A method and system for personnel emergency evacuation based on an improved vector graphic

Abstract

The present invention discloses a method and system for personnel emergency evacuation based on an improved vector vector map, belonging to the field of emergency simulation technology. The method includes: initializing the evacuation environment, including initializing static environmental space elements and the individual positions of the evacuating crowd; establishing a visual field containing multiple sensing points according to the individual positions and velocity directions of the evacuating crowd; for each individual in the evacuating crowd, based on the established visual field and through continuous perception of the static environment and interaction among individuals within the group, individual movement is carried out to complete the evacuation of the crowd. Through the above method and system, the present invention fully considers the information exchange among groups and the perception-feedback process of the crowd to the environment during the evacuation simulation process, improving the authenticity of the simulation process.

Description

Technical Field

[0001] The present invention relates to the technical field of emergency simulation, and more specifically, to a method and system for personnel emergency evacuation based on an improved vector map. Background Art

[0002] Natural disasters often cause drastic changes in the urban environment, such as damage to infrastructure like buildings and roads. At this time, to save lives and reduce losses, it is the most effective measure for the crowd to quickly leave the dangerous environment. However, this process is often difficult to conduct on-site experiments due to high costs and complex operations. As an efficient and low-cost research method, computer simulation is of great help for the problem of urban emergency evacuation under natural disasters: such as calculating the evacuation time and casualty number of the crowd and evaluating the evacuation process. Some parameters can reveal the essence and key points of evacuation, and the construction of the evacuation model is crucial, directly affecting the accuracy and scientific nature of the evacuation simulation.

[0003] Currently, the known emergency simulation evacuation models need to establish the movement rules of individuals in the environment, mainly including three categories: Cellular Automata, Social Force Model, and Multi-Agent System.

[0004] Among them, Cellular Automata discretizes the space into grid cells and realizes movement through different cell states and adjacent conversion rules; the Social Force Model completes movement by vectorially superimposing the "forces" generated by each element; the Multi-Agent System sets a series of movement rules for individuals and finally reaches the destination. However, most of the above models lack the description of the real evacuation environment and do not well establish the perception-feedback process of the crowd to the environment, lacking the definition and description of the entire evacuation process.

[0005] Therefore, how to improve the feedback perception ability of the crowd to the environment in the emergency simulation evacuation model is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a method and system for personnel emergency evacuation based on an improved vector map, which is used to improve the feedback perception ability of the crowd to the environment in the emergency simulation evacuation model.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] First, the present invention discloses a method for personnel emergency evacuation based on an improved vector map, which includes the following steps:

[0009] Initialize the evacuation environment, including the initialization of static environmental space elements and the initialization of the individual positions of the evacuating crowd;

[0010] Establish a visual field containing multiple sensing points based on the individual positions and velocity directions of the evacuating crowd;

[0011] For each individual in the evacuating crowd, perform individual movement based on the established visual field and through continuous perception of the static environment and interaction among individuals within the group to complete the evacuation of the crowd.

[0012] Furthermore, the static environmental space elements include indoor environmental elements and outdoor environmental elements.

[0013] Furthermore, the individual positions of the evacuating crowd are initialized through the following steps:

[0014] Randomly generate the initial positions of the individuals in the evacuating crowd in the evacuation grid environment;

[0015] Or obtain the initial positions of the individuals in the evacuating crowd in the evacuation grid environment according to the crowd distribution information.

[0016] Furthermore, establishing a visual field containing multiple sensing points based on the individual positions and velocity directions of the evacuating crowd specifically includes:

[0017] For each individual in the evacuating crowd, establish a vector vector starting from the individual position, and determine the radius of the visual field according to the line-of-sight length of the individual;

[0018] Determine the visual angle of the visual field according to the velocity direction of the individual: Where represents the movement velocity direction of individual i at time t, and θ represents the set visual half-field angle;

[0019] Discretize the visual field, and evenly divide the visual angle of the visual field into several sub-directions;

[0020] Set several sensing points in each sub-direction according to the distance from the starting point.

