Emergency evacuation simulation method based on non-uniform floor field model with multiple evacuation factors

Abstract

The present invention discloses an emergency evacuation simulation method based on a non-uniform floor field model with multiple evacuation factors. The method of the present invention takes the overlapping area of ​​a circle with an exit as the center and an integer multiple of the exit width as the radius and each cell as the basis for setting the static floor field value, introduces a constraint factor to reflect the relationship between the influencing factors of the dynamic and static floor fields, and expands the floor field value setting to three-dimensional space. It demonstrates the static floor field value setting method under four different evacuation scenarios, proposes improvement ideas for the irrationality of the static floor field value setting, and expands the scope of application of the floor field model. Through MATLAB, an evacuation simulation experiment was conducted, and it was found that the sensitivity of the model to the guiding effect is significantly better than that of the typical floor field model. The evacuation simulation results are helpful to provide support for the formulation of evacuation induction strategies for typical emergency scenarios.

Description

Technical Field

[0001] The invention relates to the field of emergency evacuation modeling and simulation, and in particular to an emergency evacuation simulation method based on a multi-evacuation factor non-uniform floor field model. Background Art

[0002] With the acceleration of urbanization, the population density in cities is gradually increasing, and there are more large-scale crowded public places. When the flow of people is large, it is easy to cause crowds and even stampedes due to emergencies. In order to ensure that people can be evacuated quickly and efficiently in the event of an emergency, reduce casualties, and reduce economic and property losses, emergency evacuation and simulation of people in emergency situations has gradually become an important research topic.

[0003] In order to approach the actual evacuation on site, objectively present the crowd evacuation effect, and improve the feasibility of calculation, experts and scholars have constructed many personnel evacuation models. Generally speaking, emergency evacuation models are mainly divided into macro models and micro models; among them, the macro model starts from the whole crowd and studies the causes of pedestrian behavior from a macro perspective; while the micro model studies the behavioral characteristics of people from the perspective of individual differences of pedestrians. Among many models, the cellular automaton model in the micro model is the most widely used. As a deepening form of the cellular automaton model, Bursedde et al. proposed the floor field model in 2001. In the floor field model, the evacuation scene is usually divided into multiple cells of equal area, and it is stipulated that there can only be one pedestrian in each cell at each moment, and each cell corresponds to a different floor field value, which is determined by the static floor field value and the dynamic floor field value. Generally, the static floor field value is determined by the distance of the evacuated pedestrian from the exit, and the dynamic floor field value is determined by the number of people around the evacuated pedestrian. The evacuated pedestrian evacuates according to the law of moving from the area with higher floor field value to the area with lower floor field value. Since the floor field model studies the spatial position of pedestrians at the moment of evacuation from the microscopic perspective of pedestrians, and determines the floor field value of the evacuation scene, it can subtly show the position changes of pedestrian evacuation. The application of the floor field model can not only quantify the evacuation scene and pedestrian position, but also conduct evacuation research through quantitative calculation, thus providing a basis for formulating corresponding induction strategies. However, the typical floor field value setting method has the following problems:

[0004] First, the factors considered in setting the static floor field value are too single, and other environmental factors that affect the efficiency of pedestrian evacuation are rarely considered.

[0005] Second, the existing setting method of static floor field values ​​does not meet the standard of uniqueness of pedestrian motion paths, and the field values ​​of a single cell set in different ways have different values.

[0006] Third, there is a correlation between the factors that affect the dynamic and static floor field values, but the coefficients between the existing dynamic and static floor fields lack connection, which leads to the lack of systematicity and integrity of the model.

[0007] Fourth, the application scenarios of existing floor field models are limited to two-dimensional planes, which limits the scope of application of the model.

