Disclosure of Invention
The present invention is directed to solving the above problems of the prior art. The urban intersection pedestrian detection and identification system based on C-V2X is improved in identification precision, strong in anti-interference capability and capable of achieving dynamic real-time tracking. The technical scheme of the invention is as follows:
a city intersection pedestrian detection and identification system based on C-V2X, comprising: the system comprises a multimode communication information acquisition module, a position judgment module, a speed judgment module, a density judgment module and a direction judgment module; the system comprises a multimode communication information acquisition module, a data processing module and a data processing module, wherein the multimode communication information acquisition module is used for acquiring basic information including positions, course angles, speeds and altitudes of a vehicle-mounted terminal, a mobile phone and road side equipment through an information acquisition device based on a C-V2X communication technology, and provides original data information for other modules of the system;
the position judging module is used for judging the probability that a C-V2X mobile phone carrier is a pedestrian when the high-precision positioning information of the C-V2X mobile phone is in a certain area of the intersection by utilizing the position information of the C-V2X mobile phone collected by the multimode communication information collecting module, and providing area influence factors for the speed judging module (13), the density judging module (14) and the direction judging module (15);
the speed judging module is used for calculating the speed range of the pedestrian by utilizing the mobile phone speed information and the position information acquired by the multimode communication information acquisition module through different types of initial speed, influence factors of position on speed, influence factors of C-V2X mobile phone signals on speed and influence factors of direction on speed, wherein the initial speed, the influence factors of position on speed, the influence factors of C-V2X mobile phone signals on speed and the influence factors of direction on speed are not influenced by any factor, and the probability that the C-V2X mobile phone carrier is the pedestrian at the speed is calculated by combining with the actually received speed information of the C-V2X mobile phone;
the density judging module is used for calculating the pedestrian density around the C-V2X mobile phone carrier by utilizing the C-V2X mobile phone position information acquired by the multimode communication information acquisition module and the information received by the roadside equipment, and calculating the probability that the C-V2X mobile phone carrier is a pedestrian under the pedestrian density, and the density judging module (14) can reduce errors of detection and identification of the pedestrian by using the position judging module (12) and the speed judging module (13) in consideration of a bus station approaching scene;
and the direction judging module comprehensively considers the influence of the position, the speed and the density of the C-V2X mobile phone carrier on the direction, utilizes the direction and the position information of the C-V2X mobile phone acquired by the multimode communication information acquisition module (11), and calculates the probability that the C-V2X mobile phone carrier is a pedestrian according to the information including the current C-V2X mobile phone direction and the C-V2X mobile phone position.
Further, the multi-mode communication information acquisition module realizes inter-vehicle communication by using a V2V vehicle-vehicle technology of C-V2X; the communication between the vehicle and the roadside equipment is realized by using V2I vehicle-infrastructure technology of C-V2X, the mobile phones of a driver and a passenger interact with the roadside unit by using P2I pedestrian-infrastructure technology of C-V2X, the vehicle-mounted unit and the information service management platform of the vehicle interact information by using V2N vehicle-Internet technology communication technology of C-V2X, and the vehicle and the pedestrian interact information by using V2P vehicle-pedestrian technology of C-V2X through the vehicle-mounted unit and the mobile phones; the pedestrian communicates with the information service platform through C-V2X mobile phones carried by the pedestrian and the P2N pedestrian-Internet technology of C-V2X, and the pedestrian communicates with the road side unit through the C-V2X mobile phones carried by the pedestrian and the P2I pedestrian-basic equipment technology of C-V2X; the road side equipment and the information service management platform interact by using I2N basic equipment-Internet technology of C-V2X.
Furthermore, the method also comprises modules which are divided into different functional areas according to the functional characteristics of the urban intersections, and the functional areas are represented by using intervals, wherein the road near the intersections is represented in the following way: { (type, orientation, startPoint, endPoint, length, width, AddPoint) | type ═ {0,1,2,3,4}, orientation ∈ [0,2 pi), {0 in { point1, point2,. ], point } } type represents a sidewalk, 1 represents a bike lane, 2 represents a motor lane, 3 represents a zebra crossing, and 4 represents a road intersection center; n is a positive integer.