[0021] Furthermore, the continuous perception of the static environment specifically includes the following steps:

[0022] S31. Determine the passage cost of each individual in the k-th direction according to the exit position and static environmental space elements in the evacuation environment

[0023]

[0024] Among them, the first part + represents the exit position direction weight of individual i at time t, Denote the velocity direction of individual \(i\) at time \(t\). is the unit direction from the position of individual \(i\) to the exit position at time \(t\); The second part Denote an environmental factor influence value on a sector \(p\) K , \(H(p\) xy ) = Envi(p xy ) represents the position coordinates in the evacuation environment at the position \((x, y)\) of the individual in the evacuation grid environment, \(K\) o (d w ) represents the weights at different distance perception points;

[0025] S32. Determine the optimal movement direction of each individual after static environment perception at time \(t\) according to the passing cost of each individual in the \(k\)-th direction :

[0026]

[0027] S33. Determine the perception amount of the static environment according to the optimal movement direction \(Obj\) i of each individual at time \(t\) after static environment perception:

[0028]

[0029] In the formula, \(\beta\) is the static environment amplitude adjustment coefficient, is the optimal movement direction of individual \(i\) after static environment perception at time \(t\), \(a\) i is the basic acceleration of individual \(i\).

[0030] Furthermore, in step S31, the exit position direction weight of individual \(i\) at time \(t\) is obtained through the following formula:

[0031]

[0032] In the formula, \(\gamma\) represents the adjustment coefficient, is the angle deviation between the current velocity direction of individual \(i\) and the exit direction at time \(t\).

[0033] Furthermore, the interaction between individuals within the group is obtained by constructing an interaction amount equation between individuals within the group. The interaction amount equation between individuals within the group specifically includes the following expressions:

[0034]

[0035] where \(a\) i is the basic acceleration of individual \(i\), \(m\) i is the mass of individual \(i\), represents the pressure gradient generated by the surrounding individuals on individual \(i\) at time \(t\).

[0036] Further, the pressure gradient generated by the surrounding individuals on individual i at time t is obtained through the following steps:

[0037]

[0038] where α is the pressure adjustment coefficient; is called the neighboring group of individual i, indicating the set of the individuals within the sensing radius r centered on individual i at time t p range; is expressed as the pressure value exerted by any individual j in the neighboring group on individual i at time t; represents a kernel function for measuring the importance or influence of other individuals j in the neighboring group on the central individual i at time t, represents the kernel function gradient function.

[0039] Further, the kernel function is specifically represented by the following expression:

[0040]

[0041] where U is the distance variable; r i is the physical radius of individual i; r j is the physical radius of individual j; represents the distance between the center point of individual i and the center point of any individual j in the neighboring group at time t; r p is the sensing radius of individual i.

[0042] Secondly, the present invention also discloses a personnel emergency evacuation system based on an improved vector vector diagram, including

[0043] Evacuation environment construction module: used for the spatial elements of the evacuation environment and complete the initialization of the evacuation environment, including the initialization of static environment spatial elements and the initialization of the individual positions of the evacuation crowd;

[0044] Multi-sensing point visual field construction module: used to establish a visual field containing multiple sensing points in the evacuation environment according to the individual positions and velocity directions of the evacuation crowd;

[0045] Perception-feedback based crowd evacuation model: based on the established visual field and through continuous perception of the static environment and the interaction between individuals within the group, individual movement is carried out to complete crowd evacuation.

[0046] Through the above technical solutions, compared with the prior art, the present invention discloses a personnel emergency evacuation method and system based on an improved vector vector diagram:

[0047] The present invention first discretizes the evacuation environment to obtain a two-dimensional grid that can reflect the characteristics of the real environment. The personnel aim to reach the evacuation end point, while considering the influence of obstacles and other individuals. By borrowing the basic idea of the vector diagram, the personnel will establish a discrete visual field containing multiple sensing points to quickly extract information in the grid environment, combine the exit position to obtain the passing cost of each sub-direction in the local environment, and initially obtain the optimal moving direction of the personnel at this position. According to the perception kernel function of the personnel, the population density related to the distance is obtained, and the density gradient is further transformed into the pressure effect of other individuals to correct the above optimal moving direction so that a certain distance is maintained between individuals during the movement. After the personnel move in the corrected direction, the next perception is carried out.

[0048] Through the above method and system, the present invention fully considers the information exchange between groups and the perception-feedback process of the crowd to the environment during the evacuation simulation process, improving the authenticity of the simulation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0050] Figure 1 It is a schematic diagram of the overall process of the personnel emergency evacuation method based on the improved vector diagram provided by the present invention.

[0051] Figure 2 It is a flowchart of the evacuation initial state setting provided by the present invention.

[0052] Figure 3 It is a flowchart of the evacuation update provided by the present invention.

[0053] Figure 4 It is a schematic diagram of the individual visual field provided by the embodiment of the present invention.

[0054] Figure 5 It is a schematic diagram of the initial layout of a certain classroom and the initial positions of students provided by the embodiment of the present invention.

