KR20090063002A - Method and apparatus for avoiding vehicle collision - Google Patents

Abstract

A method and a system for avoiding the vehicle collision are provided, which can avoid collision between the vehicles by grasping location and movement route of the adjacent vehicle by transmitting and receiving of the radio frequency signal about the adjacent vehicle. A plurality of directional antennae receive the first radio frequency signal from the adjacent vehicle. The second radio frequency signal is transmitted to the adjacent vehicle. The antenna switching part(230) is connected to a plurality of directional antennae. The directional antenna each operation is switched. The receiver(210) is connected to the antenna switching part. The transmission unit(220) is connected to the antenna switching part. The transmission unit delivers the second radio frequency signal to the directional antenna through the antenna switching part.

Description

Vehicle collision avoidance method and system {METHOD AND APPARATUS FOR AVOIDING VEHICLE COLLISION}

The present invention relates to a vehicle collision avoidance method and system, and more particularly, to a vehicle collision avoidance method and system that can avoid the collision between the vehicle by grasping the position and the movement path of the adjacent vehicle in a relatively short distance such as an intersection. It is about.

The present invention is derived from a study conducted as part of the IT source technology development project of the Ministry of Information and Communication and the Ministry of Information and Communication Research and Development (Task Management No .: 2007-F-039-01, Task Name: VMC Technology Development).

If the direction and location information of a moving vehicle can be accurately understood, there are many technical fields that can use it.

Conventional techniques for grasping direction and location information of a moving vehicle include a method using a signal of a mobile communication base station, a method using GPS, and the like. The former is to grasp the moving direction and position of the mobile station based on the signals transmitted and received between the plurality of mobile communication base stations and the mobile station, and the latter is to determine the moving direction and position of the mobile station based on geographic information received from the plurality of GPS satellites. To figure out.

However, a method of using a signal of a mobile communication base station and a method of using a GPS have a problem in that resolution is very low in common.

For example, in the case of using a commercial GPS, the measurement error reaches 5 to 10 m, and in the case of using a signal of a mobile communication base station, the measurement error is larger than in the case of using GPS.

Therefore, it is difficult to know how and in which direction the other vehicle moved in a relatively narrow area such as an intersection.

Another technique for identifying direction and position information of a moving vehicle is an anti-collision sensor mounted on the front and rear bumpers of the vehicle.

However, in the case of the collision avoidance sensor, it is only possible to detect an object approaching at a slow speed at an extremely close distance within several tens of centimeters, so it is difficult to understand the movement of other vehicles several meters to tens of meters away. to be.

Therefore, requests for a method and system for avoiding vehicle collision by grasping the direction and path of movement of another vehicle in a relatively narrow area such as an intersection have been steadily raised.

The present invention has been conceived in response to the above-mentioned request, and provides a vehicle collision avoidance method and system that can avoid collisions between vehicles by grasping the position and movement path of adjacent vehicles located at relatively short distances such as intersections. The purpose.

In order to achieve the above object, a vehicle collision avoidance system according to the present invention includes a plurality of directional antennas for receiving a first radio frequency signal from an adjacent vehicle and transmitting a second radio frequency signal to an adjacent vehicle; An antenna switching unit connected to each of the directional antennas and switching operations of each of the directional antennas, and connected to the antenna switching unit, and receiving the first radio frequency signal from the directional antenna through the antenna switching unit; A receiver for demodulating a radio frequency signal, and a transmitter connected to the antenna switching unit, modulating a second radio frequency signal and transmitting the modulated second radio frequency signal to the directional antenna through the antenna switching unit, and the antenna switching unit, the receiver, and the transmitter; A plurality of the directivity connected to the antenna switching unit It sends a switching control signal for controlling each operation state of the tena, receives the information about the first radio frequency signal from the receiving unit, the collision risk for the adjacent vehicle based on the information about the first radio frequency signal The controller is installed in the reference vehicle, including a control unit for transmitting the second radio frequency signal.