Further, the position determination module determines that the C-V2X mobile phone carrier is a pedestrian specifically includes: mobile phone carriers are divided into four categories according to different traffic participant types: classifying the road users into pedestrians, bicycles, bus passengers and other motor vehicle drivers according to the categories of the road users;
C-V2X handset carriers are represented as follows: { (type, pos, v, orientation, acc, accOrien) | type {0,1,2,3}, orientation ∈ [0,2 π ], accO rien ∈ [0,2 π) }
the type 1 represents that the C-V2X mobile phone carrier is a pedestrian, the type 2 represents that the C-V2X mobile phone carrier is a bicycle, the type 3 represents that the traffic participant is a driver of a motor vehicle, and the type 0 represents other situations.
Further, the position determination module determines the probability that the C-V2X mobile phone carrier is a pedestrian at the current position through the current position of the C-V2X mobile phone and by combining functional area division of the urban intersection road, and the expression formula is as follows.
Where k is {0,1,2,3,4},
S
0-S
4respectively corresponding to sidewalks, zebra crossings, motor vehicle lanes, non-motor vehicle lanes and intersection central areas.
Wherein
Respectively shows the probability that the C-V2X mobile phone carriers are pedestrians, vehicles and bicycles in the area k.
Further, the density determination module calculates the signal density of a certain area by using the information service management platform, where the terminal of the area is C-V2X mobile phone information, and the expression manner is as follows:
sito study the area of region i, PiThe number of signals which can be judged to be transmitted by the mobile phone of C-V2X in the study area i.
Further, the speed determination module obtains the speed at the moment by using the speed, the influence factor of the position, the signal density influence factor and the direction influence factor information of the C-V2X mobile phone carrier, combines the speed with the received speed information of the C-V2X mobile phone, and calculates the speed of the C-V2X mobile phone carrier when the mobile phone carrier moves at the speedThe probability of a person is expressed as follows.
Suppose vrealVelocity, V, when the C-V2X cell phone carrier is a pedestrianinitial、q1pos、q1ρ、q1direRespectively as initial pedestrian speed value, pedestrian position influence factor, C-V2X mobile phone carrier surrounding density influence factor, and advancing direction influence factor, assuming that the region value set of pedestrian influence factor is T, and assuming C-V2X mobile phone carrier as pedestrian, that is q1typeE.g., T, let [ v1,v2]Is the calculated pedestrian speed range.
Further, the direction determination module uses a neighborhood method to represent the advancing direction, and the representation manner is as follows:
g (x, y, z) represents the C-V2X handset position, G1(x1,y1,z1) Represents the position of the C-V2X handset at the next time, and G1The region is a G neighborhood; the direction of the C-V2X mobile phone carrier can be obtained through the advancing direction of the C-V2X mobile phone carrier and the type and the position of the C-V2X mobile phone carrier, and the probability that the C-V2X mobile phone carrier is a pedestrian can be obtained by combining the direction information of the C-V2X mobile phone. Suppose Ppedes(theta) represents a relation function when the probability that the C-V2X mobile phone carrier is a pedestrian and the positive direction included angle of the area is theta, and the direction set of the pedestrian is [ -alpha, alpha]∪[π-α,π+α]And the following relationship exists:
at this time, the probability of being a pedestrian is calculated according to the direction theta of the C-V2X mobile phone carrier:
the invention has the following advantages and beneficial effects:
1. traditional pedestrian discernment based on image can not accurately discern under the condition that the pedestrian is a lot or has the building to shelter from, and the pedestrian based on technologies such as infrared, radar detects that the influence that receives temperature, shelter from the thing is great, need increase extra research and use cost with the help of equipment such as camera, infrared sensor appearance, radar. The V2X function and the high-precision positioning function of the C-V2X mobile phone can realize the interaction between the C-V2X mobile phone and other Internet of vehicles terminals and obtain the high-precision position information of the C-V2X mobile phone in real time. The mobile phone mobile terminal which is used for pedestrian detection and identification through mobile phone information and is gradually popularized uses various communication technologies for information interaction, is not influenced by weather, is less influenced by shielding of buildings, does not need to be added with extra equipment, and can also realize dynamic real-time tracking.