[0055] Figure 6 It is a schematic diagram of the evacuation grid environment of a certain classroom constructed by the embodiment of the present invention.

[0056] Figure 7 It is a schematic diagram of the comparison between the simulation results of the present invention and the actual situation for a certain classroom provided by the embodiment of the present invention.

[0057] Figure 8 For a certain classroom, it is a schematic diagram comparing the simulation effects of the present invention and other existing simulation methods. Specific implementation manners

[0058] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0059] A method for emergency evacuation of personnel based on an improved vector vector diagram is as Figure 1 shown, including the following steps: initializing the evacuation environment, including initializing the static environment space elements and the individual positions of the evacuating crowd;

[0060] Establishing a visual field containing multiple sensing points according to the individual positions and velocity directions of the evacuating crowd;

[0061] For each individual in the evacuating crowd, based on the established visual field and through continuous perception of the static environment and the interaction between individuals within the group, individual movement is performed to complete the evacuation of the crowd.

[0062] Specifically, the automated modeling of the evacuation environment classifies the spatial elements in the urban environment and maps them onto a two-dimensional grid; then describes the movement ability of people according to the basic characteristics of the crowd and establishes a visual field; finally, overall path planning for evacuation is carried out in the established evacuation environment, and combined with the initial position distribution of the crowd, the evacuation destination of each individual is judged.

[0063] The whole of the present invention can utilize a perception-feedback-based crowd evacuation model for local path planning of evacuation, including: 1) perception of static environment information 2) interaction between individuals within the group;

[0064] Constructing a grid environment for simulating evacuation based on the initial environment information and generating the initial positions of the crowd; calculating the overall direction of crowd evacuation to ensure a reasonable evacuation path; guiding the crowd to complete the movement by simulating the response of the crowd to environmental changes in combination with the perception-feedback model. This process realizes the full-process simulation from establishing the evacuation environment to the movement of the crowd, ensuring the efficiency and safety of the evacuation process.

[0065] The automated modeling of the evacuation environment in the present invention includes:

[0066] Extract key elements based on the main environmental information of the city, including roads, buildings, obstacles, etc.; classify the impacts of spatial elements on the evacuation process after detailed analysis, and finally map them to a two-dimensional grid to establish a two-dimensional grid environment for evacuation.

[0067] The main reason for classification is that the impacts of various elements in the environment on evacuation are different. For example, roads and open spaces are the main evacuation routes, and they are beneficial to evacuation, but the degrees of benefit are different. For example, the wider the road, the more beneficial it is for evacuation; while buildings, rivers, desks and chairs hinder evacuation, and people need to detour, and the degrees of obstruction of these elements to evacuation are different. The classified elements are stored in the grid environment with different values for distinction.

[0068] The grid stores the basic information of environmental elements, and the accuracy can be controlled by the grid size, which can effectively construct evacuation environments at two scales, micro and macro, laying an environmental foundation for the subsequent evacuation process and being an important manifestation of the model's generality.

[0069] In the construction of the basic characteristics of the crowd in the present invention, the inherent attributes include people, mass, speed range, etc., which mainly affect the movement ability of individuals; while the visual field is the main way of the perception process, and its function is to input environmental information.

[0070] In the establishment of the individual visual field in the crowd in the present invention, it mainly includes determining the main direction of the viewing angle according to the speed direction, and its size is taken as 2θ = 180°; determining the radius of the visual field according to the line-of-sight length, and the visual radius will be adjusted according to the spatial scale.

[0071] The overall path planning described in the present invention mainly determines the main evacuation direction and destination of each individual in the group based on the established environment and in combination with the location of the evacuation destination, and this process is carried out according to the distance rule. The destination, as the end point of the entire evacuation, will play a role throughout the movement process of the individual.

[0072] In the perception process of the present invention, not only the influence of the static environment is considered, but also other moving individuals are considered, making the perception process more real and comprehensive. The destination is the end point of the entire feedback mode, while the local route planning and speed adjustment constitute the main process, and this process can be described as:

[0073] M = L(D, E, C)

[0074] Among them, M represents the local movement (Movement) during the evacuation process, L represents the perception - feedback rule (Law), D represents the evacuation destination (Destination), and E represents the local environment information (Environment) of the evacuation. During the above - mentioned perception - feedback process, the local environment information E and the evacuation destination D have been set in advance. The basic characteristics C of the crowd include the above - mentioned movement attributes and visual fields. Under the perception - feedback rule L, the local movement M of the evacuation is completed.

