KR102248588B1 - Vehicle positioning system in tunnel using wave communication and radar - Google Patents

Abstract

The present invention relates to a vehicle positioning system in a tunnel using wave communication and radar. The vehicle positioning system in a tunnel using wave communication and radar, according to the present invention, comprises: a road side unit (RSU) which receives basic safety message (BSM) information including GPS-based location and time information from a vehicle terminal installed in the vehicle entering the tunnel; the radar which is installed in the tunnel, detects each vehicle entering the tunnel, generates information about the location and time of each vehicle, and transmits the generated information; and a control device which matches the information on the location and time of the vehicle received through the road side device and the radar, corrects an error when the vehicle recognition error occurs from the radar as a result of matching, and determines the locations of continuous vehicles. According to the present invention, the vehicle in the tunnel can be tracked by matching a signal received from the radar and a BSM received from the vehicle, and there is no need for separate radar installation in the vehicle, thereby reducing costs and increasing location accuracy. In addition, information on the vehicle not detected by the radar can be detected using a linked list between the vehicles.

Description

Vehicle positioning system in tunnel using wave communication and radar

The present invention relates to a vehicle positioning system in a tunnel using wave communication and radar, and more particularly, before and after tunnel entry by synchronizing a GPS tracking signal before entering the tunnel and a radar tracking signal after entering the tunnel through wave communication. It relates to a vehicle positioning system capable of positioning the vehicles of the.

It is assumed that WAVE communication uses vehicle technology based on the EEE 802.11p standard. Currently, it is used under the name C-ITS in Korea.

The IEEE 802.11p protocol is composed of an OBU (On-Board Unit) installed in a vehicle and an RSU (Road Side Unit) built in the road to support communication between the vehicle and various detectors (eg, radar) on the road. Specifically, the terminals (OBU and RSU) are based on a competition technique called CSMA/CA (Carrier Sense Multiple Access and Collision Avoidance) for wireless medium access.

In addition, each vehicle broadcasts its own status information (ID, location, speed, direction, etc.) at intervals of 100ms using BSM (Basic Safety Message) to notify surrounding vehicles. In addition, the BSM broadcast from a plurality of vehicles is transmitted using a channel contention scheme to avoid collision between packets.

However, when a vehicle enters the tunnel, it cannot receive a GPS signal, and thus location tracking is impossible. Therefore, conventionally, a radar was installed in a tunnel to track a vehicle in real time. However, since Radar allocates an ID by itself, a problem occurs that does not match the ID of the vehicle included in the BSM. For example, if three vehicles A, B, and C enter the tunnel before entering the tunnel, three movements can be checked, but it is not possible to explicitly distinguish which object is A, B, or C. This is because Radar assigns its own ID (eg X, Y, Z).

In addition, the detection of the vehicle may fail due to an error in signal reception of the radar and GPS itself. For example, 3 vehicles enter the tunnel, but the radar recognizes only 2 (False Negative), or only 1 enters, but recognizes as 2 or more. (False Positive)

Accordingly, in the present invention, the GPS-based vehicle ID before the tunnel entry and the radar-based ID after the tunnel entry are mapped, and at the same time, an error in recognition is reduced through a linked list of vehicles.

The technology behind the present invention is disclosed in Korean Patent Publication No. 10-1663985 (announced on October 4, 2016).

The technical problem to be achieved by the present invention is to use wave communication and radar that can locate vehicles before and after entering the tunnel by synchronizing the GPS tracking signal before entering the tunnel and the radar tracking signal after entering the tunnel through WAVE communication. It is an object to provide a vehicle positioning system in a tunnel.

In the vehicle positioning system in a tunnel using wave communication and radar according to an embodiment of the present invention for achieving this technical problem, BSM (Basic Safety Message), a roadside unit (RSU) that receives information, installed in the tunnel, and a radar that detects each vehicle entering the tunnel and generates and transmits information on the location and time of each vehicle, And a control device that mutually matches the information on the location and time of the vehicle received through the roadside device and the radar, and when a vehicle recognition error occurs from the radar as a result of the matching, corrects the error to determine the position of consecutive vehicles. Includes.

