipped with the DSRC in-vehicle device that is within a measurement range of a radar , collects driving log data, and updates traffic information based on the collected driving log data, and the driving log data contains information about the vehicle. and the radar is provided so that its measurement range is located at the same position as or downstream from the position of a vehicle equipped with a DSRC vehicle-mounted device when the first DSRC base station detects radio waves emitted by the DSRC vehicle-mounted device on the road, and when the first DSRC base station newly detects radio waves emitted by the DSRC vehicle-mounted device after the traffic information has been updated, the first DSRC base station obtains the updated traffic information from the radar base station via the network and transmits the traffic information to the DSRC vehicle-mounted device emitting the newly detected radio waves.

The traffic information providing method according to the present disclosure includes the steps of: detecting radio waves emitted by a DSRC vehicle-mounted device mounted on a vehicle traveling on a road with a first DSRC base station installed on a gantry on the road or on the roadside of the road; and transmitting, via a network, information that the first DSRC base station has detected the radio waves, at a radar base station installed on the gantry on the road or on the roadside of the road such that a radar measurement range is located at the same position as or downstream from the position of the vehicle equipped with the DSRC vehicle-mounted device when the radio waves emitted by the DSRC vehicle-mounted device are detected on the road by the first DSRC base station. Upon receiving the notification , the method includes the steps of: measuring the position and speed of a vehicle equipped with the DSRC in-vehicle device that is within the measurement range of the radar, collecting driving log data, and updating traffic information based on the collected driving log data including information about the vehicle ; and, after the traffic information has been updated, when the first DSRC base station detects new radio waves emitted by the DSRC in-vehicle device , obtaining the updated traffic information from the radar base station via the network and transmitting the traffic information to the DSRC in-vehicle device that is emitting the newly detected radio waves.

According to the traffic information system and traffic information providing method disclosed herein, when the first DSRC base station detects radio waves, the radar base station, not the vehicle, collects the vehicle's driving log data and updates the traffic information based on the collected driving log data. After the traffic information is updated, when the first DSRC base station detects radio waves, the updated traffic information is transmitted to the DSRC base station that is emitting the detected radio waves. This makes it possible to reduce delays in providing traffic information to vehicles compared to conventional methods.

1 is a diagram showing a configuration of a traffic information system according to an embodiment; FIG. 2 is a diagram showing an example of installation of base stations in the traffic information system according to the embodiment; 1 is a diagram showing a state in which vehicles A and B are traveling on a two-lane road on which base stations of a traffic information system according to an embodiment are installed. FIG. 2 is a diagram showing a control flow of the traffic information system according to the embodiment.

Below, an embodiment of the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the embodiment described below. Also, the size relationships of the components in the following drawings may differ from the actual ones.

Embodiment
FIG. 1 is a diagram showing a configuration of a traffic information system 100 according to an embodiment.
The traffic information system 100 according to the embodiment is a system that aims to improve the safety of vehicles and pedestrians at intersections and T-junctions by providing vehicles with information on danger at intersections, information on the color of traffic lights, information on vehicles that have ignored traffic lights, information on vehicles approaching from secondary roads, and the like. Traffic information is provided to vehicles by DSRC (Dedicated Short Range Communication), and various warnings are issued to drivers. DSRC is a short-range wireless communication technology specialized for vehicle communication, and although the communication distance is only several tens of meters, it is characterized by being faster than other short-range wireless communications. In addition, the traffic information system 100 uses a radar to measure the position and speed of the vehicle and collects driving log data. Note that the performance of the radar is not degraded by external environments such as weather and day and night, and the 24 GHz band millimeter wave radar in particular is characterized by being suitable for detecting obstacles at short to medium distances.

As shown in FIG. 1, the traffic information system 100 according to the embodiment includes a second DSRC base station 10, a first DSRC base station 20, and a radar base station 30. The second DSRC base station 10, the first DSRC base station 20, and the radar base station 30 are connected to each other via a network N so that they can communicate with each other. Each vehicle is equipped with a DSRC vehicle device 40.

The second DSRC base station 10 is installed on a gantry on the road or on the roadside, and includes a radio unit 11 and a control unit 12. The radio unit 11 communicates with the DSRC vehicle-mounted device 40 installed in each vehicle using radio waves as a carrier wave. The control unit 12 controls the radio unit 11. The control unit 12 is composed of, for example, dedicated hardware, or a CPU (Central Processing Unit, also called a central processing unit, processing unit, arithmetic unit, microprocessor, or processor) that executes a program stored in memory.

The first DSRC base station 20 is installed on a gantry on the road or on the roadside, and includes a radio unit 21 and a control unit 22. The radio unit 21 communicates with the DSRC vehicle-mounted device 40 installed in each vehicle using radio waves as a carrier wave. The control unit 22 controls the radio unit 21. The control unit 22 is composed of, for example, dedicated hardware, or a CPU (Central Processing Unit, also called a central processing unit, processing unit, arithmetic unit, microprocessor, or processor) that executes a program stored in memory.