[0075] The local environment information E includes 1) static environment information, mainly including information such as buildings, roads, and obstacles stored in the grid environment, and 2) dynamic environment information, that is, other moving individuals around. Individuals complete corresponding speed adjustments during the local perception process to reasonably respond to the local environment during the evacuation process.

[0076] The influence of the static environment mainly comes from the influence of obstacles and roads on the overall route. This part of the information is stored in the grid environment. The perception points in each direction of the individual's visual field extract the corresponding values in the grid environment and evaluate each direction to adjust the speed direction.

[0077] The role of the dynamic environment, that is, during the movement process, the interaction between individuals. Here, we establish a corresponding smoothing kernel function to calculate the crowd density value at each individual's position, and then convert the density gradient into a pressure gradient. The acceleration generated by the pressure gradient continuously adjusts the individual's speed.

[0078] The environmental modeling method in the embodiment of the present invention is used for the construction of the grid environment for evacuation. The influence of various spatial elements such as roads, buildings, and obstacles on the evacuation process will be analyzed in detail, then classified and processed and mapped onto a classic two - dimensional grid. The environmental accuracy can be achieved through the grid size to effectively construct evacuation environments at two scales, micro - scale and macro - scale. The evacuation environment shows good generality. Such a centralized description and abstract expression are necessary, which simplifies the difficulty of establishing the spatial model. The subsequent perception - feedback is also based on this process.

[0079] The process of setting the initial state of crowd evacuation is as Figure 2 shown, including the following steps:

[0080] Automatically model the evacuation environment by classifying spatial elements in the urban environment and mapping them onto a two - dimensional grid;

[0081] Describe the movement ability of people according to the basic characteristics of the crowd and establish a visual field;

[0082] Based on the established evacuation grid environment, conduct the overall path planning for the evacuation, and combined with the initial position distribution of the crowd, judge the evacuation destination of each individual;

[0083] The perception - feedback - based crowd evacuation model is used for local path planning during evacuation, including: 1) perception of static environmental information; 2) interaction among individuals within the group.

[0084] Based on the initial environmental information, a grid environment for simulating evacuation is constructed, and the initial positions of the crowd are generated. The overall direction of crowd evacuation is calculated to ensure a reasonable evacuation path. By combining the perception - feedback model, the response of the crowd to environmental changes is simulated to guide the crowd to move. This process realizes the full - process simulation from establishing the evacuation environment to the movement of the crowd, ensuring the efficiency and safety of the evacuation process.

[0085] In an embodiment of the present application, after classifying and processing environmental elements, a grid environment is generated through mapping. The value examples of this mapping rule are shown in Table - 1 and Table - 2. By querying Table - 1, the values of indoor environmental elements are obtained, and by querying Table - 2, the values of outdoor environmental elements are obtained.

[0086] Table - 1:

[0087] Type Value Example Boundary 1 Wall Exit -1 Door Obstacle 1 Furniture, Counter Road -1 Passage Others 0 Useless Space

[0088] Table - 2:

[0089] Type Value Example Safe Area -10 Park, Playground Obstacle Height Building, Lake Road - Width Urban Roads at All Levels Others 0 Other Spaces

[0090] The values of environmental elements are necessary in the subsequent process of environmental perception. The perception points of individuals finally fall in the grid environment to quickly and efficiently obtain environmental information to evaluate the passage cost in that direction. This process is inseparable from the above - mentioned classification of environmental elements, and environmental information is the basis for measuring the passage cost in each direction.

[0091] In an embodiment of the present application, the basic characteristic information of the crowd and its values are shown in Table - 3.

[0092] Table - 3:

[0093]

[0094] Regarding mass, the general weight of an adult male is given as 70 kg here, and other values can also be taken. The basic acceleration can also be adjusted. The physical radius of a person can be taken as 0.3 m, and the perception radius is taken as 2.0 m. Such values conform to the actual situation and can achieve good results in the simulation. The pressure adjustment coefficient α adjusts the strength of the interaction among crowd individuals, and the static environment amplitude adjustment coefficient β represents the influence of the static environment on individual movement. The sum of the two is 1. Generally, the values of both are 0.5, representing considering the influence of environmental factors and surrounding individual factors simultaneously and equivalently. If the stimulating effect of the environment is stronger than that of the surrounding crowd, then the environmental influence dominates, and the value of β can be increased while the value of α is decreased.

[0095] Obtain the distribution of the crowd, initialize the positions of individuals, and then establish the visual field of each individual.