[0008] Therefore, there is a lack of a comprehensive, integrated and accurate floor field model that can objectively quantify the factors affecting personnel evacuation in multiple evacuation scenarios and provide a rational field value calculation and setting method. Summary of the invention

[0009] Aiming at the irrationality of the existing floor field model, the present invention proposes an emergency evacuation simulation method based on a non-uniform floor field model with multiple evacuation factors, which sets the floor field value more scientifically, enriches the application scope of the floor field model, and truly displays the path of pedestrian movement, which helps to formulate more practical evacuation measures and improve evacuation efficiency. In the improved floor field model, the setting of the static floor field value is based on the overlap area of ​​each cell with the exit as the center and the circle with the exit width as an integer multiple as the radius. At the same time, a constraint factor is introduced into the floor field model to quantify the interaction between the dynamic and static floor field influencing factors.

[0010] The object of the present invention is achieved through the following technical solution: an emergency evacuation simulation method based on a multi-evacuation factor non-uniform floor field model, the method comprising the following steps:

[0011] Step 1: Determine the static floor field value in combination with the scene without environmental factors and with obstacles, guide personnel, inclined ground or stairs; the calculation formula is as follows:

[0012]

[0013] Among them, S uv represents the static floor field value of the cell (u, v) position considering the combined influence of obstacles, guides, inclined ground or stairs. δ1, δ2, and δ3 are selective variables, that is, when there are obstacles in the evacuation scene, δ1=1; when there are no obstacles in the evacuation scene, δ1=0; similarly, when there are guides in the evacuation scene, δ2=1; when there are no guides in the evacuation scene, δ2=0; similarly, when the evacuation scene is a staircase area, δ3=1; when the evacuation scene is a plane area, δ3=0; l i Represents the radius of the circle with the cell where the exit is located as the center. The radius increases in integer multiples. S li Represents a radius of l i The circle of the cell (u, v) overlaps with the cell (u, v), m represents the number of circles with the exit as radius that overlap with each cell; h jrepresents the radius of the circle centered at the cell where the obstacle is located, S hj Represents the radius h j The overlap area of ​​the circle and the cell, p represents the number of circles with the length of the cell where the obstacle is located as the radius that overlap with each cell; Represents the radius of the guiding effect, S k The representative radius is The circle of the guide is the overlapping area with the cell, q represents the number of circles with the length of the cell where the guide is located as the radius that overlaps with each cell; a f represents the shortest distance between the lowest floor or stairs and the exit, n represents the number of spheres on the inclined floor or stairs that overlap with the three-dimensional cell, V f Represents radius a f The overlapping volume of the sphere and the three-dimensional cell space;

[0014] Step 2: Set the dynamic floor field value; Dynamic floor field value D uv It is related to the number of people around the evacuated pedestrians at time t, the diffusion coefficient and attenuation coefficient of the dynamic floor field value; assuming that the pedestrian is in the cellular space at position (u, v) at time t, in order to ensure that the direction of pedestrian movement is minimally disturbed, it is stipulated that the pedestrian chooses four adjacent directions to move, and the dynamic field calculation formula is as follows:

[0015]

[0016] Where D uv t , D uv t-1 They represent the dynamic field values ​​of the cell (u, v) at time t and t-1, respectively, α is the diffusion coefficient of the dynamic floor field, and β is the attenuation coefficient of the dynamic floor field;

[0017] Step 3: Introduce the constraint factor γ to establish a multi-evacuation factor non-uniform floor field model for quantifying the evacuation efficiency of personnel; the details are as follows:

[0018] P uv =Nξ uv exp[γS uv +(1-γ)D uv t ]

[0019] Among them, P uv is the pedestrian movement probability, N is the normalization factor, when ξ uv = 1, indicating that the cell (i, j) is occupied by pedestrians; when ξ uv = 0, indicating that cell (i, j) is not occupied by pedestrians.

[0020] Step 4: Under the given personnel emergency evacuation scenario conditions, determine the relevant input parameters according to the multi-evacuation factor non-uniform floor field model, implement emergency evacuation simulation, and analyze the evacuation effect.

[0021] Furthermore, the cells of the multi-evacuation factor non-uniform floor field model are square and have the same width.

[0022] Furthermore, obstacles have a hindering effect on the evacuation of personnel, and the static floor field value of the cell affected by the obstacle increases.