2. The characteristic representation mode is used for describing each region and road user of the urban intersection, and each traffic object can be more comprehensively and simply described. The functional characteristics of the urban intersections are divided into different functional areas, and the functional areas are represented by using intervals, wherein the road near the intersections is represented in the following way:
{(type,orientation,startPoint,endPoint,length,width,AddPoint)|type={0,1,2,3,4},orientation∈[0,2π),AddPoint={point1,point2,...,pointN}}
0 in type represents sidewalk, 1 represents bicycle lane, 2 represents motor lane, and 3 represents spot
A horse line, 4 represents a road intersection center; n is a positive integer
The road user representation is as follows:
{ (type, pos, V, orientation, acc, accOrien) | type ═ {0,1,2,3}, orientation ∈ [0,2 pi ], 1 in accO rien ∈ [0,2 pi) } type represents that the mobile phone carrier of C-V2X is a pedestrian, 2 represents that the mobile phone carrier of C-V2X is a bicycle, 3 represents that the traffic participant is a driver of a motor vehicle, and 0 represents other cases.
3. The urban intersection has complex scenes, pedestrians are likely to appear at all positions and directions, the category of the mobile phone carrier is judged by using the comprehensive influence of the information such as the position, the speed, the density, the advancing direction and the like, and the error probability caused by only considering a single factor can be reduced.
4. The urban intersection is divided into different areas according to functions, the characteristics of road users in the different areas are obviously different, the probability of pedestrian occurrence can be better quantified by using a regionalization method, and a basis is provided for pedestrian detection and identification.
5. The influence of the position, the pedestrian density and the direction on the speed of the C-V2X mobile phone carrier is quantized into influence factors, the values of the influence factors are calculated by collecting multiple groups of pedestrian data at the intersection, and the probability that the C-V2X mobile phone carrier is a pedestrian is calculated by combining the speed of the mobile phone. The method comprehensively considers the situations of traffic jam, arrival of public transport vehicles, running of pedestrians and the like, avoids the situation that the motor vehicles are identified as the pedestrians or the pedestrians are identified as the vehicles under the conditions of traffic jam and deceleration of the public transport vehicles based on single speed judgment, and improves the identification precision.
6. The influence of the position and the speed on the surrounding density of the C-V2X mobile phone carrier is quantized into influence factors, and the probability that the C-V2X mobile phone carrier is a pedestrian can be more accurately predicted by combining the density of the position where the mobile phone is located. The method comprehensively considers the situations of more pedestrians in the areas of the pedestrian paths, the zebra crossings and the like and more passengers in the motor vehicles, particularly the public transport vehicles, and avoids the false recognition of the pedestrians as the vehicle passengers or the false recognition of the vehicle passengers as the pedestrians.
7. The method of the application field represents the advancing direction of the C-V2X mobile phone, is distinguished from the direction of the C-V2X mobile phone at the current moment, and obtains the motion trail of the pedestrian and the direction change in the whole motion process through the positions of the pedestrian at different moments. The pedestrian movement has great randomness, the direction is vertical to the zebra crossing direction in the process of passing through the sidewalk and the zebra crossing, the method is designed for solving the randomness of the pedestrian movement, and the direction is comprehensively judged through a series of directions, so that the pedestrian on the sidewalk or the zebra crossing is prevented from being identified as a vehicle passenger.
8. The influence of the position of the C-V2X mobile phone carrier on the direction is quantized into a position influence factor, the direction range of the pedestrian is calculated according to the use regulations of different types of road users in the area, and the probability that the C-V2X mobile phone carrier is the pedestrian when the C-V2X mobile phone carrier is downward in the front is convenient to calculate. The method comprehensively considers the comprehensive action between the positions and the directions, and avoids the condition that the pedestrians in the areas of the sidewalks and the zebra crossings are mistakenly identified as the vehicle passengers or the vehicle passengers at the zebra crossings are mistakenly identified as the pedestrians.
Detailed Description
The technical solutions in the embodiments of the present invention will be described in detail and clearly with reference to the accompanying drawings. The described embodiments are only some of the embodiments of the present invention.