The radar base station 30 is installed on a gantry on the road or on the roadside, and includes a wireless unit 31, a log collection unit 32, an evaluation processing unit 33, and a control unit 34. The wireless unit 31 transmits and receives radar waves. The log collection unit 32 collects driving log data. Here, the driving log data is data indicating vehicle driving information based on the vehicle's position and speed. The evaluation processing unit 33 processes the driving log data. Specifically, the evaluation processing unit 33 evaluates the vehicle driving information indicated by the driving log data collected by the log collection unit 32 and updates the traffic information. Here, the traffic information is congestion information, construction information, accident information, danger information at intersections, traffic light color information, information on vehicles that have ignored traffic lights, and information on vehicles approaching from minor roads. The control unit 34 controls the wireless unit 31, the log collection unit 32, and the evaluation processing unit 33. The control unit 34 is composed of, for example, dedicated hardware or a CPU (Central Processing Unit, also called a central processing unit, processing unit, arithmetic unit, microprocessor, or processor) that executes programs stored in memory.

The DSRC in-vehicle device 40 is mounted on a vehicle and includes a radio unit 41 and a control unit 42. The radio unit 41 communicates with the second DSRC base station 10 and the first DSRC base station 20 using radio waves as a carrier wave. The control unit 42 controls the radio unit 41. The control unit 42 is configured, for example, by dedicated hardware or a CPU (Central Processing Unit, also called a central processing unit, processing unit, arithmetic unit, microprocessor, or processor) that executes a program stored in memory.

Figure 2 is a diagram showing an example of the installation of each base station of the traffic information system 100 according to the embodiment. Figure 3 is a diagram showing a state in which vehicles A and B are traveling on a two-lane road on which each base station of the traffic information system 100 according to the embodiment is installed.

2 and 3, the second DSRC base station 10 is installed on the roadside at an intersection or before the intersection. The first DSRC base station 20 is installed on the roadside upstream of the position where the second DSRC base station 10 is installed. In other words, the first DSRC base station 20 is installed on the upstream side, and the second DSRC base station 10 is installed on the downstream side. The radar base station 30 is installed on the roadside between the position where the second DSRC base station 10 is installed and the position where the first DSRC base station 20 is installed, and closer to the first DSRC base station 20. In addition, the DSRC vehicle-mounted device 40 is mounted on each vehicle. Note that the position where the radar base station 30 is installed is not limited to the above. For example, the radar base station 30 may be installed on the roadside upstream of the position where the first DSRC base station 20 is installed, or on the roadside downstream of the position where the second DSRC base station 10 is installed.

The first DSRC base station 20 constantly detects whether a vehicle is approaching. Specifically, the first DSRC base station 20 determines whether there is radio waves emitted by the DSRC vehicle-mounted device 40 mounted on the vehicle, and if it determines that there is radio waves, it detects that a vehicle is approaching. The first DSRC base station 20 receives radio waves and determines that there is radio waves when the strength of the received radio waves is equal to or greater than a reference value, and otherwise determines that there is no radio waves. The second DSRC base station 10 also constantly detects whether a vehicle is approaching. Then, when the first DSRC base station 20 detects that a vehicle is approaching, this triggers the radar base station 30 to measure the position and speed of the vehicle and collect driving log data. The radar base station 30 evaluates the vehicle's driving information indicated by the collected driving log data and updates the traffic information. Then, when the second DSRC base station 10 detects the approach of a vehicle, the second DSRC base station 10 provides traffic information to the vehicle equipped with the DSRC in-vehicle device 40 that is emitting the detected radio wave. Furthermore, when the first DSRC base station 20 detects the approach of another vehicle, it provides traffic information to the other vehicle equipped with the DSRC in-vehicle device 40 that is emitting the detected radio wave.

In the example shown in FIG. 3, vehicles A and B are traveling on a two-lane road, with vehicle A traveling ahead of vehicle B in the left lane. In addition, a first DSRC base station 20, a radar base station 30, and a second DSRC base station 10 are installed on the side of the road in this lane, and vehicles A and B are traveling in a direction passing by the first DSRC base station 20, the radar base station 30, and the second DSRC base station 10 in that order. In addition, vehicle C is traveling in the oncoming lane. The operation of each component of the traffic information system 100 at this time is described below.