[0023] Furthermore, the role of guiding personnel has a promoting effect on the evacuation process, and the static floor field value of the cell affected by the guiding personnel factor is reduced.

[0024] Furthermore, in the inclined ground or stair scene, the stairs are divided into equal-volume cubic cells with equal side lengths based on the number of steps and the width of the stairs. A sphere is drawn with the midpoint of the side of the three-dimensional cell space closest to the bottom exit as the sphere center and an integer multiple of the exit width as the radius. The sum of the overlapping volumes of each sphere and the three-dimensional cell space and the product of the volume of each sphere is recorded as the field value of the three-dimensional cell.

[0025] Furthermore, the attractiveness of the exit to people will cause pedestrians to evacuate to the exit, resulting in changes in the interaction between people. The interaction between people will also change the attractiveness of the exit to people. The constraint factor γ is used to represent the correlation between the influencing factors of the dynamic floor field value and the static floor field value. γ is a dimensionless number with a value range of [0,1].

[0026] Furthermore, for the set emergency evacuation scenario of personnel, the multi-evacuation factor non-uniform floor field model is applied to determine the relevant input parameter values, implement emergency evacuation simulation, and obtain the emergency evacuation step length, path and time and other element information.

[0027] Beneficial effects of the present invention:

[0028] 1. The non-uniqueness of static floor field value setting is solved by introducing a method for calculating two-dimensional overlap area;

[0029] 2. This method can also expand the floor field model to three-dimensional space, expanding the application scenarios of the floor field model;

[0030] 3. By introducing the constraint factor γ, the correlation between the factors affecting the dynamic and static floor fields is enhanced, making the floor field model tend to be integrated;

[0031] 4. After simulating the model through MATLAB, it was found that the actual fit of the model in crowded places was significantly improved compared with the previous cellular automaton model. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a flow chart of the steps to build a floor field model considering multiple evacuation factors;

[0033] Figure 2 It is the effect diagram of static floor field value setting on the plane without obstacles and guiding personnel;

[0034] Figure 3 It is a static floor field value setting effect diagram on a plane with obstacles and no guide personnel;

[0035] Figure 4 It is the effect diagram of static floor field value setting on the plane with obstacles and guide personnel;

[0036] Figure 5 It is the effect diagram of static floor field value setting on stairs and inclined ground;

[0037] Figure 6 It is a schematic diagram of the evacuation simulation scene of the present invention. DETAILED DESCRIPTION

[0038] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings.

[0039] like Figure 1 As shown, the present invention provides an emergency evacuation simulation method based on a non-uniform floor field model with multiple evacuation factors, the method comprising the following steps:

[0040] Step 1, establish a basic floor field model for personnel evacuation;

[0041] The probability of pedestrian movement is determined by the static floor field value and the dynamic floor field value. The expression of pedestrian movement probability is as follows:

[0042] P uv =Nξ uv exp[k s S uv +k d D uv ]

[0043] Among them, P uv is the pedestrian movement probability, N is the normalization factor, k s It is the sensitivity parameter for adjusting the static floor field value, reflecting the influence of the exit position on the evacuation of personnel, S uv is the static floor field value, k d It is the sensitivity parameter for adjusting the static and dynamic plate field value, reflecting the influence intensity of the interaction between people, D uv is the dynamic floor field value. uv = 1, indicating that the cell (u, v) is occupied by pedestrians; when ξ uv= 0, indicating that the cell (u,v) is not occupied by a pedestrian.

[0044] Step 2, set the static floor field value in special scenarios;

[0045] Although the method of setting the static floor field value based on the exit distance has its defects, it is worth learning from. The location, width and number of exits, obstacles and guides will affect the setting of the static floor field value, which indicates the attractiveness of the exit to pedestrians.

