CN105847369A - Vehicle network information transmission method based on event driving - Google Patents

Abstract

The invention provides a vehicle network information transmission method based on event driving, comprising: according to different influence on front and rear vehicles, dividing road events into events having greater influence on a rear vehicle than on a front vehicle, and events having less influence on a rear vehicle than on a front vehicle; each vehicle keeping a vehicle information packet in real time; in case of a traffic accident, a traffic accident vehicle forming a danger information packet, wherein the danger information packet is generated by the traffic accident vehicle, and transmitted among vehicles; each vehicle keeping a density packet in real time, and determining in which direction of a vehicle communication range a vehicle exists; when a vehicle is in a traffic accident, a microprocessor installed on the vehicle generating the danger information packet according to vehicle information, and selecting a next-hop vehicle according a current vehicle density packet; and the next-hop vehicle selecting a next-hop vehicle according to a self vehicle density packet and danger information packet, and so on. The method can effectively improve information transmission efficiency, and ensure that information can be timely and effectively transmitted to target vehicles.

Description

A kind of based on event driven vehicle area network message transmission method

Technical field

The present invention relates to a kind of based on event driven vehicle area network message transmission method, belong to In-vehicle networking communication technical field.

Background technology

Different types of sensor is arranged on vehicle the speed of the parameter of the different conditions that can obtain vehicle, such as vehicle, acceleration etc., can decide whether certain accident according to the kinestate of one or more vehicle.So vehicular ad hoc network can be regarded as a kind of special wireless sensor network.Vehicle can be sensor power, so without the concern for the problem of sensor power, this is the difference at vehicular ad hoc networking and wireless sensor network.The research direction of the existing Routing Protocol of In-vehicle networking can be divided three classes: Routing Protocol TBR (Topology-based Routing protocol), Routing Protocol PBR based on positional information (Position-based Information Routing protocol) of based on topology, Routing Protocol MBR based on map (Map-based Routing Protocol).

Along with the development of science and technology, road vehicle gets more and more, and this also results in the generation of various road accident, when vehicle is able to detect that certain accident, if it is possible to accident transferred out in time and more serious thing perhaps can be avoided to occur.So, if can improve on the basis of existing VANET (vehicle self-organizing network) Routing Protocol, propose a kind of based on event driven Routing Protocol, perhaps can preferably solving road safety problem.

The design object of Routing Protocol is mainly: reduces network overhead while the application demands such as satisfied such as network delay, delay variation, packet loss as far as possible, expand network throughput, improves the overall effectiveness of network.

Summary of the invention

The present invention is to solve the promptness transmitted on a highway of information and the technical problem of continuity.

In order to solve above-mentioned technical problem, the technical scheme is that offer is a kind of based on event driven vehicle area network message transmission method, it is characterised in that: the method is made up of following 5 steps:

Step 1, road incidents are divided into two big classes according on the difference that affects of fore-aft vehicle: a kind of be the event impact on vehicle below more than the impact on front vehicles, a kind of is that the event impact on front vehicles is more than the impact on front vehicle；

Step 2, each car maintain an information of vehicles bag in real time；

Step 3, when a fault occurs, accident vehicle can form a dangerous information bag；Dangerous information bag is produced by accident vehicle and transmits between vehicle；

Step 4, each car maintain a density bag in real time, and in the range of obtaining vehicle communication according to density bag, which direction exists vehicle；

Step 5, when there is accident in a car, mounted in a vehicle microprocessor according to information of vehicles bag generate dangerous information bag, then further according to now traffic density bag select down hop vehicle；The vehicle of down hop selects down hop vehicle with dangerous information bag, by that analogy further according to the traffic density bag of self.

Preferably, the specifically comprising the following steps that of described step 1

Step 1.1: affected big vehicle to allow event preferentially be sent to by this event, therefore by event classification；Differentiating by the velocity sensor being arranged on vehicle, acceleration transducer, the perception of angular-rate sensor of event type, then be analyzed process by microprocessor and complete；

Step 1.2: brake, block up, deceleration event is greater than the impact of the vehicle on vehicle front to the impact of the vehicle of rear view of vehicle, so these event informations are preferentially sent to the vehicle of rear view of vehicle in the protocol；

Step 1.3: overtake other vehicles, accelerated events is greater than the impact of the vehicle on rear view of vehicle to the impact of the vehicle of vehicle front, so these event informations are preferentially sent to the vehicle of vehicle front in the protocol.