The BSM includes at least one of the ID, coordinates, speed, traveling direction, brake state, and size of the vehicle,

The vehicle terminal may broadcast the BSM based on a competition technique of CSMA/CA (Carrier Sense Multiple Access and Collision Avoidance).

The vehicle terminal generates a linked list using IDs of vehicles located in the front and rear sides of the same lane based on the own vehicle, and further includes the generated linked list in the BSM to broadcast. Can be cast.

When the vehicle terminal transmits the BSM to the roadside device immediately before the vehicle enters the tunnel, the vehicle terminal may adjust the contention window (CW) value of the backoff.

Contention window (New_CW) value of the back-off, can be changed to a minimum value of (CW_ _min) and maximum values (= _max CW_ CW_ _min + tunnel front position) according to the following equation.

Here, the position in front of the tunnel represents the distance value in meters from which the vehicle enters the tunnel.

The vehicle terminal may set the contention window value to a normal range when the vehicle enters the tunnel.

The control device receives the BSM from the roadside device, a receiving unit that receives the vehicle ID, location, and time information measured through a radar, respectively, the vehicle ID, location, and time information included in the BSM, and A matching unit that creates a mapping table by mapping the ID, location, and time information of the vehicle detected by the radar, the error of the radar is generated by comparing the connection list of vehicles included in the BSM with the number of vehicles detected by the radar A determination unit that determines whether or not, and if it is determined as an error, correction is performed using the context of the consecutive vehicles included in the connection list of the vehicle and the location information of the vehicle included in the BSM received at the time of entering the tunnel. It may include a control unit that performs.

If the number of vehicles included in the connection list is greater than the number of vehicles detected through the radar, the control unit determines it as a negative error,

If it is determined as a negative error, an undetected vehicle may be detected using the context of a vehicle included in the connection list, and a new radar ID and vehicle information may be generated for the undetected vehicle.

When the number of vehicles included in the connection list is less than the number of vehicles detected by the radar, the control unit determines it as a positive error,

If it is determined as a positive error, it is possible to select a vehicle in a position closest to the radar from among a plurality of vehicles detected by the radar at the time of entering the tunnel, and delete ID, location, and time information for the remaining vehicles.

The vehicle terminal performs wave communication through a control channel (CCH, Control Channel) and a service channel (SCH, Service Channel), and transmits and receives BSM through a control channel (CCH) when the vehicle enters the tunnel. , It is possible to transmit and receive an accident or warning message through the service channel (SCH).

As described above, according to the present invention, the vehicle in the tunnel can be tracked by matching the signal received from the radar and the BSM received from the vehicle. Position accuracy can be improved. In addition, information on vehicles not detected by radar can be detected using a linked list between vehicles.

In addition, according to the present invention, the BSM of the vehicle at the time of entering the tunnel can be selected and transmitted with a high priority, and since real-time vehicle tracking in the tunnel is possible, immediate monitoring and response in the event of an accident is possible.

1 is a block diagram illustrating a vehicle positioning system according to an embodiment of the present invention.
2 is a flowchart illustrating a method of performing communication using the IEEE 802.11p protocol.
3 is a flowchart illustrating a method of transmitting and receiving a BSM using the vehicle terminal shown in FIG. 1.
FIG. 4 is a diagram illustrating generation and maintenance of a connection list in step S320 shown in FIG. 3.
FIG. 5 is a diagram for explaining step S340 shown in FIG. 3.
6 is a configuration diagram illustrating the control device illustrated in FIG. 1.
7 is a flowchart illustrating a method of positioning a vehicle in a tunnel using the control device shown in FIG. 6.
FIG. 8A is a diagram illustrating a matched state at a time point T1 in step S730 shown in FIG. 7.
FIG. 8B is a diagram illustrating a matched state at a time point T2 in step S730 shown in FIG. 7.
FIG. 8C is a diagram illustrating a matched state at a time point T3 in step S730 shown in FIG. 7.
FIG. 8D is a diagram illustrating a matched state when vehicles A and B enter at the same time at a time point T2 in step S730 shown in FIG. 7.
9A is a diagram illustrating a method of correcting a negative error in step S750 shown in FIG. 7.
9B is a diagram illustrating a method of correcting a positive error in step S750 shown in FIG. 7.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thickness of the lines or the size of components shown in the drawings may be exaggerated for clarity and convenience of description.