In addition, the vehicle collision avoidance method according to the present invention, receiving a radio frequency signal that uniquely identifies each of the adjacent vehicles from at least one adjacent vehicle, by reading the radio frequency signal of the adjacent vehicle relative to the reference vehicle Calculating the relative speed and the relative acceleration of the adjacent vehicle with respect to the reference vehicle by repeatedly calculating the relative distance and the relative direction, and repeatedly calculating the relative distance and the relative direction by a predetermined number of times; and And determining a collision possibility of the adjacent vehicle based on the relative distance, the relative direction, the relative speed, and the relative acceleration.

By using the vehicle collision avoidance method and system according to the present invention, the collision between the vehicles can be avoided by grasping the position and the movement path of the adjacent vehicle located at a relatively short distance such as an intersection.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. In addition, the terms “… unit”, “… unit”, “module”, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. have.

1 is a view showing the relationship between the beam coverage of the antenna, the reference vehicle and the adjacent vehicle for explaining the vehicle collision avoidance system according to the present invention.

As shown in FIG. 1, the vehicle collision avoidance system according to the present invention uses a plurality of directional antennas to grasp the relative position and the movement path of an adjacent vehicle. That is, based on the strength of the RF signal received by the plurality of directional antennas 102a, b, c, and d provided in various directions of the reference vehicle 100, the position, direction, speed, and acceleration of the adjacent vehicle 110 may be adjusted. It calculates and uses the calculation result for vehicle collision avoidance.

Due to the characteristics of the RF signal, the strength of the RF signal from the adjacent vehicle received by the antenna of the reference vehicle is inversely proportional to the log square of the distance between the reference vehicle and the adjacent vehicle.

In consideration of this, when the distance between the reference vehicle and the adjacent vehicle is close, the difference in the intensity of the signal received by each of the plurality of directional antennas becomes large, whereas when the distance between the reference vehicle and the adjacent vehicle is far, It can be seen that the difference is small.

For example, since the adjacent vehicle 110 of FIG. 1 belongs to the beam coverage 10 of the front antenna 102a and the beam coverage 16 of the right-side antenna 102d, the RF signal from the adjacent vehicle 110 is transmitted to the front antenna. Received at 102a and the right-side antenna 102d.

Although it may also belong to the beam coverages 14 and 12 of the left antenna 102c or the rear antenna 102b, the reception strength of the signal will be extremely weak due to the characteristics of the directional antenna.

As such, by receiving the RF signal from the adjacent vehicle 110 through the plurality of directional antennas, the relative direction as well as the relative distance between the reference vehicle 100 and the adjacent vehicle 110 may be determined.

On the other hand, if the distance and the direction data is measured several times over time, the relative speed (acceleration) and the relative acceleration (acceleration) of the adjacent vehicle 110 can also be grasped. This is because speed is a change amount of displacement per unit time, and acceleration is a change amount of speed per unit time.

2 is a configuration diagram showing an example of a vehicle collision avoidance system according to the present invention.

As shown in FIG. 2, the vehicle collision avoidance system 20 according to the present invention includes a plurality of directional antennas 240a to 240n, a receiver 210, a transmitter 220, an antenna switch 230, and a controller 200. It is made, including.

The plurality of directional antennas 240a to 240n receive RF signals from surrounding vehicles or transmit RF signals to surrounding vehicles.

The directional antennas 240a to 240n are installed in each direction of the vehicle. In the embodiment of FIG. 1, four directional antennas are installed one by one in the front, rear, right, and left sides.

The receiver 210 demodulates the RF signals received from the plurality of directional antennas 240a to 240n and transmits the demodulated RF signals to the controller.

The transmitter 220 modulates the transmitted RF signal from the controller and transmits the modulated RF signal to the plurality of directional antennas 240a to 240n.

The antenna switching unit 230 switches the path of the RF signal so that a specific directional antenna is selected among the directional antennas 240a to 240n based on the switching control signal of the controller 200.

The controller 200 receives the RF signal received from the directional antennas 240a to 240n from the receiver 210 and calculates the distance, direction, speed, acceleration, etc. of the adjacent vehicle to be measured. In addition, the controller 200 transmits an RF signal to an adjacent vehicle through the transmitter 220 and the plurality of directional antennas 240a to 240n.

3 is a block diagram showing another embodiment of a vehicle collision avoidance system according to the present invention.