Preferably, in described step 2, information of vehicles bag includes: vehicle ID, vehicle heading, vehicle location, road direction；Information in information of vehicles bag is obtained by the GPS device being arranged on vehicle, then preserves in the microprocessor.

Preferably, described vehicle ID is used for uniquely identifying vehicle；

Described vehicle heading obtains according to the vector calculus of the gps data of nearest twice of vehicle；

Described road direction depends on the travel direction of vehicle on this road, and needing the most artificially one direction of regulation is positive direction.

Preferably, in described step 3, dangerous information bag includes: transmission direction, accident vehicle ID, accident vehicle position, the road direction at accident vehicle place.

Preferably, in described step 4, density bag includes: whether there is vehicle ρ in vehicle front communication range_f, in rear view of vehicle communication range, whether there is vehicle ρ_h, in the communication range of vehicle side, whether there is vehicle ρ_s。

Preferably, in described step 4, if there is vehicle in the communication range in certain direction, then the parameter characterizing the direction is 1, otherwise is 0；When in certain direction, at least the parameter of Q car of continuous print is 1, Q is setting value, takes the mode of sub-clustering to be transmitted information, otherwise, then it is chosen at the farthest vehicle of distance in the range of vehicle communication as down hop vehicle.

Preferably, described Q is 42.

Preferably, the mode detailed process of described sub-clustering is:

A. vehicle arrives each point and obeys Poisson distribution；X represents the interval between Adjacent vehicles, and exponential is obeyed at this interval, then this interval average isWherein λ is rate parameter；This interval probability distributing density function is f (x)=λ e^{- λ x}；Again because bunch in distance between vehicle be necessarily less than the transmission radius r of vehicle, i.e. the vehicle distances probability less than transmission radius r is:

B., in clustering process, have two kinds different bunches: beginning and least significant end bunch size be as, the size of intermediate tufts is the same；Assume that one bunch has n interval, then:

Beginning and least significant end bunch probability function be g₁(n)=e^{- λ r}(1-e^{- λ r})⁽ⁿ⁺¹⁾；

The probability function of intermediate tufts is g₂(n)=(1-e^{- λ r})ⁿ⁺²；

Beginning and least significant end bunch mean size be:

$E_a=\underset{x\→\mathrm{\∞}}{\lim }\frac{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\left(g_1\right(i\left)\underset{j=1}{\overset{i}{\mathrm{\Σ}}}{d}_j\right)}{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{g}_1\left(i\right)}$

The mean size of intermediate tufts is:

$E_b=\underset{n\→\mathrm{\∞}}{\lim }\frac{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\left(g_2\right(i\left)\underset{j=1}{\overset{i}{\mathrm{\Σ}}}{d}_j\right)}{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{g}_2\left(i\right)}$

Calculate in conjunction with formula in B:

D. assume to be divided into altogether m cluster between first car and last car；L represents the distance between first car and last car, and this distance can be obtained by gps data；D represents the width of road；Again because the transmission radius r of vehicle is greater than the width d's of road, so the computing formula of cluster is:

$G\left(m\right)=\left\{\begin{array}{c}L=2E_a+m{E}_b\\ r>d\end{array}\right.$

Preferably, the specifically comprising the following steps that of described step 5

If dangerous information needs first to travel to front vehicles, then, ρ_fThis parameter needs to be detected first；If ρ_f=1, then information takes the mode of single-hop or use bunch to carry out propagating dangerous information；If but ρ_f=0, ρ_sWill be detected；If ρ_s=1, dangerous information will be transmitted to reverse track；Otherwise, dangerous information can only wait selection；

If dangerous information needs to travel to front vehicle, then, ρ_hThis parameter needs to be detected first；If ρ_h=1, then information takes the mode of single-hop or use bunch to carry out propagating dangerous information；If but ρ_h=0, ρ_sWill be detected；If ρ_s=1, dangerous information will be transmitted to reverse track；Otherwise, dangerous information can only wait selection.