The technical scheme for solving the technical problems is as follows:
a city intersection pedestrian detection, identification method and system based on C-V2X have five functional modules, as shown in figure 1, the multimode communication information acquisition module (11) uses multiple communication technologies based on C-V2X to acquire the basic information of C-V2X mobile phone carriers, describe different types of functional areas and road users of the city intersection according to the characteristics of the city intersection and the characteristics of road users; the position determination module (12) is used for determining the probability that the carrier of the C-V2X mobile phone is a pedestrian under the current position of the C-V2X mobile phone; the speed determination module (13) is used for calculating the probability that the carrier of the C-V2X mobile phone at the current speed is a pedestrian under the influence of the position, the signal density and the direction of the C-V2X mobile phone; the density determination module (14) is used for calculating the probability that the current position signal density can determine that the C-V2X mobile phone carrier is a pedestrian under the influence of the position and the speed; the direction determination module (15) is used for calculating the probability that the mobile phone carrier is a pedestrian at the current position and in the direction C-V2X.
2C-V2X-based traffic entity information interaction framework
The information collection of the urban intersections is realized by adopting a C-V2X-based traffic entity information interaction framework, as shown in FIG. 2. Pedestrian detection and identification utilizes existing road infrastructure and widely distributed C-V2X smartphones to collect basic road base condition and road usage information. The information service management platform stores information of vehicles, pedestrians and other equipment collected by the road side equipment and broadcasts relevant road condition information. Information interaction between the vehicle and the information service management platform is realized through vehicle-mounted equipment, a C-V2X mobile phone and the like, and the interaction is completed by using a V2N technology of C-V2X in the communication process; the roadside equipment transmits the collected information and the data generated by the roadside equipment to an information service management platform through a roadside unit, and the I2N technology of C-V2X is used in the communication process; the pedestrian generates interaction with the information service management platform through a mobile phone and completes communication by using P2N of C-V2X; the information interaction and communication between the vehicles and the pedestrians are completed through the vehicle-mounted unit and the mobile phone, and the V2P technology of C-V2X is used in the communication process. The special pedestrian carrying equipment needs to consider factors such as popularization and holding amount, and the C-V2X mobile phone is a practical choice for researching pedestrian states in the current vehicle-road cooperation. Therefore, in the process of detecting the pedestrian, the information service management platform only needs to process data from the smart phone.
The C-V2X mobile phone becomes a tool which is basically carried by people in the traveling process, the addition of terminal equipment in the research of the vehicle-road cooperative system can be reduced by collecting basic information provided by the C-V2X mobile phone, and the research cost and the popularization difficulty are effectively reduced. The rapid development of mobile phone communication technology and the replacement of mobile phone version and hardware promote the application and development of mobile phones in the internet of vehicles. The C-V2X mobile phone is used as a communication terminal to realize a V2X communication system with perfect Internet of vehicles, and can provide high-precision positioning information, real-time speed, acceleration and other information for the Internet of vehicles. The basic information of the mobile terminals such as the C-V2X mobile phones and the like acquired by the road side equipment or the information service platform through a wireless communication means is as follows:
table 1 collects the information table of the road using the portable phone:
species of
|
Description of the invention
|
Position of
|
Obtaining high-precision position information including longitude and latitude data and height data through mobile phone
|
Speed of rotation
|
Speed, scalar quantity of mobile phone at current moment
|
Direction
|
Using heading angle representation
|
Acceleration of a vehicle
|
Scalar quantity |
3 intersection road region partitioning
Roads near urban intersections typically include sidewalks, bicycle lanes, and motor lanes, as shown in fig. 3. The zebra crossing at the intersection provides a safe crossing road area for pedestrians and bicycles. Roads at non-intersections have obvious functional partitions and regional divisions. As shown in fig. 3, the sidewalk, the non-motor vehicle lane and the motor vehicle lane have obvious height difference in the actual scene or use a guardrail, and the traffic participants in the areas can directly determine the categories according to the collected mobile phone signal positions.
Compared with the roads near the intersection, scenes such as zebra crossings, start and stop lines, intersection center areas and the like are added at the intersection, and in order to achieve the effect of controlling traffic, markers such as traffic lights, speed limit, direction indication and the like are added, as shown in fig. 4.
The basic information of the road is collected by road side equipment, and the basic information of the road provides a basis for judging the category of road users. The representation of the road near the intersection is shown by the following formula:
{(type,orientation,startPoint,endPoint,length,width,AddPoint)|type={0,1,2,3,4},orientation∈[0,2π),AddPoint={point1,point2,...,pointN}}
0 in type represents a sidewalk, 1 represents a bicycle lane, 2 represents a motor lane, 3 represents a zebra crossing, and 4 represents a road intersection center; n is a positive integer
The road is described in the following table.
