KR102032062B1 - Terminal device in vehicle included in TDMA-based vehicle ad-hoc network and Method for preventing resource collision of the vehicle - Google Patents

Abstract

Disclosed are a terminal device in a vehicle included in a TDMA-based vehicle ad-hoc network and a method for preventing resource collision for the vehicle. The terminal device comprises: a location-direction calculation unit calculating location-direction information of the vehicle and location-direction information of other vehicles at time t+Δt on the basis of traveling information of the vehicle and the other vehicles on the network at time t, wherein the location-direction information is location information in which the moving direction is reflected from time t to time t+Δt, and the traveling information includes speed information, acceleration information, and location information; a probability calculation unit calculating merge collision probability of the vehicle with the other vehicles and access collision probability when the merge collision probability occurs on the basis of the location information of the vehicle and the other vehicles at time t and the location-direction information of the vehicle and the other vehicles at time t+Δt; and a determination unit determining whether or not a resource collision has occurred on the basis of the merge collision probability and the access collision probability.

Description

Terminal device in vehicle included in TDMA-based vehicle ad-hoc network and Method for preventing resource collision of the vehicle}

Embodiments of the present invention provide a method of preventing a resource collision of a vehicle performing efficient and stable broadcasting by efficiently predicting a moving direction of vehicles in a TDMA-based vehicle ad hoc network and avoiding resource collision between vehicles and vehicles. It relates to a terminal device.

IEEE 802.11p is a standard for wireless transmission technology for providing traffic conditions and safety information and various kinds of commercial services in a high-speed moving vehicle network based on the existing wireless LAN standard IEEE 802.11. The medium access control function follows the CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance) mechanism defined in IEEE 802.11. However, there is a limit that can not effectively reduce the collision between vehicles moving at high speed with the competition-based CSMA / CA.

In order to reduce resource collisions between vehicles, a time division multiple access (TDMA) method, which is a non-competitive method of dividing the same resource into smaller times and then allowing the user to use the resource at a given time, is mainly used. At this time, in a technique using TDMA, a method of classifying resource occupancy through vehicle driving information is used to mitigate a collision, and a vehicle speed is calculated by calculating a vehicle speed at a next time point based on the current position and speed of the vehicle at the present time. A method has been proposed to avoid resource conflicts between them.

However, there are situations in which the speed of the vehicle changes, the U-turn, the direction of movement changes, or the density of the vehicle changes frequently depending on the road conditions. The conventional method using the TDMA technique is one of the above situations. In addition, there may be a problem of wasting resources or using excessively, and there is a disadvantage that an accident between vehicles may occur due to data delay in terms of network.

In order to solve the problems of the prior art as described above, in the present invention, in the TDMA-based vehicle ad hoc network, efficiently predicting the direction of movement of the vehicles to avoid the resource collision between the vehicle to perform efficient broadcasting efficiently A resource collision prevention method of a vehicle and a terminal device performing the same are proposed.

Other objects of the present invention may be derived by those skilled in the art through the following examples.

According to a preferred embodiment of the present invention for achieving the above object, a terminal device in a vehicle included in a TDMA-based vehicle ad hoc network, based on the driving information of the vehicle and other vehicles of the network at time t A position-direction calculator for calculating the position-direction information of the vehicle and the position-direction information of the other vehicles at time t + Δt, wherein the position-direction information has a moving direction from time t to time t + Δt Reflected position information, wherein the driving information includes speed information, acceleration information, and position information; The merge collision probability and the merge collision of the vehicle with respect to the other vehicle based on the position information of the vehicle and the other vehicle at time t and the position-direction information of the vehicle and the other vehicle at time t + Δt A probability calculator configured to calculate an access collision probability when a probability occurs; And a determination unit determining whether a resource collision has occurred based on the merge collision probability and the access collision probability.

The terminal device may further include a resource allocator configured to change a time slot of the TDMA occupied by the vehicle before the next broadcasting to prevent resource collision when the resource collision occurs.

The location-direction information at time t + Δt for each of the vehicle and the other vehicles may be expressed by the following equation.

는 상기 위치 정보, θ는 이동 방향의 각도, α는 상기 이동 방향의 각도의 변화량, τ는 α의 시간 변화량을 각각 의미함.Where V is location-direction information,

Is the positional information, θ is the angle of the moving direction, α is the amount of change in the angle of the movement direction, τ is the amount of time change of α, respectively.