[0096] In the case of no basic distribution information of the crowd, randomly generate the initial positions of people in the environment; in the case of having distribution information, directly read the initial positions of the crowd based on the distribution information.

[0097] Establish a visual field based on the position and velocity direction of each individual. The direction of the visual field is determined by the velocity direction, and the size is taken as 2θ = 180°. Combining with the velocity direction, the viewing direction is The visual radius (line-of-sight length) of the visual field is related to the environment where the individual is located. In an indoor environment, the line-of-sight length L In = 4 meters, while in an outdoor environment, L Out = 8 meters.

[0098] The established individual visual field is as Figure 4 shown. There are two obstacles, Barrier1 and Barrier2, in the environment. The position of individual i at time t The velocity direction is The viewing angle size is 2θ, and the viewing angle range is is the exit direction. Three sensing points (represented by the black dots in the figure) are set in each sub-direction in the figure. Then, through the selection and determination of the evacuation destination, global path planning is carried out: The global path planning mainly means that individual i locks the evacuation destination according to the nearest distance principle. At time t, there is a clear exit position and destination direction for each individual i, and moves in this direction with a certain acceleration. The overall evacuation process is as Figure 3 shown.

[0099] The exit position and destination direction can be expressed as:

[0100]

[0101] where is the position of individual i at time t, E i is the position of the target point, is the vector difference between the two, is the modulus of this direction. Therefore is actually the unit direction of individual i pointing from its current position to the exit position at time t.

[0102] In the present invention, the maximum acceleration of an individual is obtained by superimposing the velocity perception of the static environment and the interaction amount between individuals within the group: where represents the velocity perception of individual i for the static environment at time t, Represents the amount of interaction among individuals within the group at time t.

[0103] In this embodiment, the speed perception amount of the static environment is represented by the passing cost. The process of obtaining the speed perception amount of the static environment using the passing cost is described in detail below.

[0104] First, the passing cost of individual i in the k-th direction at time t in the individual's visual field is determined by the exit position and environmental factors. Specifically, it can be expressed by the following formula:

[0105]

[0106] In the passing cost formula, the first part represents the exit direction weight, and the second part represents the influence value of environmental factors in a sector p. The following details the two parts of the passing cost. K The first part of the passing cost, the exit direction weight, can be expressed by the following expression:

[0107] The first part of the passing cost, the exit direction weight, can be expressed by the following expression:

[0108]

[0109] In the formula, γ is the adjustment coefficient, and in specific practice, it can take the value of 2; is the velocity direction of individual i at time t and the direction from the position of individual i to the exit position at time t The angle deviation measures the angular difference between each sub-direction of individual i at different times and the exit direction. The smaller this difference, the smaller the passing cost.

[0110] The angle deviation can be obtained by the following numerical formula. In this method, the visual field needs to be discretized. The complete visual field is discretized into multiple different sub-directions, and each sub-direction is numbered. For example, in a specific embodiment, one sub-direction can be 15°, and they are numbered in the counterclockwise direction. At this time, there are 24 sub-directions in the whole circle, and the visual angle occupies 12 sub-directions. m perception points are set in the k-th (1 ≤ k ≤ 12) direction, distributed from near to far. At each position, individual i forms a complete visual field through 12 × m perception points. The angle deviation between any two directions k1 and k2 is denoted as L P (k1,k2) = |Num(k1) - Num(k2)|, where Num(k1) and Num(k2) are the two numbers in the counterclockwise direction among the overall 24 directions respectively.

[0111] It can be seen that the velocity direction of individual i at time t and the direction from the position of individual i to the exit position at time t Angle deviation Can be expressed as:

[0112]

[0113] Num() represents the direction number. The visual field is discretized. Taking 15° as a sub - direction, numbering is carried out in the counter - clockwise direction. There are 24 sub - directions in the whole circumference, and the viewing angle occupies 12 sub - directions. m perception points are set in the k(1 ≤ k ≤ 12)th direction, distributed from near to far. At each position, an individual forms a complete visual field through 12×m perception points.

[0114] In the angle deviation Among them, is the velocity direction of individual i at time t, is the unit direction from the position of individual i at time t to the exit position; Can be understood as is the position of individual i at time t, E i is the position of the target point, is the vector difference between the two, is the modulus of this direction.

[0115] The second part of the passage cost is the influence value of environmental factors on a sector p K Specifically, it can be expressed by the following expression:

[0116]

[0117] Among them, H(p xy ) = Envi(p xy ) represents the environmental grid value at the position (x, y) of the individual in the evacuation grid environment. The environmental grid is obtained by mapping environmental factors. K o (d w ) represents the weights of perception points at different distances, representing the weights at different distance perception points. The closer the perception point is to the center of individual i, the greater the weight.

