KR101221374B1 - Noticing accident system and method for vehicle to vehicle - Google Patents

Abstract

PURPOSE: A notification system and a method for accidents between vehicles are provided not to retransmit an accident notification message when accident probability is low by calculating the collision probability between a vehicle, which receives the accidents notification message, and an accident vehicle. CONSTITUTION: A transceiver(10) transceives an accident notification message. A collision probability calculator(20) calculates the accident probability of a vehicle. A channel access waiting time calculator(30) calculates a channel access waiting time. A standby unit(40) waits as long as the channel access waiting time. A controller(50) checks the reception of the accident notification message from the other vehicles. The controller controls to transmit the accident notification message through the transceiver. [Reference numerals] (10) Transceiver; (20) Collision probability calculator; (30) Channel access waiting time calculator; (40) Standby unit; (50) Controller; (60) Sensor unit; (70) Output unit

Description

In-vehicle accident notification system and method {NOTICING ACCIDENT SYSTEM AND METHOD FOR VEHICLE TO VEHICLE}

The present invention relates to an inter-vehicle accident notification system and method, and more particularly, in order to prevent a serial collision of rear vehicles during an accident of a vehicle, an inter-vehicle accident notification system capable of transmitting and receiving an accident notification message in a broadcast manner. And to a method.

Republic of Korea Patent No. 10-0835385 (registered May 29, 2008) is introduced "system and method for reporting a car accident using a telematics device".

System and method for notifying a car accident using the telematics device is a method for notifying a car accident using a telematics device,

(a) establishing a vehicle-to-vehicle network between the vehicle and its surrounding vehicles by an ad-hoc communication method by a telematics device installed in the vehicle; and (b) detecting a shock through a vehicle sensor installed in the vehicle. Transmitting the shock data to the telematics device; (c) determining, by the telematics device, the severity of the accident based on the transmitted shock data; and (d) determining in step (c). And controlling the vehicle according to the seriousness of the accident, and (e) transmitting an accident notification message to the telematics devices of the surrounding vehicles connected to the inter-vehicle network.

However, a system and method for notifying a car accident using the telematics device is an IEEE 802.11 based wireless LAN technology using a distributed coordination function (DCF) transmission scheme in which various vehicles share a common channel between vehicles without an infrastructure. I am exchanging data. As shown in FIG. 1, the DCF transmission scheme is based on competition for a common available channel (shared channel) of each node. When two or more nodes want to use a channel at the same time, the channel is detected as empty. After that, the user waits for each contention window (CW) and accesses the channel at any time to acquire the permission. This has the advantage that it is easy to implement and can bring high efficiency in an ad hoc based vehicle communication environment without a certain type of network configuration, but collision can occur by any two nodes approaching the vehicle at the same time. Because of the high risk of delayed message transmission time, it may be difficult to prevent a chain collision of a vehicle.

In addition, in broadcasting of vehicle-to-vehicle communication (V2V), it is important to relay a message to a suitable area without duplicate transmission and reception. There is a problem of overloading a transceiver by receiving a message repeatedly from the above node.

In addition, since the accident notification message is spread more widely than necessary through the common channel, there is a problem that the common channel in a distant region is inefficiently used.

Accordingly, an object of the present invention is to calculate the probability that a vehicle that receives an accident notification message has a serial collision with the vehicle, and if the probability of the accident is low, the message is not required by not resending the accident notification message. By preventing transmission to the area and calculating the channel access waiting time according to the probability of the accident, it is possible to retransmit the accident notification message through the common channel from the vehicle with a short channel access waiting time, so that multiple vehicles share the common channel To minimize collisions and to receive accident notification messages from other vehicles while the vehicle is waiting for channel access latency, avoiding retransmission of accident notification messages, thereby allowing the vehicle to It is to provide an inter-vehicle accident notification system and method that can be minimized.

According to an aspect of the present invention, an inter-vehicle accident notification system includes a transceiver for transmitting and receiving an accident notification message; A collision probability calculator configured to calculate a probability that the own vehicle suffers an accident based on the accident notification message received through the transceiver; A channel access waiting time calculating unit for calculating a channel access waiting time for transmitting the accident notification message by the host vehicle approaching a shared channel; The waiting unit waiting for the channel access waiting time calculated by the channel access waiting time calculating unit and the standby unit checks whether an accident notification message is received from another vehicle through the transmitting and receiving unit while waiting for the channel access waiting time. If there is no notification message, characterized in that it comprises a control unit for controlling the accident notification message to be transmitted through the transceiver.