In the merge collision, for the vehicle i and the vehicle j using the same time slot, the distance between the vehicle i and the vehicle j at a time t is greater than or equal to a preset distance, but no resource collision occurs, but the time t + Δt Is defined as a resource collision occurring when the predicted distance between the vehicle i and the vehicle j is less than the set distance, and the merging collision probability may be expressed by the following equation.

Where P _MC (i, t) is the probability that a merge collision will occur in the vehicle i at time t, and M _mc is a vehicle that can generate a merge collision calculated based on the location-direction information of vehicles in the vehicle ad hoc network. , R is the transmission radius, 2R is the set distance, l is the width of the road, w is the length of the road, P _mc (i, j, t) is in the vehicle i due to the vehicle j at time t The probability that a merge collision will occur, Pr {} is a probability function, d _ij (t) is the distance between the vehicle i and the vehicle j at time t, and d _ij (t + Δt) is the time at time t + Δt Distance between vehicle i and vehicle j, n _i (t) is the number of time slots occupied by vehicle i at time t, and n _j (t) is the time slot occupied by vehicle j at time t number, v _ij (t) is the vehicle speed difference between the i and j of the vehicle at time t, N is the total time slot of a frame Number, △ t is a time change amount, v _max is also based maximum speed, θ _ij (t) is set, meaning the vehicle i and the angle of the direction of movement of the car between the car j at time t, respectively.

The access collision is defined as a resource collision occurring when the vehicle i and the vehicle j occupy the same time slot when the distance between the vehicle i and the vehicle j is less than the set distance, and the merge collision occurs. The access collision probability may be expressed as the following equation.

Where P _AC (i, t) is the probability that an access collision will occur in the vehicle i at time t, A _ac is the number of vehicles in which a merge collision has occurred, and P _ac (i, j, t) is the vehicle at time t j is the probability that an access collision occurs in the vehicle i, N is the total number of time slots per frame, N _e is the number of time slots not occupied in the one frame, respectively.

In addition, according to another embodiment of the present invention, in the resource collision prevention of the vehicle included in the TDMA-based vehicle ad hoc network, to the operation information of the vehicle and other vehicles of the network at time t. Calculating the position-direction information of the vehicle and the position-direction information of the other vehicles at time t + Δt based on the position-direction information, the position information reflecting the moving direction from time t to time t + Δt The driving information includes speed information, acceleration information and location information; The merge collision probability and the merge collision of the vehicle with respect to the other vehicle based on the position information of the vehicle and the other vehicle at time t and the position-direction information of the vehicle and the other vehicle at time t + Δt Calculating an access collision probability when the probability occurs; Determining whether a resource collision has occurred based on the merge collision probability and the access collision probability; And when the resource collision occurs, changing the time slot of the TDMA occupied by the vehicle before the next broadcasting to prevent resource collision.

According to the present invention, in a TDMA-based vehicle ad hoc network, there is an advantage that efficient broadcasting can be efficiently performed by efficiently predicting a moving direction of vehicles to avoid resource collision between vehicles.

In addition, the effect of this invention is not limited to the above-mentioned effect, It should be understood that it includes all the effects which can be inferred from the structure of the invention described in the detailed description of this invention, or a claim.

1 is a diagram illustrating the concept of a vehicle ad hoc system according to an embodiment of the present invention.
2 is a diagram illustrating an example of a structure of a frame and FI message of a TDMA according to an embodiment of the present invention.
3 is a diagram illustrating a schematic configuration of a terminal apparatus in a vehicle according to an embodiment of the present invention.
4 is a flowchart illustrating a resource collision prevention of a vehicle included in a TDMA-based vehicle ad hoc network according to an embodiment of the present invention.
5 illustrates the concept of θ according to an embodiment of the present invention.

As used herein, the singular forms "a", "an" and "the" include plural forms unless the context clearly indicates otherwise. In this specification, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various components or steps described in the specification, and some of the components or some steps It should be construed that it may not be included or may further include additional components or steps. In addition, the terms "... unit", "module", etc. described in the specification mean a unit for processing at least one function or operation, which may be implemented in hardware or software or a combination of hardware and software. .

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

1 is a diagram illustrating the concept of a vehicle ad hoc system according to an embodiment of the present invention.

Since vehicle-to-vehicle in a vehicle ad hoc network communicates without going through a base station, broadcasting with neighboring vehicles is important. Broadcasting is used to collect driving information of neighboring vehicles or to inform neighboring vehicles of themselves and neighboring vehicle information. In this case, broadcasting is repeatedly performed according to a predetermined period, and the driving information includes location information, speed information, and the like obtained through GPS.