The vehicle collision avoidance system 30 according to the embodiment of FIG. 3 includes a controller 300 and a plurality of signal processors 32a to 32n. The signal processor 32a includes a receiver 310a, a transmitter 320a, an antenna switching unit 330a, and a directional antenna unit 340a. The rest of the signal processing units 32b to 32n are similar to the signal processing unit 32a.

The difference between the vehicle collision avoidance system 30 according to the embodiment of FIG. 3 and the vehicle collision avoidance system 20 according to the embodiment of FIG. 2 is different from the plurality of directional antennas 240a to 240n in the embodiment of FIG. 2. Share the receiver 210 and the transmitter 220, except for the controller 300 in the embodiment of FIG. 3, each signal processor 32a to 32n shares the transmitter, the receiver, the antenna switching unit, and the directional antenna unit. Is not.

4 is a flowchart illustrating an example of a vehicle collision avoidance method according to the present invention.

In the embodiment of FIG. 4, the RF signals received by the directional antennas 102a to 102d mounted in each direction by the vehicle collision avoidance system installed in the reference vehicle 100 are analyzed, and the reference vehicle 100 and the adjacent vehicle 110 are analyzed. The relative distances and directions between the two vehicles are calculated to avoid collision between the two vehicles.

First, in the antenna number input step S400, the number of directional antennas installed in the reference vehicle 100 is input. In the present embodiment, four directional antennas, that is, a front directional antenna 102a, a rear directional antenna 102b, a left directional antenna 102c and a right directional antenna 102d, are included in the vehicle collision avoidance system of the reference vehicle 100. Since the number is included, (antenna number) = 4 in the antenna number input step (S400).

Next, in the reception antenna selection step S410, an antenna to scan an RF signal is selected from the plurality of directional antennas, and in the signal scan storage step S420, information about the RF signal scanned by the selected directional antenna is stored in the controller. .

Since the vehicle collision avoidance system scans each directional antenna sequentially activated by the antenna switching unit one at a time, the RF signal scan is performed for all the directional antennas.

(Number of signal scans) = (number of antennas input)

Is established.

Therefore, in step S430, after determining whether the RF signal scan of the directional antenna is performed by the number of antennas input in the antenna number input step (S400), and if the number of scans is less than the number of input antennas, the reception antenna selection step ( Returning to step S410, by selecting an unscanned antenna, the RF signal is scanned for all the directional antennas.

When the scan of the RF signal is performed for all the directional antennas, the reading object vehicle number input step S440 is performed.

In the input number of vehicles to be read (S440), the number of adjacent vehicles to be subjected to the vehicle collision avoidance processing is set. The number of neighboring vehicles corresponds to the number of identification codes of each neighboring vehicle included in the RF signal from the neighboring vehicle detected in the signal scanning process according to the procedure of the previous steps (S400 to S430).

In the step of selecting a vehicle to be read (S450), an adjacent vehicle whose distance and direction are to be calculated is selected. By selecting the adjacent vehicle, only RF signals including the identification code of the adjacent vehicle selected from the at least one RF signal scanned in the signal scanning process are selected for reading, and a reading procedure of distance and direction for the adjacent vehicle is prepared. do.

In the reading object vehicle distance and direction reading step (S460), RF signals including the identification code of the adjacent vehicle selected as the reading object vehicle are read, and the relative distance and direction with respect to the reference vehicle are calculated.

In this case, two signals having the largest signal strength among the RF signals including the corresponding identification code may be selected to calculate distance and direction.

After the relative distance and direction values for the reference vehicle are calculated by reading the RF signal for the specific adjacent vehicle, the vehicle collision avoidance system determines whether the RF signal has been read for all adjacent vehicles (S470). If the RF signal reading for all adjacent vehicles is not completed, the process returns to the step of selecting a target vehicle for reading (S450) again, and selects an adjacent vehicle having an identification code for which the RF signal has not been read yet and reads the reading (S450). S470) is repeated.

5 is a flowchart illustrating the reading distance and direction reading step of FIG. 4 in more detail.

As shown in FIG. 5, the reading object vehicle distance and direction reading step S460 further includes three steps of a signal strength measuring step S462, a reading signal selecting step S464, and a distance and direction reading step S466. Is done.