According to another aspect of the present invention, an inter-vehicle accident notification method includes: receiving and receiving an accident notification message by a transceiver; A collision probability calculation unit calculating a probability that the own vehicle suffers an accident based on the accident notification message received through the transceiver; Determining, by the controller, whether the probability of causing the accident is greater than or equal to a threshold probability value; If the probability that the host vehicle is in an accident is greater than or equal to a threshold probability value, calculating a channel access waiting time for the host vehicle to access the shared channel and transmit an accident notification message; Waiting by the waiting unit for the channel access waiting time calculated by the channel access waiting time calculating unit; The control unit checks whether or not an accident notification message is received from another vehicle through the transceiver while the standby unit waits for a channel access waiting time, and if there is no accident notification message, controlling the transmission of the accident notification message through the transceiver. It is characterized by including.

Accordingly, the inter-vehicle accident notification system and method according to the present invention calculates the probability that the vehicle, which has received the accident notification message, has a serial collision with the accident vehicle, and retransmits the accident notification message if the probability of the accident is low. By not doing so, it is possible to prevent the message from being transmitted to an area that does not need it, and to calculate the channel access waiting time according to the probability of the accident, and to retransmit an accident notification message through a common channel from a vehicle having a short channel access waiting time. To minimize collisions with multiple vehicles accessing a common channel and to receive an accident notification message from another vehicle while the vehicle is waiting for channel access latency, thereby not retransmitting the accident notification message, thereby causing the vehicle to There is an effect that can minimize the duplicate transmission and reception of the notification message.

1 is an exemplary diagram illustrating a channel access procedure and a transmission procedure between multiple nodes in an IEEE 802.11 DCF model
Figure 2 is a block diagram showing the configuration of an inter-vehicle accident notification system according to an embodiment of the present invention
3 is an exemplary view for explaining a collision probability calculation unit in an inter-vehicle accident notification system according to an embodiment of the present invention.
4 and 5 are exemplary diagrams for explaining a process of transmitting an accident notification message of the accident notification system between vehicles according to an embodiment of the present invention.
6 is a flowchart illustrating an inter-vehicle accident notification method according to an exemplary embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 2, an inter-vehicle accident notification system according to an exemplary embodiment of the present invention includes a transceiver 10, a collision probability calculator 20, a channel access waiting time calculator 30, a standby unit 40, and The control unit 50 is included. Here, it is assumed that the inter-vehicle accident notification system is applied to vehicles traveling in the same direction in one or more lanes.

The transceiver 10 transmits and receives an accident notification (or danger warning: AW) message. The inter-vehicle accident notification system is installed in each vehicle and receives an accident notification message from surrounding vehicles within the corresponding range, or transmits an accident notification message to the surrounding vehicles. The corresponding range means a range in which communication is possible through the transceiver 10 and assumes that communication with a vehicle outside of the range is impossible.

The accident notification message includes accident related information such as accident occurrence time and accident location information.

In addition, the transceiver 10 transmits an accident notification message through a common channel in a broadcast manner. This eliminates the need for periodic exchange of beacon messages for sharing the state between each node required for Ad-hoc communication, which is the communication method of Korean Patent Registration No. 10-0835385. In-vehicle communication technology (V2V) requires beacon message exchange of each vehicle to manage a certain network structure. However, it is very difficult to properly exchange beacon messages due to the moving nature of vehicles traveling at high speeds and changing directions from time to time, and frequent beacon message exchanges can increase the load on the system. Therefore, the transceiver 10 of the present invention may solve this problem by transmitting and receiving an accident notification message in a broadcast manner without exchanging beacon messages.

The collision probability calculation unit 20 calculates a probability RC of causing an accident on its own (vehicle: the vehicle receiving the accident notification message) based on the accident notification message received through the transmission / reception unit 10. The probability of the accident refers to the probability that the own vehicle is subjected to a serial collision accident by the accident vehicle (Rear-end collision probablity (RC)).

The probability of accident (RC) is calculated based on Equation 1 as a product of the probability (FC) of the impact of the accident on the host vehicle and the probability (DC) of the host vehicle colliding the front vehicle when the front vehicle suddenly stops.

k: any vehicle

The collision probability calculation unit 20 calculates the FC (k) based on Equations 2 and 3 below.