However, in vehicle ad hoc networks, topology changes occur dynamically due to the high mobility of the vehicles. In addition, limited communication time is required for frequent link disconnection and accident prevention between vehicles. Also, in areas where vehicles are concentrated, frequent resource collisions occur due to competition between vehicles sharing a common wireless channel.

Considering the actual traffic environment, there are two situations in which resource collision occurs when using the TDMA technique in a vehicle ad hoc network. That is, an access collision occurs when two different vehicles occupy the same time slot within a preset radius, and two vehicles located outside the different radius at the present time use the same time slot. In the future there is a merging collision, which is predicted to occur with two vehicles entering the radius and using the same slot.

Accordingly, the present invention proposes a method for avoiding resource collision of a vehicle by estimating an expected position of each vehicle in order to stably broadcast each vehicle, and a terminal apparatus performing the same.

Here, it is assumed that each vehicle obtains the driving information (the longitude, the direction, the speed, etc.) of the vehicle from the GPS device installed inside the vehicle, and the position of the vehicle may be expressed in a vector space. Each vehicle is randomly allocated resources regardless of the vehicle information state at the time of initial network entry, and it is assumed that continuous resource allocation continues unless resource collision occurs with a vehicle within two hops of communication range. In this case, the hop corresponds to a preset transmission radius. In addition, every vehicle broadcasts a FI (Frame Information) message including its own driving information to one neighboring vehicle, and the driving information of the vehicle received from the one hop neighboring vehicle is transmitted together. Accordingly, each vehicle can grasp the FI messages of neighboring vehicles distributed in two hops, and can also confirm that time slot collision will occur in the vehicles distributed in three hops. A collision of control time slots is found every frame and each vehicle updates the FI message of the neighboring vehicle each time.

2 is a diagram illustrating an example of a structure of a frame and FI message of a TDMA according to an embodiment of the present invention.

Referring to FIG. 2, the frame is composed of C control time slots and D data time slots, and each vehicle transmits and receives FI messages through a control channel.

The FI message includes the vehicle ID, hop information, vehicle travel direction, vehicle position (= longitude, latitude), occupied control time slot, speed, and acceleration for performing broadcasting on the control channel. ID information of each vehicle is used as ID information. In Hop Info, oneself is represented by '0', one hop neighboring vehicle is represented by '1', and two hops neighboring vehicle is represented by '2'. Direction Info, Longitude Info, Longitude Info, Time Slot Info, Speed Info, and Acceleration Info are the driving status information of each vehicle at time t. Is expressed.

At this time, as mentioned above, each vehicle occupies one control time slot at random upon initial network entry. The vehicle assigned the c-th control time slot without collision transmits a FI message through the corresponding time slot every frame. The crashed vehicle attempts to reoccupy at the next frame (i.e., the next broadcast time point) by selecting one of the control time slots to which neighboring vehicles within two hops of the previous frame are not assigned. Since at least two frames are required to allocate the control time slot without collision, each vehicle performs the control time slot occupancy procedure every two frame periods.

Each vehicle assigned a Control time slot broadcasts a FI message to the 1-hop neighbor vehicle through that slot in every frame. The FI message received from the 1-hop neighboring vehicle combines the information of itself and the 1-hop neighboring vehicle and transmits it to the 1-hop neighboring vehicle again.

Hereinafter, a method of preventing resource collision of a vehicle performed by a terminal device located in each vehicle will be described in detail.

3 is a diagram illustrating a schematic configuration of a terminal apparatus in a vehicle according to an embodiment of the present invention.

Referring to FIG. 3, the terminal device 300 may include a communication unit 310, a location calculator 320, a probability calculator 330, a determiner 340, and a resource allocator 350.

In this case, the location calculator 320, the probability calculator 330, the determiner 340, and the resource allocator 350 may be modules implemented by a processor in the terminal device 300. In this case, the module may mean a functional and structural combination of hardware for performing the technical idea of the present invention and software for driving the hardware. For example, the module may mean a logical unit of a predetermined code and a hardware resource for performing the predetermined code, and means a physically connected code or does not necessarily mean one kind of hardware. It can be easily inferred by the average expert in the art.

4 is a flowchart illustrating resource collision prevention of a vehicle included in a TDMA based vehicle ad hoc network according to an embodiment of the present invention.