In the reading target vehicle distance and direction reading step (S460), a signal that is significant for reading is selected from RF signals received from a specific adjacent vehicle through a plurality of directional antennas to calculate a relative distance and direction between the corresponding adjacent vehicle and the reference vehicle. For example, since the strength of the signal is inversely proportional to the square of the distance, a signal having a large signal strength can be usefully used for calculating the distance. Therefore, it is also meaningful to select and read only signals having a large signal strength among RF signals received from a plurality of directional antennas (for example, four directional antennas installed in front, rear, left, and right directions).

First, in the signal strength measurement step (S462), the signal strength of each of the RF signals from the specific adjacent vehicle received through each directional antenna is measured by the control unit of the vehicle collision control system.

When the signal strength of each RF signal is measured in the signal strength measurement step S462, the two RF signals having the largest signal strength are selected in the read signal selection step S464.

In the distance and direction reading step S466, relative distances and directions between the reference vehicle and the adjacent vehicle are calculated using the signal strengths of the two RF signals selected in the reading signal selecting step S464.

The calculation of the relative distance is made based on the table showing the correlation of the distance-signal intensity.

Table 1 is an example of a table showing the correlation between the distance and the signal strength.

Distance (m) One 1.1 1.2 1.3 … 10 Signal strength (dBm) 10.23 12.58 14.20 16.74 … 22.97

The distance-signal strength correlation table as shown in Table 1 is generated based on empirical results obtained through repeated experiments.

For example, when the signal intensity measured in the signal strength measurement step S462 is 10.23 dBm, the relative distance corresponding to this signal intensity is 1 m. If the distance between the vehicle collision avoidance systems installed in the two vehicles is 1m, the two vehicles must be extremely approaching, so it can be assumed to be a collision state when the relative distance is 1m.

In addition, when the distance between the two vehicles is 10m, it can be assumed that the two vehicles are far enough apart.

In the section where the distance between two vehicles is larger than 1m and smaller than 10m, the distance-signal strength correspondence table is filled through the results of repeated experiments.

The distance-signal strength correlation table is stored in a storage device (memory, etc.) in the control unit of the vehicle collision prevention system according to the present invention, thereby causing the vehicle collision prevention system to determine the distance between the reference vehicle and the adjacent vehicle from the signal strength of the RF signal. To calculate.

On the other hand, the values of the signal strength shown in Table 1 (10.23, 12.58, 14.20, etc.) is just one example, and the various types such as the type of directional antenna, the signal intensity emitted from the antenna constituting the vehicle collision prevention system according to the present invention The value may vary depending on the conditions.

Next, the relative direction of the adjacent vehicle to the reference vehicle is calculated based on the correlation table of the signal intensity ratio of the two directional antennas.

Table 2 is an example of a table showing the signal strength ratio-direction correlation.

Direction 0 0.2 … 45 … 90.0 Signal strength ratio (S1 / S2) 0.844 0.872 … 1.000 … 1.849

The table showing the signal strength ratio-direction correlation shown in Table 2 is also generated based on empirical results obtained through repeated experiments, similar to the distance-signal strength correlation table shown in Table 1.

For example, assuming that the signal strength of the RF signal received from the adjacent vehicle is the highest in the front direction antenna and the right direction antenna, the front direction antenna and the right direction antenna with the maximum signal strength are used for the direction measurement of the adjacent vehicle. do.

At this time, the signal strength of the RF signal received from the front directional antenna is S1, the signal strength of the RF signal received from the right directional antenna is S2, the traveling direction of the reference vehicle is 0 (degree), and the right direction of the reference vehicle is 90. (degree), based on this table, the direction of the adjacent vehicle can be calculated from the signal intensity ratio (S1 / S2) value in a specific situation.

The signal strength ratio-direction correlation table is stored in a storage device (memory, etc.) in the control unit of the vehicle collision avoidance system according to the present invention, thereby causing the vehicle collision avoidance system from the signal strength ratios of two RF signals to the reference vehicle. The direction of the adjacent vehicle can be calculated.