The present invention is special wireless sensor network from vehicular ad hoc network, has research angle based on event driven characteristic, set out in conjunction with the road scene of different densities can be designed that under applicable different densities scene based on event driven Routing Protocol so that the time delay of information transmission, packet loss, channel capacity etc. to the greatest extent can be optimum.

The method that the present invention provides overcomes the deficiencies in the prior art, and according to this standards different on the impact of surrounding vehicles, the accident on road is divided into two classes.The sensor acquisition information being arranged on vehicle, and information is transferred to microprocessor, these information are analyzed processing by microprocessor.Each car needs to maintain a density bag, is mainly to carry out information transmission according to the data of density bag when vehicle has an accident.So accident vehicle just can efficiently find the vehicle of down hop, it is possible to effectively improves information transfer efficiency, it is ensured that information is transferred to target vehicle timely and effectively, improves promptness and the continuity of transmission on highway.

Accompanying drawing explanation

Fig. 1 is based on event driven vehicle area network message transmission method flow chart；

Fig. 2 be beginning with least significant end bunch mean size E_aSimulated effect figure；

Fig. 3 is the mean size E of intermediate tufts_bSimulated effect figure；

Fig. 4 be embodiment 1 road scene figure；

Fig. 5 be embodiment 2 road scene figure；

Fig. 6 be embodiment 3 road scene figure.

Detailed description of the invention

Below in conjunction with specific embodiment, the present invention is expanded on further.Should be understood that these embodiments are merely to illustrate the present invention rather than limit the scope of the present invention.In addition, it is to be understood that after having read the content that the present invention lectures, the present invention can be made various changes or modifications by those skilled in the art, and these equivalent form of values fall within the application appended claims limited range equally.

Promptness that information that what the present embodiment was to be solved is is transmitted on a highway and the technical problem of continuity.For promptness problem, event is divided into two class guarantee informations be initially transmitted to suffer from this big vehicle.For continuity problem, each vehicle can maintain a density bag.

In conjunction with Fig. 1, the step based on event driven vehicle area network message transmission method that the present embodiment provides is as follows:

1). road incidents is divided into two big classes according on the difference that affects of fore-aft vehicle: a kind of be the event impact on vehicle below more than the impact on front vehicles, a kind of is that the event impact on front vehicles is more than the impact on front vehicle.

2). each car all can maintain a vehicle data bag in real time, and its major responsibility is the parameter providing necessity for dangerous information, such as, the ID of vehicle, the positional information etc. of vehicle.

3). accident vehicle can form a dangerous information bag when a fault occurs.It is produced by accident vehicle and transmits between vehicle.

4). each car also needs to maintain a density bag in real time, and its major responsibility is to judge the transmission route of dangerous information.

5). when certain accident occurs in a car, mounted in a vehicle microprocessor can form dangerous information bag according to vehicle data bag, then selects the vehicle of down hop further according to traffic density bag now.The vehicle of down hop selects down hop vehicle with dangerous information bag, by that analogy further according to the traffic density bag of self.

Described step 1) specifically comprise the following steps that

A). by event classification primarily to allow event preferentially be sent to by this event affected big vehicle.The differentiation of event type can be by the velocity sensor being arranged on vehicle, acceleration transducer, the perception of the sensors such as angular-rate sensor, then is analyzed process by microprocessor and completes.

B). brake, traffic congestion, deceleration waits these events the impact of the vehicle of rear view of vehicle to be greater than the impact of the vehicle on vehicle front, so these information to be preferentially sent to the vehicle of rear view of vehicle in the protocol.

C). overtaking other vehicles, acceleration waits these events the impact of the vehicle of vehicle front to be greater than the impact of the vehicle on rear view of vehicle, so these information to be preferentially sent to the vehicle of vehicle front in the protocol.

Described step 2) specifically comprise the following steps that

A). vehicle data bag includes: vehicle ID, vehicle heading, vehicle location, road direction.These information are obtained by GPS device and then preserve in the microprocessor.

B). vehicle ID is used to uniquely identify vehicle, can be by the license plate number of vehicle as vehicle ID.

C). vehicle location can be obtained by the GPS device being arranged on vehicle.

D). vehicle heading can obtain according to the vector calculus of the gps data of nearest twice of vehicle, and road direction depends on the travel direction of vehicle on this road.Needing one direction of the most artificial regulation before this is positive direction.