In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of users or operators. Therefore, definitions of these terms should be made based on the contents throughout the present specification.

Hereinafter, a vehicle positioning system according to an embodiment of the present invention will be described with reference to FIG. 1.

1 is a block diagram illustrating a vehicle positioning system according to an embodiment of the present invention.

As shown in FIG. 1, a vehicle positioning system according to an embodiment of the present invention includes a vehicle terminal 100, a roadside device 200, a radar 300, and a control device 400.

First, the vehicle terminal 100 is a communication terminal installed in a vehicle, and transmits and receives a Basic Safety Message (BSM). In addition, all vehicles locate the vehicle's absolute coordinates (X,Y) in real time through GPS, and broadcast the BSM defined by the WAVE standard. Here, the BSM includes information such as ID, coordinates, speed, traveling direction, brake state, and size of the vehicle. Accordingly, the vehicle terminal 100 detects the location of the vehicle and surrounding vehicles by transmitting and receiving BSM messages with other vehicles. Meanwhile, the vehicle terminal 100 uses wave (WAVE) communication based on the IEEE 802.11p standard, and performs inter-vehicle communication based on a competition technique called CSMA/CA (Carrier Sense Multiple Access and Collision Avoidance).

Hereinafter, a method of transmitting and receiving a BSM through the vehicle terminal 100 according to an embodiment of the present invention will be described in more detail with reference to FIGS. 2 to 5.

FIG. 2 is a flowchart illustrating a method of performing communication using the IEEE 802.11p protocol, FIG. 3 is a flowchart illustrating a BSM transmission/reception method using the vehicle terminal shown in FIG. 1, and FIG. It is a diagram for explaining the generation and maintenance of the connection list in the illustrated step S320, and FIG. 5 is a diagram for explaining the step S340 of FIG.

First, wave communication is based on the IEEE 802.11p protocol. The IEEE 802.11p protocol performs communication using a control channel (CCH, Control Channel) and service channels (SCH, Service Channel) having different frequency bands, and transmits/receives messages by periodically switching in units of 50ns.

In addition, the IEEE 802.11p protocol performs vehicle-to-vehicle communication based on a competition technique called Carrier Sense Multiple Access and Collision Avoidance (CSMA/CA) in order to access a wireless medium.

In addition, as shown in FIG. 2, when a message to be transmitted/received occurs, the vehicle-to-vehicle communication protocol checks whether the channel at the current time is in an idle state or an occupied state. That is, if the channel at the current time is not used for a random backoff time, the inter-vehicle communication protocol determines that the channel is idle and transmits a message to be transmitted. If the channel is in the occupied state, it waits for an arbitrary time through a back-off process, then confirms that the channel is in an idle state, and then performs a process of transmitting.

Meanwhile, the vehicle terminal 100 according to an embodiment of the present invention transmits and receives a BSM through a control channel (CCH) and transmits and receives an application message through a service channel (SCH). Therefore, when transmitting the BSM, the vehicle terminal 100 transmits the BSM in a 100ms cycle. Here, the application message includes the presence or absence of an accident or a specific emergency message.

As shown in FIG. 3, the vehicle terminal 100 according to an embodiment of the present invention measures the current location using GPS before entering the tunnel, and transmits information about the measured current location in the BSM (S310). ).

At this time, since the wireless transmission range of the wave (WAVE) communication is a radius of 1Km, the vehicle terminal 100 transmits the BSM to all surrounding vehicles located within a radius of 1Km around the vehicle. Here, the BSM includes information such as vehicle ID, coordinates, speed, traveling direction, brake status, and size.

Then, the vehicle terminal 100 generates a connection list using the BSM received from another vehicle (S320).

In addition, since the transmitted/received BSM includes location information, the vehicle terminal 100 determines the location of the vehicle and the location of the surrounding vehicles. In addition, the vehicle terminal 100 generates a linked list of vehicles located in the front and vehicles located in the rear centering on the vehicle in the same lane using information of surrounding vehicles.