[0046] like Figure 2 As shown in the figure, in a plane evacuation scenario without obstacles and guides, the cells are set to be squares with the same width of l. A circle is drawn with the total length l of the cell where the exit is located as the radius and the midpoint of the exit as the center, which is counted as C1. The area of ​​the overlap between the circle C1 and the cell closest to the exit is calculated as S1. A circle is drawn with twice the length of the cell where the exit is located as the radius and the midpoint of the exit as the center, which is counted as C2. Figure 1 The part pointed by the arrow is the overlap area S2 of the circle C2 and the cell closest to the exit. Draw all the circles C corresponding to the exit in the above way. i , calculate the size S of the overlapping area between each circle and each cell li . The overlapping areas S li The sum of the products of the area of ​​the corresponding circle Ci is the static floor field value of the cell that is not affected by any action. The calculation formula is as follows;

[0047]

[0048] Among them, S A Represents the static floor field value without environmental factors, l i Represents the radius of the circle with the cell where the exit is located as the center. The radius increases in integer multiples. S li Represents a radius of l i The circle represents the overlapping area with the cell, and m represents the number of circles with the exit as radius that overlap with each cell.

[0049] like Figure 3 As shown, in a flat evacuation scenario with obstacles and no guides.

[0050] Similarly, set the cells to be square and have the same width of l. Similarly, draw a circle with the total length of the cell where the exit is located as the radius and the midpoint of the exit as the center, which is counted as C1. Calculate the area of ​​the overlap between circle C1 and the cell closest to the exit, which is counted as S1. Continue to draw a circle with twice the length of the cell where the exit is located as the radius and the midpoint of the exit as the center, which is counted as C2. Figure 3The part pointed by the arrow is the overlap area between the circle C2 and the cell closest to the exit. The area of ​​this area is calculated as S2. All circles C corresponding to the exit are drawn according to the above method. i , calculate the size of the area S of the overlap between the circle and each cell li .

[0051] Figure 3 The gray area is the cell occupied by the obstacle. Draw a circle with the center of the cell occupied by the obstacle as the center and the width of the cell occupied by the obstacle as the radius, which is recorded as C4. The area indicated by the arrow in the figure is the overlap area of ​​the circle C4 and the cell closest to the exit. Calculate the area of ​​this area and record it as S3. When the obstacle occupies multiple cells, draw the circle C corresponding to each obstacle according to the above method. j , calculate the area size S of each overlapping area hj Obstacles hinder the evacuation of personnel, which will increase the value of the cellular static floor field. Therefore, the overlap area S li The sum of the products of the areas of the circles Ci corresponding to the exits and the overlapping areas S hj The circle C corresponding to the obstacle j The sum of the product of the areas is the static floor field value of the cell affected by the obstacle. The calculation formula is as follows;

[0052]

[0053] Among them, S B represents the static floor field value considering only the influence of obstacles, h j represents the radius of the circle centered at the cell where the obstacle is located, S hj Represents the radius h j The overlapping area of ​​the circle and the cell, p represents the number of circles with the length of the cell where the obstacle is located as the radius that overlap with each cell.

[0054] like Figure 4 As shown, on a flat evacuation scenario with obstacles and guiding personnel.

[0055] Similarly, set the cells to be squares with the same width of l. Draw a circle with the total length of the cell where the exit is located as the radius and the midpoint of the exit as the center, which is counted as C1. Calculate the area of ​​the overlap between circle C1 and the cell closest to the exit, which is counted as S1. Draw another circle with twice the length of the cell where the exit is located as the radius and the midpoint of the exit as the center, which is counted as C2. Calculate the area of ​​the overlap between circle C2 and the cell closest to the exit, which is counted as S2. Draw the circle C corresponding to each exit in the same way as above. i , calculate the area size S of each region li .

[0056] Likewise, Figure 4 The gray area is the cell occupied by the obstacle. Draw a circle with the center of the cell occupied by the obstacle as the center and the width of the cell occupied by the obstacle as the radius, which is recorded as C4. Calculate the area of ​​the overlap between circle C4 and the cell closest to the exit, which is recorded as S3. When the obstacle occupies multiple cells, draw the circle C corresponding to each obstacle according to the above method. j , calculate the area size S of each region hj .