Described step 3) specifically comprise the following steps that

A). dangerous information bag includes: transmission direction, accident vehicle ID, accident vehicle position, the road direction at accident vehicle place.

B). transmission direction be intended to according to microprocessor processes sensor collection to informix judge after by being given.

C). accident vehicle ID, accident vehicle position, the road direction at accident vehicle place can be obtained by the vehicle bag of accident vehicle.

Described step 4) specifically comprise the following steps that

A). density bag includes: whether there is vehicle (ρ in vehicle front communication range_f), rear view of vehicle leads to

Vehicle (ρ whether is there is in the range of letter_h), whether there is vehicle (ρ in the communication range of vehicle side_s)。

If b). there is vehicle in the communication range in certain direction, this parameter is 1, otherwise, then it is 0.When at least the parameter of 42 cars of continuous print is 1 in certain direction, the mode of sub-clustering is taked to be transmitted information, otherwise, then it is chosen at the farthest vehicle of distance in the range of vehicle communication as down hop vehicle.

C). above-mentioned b) in sub-clustering method particularly includes:

The most substantial amounts of experiment shows, vehicle arrives each point and obeys Poisson distribution.X represents the interval between Adjacent vehicles, and exponential is obeyed at this interval, then average isWherein λ is rate parameter；Probability distributing density function is f (x)=λ e^{- λ x}.Because bunch in, the distance between vehicle be necessarily less than the transmission radius r of vehicle, i.e. vehicle distances less than transmission radius r probability be:

B., in clustering process, have two kinds different bunches: beginning and least significant end bunch size be as, the size of intermediate tufts is the same.We assume that there be n interval in one bunch, then the probability function of two kinds bunches is: g₁(n)=e^{- λ r}(1-e^{- λ r})⁽ⁿ⁺¹⁾, g₂(n)=(1-e^{- λ r})ⁿ⁺²。

Bunch C. mean size is:Calculate in conjunction with formula in B:When Fig. 2 and Fig. 3 respectively λ is 0.01,0.011,0.012, E_aAnd E_bSimulated effect figure.

D. assuming to be divided into altogether m cluster between first car and last car, L represents the distance between first car and last car, and this distance can be obtained by gps data.D represents the width of road.Again because the transmission radius r of vehicle is greater than the width d's of road, so the computing formula of cluster is:

Described step 5) specifically comprise the following steps that

If a). dangerous information needs first to travel to front vehicles, then, ρ_fIf this parameter needs to be detected first. ρ_f=1, then information just takes the mode of single-hop or use bunch to carry out propagating dangerous information.If but ρ_f=0, ρ_sWill be detected.If ρ_s=1, dangerous information will be transmitted to reverse track.Otherwise, dangerous information can only wait selection.

If b). dangerous information needs to travel to front vehicle.So, ρ_hThis parameter needs to be detected first.If ρ_h=1, then information just takes the mode of single-hop or use bunch to carry out propagating dangerous information.If but ρ_h=0, ρ_sWill be detected.If ρ_s=1, dangerous information will be transmitted to reverse track.Otherwise, dangerous information can only wait selection.

It is illustrated below in conjunction with concrete application example.

Embodiment one

As shown in Figure 4, square vehicle represents accident vehicle, and the density bag of this vehicle is (0,1,1) as shown in Figure 3.If vehicle needs dangerous information bag is traveled to vehicle front, density bag obtaining this front side does not has vehicle, so information cannot directly be propagated the vehicle of vehicle front.But the ρ of traffic density bag_s=1, so dangerous information bag first can be broadcast to reverse vehicle by this accident vehicle.When reverse vehicle receiver to this dangerous information bag, can first judge the transmission direction of dangerous information bag, reverse vehicle finds that this direction of propagation wrapped is contrary with the travel direction of oneself, this bag can travel to its reverse vehicle again, by that analogy.If vehicle needs dangerous information bag is traveled to rear view of vehicle, density bag understand ρ_h=1, if there being the ρ of at least 42 cars of continuous print_h=1, then the mode that dangerous information bag can use bunch is propagated, otherwise, the vehicle farthest in selecting its communication range of accident vehicle is propagated.