As shown in FIG. 4, for example, if vehicles A, B, and C are driving, vehicle A creates a linked list of [Null, A, B], and vehicle B is called [A, B, C]. A connection list is created, and vehicle C creates a connection list called [B, C, Null]. The generated connection list includes the vehicle's coordinates and speed.

As described above, in a state in which vehicles A, B, and C are continuously driving, when a specific vehicle is changed due to overtaking, lane change, entrance to an intersection, etc., the vehicle terminal 100 updates the new connection list in real time using the BSM. . Then, the vehicle terminal 100 includes the updated information in the BSM and retransmits it to share it with other vehicles. At this time, the connection list is limited to the currently driving lane.

Therefore, as shown in FIG. 4, when vehicle B overtakes other vehicles or changes lanes, vehicle A regenerates the link list [Null, A, C], and vehicle C regenerates [A, C, Null]. Regenerate the linked list called.

In a state in which step S320 is completed, the vehicle terminal 100 determines whether or not the vehicle is located at a position 0 to 10m away from the entrance of the tunnel (S330).

The vehicle terminal 100 locates the vehicle using GPS. However, the inside of the tunnel is a shaded area with GPS, and the vehicle terminal 100 cannot obtain coordinate values through GPS, and thus cannot locate the vehicle in the tunnel.

Therefore, when a vehicle enters the tunnel, the BSM is transmitted in preference to other vehicles, that is, subsequent vehicles that have not entered the tunnel, so that the GPS tracking signal before entering the tunnel and the radar tracking signal after entering the tunnel are quickly mapped. There is a need.

Accordingly, the vehicle terminal 100 determines whether the vehicle is located between 0 and 10 m before entering the tunnel. Here, the location of the tunnel is checked through the navigation and GPS created in the vehicle. Meanwhile, in the embodiment of the present invention, the distance value to the tunnel entry is limited to 0 to 10 m in order to adjust the contention window value, but the distance value may be changed according to the environment around the tunnel.

And when it is determined that the vehicle is located at a location 0-10m away from the tunnel entry part, the vehicle terminal 100 generates and transmits the BSM, but the contention window (Contention window) so that the BSM generated by other vehicles can be transmitted preferentially. Window, CW) value is adjusted (S340).

In addition, the vehicle terminal 100 determines whether the channel to which the BSM of the vehicle is transmitted is an idle state or an occupied state. When the channel is in an occupied state, it means that it is connected to and communicates with another device, and when the channel is in an idle state, it means that it is possible to connect and communicate.

Accordingly, when the channel is in an idle state, the vehicle terminal 100 controls to immediately transmit the state information of the vehicle to the surrounding vehicles. On the other hand, when the channel is in the occupied state, the vehicle terminal 100 controls to transmit state information of the vehicle to surrounding vehicles at a time delayed by a predetermined back-off value. Here, the contention window (CW) of the backoff has a value between [CWmin, CWmax].

However, in the embodiment of the present invention, priority is set for the BSM according to the distance from the tunnel. That is, the vehicle terminal 100 sets a high priority to the BSM transmitted from a vehicle located within 0 to 10 m before entering the tunnel.

In addition, the vehicle terminal 100 changes the contention window (New_CW) value according to whether or not the tunnel enters.

Here, the adjusted contention window (New_CW) value is expressed through the following equation.

Here, CW_min + the position in front of the tunnel represents the maximum value (CW_max), and the distance between the entrance of the tunnel and the vehicle represents the distance the vehicle is separated from the entrance of the tunnel.

To explain this in more detail, each vehicle newly changes the competition window (New_CW) 10m before entering the tunnel. That is, the vehicle terminal 100 changes the maximum value CW_max to an arbitrary value closer to CW_min as it is closer to the tunnel using location information according to GPS. For example, a vehicle located 10m before entering a tunnel is changed to a value between CW_min and CW_min+10, and a vehicle located 1m just before entering a tunnel is changed to a value of CW_min and CW_min+1.