First, when vehicle A passes by the first DSRC base station 20, the first DSRC base station 20 receives radio waves emitted by the DSRC in-vehicle device 40 mounted on vehicle A. Then, when the first DSRC base station 20 detects that vehicle A is approaching, this triggers the radar base station 30 to measure the position and speed of vehicle A and collect driving log data. At this time, vehicle A changes lanes to the right lane to turn right at the intersection ahead. The radar base station 30 evaluates the driving information of vehicle A indicated by the collected driving log data and updates the traffic information. Then, when the second DSRC base station 10 detects the approach of vehicle A, the second DSRC base station 10 provides traffic information to vehicle A equipped with the DSRC in-vehicle device 40 that is emitting the detected radio waves. Furthermore, when the first DSRC base station 20 detects the approach of vehicle B traveling behind vehicle A, the first DSRC base station 20 provides traffic information to vehicle B equipped with the DSRC in-vehicle device 40 that is emitting the detected radio wave. At this time, the traffic information includes information about the congestion ahead due to vehicle A waiting at the intersection for vehicle C to pass through the intersection, and alerts vehicle B to the road ahead. Note that vehicle B may be prompted to change lanes to the left lane in case vehicle B wishes to continue straight ahead.

Conventionally, vehicles would collect driving log data, transmit it to a DSR base station, and then process the collected driving log data to update traffic information. On the other hand, in the embodiment, the radar base station 30 measures the vehicle's position and speed, collects driving log data, processes the collected driving log data, and updates traffic information, so there is little information delay and driving assistance can be provided according to new traffic information or traffic conditions.

FIG. 4 is a diagram showing a control flow of the traffic information system 100 according to the embodiment.
The control flow of the traffic information system 100 according to the embodiment will be described below with reference to FIG.

(Step S1)
The first DSRC base station 20 judges whether or not it has detected radio waves. If it has detected radio waves (YES), the process proceeds to step S2. On the other hand, if it has not detected radio waves (NO), the process repeats step S1.

(Step S2)
The radar base station 30 measures the position and speed of the vehicle (hereinafter referred to as vehicle A) equipped with the DSRC in-vehicle device 40 that is emitting the radio wave detected by the first DSRC base station 20, and collects driving log data. After that, the process proceeds to step S3.

(Step S3)
The radar base station 30 processes the collected travel log data and updates the traffic information. Then, the process proceeds to step S4.

(Step S4)
The first DSRC base station 20 judges whether or not it has detected radio waves. If it has detected radio waves (YES), the process proceeds to step S5. On the other hand, if it has not detected radio waves (NO), the process repeats step S4.

(Step S5)
The first DSRC base station 20 provides updated traffic information to a vehicle (hereinafter referred to as vehicle B) equipped with a DSRC in-vehicle device 40 that is emitting the detected radio wave. Here, vehicle B is a vehicle traveling behind vehicle A.

In this way, the detection of radio waves from the leading vehicle A by the first DSRC base station 20 is used as a trigger to allow the trailing vehicle B to obtain traffic information including the driving log data of vehicle A updated by the radar base station 30.

As in steps S4 to S5, the second DSRC base station 10 determines whether it has detected radio waves, and if it determines that it has detected radio waves, the second DSRC base station 10 may provide traffic information to vehicle A equipped with the DSRC in-vehicle device 40 that is emitting the detected radio waves.

The traffic information system 100 according to the embodiment includes a first DSRC base station 20 that detects radio waves emitted by a DSRC vehicle-mounted device 40 mounted on a vehicle traveling on a road, and a radar base station 30 that, when the first DSRC base station 20 detects radio waves, measures the position and speed of the vehicle equipped with the DSRC vehicle-mounted device 40 that is emitting the radio waves detected by the first DSRC base station 20, collects driving log data, and updates traffic information based on the collected driving log data. After the traffic information is updated, when the first DSRC base station 20 detects radio waves emitted by the DSRC vehicle-mounted device 40, it transmits the updated traffic information to the DSRC vehicle-mounted device 40 that is emitting the detected radio waves.

The traffic information providing method according to the embodiment includes the steps of: detecting radio waves emitted by a DSRC vehicle-mounted device 40 mounted on a vehicle traveling on a road with a first DSRC base station 20 installed in a gantry on the road or on the roadside; measuring the position and speed of the vehicle equipped with the DSRC vehicle-mounted device 40 emitting the radio waves detected by the first DSRC base station 20 with a radar base station 30 installed in a gantry on the road or on the roadside when the first DSRC base station 20 detects the radio waves, collecting driving log data, and updating the traffic information based on the collected driving log data; and transmitting the updated traffic information to the DSRC vehicle-mounted device 40 emitting the detected radio waves after the traffic information is updated with the first DSRC base station 20 when the first DSRC base station 20 detects the radio waves emitted by the DSRC vehicle-mounted device 40.