Embodiment two

As it is shown in figure 5, square vehicle represents accident vehicle, the density bag of this vehicle is (1,1,0) as shown in Figure 4.If vehicle needs dangerous information bag is traveled to vehicle front, density bag there is vehicle in obtaining this front side communication range, if there being the ρ of at least 42 cars of continuous print_f=1, then the mode that dangerous information bag can use bunch is propagated, otherwise, the vehicle farthest in selecting its communication range of accident vehicle is propagated.If vehicle needs dangerous information bag is traveled to rear view of vehicle, density bag understand ρ_h=1, if there being the ρ of at least 42 cars of continuous print_h=1, then the mode that dangerous information bag can use bunch is propagated, otherwise, the vehicle farthest in selecting its communication range of accident vehicle is propagated.

Embodiment three

As shown in Figure 6, square vehicle represents accident vehicle, and the density bag of this vehicle is (1,0,1) as shown in Figure 5.If vehicle needs dangerous information bag is traveled to vehicle front, density bag there is vehicle in obtaining this front side communication range, if there being the ρ of at least 42 cars of continuous print_f=1, then the mode that dangerous information bag can use bunch is propagated, otherwise, the vehicle farthest in selecting its communication range of accident vehicle is propagated.If vehicle needs dangerous information bag is traveled to rear view of vehicle, ρ_h=0 so cannot be by Information Communication to accident vehicle rear.But ρ_s=1 can utilize reverse vehicle to propagate, when reverse vehicle receiver to this dangerous information bag, can first judge the transmission direction of dangerous information bag, reverse vehicle finds that this direction of propagation wrapped is contrary with the travel direction of oneself, this bag can be traveled to its reverse vehicle again, by that analogy.

Claims (10)

1. one kind based on event driven vehicle area network message transmission method, it is characterised in that: the method is by following 5 Individual step forms:

Step 1, road incidents are divided into two big classes according on the difference that affects of fore-aft vehicle: one is event pair The impact of vehicle is more than the impact on front vehicles below, and a kind of is that the event impact on front vehicles is more than to rear The impact of side's vehicle；

Step 2, each car maintain an information of vehicles bag in real time；

Step 3, when a fault occurs, accident vehicle can form a dangerous information bag；Dangerous information bag is by thing Therefore vehicle produces and transmits between vehicle；

Step 4, each car maintain a density bag in real time, in the range of obtaining vehicle communication according to density bag There is vehicle in which direction；

Step 5, when there is accident in a car, mounted in a vehicle microprocessor according to information of vehicles bag generate danger Danger information bag, then selects the vehicle of down hop further according to traffic density bag now；The vehicle of down hop root again Down hop vehicle is selected with dangerous information bag, by that analogy according to the traffic density bag of self.

2. as claimed in claim 1 a kind of based on event driven vehicle area network message transmission method, its feature exists In: specifically comprising the following steps that of described step 1

Step 1.1: affected big vehicle to allow event preferentially be sent to by this event, therefore by event classification； Differentiating by the velocity sensor being arranged on vehicle, acceleration transducer, angular-rate sensor of event type Perception, then be analyzed process by microprocessor and complete；

Step 1.2: brake, block up, before the impact of the vehicle of rear view of vehicle is greater than vehicle by deceleration event The impact of the vehicle of side, so these event informations are preferentially sent to the vehicle of rear view of vehicle in the protocol；

Step 1.3: overtake other vehicles, accelerated events is greater than the car to rear view of vehicle to the impact of the vehicle of vehicle front Impact, so these event informations are preferentially sent to the vehicle of vehicle front in the protocol.

3. as claimed in claim 1 a kind of based on event driven vehicle area network message transmission method, its feature exists In: in described step 2, information of vehicles bag includes: vehicle ID, vehicle heading, vehicle location, Road direction；Information in information of vehicles bag is obtained by the GPS device being arranged on vehicle, then preserves In the microprocessor.

4. as claimed in claim 3 a kind of based on event driven vehicle area network message transmission method, its feature exists In: described vehicle ID is used for uniquely identifying vehicle；

Described vehicle heading obtains according to the vector calculus of the gps data of nearest twice of vehicle；

Described road direction depends on the travel direction of vehicle on this road, needs the most artificially one direction of regulation For positive direction.