Therefore, as shown in FIG. 5, when vehicle A and vehicle B simultaneously transmit the BSM to the roadside apparatus 200, in principle, the transmission order is determined with the same probability, but in the present invention, the BSM of vehicle A ahead of the tunnel entry It is transmitted to the roadside apparatus 200 in preference to the BSM of this vehicle B.

When the step S340 is completed, the vehicle terminal 100 determines whether the GPS signal is disconnected (S350).

The disconnection of the GPS signal indicates that the vehicle has entered the tunnel.

And if it is determined in step S350 that the vehicle has entered the tunnel, the vehicle terminal 100 adjusts the contention window (CW) value to the normal range. In other words, the contention window (CW) of the backoff has a value between [CW_min, CW_max], and the contention window of the channel control channel (CCH) generally has a value of [15, 1023]. . That is, the normal range in the present invention represents a value between [15, 1023]. Therefore, the vehicle terminal 100 transmits the BSM after delaying by an arbitrary backoff value selected from values between [15, 1023], and when the vehicle is located 10m before entering the tunnel, the contention window (CW) is [15]. , 15+10], and after delaying the selected backoff between the changed [15, 25], the BSM is transmitted. After the vehicle enters the tunnel, the vehicle terminal 100 changes the contention window (CW) back to the range of [15, 1023], delays the selected backoff between [15, 1023], and then starts the BSM. send.

Then, the vehicle terminal 100 periodically transmits a BSM that does not include a location information value (S360).

In addition, since there is no need to set a priority for transmitting the BSM after the vehicle enters the tunnel, the vehicle terminal 100 transmits the BSM every 100 ms.

Meanwhile, wave communication includes a control channel (CCH) and a service channel (SCH), transmits and receives BSM through the control channel (CCH), and transmits and receives application messages through the service channel (SCH). Therefore, when a vehicle running in front suddenly stops or an accident or event occurs, it is classified as an application message and transmitted through the service channel SCH. Accordingly, accident messages or other emergency messages in the tunnel can be transmitted and received without collision or signal interference with the BSM.

In addition, since the vehicle entering the tunnel can be tracked in real time through the control device 300 to be described later, the position value of the vehicle is displayed as null and transmitted.

Then, the roadside unit (RSU) 200 is fixed on the roadside and communicates with the vehicle terminal 100. The roadside device 200 is wired to the control device 400 to be described later. Accordingly, the roadside apparatus 200 transmits the BSM received from the vehicle terminal 100 installed in the vehicle to the control apparatus 400.

In addition, a radar (Radar) 300 is installed at the entrance in the tunnel, and detects a plurality of vehicles entering the tunnel. The radar 300 allocates an ID to the vehicle detected by itself. In addition, the radar generates information on the assigned ID, the location of the detected vehicle, and the measurement time, and transmits the information to the control device 400.

Finally, the control device 400 generates a mapping table by matching table information on the location and time of the vehicle included in the BSM with table information on the location and time of the vehicle received through the radar. Then, the control device 400 determines whether a vehicle recognition error has occurred by the radar using the generated mapping table. In addition, when an error occurs, the control device 400 performs correction to locate the continuous vehicle in real time.

Hereinafter, the control device 400 according to an embodiment of the present invention will be described in more detail with reference to FIG. 6.

6 is a configuration diagram illustrating the control device illustrated in FIG. 1.

As shown in FIG. 6, the control device 400 according to an embodiment of the present invention includes a receiving unit 410, a matching unit 420, a determination unit 430, and a control unit 440.

First, the receiving unit 410 receives a GPS-based BSM through the roadside apparatus 200. In addition, the receiving unit 410 receives vehicle information detected through the radar 300 installed in the tunnel. Then, the receiving unit 410 transmits the received BSM and the vehicle information sensed through the radar 300 to the matching unit 420.

Then, the matching unit 420 matches the vehicle ID and the radar ID using the vehicle ID, location, and time information included in the received BSM and the vehicle ID, location, and time information detected by the radar. Then, the matching unit 420 generates a mapping table using the matched information.