α, β: coefficient

D (k): Relative distance between accident spot and own vehicle

L (k): The number of lanes between lanes

R: Danger radius that can affect the accident in the event of an accident

[Alpha], [beta] is an arbitrary coefficient for calculating FC (k) and is variably defined by the user. The FC (k) is closely related to the distance of the own vehicle from the accident point and whether the FC (k) is located in the same lane as the accident vehicle, and according to Equation 2 and Equation 3 according to the distance and lane separation distance of the own vehicle from the accident point. Quantitatively identify the possibility of accident risk exposure of own vehicle.

The DC (k) of the collision probability calculation unit 20 means a probability that the separation distance with the front vehicle according to the sudden stop of the own vehicle is reduced to a predetermined distance or less by the possibility of colliding with the own vehicle due to the sudden stop of the front vehicle. That is, if X (k) is defined as an expected separation distance from the vehicle ahead in the sudden stop of the vehicle and a predetermined threshold distance for the safety of the vehicle is defined as 'π', DC (k) may be expressed by Equation 4. Can be.

를 따르며, 상기 DC(k)는 X(k)의 누적 분포 함수(CDF: Cumulative Distribution Function)를 이용하여 수학식 5 및 6에 기초하여 산출한다. In addition, the collision probability calculation unit 20 has a standard deviation of σ (k) of X (k) and is normally distributed.

The DC (k) is calculated based on Equations 5 and 6 using a Cumulative Distribution Function (CDF) of X (k).

π: threshold distance for the safety of the vehicle

H: Distance between own car and front car

F (k): Stop distance of the vehicle ahead

R (k): Stop distance of the host vehicle (see Fig. 3)

E (X (k)): The predictable mean value of X (k)

The channel access waiting time calculating unit 30 calculates a channel access waiting time (CW) for the host vehicle to access the shared channel and transmit an accident notification message.

The channel access latency CW is calculated based on Equation 7.

T _min : minimum value of CW defined by user

T _max : the maximum value of CW defined by the user

λ: limit probability value

In addition, the controller 50 waits for the channel access time only when the RC value of the own vehicle is greater than or equal to the threshold probability value λ so that only a vehicle having a probability RC that has a collision probability greater than or equal to the threshold probability value λ can access the channel. The calculation unit 30 controls to calculate the channel access waiting time CW.

The threshold probability value lambda is a variable defined by the user in order to prevent all vehicles receiving the accident notification message from accessing the channel and to prevent the message from being transmitted indefinitely. That is, a vehicle having a lower probability probability λ has a lower probability of causing a crash, and thus it is not necessary to transmit an accident notification message to another vehicle by the broadcast method.

The waiting unit 40 waits for the channel access waiting time CW calculated through the channel access waiting time calculating unit 30.

The controller 50 checks whether or not an accident notification message is received from another vehicle through the transceiver 10 while waiting for the channel access waiting time CW in the waiting unit 40. The accident notification message is controlled to be transmitted through the transceiver 10.

The controller 50 controls the transfer of information in the accident notification system between vehicles.

If an accident notification message is received from another vehicle through the transceiver 10, the accident notification message is controlled not to be transmitted through the transceiver 10.

Referring back to FIG. 2, the inter-vehicle accident notification system includes a sensor unit 60.

The sensor unit 60 detects the shock data sensed by the vehicle and transmits the shock data to the controller 50, and detects the distance from the vehicle ahead and the position of the host vehicle.

 The controller 50 analyzes the shock data transmitted through the sensor unit 60 to determine whether an accident occurs.

The inter-vehicle accident notification system includes an output unit 70.

The output unit 70 provides the driver of the vehicle visually or audibly with information on the accident notification message provided through the controller 50.

4 and 5, a process of transmitting an accident notification message of an accident vehicle to a neighboring area and a vehicle by a broadcasting method will be described below.

If the accident vehicle is A and the vehicles behind it are B, C, D, E, F, G, the accident notification message is first sent from the accident vehicle A and sequentially re-sent to the neighboring area (Q, W). Casting). At this time, the accident vehicle A first transmits an accident notification message to the communication area Q, and the vehicles B, C, and D located behind the accident vehicle A receive the accident notification message.

Here, the vehicles B, C, and D that have received the accident notification message calculate the probability (RC) of having a serial collision with the accident vehicle A through the collision probability calculation unit 20, and the channel access waiting time calculation unit 30. Also calculate the channel access latency (CW) through.