[0057] Figure 4 The diamond pattern filled area is the cell where the guide is located. The center of the cell occupied by the guide is the center of the circle. Draw a circle with radius C5. Represents the maximum distance at which pedestrians can be affected by guidance. Figure 4 In the above method, the maximum distance that pedestrians can be affected by the guidance is set as one cell length, and the area of ​​the overlap between the circle C4 and the cell closest to the exit is calculated as S4. When the guide occupies multiple cells, the circle C corresponding to each guide is drawn according to the above method. k , calculate the area size S of each region k The guiding effect promotes the evacuation process of pedestrians, so it will lead to a decrease in the value of the cell static floor field. Therefore, the overlap area S li Circular C with corresponding exit i The sum of the products of the areas of the overlapped areas S hj The circle C corresponding to the obstacle j The sum of the products of the areas of k The circular C with corresponding guiding function k The sum of the product of the areas of the cells is subtracted to get the static floor field value of the cell affected by the guiding factor. The calculation formula is as follows;

[0058]

[0059] Among them, Sc represents the static floor field value considering the combined influence of obstacles and guide personnel, Represents the radius of the guiding effect, S k The representative radius is The circle represents the overlapping area with the cell, and q represents the number of circles with a radius of the length of the cell where the guide is located that overlap with each cell.

[0060] like Figure 5 As shown, on the three-dimensional evacuation scene of the stairs.

[0061] Based on the number of stairs and the width of the stairs, the stairs are divided into equal-volume cubic cells with a side length of l. Figure 5 The direction pointed by the middle arrow is the three-dimensional cell closest to the exit. Figure 5 In the example, the midpoint of the edge of the three-dimensional cell space closest to the bottom exit is used as the sphere center, and the integer multiple of the exit width is used as the radius to draw a sphere. The sum of the overlapping volume of each sphere and the three-dimensional cell space and the product of the volume of each sphere is recorded as the field value of the three-dimensional cell. The calculation formula is as follows;

[0062]

[0063] Among them, S D represents the static floor field value considering only the influence of inclined ground or stairs, a f represents the shortest distance between the lowest floor or stairs and the exit, n represents the number of spheres on the inclined floor or stairs that overlap with the three-dimensional cell, V f Represents radius a f The overlapping volume of the sphere and the three-dimensional cell space.

[0064] Step 3, consider the static floor field value setting in general scenarios;

[0065] In order to reflect the universal applicability of the non-uniform floor field model, Figure 2-Figure 5 After combining the scenarios, the static floor field value settings for a general evacuation scenario with obstacles, guides, exits, and stairs are as follows:

[0066]

[0067] Among them, S uv Represents the static floor field value of the cell position (u,v) considering the combined influence of obstacles, guides, inclined ground or stairs. δ1, δ2, and δ3 are selective variables, that is, when there are obstacles in the evacuation scene, δ1 = 1; when there are no obstacles in the evacuation scene, δ1 = 0. Similarly, when there are guides in the evacuation scene, δ2 = 1; when there are no guides in the evacuation scene, δ2 = 0. Similarly, when the evacuation scene is a staircase area, δ3 = 1; when the evacuation scene is a plane area, δ3 = 0.

[0068] Step 4, set the dynamic floor field value;

[0069] Dynamic floor field value D uv It is related to the number of people around the evacuated pedestrian at time t, the diffusion coefficient and attenuation coefficient of the dynamic floor field value. Assuming that the pedestrian is in the cell space (i, j) at time t, in order to ensure that the direction of pedestrian movement is minimally disturbed, it is stipulated that pedestrians can choose four adjacent directions to move, and the dynamic field calculation formula is as follows:

[0070]

[0071] Where D uv t , D uv t-1 They represent the dynamic field values ​​of the cell (u, v) position at time t and t-1 respectively, α is the diffusion coefficient of the dynamic floor field, and β is the attenuation coefficient of the dynamic floor field.