On the other hand, the values of the signal strength ratios (0.844, 0.872, 1.849, etc.) shown in Table 2 are just one example, the type of directional antennas, the intensity of the signal emitted from the antenna, etc. The value may vary depending on various conditions.

6 is a flowchart illustrating a speed and acceleration calculation of an adjacent vehicle of the vehicle collision avoidance method according to the present invention.

As shown in FIG. 6, the procedure for calculating the speed and acceleration of the adjacent vehicle includes the scan frequency setting step (S600), the distance and direction of the vehicle to be read (S610), the number of adjacent vehicles (S620), and the adjacent vehicle. Velocity and acceleration calculation step (S630).

The relative speed between the reference vehicle and the adjacent vehicle is determined as the change amount of the relative distance per unit time. In other words,

(Relative speed) = (relative distance) / (unit time)

The relationship is established.

In addition, the relative acceleration with respect to the reference vehicle of the adjacent vehicle is determined as the change amount of the relative speed per unit time. In other words,

(Relative acceleration) = (relative speed) / (unit time)

The relationship is established.

Therefore, in order to obtain a relative speed with respect to the reference vehicle of a specific neighboring vehicle, the calculation of the relative distance must be performed at least twice. To obtain a relative acceleration with respect to the reference vehicle of the specific neighboring vehicle, the relative distance must be calculated at least three times. do.

In addition, in order to reduce the measurement error, it is preferable to obtain the relative speed from the average value of the calculated relative distances by performing the process of calculating the relative distance by scanning the antenna more than three times.

To this end, in the scan count setting step S600, the directional antenna scan count for calculating the relative distance is set.

Next, in the reading object vehicle distance and direction calculation step S610, the relative distance and direction with the adjacent vehicle is calculated.

Detailed procedures and methods for calculating relative distances and directions with adjacent vehicles are omitted in FIG.

Next, in the calculation of the number of adjacent vehicles (S620), the number of the adjacent vehicles for which the relative speed and the acceleration should be calculated is calculated and stored.

Next, in the adjacent vehicle speed and acceleration calculation step (S630), a procedure for calculating the relative speed and the acceleration is performed for each adjacent vehicle.

If the number of adjacent vehicles set in the adjacent vehicle number calculation step S620 becomes M units, the adjacent vehicle speed and acceleration calculation step S630 is repeatedly performed M times.

FIG. 7 is a flowchart illustrating in detail a step of calculating an adjacent vehicle speed and acceleration of FIG. 6.

As shown in FIG. 6, the adjacent vehicle speed and acceleration calculation step (S620) includes selecting a reading target adjacent vehicle (S632), calculating a speed and acceleration of the selected adjacent vehicle (S634), and all adjacent vehicles. And determining whether the speed and the acceleration have been calculated (S636).

According to the vehicle collision avoidance method according to the present invention, the calculation of the speed and acceleration of the adjacent vehicle is performed sequentially for each of the M adjacent vehicles. Therefore, in the step S632 of selecting the neighboring vehicle to be read, one neighboring vehicle to which the calculation of the speed and acceleration is performed among the M neighboring vehicles is selected.

When the adjacent vehicle is selected in step S632, in step S634, the relative speed of the corresponding adjacent vehicle is calculated based on the change amount of the relative position data of the vehicle and the direction information of the vehicle, and the change amount of the relative speed with respect to the unit time is calculated. Relative acceleration of the adjacent vehicle relative to the reference vehicle is calculated.

In step S634, it is determined whether the relative speed and the relative acceleration are calculated for all the M adjacent vehicles, respectively. The speed and acceleration calculation step S634 of the adjacent vehicle is repeatedly performed M times through the determination in step S634.

8 is a flowchart illustrating a procedure of preventing a vehicle collision based on a relative distance, a direction, a speed, and an acceleration of an adjacent vehicle with respect to a reference vehicle.

The vehicle collision prevention procedure of FIG. 8 is based on the relative distance and direction data of each adjacent vehicle with respect to the reference vehicle calculated through the process of FIG. 4, and the relative speed and acceleration data calculated through the process of FIG. 5. The process of determining whether each adjacent vehicle is likely to collide with the reference vehicle and performing an action based on the determination result is shown.

First, in step S800 a safety threshold S and a safety threshold D are set for the distance between the reference vehicle and a specific adjacent vehicle.