Hereinafter, a function of each component and a process performed by each step will be described in detail.

First, in step 410, the communication unit 310 receives the driving information for the time t broadcast from other vehicles in the vehicle ad hoc network.

Next, in step 420, the position calculating unit 320, based on the driving information of the vehicle and the other vehicle at time t, the position-direction information of the vehicle at the time t + Δt and the position of the other vehicles- Calculate the direction information.

At this time, the driving information of the vehicle may be obtained through the information obtained from the GPS, and includes speed information, acceleration information, and location information. The position-direction information is position information in which the moving direction from time t to time t + Δt is reflected.

According to an embodiment of the present invention, the position-direction information at the time t + Δt of the vehicle may be expressed as Equation 1 below.

는 차량의 위치 정보, θ는 차량의 이동 방향의 각도, α는 이동 방향의 각도의 변화량 정보, τ는 α의 시간 변화량을 각각 의미한다. 도 5에서는 θ의 개념을 도시하고 있다. Where V is position-direction information of the vehicle,

Is the position information of the vehicle, θ is the angle of the moving direction of the vehicle, α is the change amount information of the angle of the moving direction, τ is the time change amount of α, respectively. 5 shows the concept of θ.

)를 산출하고, ii) 미리 산출 내지 획득된 시간 t-△t에서의 거리 정보(

)와 시간 t에서의 거리 정보(

)에 기초하여 시간 t에서의 이동 방향의 각도(θ_t)를 산출하고, iii) 미리 산출된 시간 t-△t에서의 차량의 이동 방향의 각도(θ_t-△t)와 시간 t에서의 이동 방향의 각도(θ_t)에 기초하여 시간 t에서의 이동 방향의 각도의 변화량(α_t)를 산출하고, iv) 미리 산출된 시간 t-△t에서의 차량의 이동 방향의 각도의 변화량(α_t-△t)과 시간 t에서의 이동 방향의 각도의 변화량(α_t)에 기초하여 시간 t에서의 α의 시간 변화량(τ_t)를 산출하고, v) 시간 t에서의 이동 방향의 각도(θ_t), 이동 방향의 각도의 변화량(α_t), α_t에서의 시간 변화량(τ_t) 및 △t에 기초하여 시간 t+△t에서의 이동 방향의 각도(θ_t+△t)를 산출하고, vi) 시간 t+△t에서의 거리 정보(

) 및 시간 t+△t에서의 이동 방향의 각도(θ_t+△t)에 기초하여 시간 t+△t에서의 위치-방향 정보를 산출할 수 있다. That is, the position calculating unit 320 is i) the distance information at time t + Δt based on the driving information of the vehicle at time t (

), Ii) the distance information at the time t-Δt calculated in advance or

) And distance information at time t (

) For the calculation of the angle (θ _t) of the moving direction at time t, and, iii) a pre-calculated time, the angle of the direction of movement of the vehicle in the _{t- △ t (θ t- △ t} ) with the time base t Based on the angle θ _t of the moving direction, the change amount α _t of the angle in the moving direction at time t is calculated, and iv) the change amount of the angle in the moving direction of the vehicle at the time t-Δt calculated in advance ( based on α _{t- △ t)} with variation of time t (α _t) of the moving direction angle in calculating the variation in time (τ _t) of α at time t, and, v) the angle of the moving direction at time t calculates the angle (θ _{t + Δt} ) in the moving direction at time t + Δt based on (θ _t ), the change amount of the angle in the moving direction (α _t ), the time change amount (τ _t ) at α _t , and Δt Vi) distance information at time t + Δt

) And the position-direction information at time t + Δt based on the angle θ _{t + Δt} in the moving direction at time t + Δt.

Accordingly, the present invention can calculate more accurate position-direction information.

Subsequently, in step 430, the probability calculation unit 330 determines the positional information at the time t of the vehicle and the positional information at the time t of the other vehicles, the position-direction information at the time t + Δt of the vehicle and the other vehicle. The collision collision probability of the vehicle with respect to other vehicles and the access collision probability when the merge collision probability has occurred are calculated based on the position-direction information at the time t + Δt. Each collision probability is described in detail as follows.

Regarding the merge collision, as mentioned above, the merge collision is a resource collision for the vehicle i and the vehicle j using the same time slot such that the distance between the vehicle i and the vehicle j at time t becomes more than a preset distance. Although not generated, it is defined as a resource collision that occurs when the predicted distance between the vehicle i and the vehicle j at the time t + Δt is less than the preset distance. In this case, the preset distance may be 2 hops to 2 times the preset transmission radius R.