Assuming that the accident vehicle A and the vehicle having a high probability of collision are B> C> D order, the channel access waiting time CW is also B> C> D> E. That is, as shown in FIG. 5, as the collision probability increases, the channel access waiting time also increases proportionally.

Accordingly, vehicle D, which has the shortest channel access waiting time CW, retransmits an accident notification message through a common channel in a broadcast manner, prior to other vehicles, and includes vehicles E, F, located in communication area W of vehicle D; G receives the accident notification message. In addition, vehicles B and C also receive an accident notification message again.

At this time, vehicles B and C with more channel access waiting time (CW) than vehicle D should resend an accident notification message when the channel access waiting time (CW) expires, but the vehicle has already received an accident notification message from vehicle D during waiting. Therefore, vehicles B and C cannot resend the accident notification message.

In this way, only vehicles relatively far from the accident vehicle can resend the accident notification message to another area through the common channel, so that the vehicles do not receive the accident notification message redundantly, and all vehicles receive the vehicle notification message on the common channel. Prevent transmission.

In addition, even if a vehicle far from the accident vehicle receives the accident notification message, the collision probability is low, so that the program is terminated without calculating the channel access waiting time, so that the accident notification message is not retransmitted to the rear vehicle.

Therefore, by preventing the message from being transmitted in a broadcast manner to an area where an accident notification message is not needed, it is possible to more efficiently use common channel resources in a distant area.

Referring to Figure 6, when explaining the vehicle-to-vehicle accident notification method according to an embodiment of the present invention.

The transceiver 10 receives the accident notification message (S100).

The collision probability calculation unit 20 calculates the probability RC of causing the accident based on the accident notification message received through the transmission and reception unit 10 (S110).

The controller 50 determines whether the probability RC of having the accident is greater than or equal to the threshold probability value λ (S120).

If the probability RC is greater than or equal to the threshold probability λ, the channel access waiting time calculator 30 waits for the channel access waiting time for the host vehicle to access the shared channel and transmit an accident notification message. window) (S130).

The waiting unit 40 waits for the channel access waiting time CW calculated through the channel access waiting time calculating unit 30 (S140).

The controller 50 checks whether or not an accident notification message is received from another vehicle through the transceiver 10 while waiting for the channel access waiting time CW in the waiting unit 40 (S150). If there is no control to transmit an accident notification message through the transceiver 10 (S160).

If there is an accident notification message received in step S150, the program is terminated without transmitting the accident notification message through the transceiver 10.

In step S120, if the probability RC of the host car has an accident is less than the threshold probability value λ, the program ends.

In step S110, the collision probability calculation unit 20 multiplies the probability RC of the accident by the influence of the accident on the vehicle and the probability that the vehicle collides with the preceding vehicle when the vehicle suddenly stops. Is calculated based on Equation (1).

In addition, the probability FC (k) of the influence of the accident on the host vehicle is calculated based on Equations 2 and 3 below.

이다. In addition, the probability (DC) that the host vehicle collides with the front vehicle when the front vehicle suddenly stops is determined by using a cumulative distribution function (CDF) of the expected separation distance (X (k)) from the front vehicle when the front vehicle suddenly stops. Calculated based on Equations 5 and 6 below, the standard deviation of X (k) is σ (k), and is normally distributed.

to be.

In the step S130, the channel access waiting time calculation unit 30 calculates the channel access waiting time (CW) based on Equation (7).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the invention as defined by the appended claims. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention.

10: transceiver
20: collision probability calculation unit
30: channel access waiting time calculation unit
40: waiting
50: control unit
60: sensor
70: output unit

Claims (14)

Transmitting and receiving unit for transmitting and receiving an accident notification message;
A collision probability calculation unit configured to calculate a probability (RC) of the own vehicle having an accident based on the accident notification message received through the transceiver;
A channel access waiting time calculating unit for calculating a channel access waiting time for transmitting the accident notification message by the host vehicle approaching a shared channel;
A waiting unit waiting for the channel access waiting time CW calculated through the channel access waiting time calculating unit;
The controller checks whether or not an accident notification message is received from another vehicle through the transceiver while waiting for the channel access waiting time CW in the waiting unit. Inter-vehicle accident notification system comprising a.
The method of claim 1,
The transceiver between the vehicle between the accident notification system, characterized in that for transmitting a broadcast over a common channel.
The method of claim 1,
In the collision probability calculation unit, the probability of causing an accident (RC) is a product of a probability (FC) of the impact of the accident on the host vehicle and a probability (DC) of the host vehicle colliding with the front vehicle when the vehicle ahead suddenly stops. Inter-vehicle accident notification system, characterized in that calculating.

k: any vehicle
The method of claim 3, wherein
The probability (FC) of the impact of the accident on the host vehicle is calculated based on the following equations.