5. as claimed in claim 1 a kind of based on event driven vehicle area network message transmission method, its feature exists In: in described step 3, dangerous information bag includes: transmission direction, accident vehicle ID, accident vehicle position Put, the road direction at accident vehicle place.

6. as claimed in claim 1 a kind of based on event driven vehicle area network message transmission method, its feature exists In: in described step 4, density bag includes: whether there is vehicle ρ in vehicle front communication range_f, car Vehicle ρ whether is there is in the range of communication for the rear_h, in the communication range of vehicle side, whether there is vehicle ρ_s。

7. as claimed in claim 6 a kind of based on event driven vehicle area network message transmission method, its feature exists In: in described step 4, if there is vehicle in the communication range in certain direction, then the parameter characterizing the direction is 1, Otherwise it is 0；When in certain direction, at least the parameter of Q car of continuous print is 1, Q is setting value, takes point Bunch mode be transmitted information, otherwise, then be chosen at the farthest vehicle of distance in the range of vehicle communication as under One jumps vehicle.

8. as claimed in claim 7 a kind of based on event driven vehicle area network message transmission method, its feature exists In: described Q is 42.

9. as claimed in claim 7 a kind of based on event driven vehicle area network message transmission method, its feature exists In: the mode detailed process of described sub-clustering is:

A. vehicle arrives each point and obeys Poisson distribution；X represents the interval between Adjacent vehicles, and this is spaced clothes From exponential, then this interval average isWherein λ is rate parameter；This interval probability distribution is close Degree function is f (x)=λ e^-λx；Again because bunch in distance between vehicle be necessarily less than the transmission radius r of vehicle, The i.e. vehicle distances probability less than transmission radius r is

B., in clustering process, have two kinds different bunches: beginning and least significant end bunch size be as, The size of intermediate tufts is the same；Assume that one bunch has n interval, then:

Beginning and least significant end bunch probability function be g₁(n)=e^-λr(1-e^-λr)⁽ⁿ⁺¹⁾；

The probability function of intermediate tufts is g₂(n)=(1-e^-λr)ⁿ⁺²；

Beginning and least significant end bunch mean size be:

$E_a=\underset{x\→\mathrm{\∞}}{\lim }\frac{\underset{i=1}{\overset{n}{\Σ}}\left(g_1\left(i\right)\underset{j=1}{\overset{i}{\Σ}}{d}_j\right)}{\underset{i=1}{\overset{n}{\Σ}}{g}_1\left(i\right)}$

The mean size of intermediate tufts is:

$E_b=\underset{x\→\mathrm{\∞}}{\lim }\frac{\underset{i=1}{\overset{n}{\Σ}}\left(g_2\left(i\right)\underset{j=1}{\overset{i}{\Σ}}{d}_j\right)}{\underset{i=1}{\overset{n}{\Σ}}{g}_2\left(i\right)}$

Calculate in conjunction with formula in B:

D. assume to be divided into altogether m cluster between first car and last car；L represents first car And the distance between last car, this distance can be obtained by gps data；D represents the width of road； Again because the transmission radius r of vehicle is greater than the width d's of road, so the computing formula of cluster is:

$G\left(m\right)=\left\{\begin{array}{c}L=2E_a+m{E}_b\\ r>d\end{array}\right.$

10. the one as described in any one of claim 6～8 is based on event driven vehicle area network message transmission method, It is characterized in that: specifically comprising the following steps that of described step 5

If dangerous information needs first to travel to front vehicles, then, ρ_fThis parameter needs first to be examined Survey；If ρ_f=1, then information takes the mode of single-hop or use bunch to carry out propagating dangerous information；But If ρ_f=0, ρ_sWill be detected；If ρ_s=1, dangerous information will be transmitted to reverse track；Instead It, dangerous information can only wait selection；

If dangerous information needs to travel to front vehicle, then, ρ_hThis parameter needs to be detected first； If ρ_h=1, then information takes the mode of single-hop or use bunch to carry out propagating dangerous information；If but ρ_h=0, ρ_sWill be detected；If ρ_s=1, dangerous information will be transmitted to reverse track；Otherwise, Dangerous information can only wait selection.