[0072] Step 5, introduce the constraint factor γ and set the pedestrian movement probability to establish a multi-evacuation factor non-uniform floor field model for personnel evacuation;

[0073] The attraction of the exit to people will cause pedestrians to evacuate to the exit, resulting in changes in the interaction between people. Similarly, the interaction between people will also change the attraction of the exit to people. Therefore, the static floor field and the dynamic floor field restrict and influence each other. This step sets the restriction factor γ to represent the correlation between the factors affecting the static and dynamic floor field values. Refer to the sensitivity parameter k of the static and dynamic floor field in step 1. s and k d , non-dimensionalize γ and consider the value range of γ to be [0,1].

[0074] Referring to the floor field model established in step 1, combined with the dynamic and static floor field values ​​set in steps 3 and 4, the created constraint factors are introduced, and the pedestrian movement probability is set as follows;

[0075] P uv =Nξ uv exp[γS uv +(1-γ)D uv t ]

[0076] Step 6: Build a crowd evacuation simulation scene, set personnel and environmental parameters, calculate dynamic and static floor field values, and conduct an evacuation simulation experiment.

[0077] Due to the randomness of simulation, the positions of evacuees were fixedly generated in each simulation in this experiment, and the statistical results were the average values ​​of 10 simulation results to reduce accidental data errors and study the influence of the guiding effect of the non-uniform floor field on the evacuation efficiency.

[0078] The crowd evacuation simulation scenario of a densely populated single exit built using MATLAB software is as follows: Figure 6 shown.

[0079] The evacuation environment and pedestrian parameters are set as follows: the size of the evacuation space is 16×8 cells, there is only one exit in the evacuation space, the exit width is two cell lengths, the number of obstacles is 4, the number of guides is 4, the obstacles and guides are symmetrical to the exit, and the total number of evacuees is 20.

[0080] The static floor field value in the evacuation scenario is set using the static floor field value determination method in step 3, and the dynamic floor field value in the evacuation scenario is set using the dynamic floor field value determination method determined in step 4.

[0081] Step 7, determining the α and β values ​​that achieve the highest evacuation efficiency in the evacuation scenario;

[0082] Set γ = 0.5, that is, the constraint between the dynamic and static floor fields is minimal. Set the α and β values ​​in steps of 0.1 and fully select values ​​within the effective range. Perform multiple evacuation simulation experiments under the same parameters and determine that when α = 0.4 and β = 0.6, the evacuation efficiency is the highest in this evacuation scenario, and the total evacuation step length is 46, reaching the minimum value.

[0083] Step 8: Perform difference analysis on the non-uniform floor field model.

[0084] The non-uniform floor field model NFM is compared with the typical floor field model FM. The α and β values ​​with equal step lengths are randomly selected to calculate the sparse step lengths of NFM and FM under different guiding factors. Under different α and β values, the sensitivity of the non-uniform floor field model to the guiding effect is significantly higher than that of the typical floor field model, that is, when studying the relationship between the guiding effect and the sparse step length, the non-uniform floor field model has a stronger sensitivity than the typical floor field model.

[0085] Step 9, analyzing the relationship between the constraint factor γ and the sparse step length.

[0086] In order to obtain the highest evacuation efficiency, when studying the influence of evacuation factors on step length, the α and β values ​​with smaller corresponding evacuation step lengths were selected for simulation experiments. Five groups of α and β values ​​with evacuation step lengths of 46 and 47 were selected, and the corresponding evacuation step lengths were obtained by simulation. The constraint factor and the evacuation step length roughly present an "M" type relationship. That is, when γ tends to 0 or 1, the evacuation step length gradually decreases. When γ = 0.5, the evacuation step lengths corresponding to each group of α and β values ​​all reach the minimum value.

[0087] Step 10, analyzing the relationship between the number of guiding factors and the sparse step length.