α, β: coefficient
D (k): Relative distance between accident spot and own vehicle
L (k): Spacer between accident vehicle and own vehicle
R: Danger radius that can affect the accident in the event of an accident
The method of claim 3, wherein
The probability (DC) that the host vehicle collides with the front vehicle when the front vehicle suddenly stops is calculated based on the following equations using a cumulative distribution function of the expected separation distance (X (k)) from the front vehicle when the front vehicle suddenly stops. Where the standard deviation of X (k) is σ (k) and is normally distributed.

Inter-vehicle accident notification system, characterized in that.

H: Distance between own car and front car
π: threshold distance for the safety of the vehicle
F (k): Stop distance of the vehicle ahead
R (k): Stop distance of own vehicle
E (X (k)): The predictable mean value of X (k)
The method of claim 1,
The inter-vehicle accident notification system, wherein the channel approach wait time (CW) is calculated based on the following equation.

T _min : minimum value of CW defined by user
T _max : the maximum value of CW defined by the user
λ: limit probability value
The method of claim 1,
When the controller receives an accident notification message from another vehicle through the transceiver while waiting for the channel access waiting time CW in the standby unit, the controller may control the accident notification message not to be transmitted through the transceiver. Notification system.
Receiving unit receives an accident notification message (S100);
A collision probability calculation unit calculating a probability RC of having an accident based on an accident notification message received through the transceiver unit (S110);
Determining, by the controller, whether the probability that the host vehicle has an accident (RC) is equal to or greater than a threshold probability value (λ);
If the probability that the host vehicle has an accident RC is greater than or equal to the threshold probability value lambda, calculating the channel access waiting time CW for the host vehicle to access the shared channel and transmit an accident notification message ( S130);
Waiting for the channel by the channel access waiting time CW calculated through the channel access waiting time calculating unit (S140);
Checking, by the controller, whether an accident notification message is received from another vehicle through the transceiver during the waiting for the channel access waiting time CW in the standby unit (S150);
If there is no accident notification message received, the step of controlling the accident notification message to be transmitted through the transceiver (S160) characterized in that it comprises a vehicle-to-vehicle accident notification method.
The method of claim 8,
In the step S150, if there is a received accident notification message, the vehicle-to-vehicle accident notification method characterized in that the program is terminated without transmitting the accident notification message through the transceiver.
The method of claim 8,
In the step S120, if the probability that the host vehicle has an accident (RC) is less than the threshold probability value (λ), the inter-vehicle accident notification method characterized in that the end of the program.
The method of claim 8,
In the step S110, the collision probability calculation unit calculates the probability of the accident (RC) by multiplying the probability (FC) of the impact of the accident on the own vehicle and the probability of the collision of the front vehicle (DC) when the front vehicle suddenly stops, Between-vehicle accident notification method characterized in that the calculation based on the following equation.

k: any vehicle
The method of claim 11,
The probability (FC (k)) of the impact of the accident on the host vehicle is calculated based on the following equations.

α, β: coefficient
D (k): Relative distance between accident spot and own vehicle
L (k): Spacer between accident vehicle and own vehicle
R: Danger radius that can affect the accident in the event of an accident
The method of claim 11,
The probability (DC) that the host vehicle collides with the front vehicle when the front vehicle suddenly stops is calculated based on the following equations using a cumulative distribution function of the expected separation distance (X (k)) from the front vehicle when the front vehicle suddenly stops. Where the standard deviation of X (k) is σ (k) and is normally distributed.

Inter-vehicle accident notification method characterized in that.

H: Distance between own car and front car
π: threshold distance for the safety of the vehicle
F (k): Stop distance of the vehicle ahead
R (k): Stop distance of own vehicle
E (X (k)): The predictable mean value of X (k)
The method of claim 8,
In the step S130, the channel approach waiting time calculating unit between the vehicle accident notification method, characterized in that for calculating the channel access waiting time (CW) based on the following equation.

T _min : minimum value of CW defined by user
T _max : the maximum value of CW defined by the user
λ: limit probability value

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