[0118] When in an indoor environment,

[0119] When in an outdoor environment,

[0120] d w represents the distance from the perception point at different distances w to the center of individual i; r i represents the physical radius of individual i. A fixed perception distance d is set in each direction w, describes the distance from the perception point to the individual center (after determining the perception radius, multiple perception distances can be set in each direction to form a series of perception points, but these distances cannot be greater than the perception radius. Some reference values are given below). For the indoor environment, the reference value for this setting is d w (1 ≤ w ≤ 6) ∈ {0.5, 0.8, 1.2, 1.8, 2.4, 3.6} (unit: m). The reference value for the outdoor environment setting is d w (1 ≤ w ≤ 8) ∈ {0.5, 0.8, 1.2, 2.4, 3.6, 4.8, 6.4, 7.2} (unit: m).

[0121] L In represents the indoor line-of-sight length of individual i. Generally, take L In = 4 m; L Out represents the outdoor line-of-sight length of individual i. Generally, take L Out = 8 m.

[0122] After obtaining the passage costs of individual i in all directions at time t, determine the optimal movement direction of individual i after static environment perception according to the passage costs

[0123]

[0124] According to the obtained optimal movement direction of individual i the speed perception quantity of individual i for the static environment can be obtained. The speed perception quantity can be obtained by the following formula:

[0125]

[0126] In the formula, β is the static environment amplitude adjustment coefficient. Specifically, β = 0.5 can be taken; a i represents the basic acceleration of individual i.

[0127] According to the above content, the speed perception quantity of the static environment can reflect the relevant influences of individual i avoiding obstacles in the environment and approaching the destination and exit as quickly as possible.

[0128] In the personnel emergency evacuation simulation, after considering the influence of individuals on the static environment, it is also necessary to consider the interaction quantity between individuals within the group. Specifically, in the embodiments of the present invention, the interaction quantity between individuals within the group is represented by the following formula:

[0129]

[0130] where a i is the basic acceleration of individual i, m iis the mass of individual i, indicating the pressure gradient generated by the surrounding individuals on individual i at time t.

[0131] In the embodiments of the present invention it can be obtained through the following formula:

[0132]

[0133] where α is the pressure adjustment coefficient, and specifically, α = 0.5 can be taken; is called the neighboring group of individual i, indicating the set of the individuals within the sensing radius r centered on individual i at time t p The individuals in this neighboring group have different distances from i, and their influences are also different. is expressed as the neighboring group at time t The pressure value exerted by any individual j in on individual i at time t. Specifically, the pressure value can be directly measured by the density difference based on the distance weight between individuals: where and respectively represent the density values based on the distance weight of individual i and any individual j at time t. represents the kernel function that measures the importance or influence of other individuals j at time t in the neighboring group on the central individual i, represents the kernel function The gradient function of.

[0134] In the present invention, the density value of individual i based on the distance weight is calculated through the following formula:

[0135]

[0136] In the formula, m j is the mass of any individual j in the neighboring group represents the kernel function that measures the importance or influence of other individuals j at time t in the neighboring group on the central individual i.

[0137] The specific kernel function can be expressed by the following expression:

[0138]

[0139] In the kernel function U is the distance variable; r i is the physical radius of individual i; +r j is the physical radius of individual j; represents the center point of individual i at time t and the neighboring group The distance from the center point of any individual j; r p is the perception radius of individual i.

[0140] The distance variable U is defined as:

[0141]

[0142] where represents the absolute distance between individuals i and j; Rst ij = r p -(r i + r j ) represents the absolute perception radius between individuals i and j.

[0143] From the above kernel function, when individuals i and j are not within the effective range, the kernel function When , the absolute distance between individuals i and j is less than or equal to 0, and the two individuals will cause a collision effect. Obviously, when d ij ≤ r ij , U ∈ [0, r p / (r p - r i - r j ).

[0144] According to the expression of the kernel function , its gradient function is:

[0145]

[0146] Similarly, based on the above density value of individual i based on distance weight it can be known that for any individual j at time t, the density value based on distance weight - is calculated by the following formula:

[0147]

[0148] It should be understood that at this time represents the neighboring group of individual j at time t, m j is the mass of individual j, represents the distance from the center point of individual j at time t to the center point of any individual i in the neighboring group .