TABLE 2 road Attribute Table
4 road user category
For road users with different attributes, there are significant differences in their characteristics, as shown in the following table:
TABLE 3 road user characteristics Table
In the vehicle-road cooperation system, basic information of roads, vehicles and pedestrians is collected by road side equipment, vehicle-mounted equipment, mobile phones and other equipment. The attributes of a road user include their type, location, speed, direction of travel, acceleration, direction of acceleration, which are described in the following table.
TABLE 4 road user Attribute Table
The C-V2X cell phone carrier category is represented as follows:
{(type,pos,v,orientation,acc,accOrien)|type={0,1,2,3},orientation∈[0,2π),accO rien∈[0,2π)}
the type 1 represents that the C-V2X mobile phone carrier is a pedestrian, the type 2 represents that the C-V2X mobile phone carrier is a bicycle, the type 3 represents that the traffic participant is a driver of a motor vehicle, and the type 0 represents other situations.
When a C-V2X mobile phone message is received, the type of the carrier can be roughly determined by using the information such as speed, position, density, etc. at this time, and a general determination flowchart is shown in fig. 5.
5 position decision module
The pedestrian is generally positioned on sidewalks and zebra crossings near the intersection, and some pedestrians are also present in areas adjacent to the sidewalks and the zebra crossings. For bicycles, at present, many urban bicycle tracks are arranged between sidewalks and motor vehicle tracks in China, and the bicycles can run in the motor vehicle track area under the condition of no bicycle track. The bus is in a motor vehicle lane or zebra crossing area, and the position information of pedestrians and bicycles can be overlapped at a position close to the edge of a road. Private cars are typically motorways and zebra crossings in the area of urban crossings.
As shown in fig. 6, the length L2 of the zebra crossing area is the width of the road, and the length of the zebra crossing is 5 meters as specified in the road traffic sign and marking setting specification, that is, the width of the zebra crossing area is 5 meters. Pedestrians or bicycles do not completely cross the zebra crossing area during the crossing of the road, and in the case that there are a large number of people crossing the road, some people can move forward in the area outside the zebra crossing. The overlapping areas 3 and 4 are areas outside the zebra crossing area due to habits, high traffic and the like when road users pass through the zebra crossing area. The overlap region 3 is expressed as { (x, y) | x ∈ L2, y ∈ d6}, and the overlap region 4 is expressed as { (x, y) | x ∈ L2, y ∈ d5 }. According to the behavior habit of the pedestrian, the width of the overlapping area 3 is generally the distance between the zebra crossing and the stop line, and is between 100cm and 300 cm.
The position of the pedestrian can be expressed as follows:
pos1pedes={(x,y)|x∈L,y∈d1∪d2}∪{(x,y)|x∈L2,y∈d4∪d5∪d6}
l is the length of the pavement area under study,
width of the sidewalk area under study, L
2To study the length of the zebra crossing region, d
2For the edges of pedestrian road areas and bicycle areas, but both pedestrians and bicycles will be used, d
4Width of the zebra crossing region, d
5Is the distance between the edge of the zebra crossing area and the center of the intersection, d
6Is the distance between the edge of the zebra crossing area and the start and stop line of the motor vehicle lane.
The condition that the overlapping area satisfies the pedestrian is as follows:
pos2pedes={(x,y,V)|x∈L,y∈d2,V={v0,v1,...,v29}|vi<6km/h|i=0,1,...,29}
v is the set of speed samples corresponding to the handset signal over a period of time.