Then, the determination unit 430 compares the number of IDs of the vehicle acquired through the BSM and the number of IDs of the vehicle detected through the radar 300 using the generated mapping table. As a result of the comparison, if the number of IDs of the vehicle acquired through the BSM and the number of IDs of the vehicle detected through the radar 300 are different, the determination unit 430 determines that an error has occurred in the radar 300.

Finally, the control unit 440 grasps the context of a continuous vehicle by using the connection list included in the BSM, and detects an undetected vehicle. Then, the controller 440 generates information on a new vehicle ID, speed, and time for an undetected vehicle.

Hereinafter, a method of positioning a vehicle in a tunnel using the control device 400 will be described in more detail with reference to FIGS. 7 to 9B.

FIG. 7 is a flowchart illustrating a method of positioning a vehicle in a tunnel using the control device shown in FIG. 6, and FIG. 8A is a view showing a matched state at a time point T1 in step S730 shown in FIG. 7, and FIG. 8b is a diagram showing a matched state at a time point T2 in step S730 shown in FIG. 7, FIG. 8c is a diagram showing a state matched at a time point T3 in step S730 shown in FIG. 7, and FIG. 8d is shown in FIG. It is a diagram showing a matching state when the vehicles of A and B enter at the same time at the time T2 in step S730, and FIG. 9A is a view for explaining a method of correcting a negative error in step S750 shown in FIG. 7, 9B is a diagram illustrating a method of correcting a positive error in step S750 shown in FIG. 7.

As shown in FIG. 7, the receiving unit 410 according to an embodiment of the present invention receives the BSM transmitted from a plurality of vehicles through the roadside apparatus 300. Then, the receiving unit 410 receives information on the ID, location, and time of the vehicle detected from the radar 300 (S710).

In addition, the receiving unit 410 receives the BSM from the roadside device 200, but the BSM is generated and transmitted just before the vehicle enters the tunnel, and the vehicle ID, coordinates, speed, direction, brake state, size, and connection Includes information such as a list.

In addition, the receiving unit 410 receives information on a vehicle from the radar 300. That is, the radar 300 detects a vehicle entering the tunnel, and automatically assigns an ID to the detected vehicle. Then, the radar 300 generates the location and the measured time of the vehicle to which the ID is assigned, and transmits the generated information to the receiving unit 410.

Then, the receiving unit 410 transmits the BSM received from the roadside apparatus 200 and the ID, location, and time information of the vehicle received through the radar 300 to the matching unit 420.

Then, the matching unit 420 generates each table information using the received BSM and the ID, location, and time information of the vehicle detected by the radar 300 (S720).

In addition, the matching unit 420 generates table information by extracting the ID, coordinates, time, and connection list of the vehicle from among a plurality of pieces of information included in the received BSM.

Then, the matching unit 420 generates table information by using the ID of the vehicle detected through the radar 300, location information, and information about time.

Meanwhile, among the vehicle information received from the radar 300, the vehicle ID is assigned by the radar 300 itself, and the ID of the vehicle received through the radar 300 and the ID of the vehicle included in the BSM are different.

When the step S720 is completed, the matching unit 420 generates a mapping table by matching the generated table information with each other (S730).

The matching unit 420 generates a mapping table using an order of detection according to time. That is, the matching unit 420 extracts the information acquired by the BSM and the information acquired by the radar at the corresponding time point, respectively. In addition, the matching unit 420 forms a mapping table in which the vehicle ID obtained through the BSM and the vehicle ID generated through the radar are matched using the extracted information.

For example, as shown in FIG. 8A, the time point T1 indicates before the continuously driving vehicles A, B, and C enter the tunnel, and the entry point of the tunnel is set to (10,0) and (11,0) ), it is assumed to be inside the tunnel. Then, the matching unit 420 acquires location information of each of the vehicles A, B, and C through the BSM detected at the time point T1.

As shown in FIG. 8B, the time point T2 represents a state in which vehicle A has entered the tunnel among vehicles A, B, and C that are continuously running. However, it is not possible to determine whether or not the vehicle detected through the radar 300 is vehicle A. Accordingly, the matching unit 420 generates table information for vehicles A, B, and C using respective BSM information. Here, in the BSM information for vehicle A, the position value is displayed as null. In addition, the matching unit 420 generates table information by using information on the X vehicle detected through the radar 300.