[0149] Since as the influence of surrounding individuals on individual i can be directly converted into acceleration, and thus affect its subsequent movement direction, therefore, the interaction between individuals within the group can be expressed as:

[0150]

[0151] The final acceleration obtained by superimposing the speed perception of the static environment and the interaction amount among individuals within the group: Individual i completes the evacuation process according to this final acceleration and direction.

[0152] Finally, it is judged whether the crowd in the current evacuation space has been evacuated, specifically including:

[0153] For each individual in the evacuation space, check whether they have reached the evacuation exit area;

[0154] If an individual has reached the exit area, they are regarded as having been evacuated and removed from the current evacuation space;

[0155] When all individuals in the evacuation space have been judged as having been evacuated and removed from the current space, further evacuation judgment for this space is stopped, and it is determined that the crowd evacuation in this evacuation space has been completed.

[0156] The effectiveness of the present invention will be illustrated below through specific cases

[0157] In a certain earthquake, the evacuation of 70 students in a primary school classroom was completely recorded. The initial positions of the students were the seats in the classroom. The indoor space size was 6.6 meters × 8.8 meters. The classroom had a 1-meter-wide front door exit. The seven rows of desks and chairs in the classroom could be regarded as simple obstacles. First, let's restore the classroom layout and evacuation simulation. The accuracy of the grid environment was 0.1m. The initial layout of the classroom and the initial positions of the students were as Figure 5 shown, and the evacuation grid environment was as Figure 6 shown.

[0158] Since the evacuation objects were primary school students, the individual radius was set to 0.2m. In a crowded and chaotic environment, the perception radius of individuals would be smaller. Among them, the basic density induction radius was set to 1m, and the pressure coefficient was 0.6. Because the desks and chairs and other obstacles were densely distributed, four fixed values of 0.3m, 0.6m, 0.8m, and 1.2m were set within the perception range for evacuation simulation. The comparison chart of the simulation results using this method and the actual situation was as Figure 7 shown. The comparison of the simulation results showed that during the evacuation process, people could avoid obstacles such as desks and chairs and choose the most familiar conventional channels to move towards the exit. There were some slight squeezing and collision phenomena during this process. Through comparison, the simulated path was consistent with the actual path. However, due to the overcrowding of the desks and chairs in the classroom, some people moved slowly, which led to differences between the simulation and the actual situation in the later stage of the evacuation.

[0159] Simulations were respectively carried out using the present invention and other methods, such as the multi-agent model (ABM), the social force model (SF), and the cellular automaton (CA). The comparison of several results is as Figure 8 shown. From the perspective of the overall evacuation time, the model (ABM+VFH) adopted by the present invention is closer to the real result (about 36 s), and the consumption time of other models is longer. The real evacuation video shows that the students did not start evacuating at the same time. Some students started evacuating slowly because they were tidying up their personal belongings or had a longer reaction time.

[0160] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For the relevant parts, reference can be made to the description in the method section.

[0161] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for emergency evacuation of personnel based on an improved vector graphic, characterized in that, It includes the following steps: Initialize the evacuation environment, including the initialization of static environmental space elements and the initialization of the individual positions of the evacuating crowd; Establish a visual field containing multiple sensing points based on the individual positions and velocity directions of the evacuating crowd; specifically including: For each individual in the evacuating crowd, establish a vector with the individual position as the starting point, and determine the radius of the visual field according to the individual's line of sight length; Determine the visual angle of the visual field according to the speed direction of the individual: where represents the movement speed direction of individual i at time t, and θ represents the set visual half-field angle; Discretize the visual field, and evenly divide the visual angle of the visual field into several sub-directions; Set several sensing points in each sub-direction according to the distance from the starting point; For each individual in the evacuating crowd, based on the established visual field and through continuous perception of the static environment and the interaction between individuals within the group, perform individual movement to complete the evacuation of the crowd; the continuous perception of the static environment specifically includes the following steps: S31. Determine the passage cost of each individual in the k-th direction according to the exit position and static environmental space elements in the evacuation environment Among them, the first part + represents the weight of the exit position direction of individual i at time t, represents the velocity direction of individual i at time t, is the unit direction from the position where individual i is located to the exit position at time t; The second part represents the influence value of environmental factors on a sector p K H(p xy ) = Envi(p xy ) represents the position coordinates in the evacuation environment at the position (x, y) of the individual in the evacuation grid environment, K o (d w ) represents the weights at different distance perception points; S32. Determine the optimal moving direction of the individual after static environment perception at time t according to the passing cost of each individual in the k-th direction : Determine the optimal moving direction of the individual after static environment perception at time t S33. Determine the perception amount of the static environment according to the optimal moving direction after static environment perception at each individual time t Determine the perception amount of the static environment: where β is the static environment amplitude adjustment coefficient, is the optimal moving direction of individual i after perceiving the static environment at time t, and a i is the basic acceleration of individual i.