According to an embodiment of the present invention, the merge collision probability may be expressed as Equation 2 below.

Where P _MC (i, t) is the probability that a merge collision will occur in vehicle i at time t, M _mc is the number of vehicles that can generate a merge collision calculated based on the location-direction information of vehicles in the vehicle ad hoc network, Where R is the transmission radius, 2R is the predetermined distance, l is the width of the road, w is the length of the road, and P _mc (i, j, t) is the probability that merged collision will occur in vehicle i due to vehicle j at time t. Each means.

In this case, P _mc (i, j, t) may be expressed as Equation 3 below.

Where Pr {} is the probability function, Pr {d _ij (t)> 2R} is the probability when the distance difference (= d _ij (t)) between vehicle i and j at t is greater than 2 hops, Pr {d _ij (t + Δt) ≤ 2R} is the probability when the distance difference between vehicle i and vehicle j (= d _ij (t + Δt)) at t + Δt is less than 2 hops, Pr {n _i ( t) = n _j (t)} is the number of time slots occupied by vehicle i at time t (= n _i (t)) and the number of time slots occupied by vehicle j (= n _j (t)). _Equality , v _ij (t) is the speed difference between vehicle i and j at time t, N is the total number of time slots in one frame, Δt is the amount of time change, and v _max is the preset maximum speed , θ _ij (t) means the angle difference in the moving direction between the vehicle i and the vehicle j at time t, respectively.

In this case, d _ij (t) and d _ij (t + Δt) may be expressed by Equation 4 below.

Where x _i (t) is the x-axis coordinate of vehicle i at time t, y _i (t) is the y-axis coordinate of vehicle i at time t, and x _j (t) is x of vehicle j at time t Axial coordinate, y _j (t) is the y-axis coordinate of the vehicle j at time t, θ _i (t) is the moving direction information of the vehicle i at time t, θ _j (t) is the vehicle j at time t Means the direction of movement information, respectively.

Pr {d _ij (t)> 2R}, Pr {d _ij (t + Δt) ≤ 2R} and r {n _i (t) = n _j (t)} are represented by Equation 5 below. Equation 3 may be derived.

Next, in relation to the access collision, as mentioned above, the access collision is the same time that the vehicle i and the vehicle j have the same time when the distance between the vehicle i and the vehicle j is less than the preset distance after the merge collision probability occurs; Defined as a resource conflict that occurs when occupying a slot. In this case, the preset distance may be 2 hops to 2 times the preset transmission radius R.

According to an embodiment of the present invention, the access collision probability may be expressed as in Equation 6 below.

Where P _AC (i, t) is the probability that an access collision will occur in vehicle i at time t, A _ac is the number of vehicles in which a merge collision occurred, and P _ac (i, j, t) is vehicle t at time t Each means a probability that an access collision occurs in the vehicle i.

In this case, P _ac (i, j, t) may be expressed by Equation 7 below.

Where Pr {N _e > A _ac } is the probability that the number of unoccupied time slots in one frame (= N _e ) is greater than the number of vehicles currently attempting to occupy new resources, and N is the total number of time slots per frame. Means each. At this time, Pr {N _e > A _ac } is the same as Equation 8 below, through which Equation 7 can be derived.

Thereafter, in operation 440, the determination unit 340 may determine whether a resource collision occurs based on the merge collision probability and the access collision probability. For example, preset thresholds may be set for each collision probability, and the collision threshold may be determined by comparing each collision probability with a preset threshold.

Finally, in step 450, if a resource conflict occurs, the resource allocator 350 may change the time slot of the TDMA occupied by the vehicle before the next broadcasting. Accordingly, resource collision between vehicles can be prevented.

In addition, embodiments of the present invention can be implemented in the form of program instructions that can be executed by various computer means may be recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer readable recording media include magnetic media such as hard disks, floppy disks and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks such as floppy disks. Examples of program instructions such as magneto-optical and ROM, RAM, flash memory, etc. may be executed by a computer using an interpreter as well as machine code such as produced by a compiler. Contains high-level language codes. The hardware device described above may be configured to operate as one or more software modules to perform the operations of one embodiment of the present invention, and vice versa.