The set of positions of the pedestrian is:
pospedes=pos1pedes+pos2pedes
6 speed judging module
The driving characteristics of different road users over a period of time are clearly different. For the pedestrian, the walking frequency of the normal adult is 1.5 steps/S, the step pitch is 60-75cm, the walking speed is 5.32-5.43Km/h, the walking speed of the old is 4.51-4.75Km/h, namely the speed of the pedestrian is generally 5 Km/h. The bicycle speed is typically 16 km/h. For buses, the speed is 40km/h at most, 20km/h-30km/h is common, the buses can decelerate and even stop for a short time under the conditions of waiting for traffic lights, traffic jams, arrival of vehicles and the like, and the buses and the bicycles have overlapping speed ranges. For private automobiles, the proportion of private automobiles in motor vehicles is relatively large and continues to grow. The speed is generally 40-60 Km/h. (how to distinguish the vehicle in the congestion situation, the state duration and the state transition problem need to be considered)
viFor the speed in the C-V2X cell phone signal collected at a certain moment, N generally takes a value of 30, and the speed of the pedestrian satisfies the following conditions:
vpedes∈[0km/h,6km/h]
the speed V of a C-V2X cellphone carrier is influenced by its type, location, density of surrounding pedestrians, vehicles and direction of travel, and can be expressed as
v=vinitial×q1type×q1pos×q1ρ×q1dire
Suppose vinitial×q1typeQ1 for the speed of a C-V2X mobile phone when the mobile phone carrier is of a certain type and is not affected by any factorstype、q1pos、q1ρ、q1direThe influence factors of the type, the position, the density and the direction of the mobile phone carrier of C-V2X on the speed respectively exist, and the relation exists:
q1type+q1pos+q1ρ+q1dire=1
suppose the city intersection under studyThe region set of the intersection is represented as S, and the set of pedestrian regions such as sidewalks, zebra crossings and the like is represented as Spedes∪SzebraThe area of the bicycle lane is collected as SbicyThe set of motor vehicle zones being SvehiThe method comprises the following steps:
S=Spedes∪Szebra∪Sbicy∪Svehi∪Scentre
suppose the probabilities of the pedestrian in the above three regions are P (pedes + zebra), P (bicy), P (vehi + centre), respectively, and
P(pedes+zebra)+P(bicy)+P(vehi)=1
therefore, when the C-V2X mobile phone carrier is a pedestrian, the position influence factors of different positions can be respectively expressed as:
when the C-V2X mobile phone carrier is a pedestrian, N exists in the advancing directions of the pedestrian, the zebra crossing, the bicycle and the motor vehicle respectivelypedes、Nzebra、Nbicy、Nvehi、NcentreIn this case, the directional influence factor of each region can be expressed as:
when v isrealThe speed, V, of a C-V2X mobile phone carrier as a pedestrianinitial、q1pos、q1ρ、q1direRespectively as initial pedestrian speed value, pedestrian position influence factor, C-V2X mobile phone carrier surrounding density influence factor, and advancing direction influence factor, assuming that the region value set of pedestrian influence factor is T, and assuming that the mobile phone carrier is a pedestrian, that is, q1typeE.g., T, let [ v1,v2]Is the calculated pedestrian speed range, in which case the probability that the mobile phone carrier is a pedestrian is:
7 density judging module
In a certain range, there is a mutual influence between the walking speed of the pedestrian and the density of the pedestrian in the environment, and table 2 shows the relation between the speed and the density when the pedestrian walks, and when the density of the pedestrian is less than 0.83 people/m2The walking can be carried out at normal speed.
TABLE 5 statistical table of pedestrian passing conditions under different densities
The length of the bicycle is 2 meters generally, the distance between the bicycle and the left and right bicycles in the riding process can not be less than 0.5 meter, and the density can not exceed 0.5 person/m in the safe running process2. The bus judgment can calculate the current density according to the collected position information of the passenger mobile phone, and if the density exceeds 4 persons/m2And the relative position distribution of the mobile phone information data in a long period of time is in a certain range and even can not be changed, and the carriers of the mobile phones can be judged to be bus passengers according with the characteristics. The footprint of a private car is typically 10m2The density of passengers on the vehicle is generally 2 persons/m2The relative displacement between the position of the mobile phone on the vehicle and the vehicle-mounted equipment is kept unchanged for a long time or is changed in a small range.
The density formula of the C-V2X mobile phone carrier is shown as follows
s
iTo study the area of region i, P
iThe number of signals that can be determined to be transmitted by the handset in the area i is investigated. The density range of pedestrians among mobile phone carriers in the mobile state is as follows:
the density ρ and the direction of the C-V2X mobile phone carrier are not related to each other, but are directly related to the type and the position pos, and the density of the mobile phone carrier interacts with the speed V thereof, which is faster when the number of other mobile phone carriers around is small, and slower when the number of other mobile phone carriers around is large, i.e. C ═ ρ V (C is a constant and represents the number of mobile phone carriers passing through per second) is influenced, and the density expression formula is as follows:
ρ=ρinitial×q2type×q2pos×q2v
let ρ be
initialQ2 is the density of the handset signal at the location of the handset carrier, unaffected by any factor
type、q2
pos、q2
vRespectively representing the type, the position and the current speed of the mobile phone carrier to influence the signal density of the mobile phone at the position of the mobile phone carrier, and
(C
vconstant coefficient of
Assume that the pedestrian density set is E ═ ρ1,ρ2]Is shown, i.e.