[0088] In real life, the guiding effect on pedestrian evacuation is mainly reflected in the number and distribution of guiding personnel. In this simulation, the length of the guiding factor is set to a cell space length, and the number of guiding personnel randomly set in the evacuation scene is used as a variable. α and β are taken as 0.6 and 0.4 respectively, and multiple simulations are performed to record the evacuation time steps corresponding to different numbers of guiding personnel. The simulation results show that as the number of guiding factors increases, the evacuation step length also increases, and is not affected by the constraint factor, indicating that as the number of guiding personnel increases, the evacuation step length of the evacuees shows an upward trend, which is not conducive to improving the evacuation efficiency.

[0089] In summary, the field value design of the floor field model of the present invention is reasonable, the simulation results are accurate, and it meets the actual needs of evacuation simulation. The model not only solves the uniqueness problem of the static floor field value setting in the floor field model, but also introduces factors such as exits, obstacles and guides that affect evacuation efficiency into the field value setting, and at the same time expands the floor field model to three-dimensional space, expanding the scope of application of the floor field model.

[0090] After applying the established non-uniform floor field model to the custom dense evacuation scene for simulation, the following conclusions can be drawn: 1. In the floor field evacuation model, a single dynamic and static floor field has a promoting effect on evacuation efficiency, and the interaction between the dynamic and static floor fields will increase the evacuation distance and inhibit the evacuation efficiency. 2. When the density of people in the evacuation scene reaches the threshold, the guides occupy enough evacuation space, so setting up guides is not conducive to evacuation. 3. In crowded places, the established non-uniform floor field model that considers multiple evacuation factors is more sensitive to the changes in guides than the typical floor field model, indicating that the model is more applicable in crowded places.

[0091] The above conclusions can be used to formulate the following suggestions for the induction strategy of densely populated places: 1. The evacuation simulation results based on the non-uniform floor field model with multiple evacuation factors show that a single dynamic and static floor field has a promoting effect on evacuation efficiency, while the interaction between the dynamic and static floor fields will increase the evacuation distance and inhibit the evacuation efficiency. Therefore, during the evacuation process, the positions of obstacles and guides should be fixed as much as possible to keep them unchanged, and the fluctuation range of the static floor field value should be minimized; or the utilization rate of the evacuation space should be ensured so that the evacuees can walk along the evacuation path of the remaining evacuees as much as possible to reduce the fluctuation range of the dynamic floor field value. 2. The evacuation simulation results based on the non-uniform floor field model with multiple evacuation factors show that with the increase in the number of guides, the evacuation distance of all evacuees shows an upward trend. Therefore, the evacuation guidance strategy in crowded places considers using guide signs instead of guides, which is conducive to improving evacuation efficiency. 3. The pedestrian movement probability is calculated through the multi-evacuation factor non-uniform floor field model. The pedestrian moves to the place with the largest pedestrian movement probability among the eight cells around him at the next time node. The evacuation results simulated by this logic can accurately reflect the movement law of evacuated personnel and provide a basis for formulating guidance. 4. The movement probability of each cell on the stairs calculated by the multi-evacuation factor non-uniform floor field model can provide a reference for the movement of pedestrians on the stairs and guide the evacuation guidance behavior on the stairs.