In the present invention as described above has been described by the specific embodiments, such as specific components and limited embodiments and drawings, but this is provided to help the overall understanding of the present invention, the present invention is not limited to the above embodiments, Various modifications and variations can be made by those skilled in the art to which the present invention pertains. Therefore, the spirit of the present invention should not be limited to the described embodiments, and all of the equivalents or equivalents of the claims as well as the claims to be described later belong to the scope of the present invention. .

Claims (6)

A terminal device in a vehicle included in a TDMA based vehicle ad hoc network,
A position-direction calculator for calculating position-direction information of the vehicle and position-direction information of the other vehicles at time t + Δt based on driving information of the vehicle at time t and other vehicles in the network; The position-direction information is position information reflecting a moving direction from time t to time t + Δt, wherein the driving information includes speed information, acceleration information and position information;
The merge collision probability and the merge collision of the vehicle with respect to the other vehicle based on the position information of the vehicle and the other vehicle at time t and the position-direction information of the vehicle and the other vehicle at time t + Δt A probability calculator configured to calculate an access collision probability when a probability occurs; And
And a determination unit determining whether a resource collision has occurred based on the merge collision probability and the access collision probability. The method of claim 1,
The terminal device, the terminal device, characterized in that it further comprises a resource allocator for changing the time slot of the TDMA occupied by the vehicle before the next broadcast to prevent resource conflicts. The method of claim 1,
And the position-direction information at time t + Δt for each of the vehicle and the other vehicles is expressed by the following equation.

Where V is location-direction information,

Is the positional information, θ is the angle of the moving direction, α is the amount of change in the angle of the movement direction, τ is the amount of time change of α, respectively. The method of claim 1,
In the merge collision, for the vehicle i and the vehicle j using the same time slot, the distance between the vehicle i and the vehicle j at a time t is greater than or equal to a preset distance, but no resource collision occurs, but the time t + Δt Is defined as a resource collision occurring when the predicted distance between the vehicle i and the vehicle j is less than the set distance,
The merge collision probability is represented by the following equation.

Where P _MC (i, t) is the probability that a merge collision will occur in the vehicle i at time t, and M _mc is a vehicle that can generate a merge collision calculated based on the location-direction information of vehicles in the vehicle ad hoc network. , R is the transmission radius, 2R is the set distance, l is the width of the road, w is the length of the road, P _mc (i, j, t) is in the vehicle i due to the vehicle j at time t The probability that a merge collision will occur, Pr {} is a probability function, d _ij (t) is the distance between the vehicle i and the vehicle j at time t, and d _ij (t + Δt) is the time at time t + Δt Distance between vehicle i and vehicle j, n _i (t) is the number of time slots occupied by vehicle i at time t, and n _j (t) is the time slot occupied by vehicle j at time t number, v _ij (t) is the vehicle speed difference between the i and j of the vehicle at time t, N is the total time slot of a frame Number, △ t is a time change amount, v _max is also based maximum speed, θ _ij (t) is set, meaning the vehicle i and the angle of the direction of movement of the car between the car j at time t, respectively. The method of claim 4, wherein
The access collision is defined as a resource collision that occurs when the vehicle i and the vehicle j occupy the same time slot when the distance between the vehicle i and the vehicle j is less than the set distance,
And the access collision probability when the merge collision occurs is expressed by the following equation.

Where P _AC (i, t) is the probability that an access collision will occur in the vehicle i at time t, A _ac is the number of vehicles in which a merge collision has occurred, and P _ac (i, j, t) is the vehicle at time t j is the probability that an access collision occurs in the vehicle i, N is the total number of time slots per frame, N _e is the number of time slots not occupied in the one frame, respectively. In the resource collision prevention of a vehicle performed by a processor and included in a TDMA-based vehicle ad hoc network,
Calculating the position-direction information of the vehicle and the position-direction information of the other vehicles at time t + Δt based on the driving information of the vehicle and other vehicles in the network at time t—the position-direction information Is position information reflecting a moving direction from time t to time t + Δt, and the driving information includes speed information, acceleration information, and position information;
The merge collision probability and the merge collision of the vehicle with respect to the other vehicle based on the position information of the vehicle and the other vehicle at time t and the position-direction information of the vehicle and the other vehicle at time t + Δt Calculating an access collision probability when the probability occurs;
Determining whether a resource collision has occurred based on the merge collision probability and the access collision probability; And
When the resource collision occurs, changing the time slot of the TDMA occupied by the vehicle before the next broadcasting to prevent resource collision.

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