If the distance between the reference vehicle and the adjacent vehicle is farther than the safety threshold value S, the possibility that the reference vehicle and the adjacent vehicle collide is low, that is, the reference vehicle is considered to be in a safe state.

On the other hand, when the distance between the reference vehicle and the adjacent vehicle is closer than the danger threshold D, the reference vehicle and the adjacent vehicle are likely to collide, that is, the reference vehicle is considered to be in a dangerous state.

After the safety threshold and the danger threshold are set, the distance and acceleration information calculated for the specific adjacent vehicle are read (S810).

After the distance and the acceleration information are read in step S810, a step of comparing the magnitude of the distance between the reference vehicle and the adjacent vehicle and the safety threshold value is performed (S820).

As a result of the comparison in step 820, when the distance between the reference vehicle and the adjacent vehicle is not closer than the safety threshold value, the reference vehicle and the adjacent vehicle are regarded as sufficiently separated, and are determined to be "safe" (S870).

As a result of the comparison in step S820, when the distance between the reference vehicle and the adjacent vehicle is closer than the safety threshold, the step of comparing the magnitude with the danger threshold is further performed (S830).

On the other hand, if the distance between the reference vehicle and the adjacent vehicle is farther than the critical threshold in step S830, the step of determining the acceleration of the adjacent vehicle with respect to the reference vehicle is further performed (S840).

As a result of the determination in step S840, when the relative acceleration value is negative, it is considered that the reference vehicle and the adjacent vehicle are no longer close, and are determined to be "safe" (S870).

If the distance between the reference vehicle and the adjacent vehicle is closer than the danger threshold in step S830, a step of further determining whether the adjacent vehicle is located in front of the reference vehicle is performed (S850).

As a result of the determination in step S850, when the adjacent vehicle exists behind the reference vehicle, it is determined as "safe" (S870).

As a result of the determination in step S850, when the adjacent vehicle does not exist behind the reference vehicle, a determination is further made as to whether the adjacent vehicle moves laterally with respect to the moving direction of the reference vehicle (S860).

If the adjacent vehicle is located in front of the reference vehicle and the moving direction is in the lateral direction, it is determined that "caution" is required (S880). On the other hand, in the case of the longitudinal direction rather than the transverse direction, it is determined that there is a high possibility of collision between the adjacent vehicle and the reference vehicle (S890).

For each of "Safety" (S870), "Caution" (S880), and "Danger" (S890), control signals are generated to command the progress, deceleration progress (slow) and braking respectively.

According to an embodiment, the "safety", "caution" and "dangerous" guide messages corresponding to the respective control signals may be visually output through the display device, and may be audibly output through the guide voice output means. It may be. Further, various applications are possible, such as allowing the braking device of the reference vehicle to operate in response to the "danger" (S890) control signal.

The embodiments of the present invention described above are not implemented only through the apparatus and the method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded. Implementation may be easily implemented by those skilled in the art from the description of the above-described embodiments.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 is a view showing a relationship between a beam coverage of an antenna, a reference vehicle and an adjacent vehicle for explaining a vehicle collision avoidance system according to the present invention;

2 is a configuration diagram showing an example of a vehicle collision avoidance system according to the present invention;

3 is a configuration diagram showing another embodiment of a vehicle collision avoidance system according to the present invention;

4 is a flowchart showing an example of a vehicle collision avoidance method according to the present invention;

FIG. 5 is a flowchart illustrating the reading distance and direction reading step of FIG. 4 in more detail;

6 is a flowchart of calculating speed and acceleration of an adjacent vehicle in a vehicle collision avoidance method according to the present invention;

FIG. 7 is a flowchart illustrating a step of calculating the speed and acceleration of the adjacent vehicle of FIG. 6 in more detail;

8 is a flowchart illustrating a procedure of preventing a vehicle collision based on a relative distance, a direction, a speed, and an acceleration of an adjacent vehicle with respect to a reference vehicle.