2. The method for emergency evacuation of personnel based on an improved vector map according to claim 1, characterized in that The static environmental space elements include indoor environmental elements and outdoor environmental elements.

3. The personnel emergency evacuation method based on an improved vector vector diagram according to claim 1, characterized in that, The individual positions of the evacuating crowd are initialized through the following steps: Randomly generate the initial positions of the individuals in the evacuating crowd in the evacuation grid environment; Or according to the crowd distribution information, obtain the initial positions of the individuals in the evacuating crowd in the evacuation grid environment.

4. A method for emergency evacuation of personnel based on an improved vector vector diagram according to claim 1, characterized in that, In step S31, the exit position direction weight of individual i at time t is obtained through the following formula: where γ represents the adjustment coefficient, is the angle deviation between the current velocity direction of individual i at time t and the exit direction.

5. A method for emergency evacuation of personnel based on an improved vector map according to claim 1, characterized in that, The interaction between individuals within the group is obtained by constructing an interaction quantity equation between individuals within the group. The interaction quantity equation between individuals within the group specifically includes the following expressions: where a i is the basic acceleration of individual i, m i is the mass of individual i, represents the pressure gradient generated by the surrounding individuals for individual i at time t.

6. The personnel emergency evacuation method based on an improved vector vector diagram according to claim 5, characterized in that, The pressure gradient generated by the surrounding individuals on individual i at time t is obtained through the following steps: where α is the pressure regulation coefficient; is called the neighboring group of individual i, representing the set of the individuals centered on individual i within the sensing radius r p at time t; is expressed as the pressure value exerted on individual i by any individual j in the neighboring group at time t ; represents a kernel function for measuring the importance or influence of other individuals j on the central individual i in the neighboring group at time t, is expressed as the kernel function gradient function of.

7. A method for emergency evacuation of personnel based on an improved vector map, as claimed in claim 6, wherein The kernel function Specifically, it is represented by the following expression: where U is the distance variable; r i is the physical radius of individual i; +r j is the physical radius of individual j; represents the distance between the center point of individual i at time t and the center point of any individual j in the neighboring group ; r p is the perception radius of individual i.

8. A personnel emergency evacuation system based on an improved vector map, characterized in that, Including, Evacuation environment construction module: used for the space elements of the evacuation environment and complete the initialization of the evacuation environment, including the initialization of static environmental space elements and the initialization of the individual positions of the evacuating crowd; Multi-sensing point visual field construction module: used to establish a visual field containing multiple sensing points in the evacuation environment according to the individual positions and velocity directions of the evacuating crowd; specifically including: For each individual in the evacuating crowd, establish a vector with the individual position as the starting point, and determine the radius of the visual field according to the individual's line of sight length; Determine the visual angle of the visual field according to the speed direction of the individual: where represents the moving speed direction of individual i at time t, and θ represents the set visual half-field angle; Discretize the visual field, and evenly divide the visual angle of the visual field into several sub-directions; Set several sensing points in each sub-direction according to the distance from the starting point; Perception-feedback based crowd evacuation model: Based on the established visual field and through continuous perception of the static environment and the interaction between individuals within the group, perform individual movement to complete the evacuation of the crowd; the continuous perception of the static environment specifically includes the following steps: S31. Determine the passing cost of each individual in the k-th direction according to the exit position in the evacuation environment and the static environmental space elements Among them, the first part + represents the weight of the exit position direction of individual i at time t, represents the velocity direction of individual i at time t, is the unit direction from the position where individual i is located to the exit position at time t; The second part represents the influence value of environmental factors on a sector p K , H(p xy ) = Envi(p xy ) represents the position coordinates in the evacuation environment at the position (x, y) of the individual in the evacuation grid environment, K o (d w ) represents the weights at different distance perception points; S32. Determine the optimal movement direction of the individual after static environment perception at time t according to the passing cost of each individual in the k-th direction Determine the optimal movement direction of the individual after static environment perception at time t: S33. Determine the perception amount of the static environment according to the optimal moving direction after static environment perception at each individual's t moment Determine the perception amount of the static environment: where β is the static environment amplitude adjustment coefficient, is the optimal moving direction of individual i after perceiving the static environment at time t, and a i is the basic acceleration of individual i.

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