Suppose that the current density of the position of the mobile phone is rhorealThen the probability that the carrier is a pedestrian is expressed as
8 direction decision module
The advancing direction of road users generally changes at intersections, in the zebra crossing areas, the direction of pedestrians is the same as or opposite to that of the zebra crossings, and other road users are vertical or nearly vertical.
As shown in fig. 8, the pedestrian direction in the zebra crossing region is expressed as follows:
dire1
pedes∈[-α,α]∪[π-α,π+α](
and is
)
For the overlapping regions 3 and 4 outside the zebra crossing region, the pedestrian direction is represented as follows:
dire2
pedes∈[π-θ,π]∪[0,θ](
and is
)
dire3
pedes∈[-π,β-π]∪[β,0](
And is
)
As shown in FIG. 6, L2Is the length of the zebra crossing region, d4Width of zebra crossing, d6Is the distance between the zebra crossing area and the start and end line of the road, d5The distance between the zebra crossing area and the intersection center point is thus expressed as follows:
direpedes=dire1pedes+dire2pedes+dire3pedes
in the sidewalk area, there are two general classifications of pedestrian directions:
dire1
pedes∈[-α,α]∪[π-α,π+α](
and is
)
dire2
pedes∈[π-θ,π]∪[0,θ](
And is
)
L denotes the length of the pavement area under investigation,
for the width of the pavement area under consideration,
the pedestrian direction in the sidewalk area and its vicinity is therefore:
direpedes=dire1pedes+dire2pedes
if the unit area of the current position area of the C-V2X mobile phone carrier is defined as the standard, the surrounding area is the forward direction neighborhood, the different neighborhood sets represent the position of the mobile phone carrier at the next moment, and the connection line between the two positions is the forward direction of the mobile phone carrier, as shown in fig. 7. As shown in fig. 5, the road direction is represented by areas 1, 3, when the road user is in areas 1, 3 at the next moment, representing that he is traveling along the road or crossing the road by a zebra crossing, and if in areas 2, 4, representing that the road user is crossing the road or crossing the zebra crossing.
The orientation of the C-V2X cell phone carrier is related to its location and type, i.e.
dire=direinitial×q3type×q3pos
direinitialQ3 is the positive direction of the area where the mobile phone carrier is locatedtype、q3posRespectively representing the influence factors of the type and the area of the mobile phone carrier on the advancing direction of the mobile phone carrier. Assuming that the set of type influence factors is T when the type is a pedestriandireThe position influence factor is taken to be EdireWhen the mobile phone carrier is a pedestrian, q3type∈TdireAnd q3pos∈EdireAt this time, the advancing directions of different types of mobile phone carriers are within a certain range, and the geometric Dire is used for the range of the advancing directions of the pedestrianspedesShowing that when the mobile phone carrier and the image factor are set TdireThe obtained direction of the element(s) satisfies that Dire belongs to DirepedesIn time, it can be judged that the mobile phone carrier meets the pedestrian condition in the direction.
Taking the zebra crossing region as an example, the division of the directions is shown in fig. 8. In general, the included angle between the pedestrian direction and the zebra crossing direction is not more than α, the probability distribution is approximately symmetrical about the positive direction and the negative direction of the zebra crossing region as the center, the pedestrian direction probability distribution diagram is shown in fig. 9, Ppedes(theta) represents a relation function between the probability that the mobile phone carrier is a pedestrian and the Zebra crossing included angle is theta, and the direction set of the pedestrian is [ -alpha, alpha]∪[π-α,π+α]And the following relationship exists:
at this time, the probability of being a pedestrian is calculated according to the direction theta of the mobile phone carrier as follows:
the above examples are to be construed as merely illustrative and not limitative of the remainder of the disclosure. After reading the description of the invention, the skilled person can make various changes or modifications to the invention, and these equivalent changes and modifications also fall into the scope of the invention defined by the claims.