(Short description of drawing)

100. . . Standard vehicle

110. . . Adjacent vehicle to be measured

102a. . . Front antenna

102b. . . Rear antenna

102c. . . Left-side antenna

103d. . . Right-side antenna

10. . . Beam coverage of the front antenna

12. . . Beam coverage of the rear antenna

14. . . Beam coverage of left side antenna

16. . . Beam coverage of the right side antenna

Claims (10)

A plurality of directional antennas for receiving a first radio frequency signal from an adjacent vehicle and transmitting a second radio frequency signal to the adjacent vehicle; An antenna switching unit connected to each of the plurality of directional antennas and switching an operation of each of the directional antennas; A receiving unit connected to the antenna switching unit and receiving the first radio frequency signal from the directional antenna through the antenna switching unit to demodulate the first radio frequency signal; A transmitter connected to the antenna switching unit and modulating a second radio frequency signal to transmit to the directional antenna through the antenna switching unit; A switching control signal connected to the antenna switching unit, the receiving unit, and the transmitting unit, for controlling an operating state of each of the plurality of directional antennas, to the antenna switching unit, and receiving information about the first radio frequency signal from the receiving unit. A control unit for determining a collision risk of the adjacent vehicle based on the information on the first radio frequency signal, and allowing the transmitter to transmit the second radio frequency signal Installed in the reference vehicle, including a vehicle collision avoidance system. The method of claim 1, The receiver further comprises a signal strength measurement module for measuring the signal strength of the first radio frequency signal vehicle collision avoidance system. The method of claim 2, And wherein the information about the first radio frequency signal includes a first identification code that uniquely identifies the adjacent vehicle. The method of claim 3, And wherein the information about the first radio frequency signal comprises a measurement of the signal strength of the first radio frequency signal. The method of claim 4, wherein The control unit further comprises a storage module for recording a signal intensity-relative distance correlation table indicating a relative distance corresponding to the measured value of the signal strength. The method of claim 5, The storage module further comprises a signal strength ratio-relative correlation table indicating a relative direction corresponding to a ratio of two signal strength measurements. Receiving a radio frequency signal uniquely identifying each of the adjacent vehicles from at least one adjacent vehicle, Calculating the relative distance and the relative direction of the adjacent vehicle to the reference vehicle by reading the radio frequency signal; Calculating the relative speed and relative acceleration of the adjacent vehicle with respect to the reference vehicle by repeatedly calculating the relative distance and the relative direction by a predetermined number of times; And determining the possibility of collision of the adjacent vehicle based on the relative distance, the relative direction, the relative speed, and the relative acceleration. The method of claim 7, wherein Receiving the radio frequency signal, Inputting the number of directional antennas installed in the reference vehicle; Scanning the radio frequency signal for each directional antenna; and When the radio frequency signal is detected through the step of scanning the radio frequency signal, the neighbor code based on the number of identification codes included in the detected radio frequency, the identification code uniquely identifies each of the adjacent vehicles. And storing the number of vehicles. The method of claim 7, wherein Calculating the relative distance and direction of the adjacent vehicle, For each of the radio frequency signals including the identification code of the adjacent vehicle, Measuring a first signal intensity of the radio frequency signal received at a first directional antenna among a plurality of directional antennas, Calculating a relative distance of the adjacent vehicle according to the signal strength based on a signal strength-distance correlation table; Measuring a second signal intensity of the radio frequency signal received at a second directional antenna among a plurality of directional antennas, Calculating a signal intensity ratio obtained by dividing the first signal intensity by the second signal intensity; And calculating the relative direction of the adjacent vehicle according to the signal strength ratio based on the signal strength ratio-direction correlation table, repeating as many as the number of the adjacent vehicles. The method of claim 9, Determining the collision possibility of the adjacent vehicle, If the relative distance of the adjacent vehicle is greater than the safety threshold, the relative distance is greater than the critical threshold and the relative acceleration is not greater than zero, or the relative distance is less than the critical threshold and the relative direction is behind the reference vehicle, “ Safety ”control signal is outputted, Outputting a "attention" control signal if the relative distance is less than the critical threshold and the relative direction is not rearward of the reference vehicle and the adjacent vehicle does not travel laterally; and And outputting a "danger" control signal when the relative distance is smaller than the critical threshold and the relative direction is not rear of the reference vehicle and the adjacent vehicle travels laterally.

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