[0092] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. An emergency evacuation simulation method based on a non-uniform floor field model with multiple evacuation factors, characterized in that: The method comprises the following steps: Step 1: Determine the static floor field value in combination with the scene without environmental factors and with obstacles, guide personnel, inclined ground or stairs; the calculation formula is as follows: Among them, S uv represents the static floor field value of the cell (u, v) position considering the combined influence of obstacles, guides, inclined ground or stairs. δ1, δ2, and δ3 are selective variables, that is, when there are obstacles in the evacuation scene, δ1=1; when there are no obstacles in the evacuation scene, δ1=0; similarly, when there are guides in the evacuation scene, δ2=1; when there are no guides in the evacuation scene, δ2=0; similarly, when the evacuation scene is a staircase area, δ3=1; when the evacuation scene is a plane area, δ3=0; l i Represents the radius of the circle with the cell where the exit is located as the center. The radius increases in integer multiples. S li Represents a radius of l i The circle of the cell (u, v) overlaps with the cell (u, v), m represents the number of circles with the exit as radius that overlap with each cell; h j represents the radius of the circle centered at the cell where the obstacle is located, S hj Represents the radius h j The overlap area of ​​the circle and the cell, p represents the number of circles with the length of the cell where the obstacle is located as the radius that overlap with each cell; Represents the radius of the guiding effect, S k The representative radius is The circle of the guide is the overlapping area with the cell, q represents the number of circles with the length of the cell where the guide is located as the radius that overlaps with each cell; a f represents the shortest distance between the lowest floor or stairs and the exit, n represents the number of spheres on the inclined floor or stairs that overlap with the three-dimensional cell, V f Represents radius a f The overlapping volume of the sphere and the three-dimensional cell space; Step 2: Set the dynamic floor field value; Dynamic floor field value D uv It is related to the number of people around the evacuated pedestrians at time t, the diffusion coefficient and attenuation coefficient of the dynamic floor field value; assuming that the pedestrian is in the cellular space at position (u, v) at time t, in order to ensure that the direction of pedestrian movement is minimally disturbed, it is stipulated that the pedestrian chooses four adjacent directions to move, and the dynamic field calculation formula is as follows: Where D uv t , D uv t-1 They represent the dynamic field values ​​of the cell (u, v) at time t and t-1, respectively, α is the diffusion coefficient of the dynamic floor field, and β is the attenuation coefficient of the dynamic floor field; Step 3: Introduce the constraint factor γ to establish a multi-evacuation factor non-uniform floor field model for quantifying the evacuation efficiency of personnel; the details are as follows: Among them, P uv is the pedestrian movement probability, N is the normalization factor, when ξ uv = 1, indicating that the cell (u, v) is occupied by pedestrians; when ξ uv = 0, indicating that the cell (u, v) is not occupied by pedestrians; Step 4: Under the given personnel emergency evacuation scenario conditions, determine the relevant input parameters according to the multi-evacuation factor non-uniform floor field model, implement emergency evacuation simulation, and analyze the evacuation effect.

2. The emergency evacuation simulation method based on the multi-evacuation factor non-uniform floor field model according to claim 1 is characterized in that: The cells of the multi-evacuation factor non-uniform floor field model are square and have the same width.

3. The emergency evacuation simulation method based on the multi-evacuation factor non-uniform floor field model according to claim 1 is characterized in that: Obstacles hinder the evacuation of personnel, and the static floor field value of the cell affected by the obstacles increases.

4. The emergency evacuation simulation method based on the multi-evacuation factor non-uniform floor field model according to claim 1 is characterized in that: The role of guiding personnel has a promoting effect on the evacuation process, and the static floor field value of the cell affected by the guiding personnel factor is reduced.

5. The emergency evacuation simulation method based on the multi-evacuation factor non-uniform floor field model according to claim 1 is characterized in that: In the inclined ground or stair scene, the stairs are divided into equal-volume cubic cells with equal side lengths based on the number of steps and the width of the stairs. A sphere is drawn with the midpoint of the side of the three-dimensional cell space closest to the bottom exit as the sphere center and an integer multiple of the exit width as the radius. The sum of the overlapping volume of each sphere and the three-dimensional cell space and the product of the volume of each sphere is recorded as the field value of the three-dimensional cell.

6. The emergency evacuation simulation method based on the multi-evacuation factor non-uniform floor field model according to claim 1 is characterized in that: The attractiveness of the exit to people will cause pedestrians to evacuate to the exit, resulting in changes in the interaction between people. The interaction between people will also change the attractiveness of the exit to people. The constraint factor γ is used to represent the correlation between the influencing factors of the dynamic floor field value and the static floor field value. γ is a dimensionless number with a value range of [0,1].

7. The emergency evacuation simulation method based on the multi-evacuation factor non-uniform floor field model according to claim 1 is characterized in that: For the set emergency evacuation scenario of personnel, the multi-evacuation factor non-uniform floor field model is used to determine the relevant input parameter values, implement emergency evacuation simulation, and obtain the emergency evacuation distance, path and time and other element information.

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