In addition, the matching unit 420 searches for the vehicle closest to the tunnel entry unit at the time point T1 in order to confirm the correct ID of vehicle X received from the radar 300. As a result, since vehicle A is identified as (10,0), the unidentified vehicle X is mapped to A.

Next, as shown in FIG. 8C, it is assumed that the vehicle positioned before entering the tunnel at the time point T3 is the C vehicle, and the vehicle detected inside the tunnel is the X and Y vehicles. However, the vehicle detected through the radar 300 is in a state in which vehicle X is matched with vehicle A, and vehicle Y cannot be determined whether or not vehicle B is vehicle B.

Accordingly, the matching unit 420 generates table information for vehicles A, B, and C using respective BSM information. Here, each of the BSM information for vehicles A and B displays a position value as Null. In addition, the matching unit 420 generates table information by using information on the Y vehicle detected through the radar 300.

Then, the matching unit 420 searches for the vehicle closest to the tunnel entry unit at the time point T2 in order to confirm the correct ID of vehicle Y received from the radar 300. As a result, since vehicle B is identified as (10,0), the unidentified vehicle Y is mapped to B.

Meanwhile, as shown in FIG. 8D, when vehicle A and vehicle B enter at the same time at the time point T2, the matching unit 420 may recognize the same as the X and Y vehicles detected by the radar. Accordingly, the matching unit 420 identifies the preceding relationship using the connection list included in the BSM, or matches the X, Y vehicle detected by the radar and the vehicle ID included in the BSM based on the vehicle order at the time point T1. do.

When step S730 is completed, the determination unit 430 determines whether the number of IDs of the vehicle acquired through the BSM included in the mapping table and the number of IDs of the vehicle acquired through the radar match (S740).

The reason for comparing the number of IDs of the vehicle is to determine whether a vehicle recognition error has occurred in the radar 300. In the radar 300 installed in the tunnel, a signal may be distorted by a wall in the tunnel, or a vehicle entering the tunnel may not be detected due to a signal reception error.

Accordingly, if the number of IDs of the vehicle received through the BSM is less than the number of IDs of the vehicle detected through the radar, the determination unit 430 determines that the ID number of the vehicle is a negative error.

On the other hand, when the number of IDs of the vehicle received through the BSM is greater than the number of IDs of the vehicle detected through the radar, the determination unit 430 determines that it is a positive error.

When a signal error occurs in step S740, the controller 440 performs correction (S750).

First, in the case of a negative error as a result of determination in step S740, the controller 440 recognizes the context of the vehicle using the connection list included in the BSM, and generates a new radar ID and vehicle information.

As shown in FIG. 9A, assuming that, for example, vehicles A, B, and C are running continuously, and the radar is in a state in which only vehicles A and C are detected, the control unit 440 includes A, B, and C. The connection list is extracted using the BSM transmitted from vehicle C. Then, the controller 440 detects vehicle B by using the extracted list, and generates ID and location information for the detected vehicle B. Here, the location information of vehicle B is generated by using the location information of vehicle B included in the BSM of vehicle A and vehicle C.

In addition, if the result determined in step S740 is a positive error, the control unit 440 selects a vehicle located closest to the radar from among a plurality of vehicles detected by the radar at the time of entering the tunnel, and IDs for the remaining vehicles. , Delete location and time information.

As shown in FIG. 9B, for example, when the vehicle entering the tunnel is vehicle A, the vehicle detected through the radar 300 is an X, Y vehicle, and the coordinates of the tunnel entry part are (11,0). , The controller 440 extracts the coordinates (11,0) for the X vehicle and the coordinates (12,0) of the vehicle Y. Then, the control unit 440 selects the X vehicle close to the tunnel entry part by using the extracted coordinates, and deletes the information on the Y vehicle.

As described above, the vehicle positioning system according to the present invention can track the vehicle in the tunnel by matching the signal received from the radar and the BSM received from the vehicle. Can be reduced and improved positioning accuracy. In addition, information on vehicles not detected by radar can be detected using a linked list between vehicles.