According to the traffic information system 100 and traffic information providing method of the embodiment, when the first DSRC base station 20 detects radio waves, the radar base station 30, not the vehicle, collects the vehicle's driving log data and updates the traffic information based on the collected driving log data. Then, after the traffic information has been updated, when the first DSRC base station 20 detects radio waves, it transmits the updated traffic information to the DSRC in-vehicle device 40 that is emitting the detected radio waves. This makes it possible to reduce delays in providing traffic information to vehicles compared to conventional methods.

The traffic information system 100 according to the embodiment further includes a second DSRC base station 10 downstream of the first DSRC base station 20 that detects radio waves emitted by a DSRC vehicle-mounted device 40 mounted on a vehicle traveling on a road. When the second DSRC base station 10 detects radio waves emitted by the DSRC vehicle-mounted device 40, it transmits traffic information to the DSRC vehicle-mounted device 40 that is emitting the detected radio waves.

The traffic information providing method according to the embodiment includes a step in which, when a second DSRC base station 10 installed on a gantry on the road downstream of the first DSRC base station 20 or on the roadside detects radio waves emitted by a DSRC vehicle-mounted device 40, the second DSRC base station 10 transmits traffic information to the DSRC vehicle-mounted device 40 that is emitting the detected radio waves.

According to the traffic information system 100 and the traffic information providing method of the embodiment, traffic information can be provided to other vehicles traveling behind the vehicle that triggered the collection of driving log data, and traffic information can also be provided to the vehicle itself that triggered the collection of driving log data, allowing the vehicles in front and behind to avoid congestion, etc.

Note that the traffic information system 100 according to the embodiment is configured with two DSRC base stations and one radar base station, but is not limited to this, and may have three or more DSRC base stations, or two or more radar base stations.

10 Second DSRC base station, 11 Radio unit, 12 Control unit, 20 First DSRC base station, 21 Radio unit, 22 Control unit, 30 Radar base station, 31 Radio unit, 32 Log collection unit, 33 Evaluation processing unit, 34 Control unit, 40 DSRC vehicle device, 41 Radio unit, 42 Control unit, 100 Traffic information system.

Claims (4)

a first DSRC base station for detecting radio waves emitted by a DSRC vehicle-mounted device mounted on a vehicle traveling on a road;
a radar base station that is communicatively connected to the first DSRC base station via a network, and that, when notified via the network that the first DSRC base station has detected radio waves, measures the position and speed of a vehicle equipped with the DSRC in-vehicle device that is within a measurement range of a radar , collects travel log data, and updates traffic information based on the collected travel log data;
The traveling log data includes information about the vehicle,
a measurement range of the radar is set to be located at the same position as or downstream of a position of a vehicle equipped with a DSRC vehicle-mounted device when a radio wave emitted by the DSRC vehicle-mounted device is detected by the first DSRC base station on the road;
The first DSRC base station:
After the traffic information is updated,
When a new radio wave emitted by the DSRC vehicle-mounted device is detected, the traffic information system obtains updated traffic information from the radar base station via the network and transmits the traffic information to the DSRC vehicle-mounted device that is emitting the newly detected radio wave. a second DSRC base station that is downstream of the first DSRC base station and detects radio waves emitted by a DSRC vehicle-mounted device mounted on a vehicle traveling on a road;
The second DSRC base station:
a radar base station connected to the network for communication therewith;
2. The traffic information system according to claim 1, wherein, when radio waves emitted by the DSRC vehicle-mounted device are detected, updated traffic information is obtained from the radar base station via the network, and the traffic information is transmitted to the DSRC vehicle-mounted device that is emitting the detected radio waves. A step of detecting radio waves emitted by a DSRC vehicle-mounted device mounted on a vehicle traveling on the road, using a first DSRC base station installed on a gantry on the road or on the roadside of the road;
a radar base station installed on a gantry on the road or on the roadside of the road so that its radar measurement range is located at the same position as or downstream of the position of a vehicle equipped with the DSRC in-vehicle device when the radio waves emitted by the DSRC in-vehicle device are detected on the road by the first DSRC base station, when the first DSRC base station is notified via a network that it has detected the radio waves, measures the position and speed of a vehicle equipped with the DSRC in-vehicle device that is within the radar measurement range , collects driving log data, and updates traffic information based on the collected driving log data including information about the vehicle ;
and when the first DSRC base station detects new radio waves emitted by the DSRC vehicle-mounted device after updating the traffic information, acquiring the updated traffic information from the radar base station via the network and transmitting the traffic information to the DSRC vehicle-mounted device emitting the newly detected radio waves. 4. The traffic information providing method according to claim 3, further comprising a step of, when a second DSRC base station installed in a gantry on the road downstream of the first DSRC base station or on the roadside of the road detects radio waves emitted by the DSRC vehicle-mounted device, acquiring updated traffic information from the radar base station via the network and transmitting the traffic information to the DSRC vehicle-mounted device emitting the detected radio waves.

Images