In addition, the vehicle positioning system according to the present invention allows the BSM of the vehicle at the time of entering the tunnel to be selected and transmitted with a high priority, and because real-time vehicle tracking in the tunnel is possible, immediate monitoring and response in the event of an accident is possible. Do.

The present invention has been described with reference to the embodiments shown in the drawings, but these are only exemplary, and those of ordinary skill in the art will understand that various modifications and other equivalent embodiments are possible therefrom. will be. Therefore, the true technical protection scope of the present invention should be determined by the technical idea of the following claims.

100: vehicle terminal
200: roadside device
300: radar
400: control device
410: receiver
420: matching unit
430: judgment unit
440: control unit

Claims (10)

In a vehicle positioning system in a tunnel using wave communication and radar,
Roadside Unit (RSU) receiving a Basic Safety Message (BSM) including GPS-based location and time information from a vehicle terminal installed in a vehicle entering the tunnel,
A radar installed in the tunnel that detects each vehicle entering the tunnel and generates and transmits information about the location and time of each vehicle, and
A control device that mutually matches information on the location and time of the vehicle received through the roadside device and the radar, and when a vehicle recognition error occurs from the radar as a result of matching, corrects the error and determines the position of a continuous vehicle. Includes,
The vehicle terminal,
Based on the own vehicle, a linked list is created by using the IDs of vehicles located in the front and rear of the same lane,
The BSM,
A vehicle positioning system including at least one of the ID, coordinates, speed, driving direction, brake state, size, and the generated connection list of the vehicle. The method of claim 1,
The vehicle terminal,
Vehicle positioning system for broadcasting the BSM based on a competition technique of CSMA/CA (Carrier Sense Multiple Access and Collision Avoidance). delete The method of claim 1,
The vehicle terminal,
A vehicle positioning system that adjusts a contention window (CW) value of a backoff when a corresponding vehicle transmits a BSM to the roadside device immediately before entering a tunnel. The method of claim 4,
The contention window (New_CW) value of the backoff is,
Vehicles to which the switching to the minimum value (CW_ _min) and maximum values (= _max CW_ CW_ _min + tunnel front position) according to the expression positioning system:

Here, the position in front of the tunnel represents a distance value in meters from which the vehicle is separated from the tunnel entry part. The method of claim 5,
The vehicle terminal,
Vehicle positioning system for setting the contention window value to a normal range when the vehicle enters the tunnel. The method of claim 1,
The control device,
Receiving unit for receiving BSM from the roadside device and receiving ID, location, and time information of the vehicle measured through a radar,
A matching unit for generating a mapping table by mapping the ID, location, and time information of the vehicle included in the BSM with the ID, location, and time information of the vehicle detected by the radar;
A determination unit that determines whether or not an error has occurred in the radar by comparing the number of vehicles detected by the radar with the connection list of vehicles included in the BSM, and
When it is determined as an error, a vehicle including a control unit that performs a correction operation by using the context of the consecutive vehicles included in the vehicle connection list and the location information of the vehicle included in the BSM received at the time of entering the tunnel. Positioning system. The method of claim 7,
The control unit,
If the number of vehicles included in the connection list is greater than the number of vehicles detected through the radar, it is determined as a negative error,
If it is determined as a negative error, a vehicle positioning system that detects an undetected vehicle using the context of vehicles included in the connection list, and generates a new radar ID and vehicle information for the undetected vehicle. The method of claim 7,
The control unit,
If the number of vehicles included in the connection list is less than the number of vehicles detected by the radar, it is determined as a positive error,
If it is determined as a positive error, a vehicle positioning system that selects a vehicle in the closest position to the radar from among a plurality of vehicles detected by the radar at the time of entering the tunnel and deletes ID, location, and time information for the remaining vehicles. The method of claim 1,
The vehicle terminal,
Wave communication is performed through control channels (CCH, Control Channel) and service channels (SCH, Service Channel),
A vehicle positioning system for transmitting and receiving BSM through a control channel (CCH) and transmitting and receiving an accident or warning message through the service channel (SCH) when the vehicle enters the tunnel.

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