A method and system for simulating emergency evacuation

Abstract

The invention relates to the technical field of emergency evacuation, and in particular discloses an emergency risk avoidance evacuation simulation method and system. In this scheme, car sensitivity is introduced when calculating the car evacuation speed, and the car acceleration and car deceleration are determined by using the car sensitivity, taking into account the situation that the driver's perception reaction time is shorter than usual in an emergency situation, thereby more realistically simulating the driving behavior and vehicle movement in an emergency situation; after the evacuation data, the proportion of evacuation transportation modes, the speed of the evacuation transportation mode, the car acceleration, and the car deceleration are input into the evacuation model, the refuge routes of the affected people can be simulated in real time, and the number of people who have arrived at the refuge point at each moment and the evacuation rate are provided, which is helpful for the emergency management department to better make emergency refuge arrangements and reduce the loss of people and property caused by disasters.

Description

Technical Field

[0001] The present invention relates to the technical field of emergency evacuation, and in particular to an emergency risk avoidance evacuation simulation method and system. Background Art

[0002] Against the backdrop of global warming, natural disasters such as floods, landslides, and mudslides are increasing. When a disaster occurs, whether the affected people can reach the shelter in time is a key concern.

[0003] In traditional technology, emergency evacuation models may pay more attention to the final result, while ignoring the specific location of the evacuees at each moment and the number of evacuees and the evacuation rate at the current moment. For emergency evacuation, the time required for the victims to reach the shelter is crucial. In the existing technology, there is a problem of insufficient consideration of the evacuation speed of the victims, that is, when evacuating by car, in an emergency, the perception reaction time is shorter than usual, and the evacuation speed is also different from usual. Therefore, it is not realistic to simulate the evacuation speed of an emergency only by using the car speed in normal conditions.

[0004] Therefore, it is of great significance to study an emergency evacuation simulation method and system that can truly and real-time simulate the evacuation situation. Summary of the invention

[0005] The purpose of the present invention is to provide an emergency evacuation simulation method and system to solve the problem that the existing emergency evacuation simulation method is not realistic enough.

[0006] In order to solve the above technical problems, in a first technical solution, the present invention provides an emergency evacuation simulation method, comprising the following steps:

[0007] Obtain evacuation data;

[0008] Constructing evacuation models;

[0009] Determine the proportion of crowd evacuation methods and the speed of crowd evacuation methods according to the evacuation data, wherein the crowd evacuation methods at least include car evacuation;

[0010] Determine the vehicle sensitivity according to the vehicle following model, and determine the vehicle acceleration and the vehicle deceleration based on the vehicle sensitivity;

[0011] The evacuation data, the proportion of the crowd evacuation method, the speed of the crowd evacuation method, the car acceleration, and the car deceleration are input into the evacuation model to obtain a simulation result.

[0012] In some embodiments of the first technical solution, in the step of determining the vehicle sensitivity according to the vehicle following model, and determining the vehicle acceleration and the vehicle deceleration based on the vehicle sensitivity, the following steps are included:

[0013] Substituting the boundary condition state into the car following model to obtain a sensitivity function;

[0014] Determining the vehicle sensitivity according to a sensitivity function;

[0015] Determining a range of speed change rate according to the vehicle sensitivity;

[0016] The acceleration and deceleration are determined based on the maximum value of the range of speed change rates.

[0017] In some embodiments of the first technical solution, the boundary condition state includes a blocked state and a free flow state.

[0018] In some embodiments of the first technical solution, the sensitivity function is:

[0019]

[0020] In the above formula, V f is the maximum speed during evacuation; K j is the blocking density.

[0021] In some embodiments of the first technical solution, the crowd evacuation method also includes walking.

[0022] In some embodiments of the first technical solution, the walking evacuation method also includes horizontal evacuation walking and vertical evacuation walking; the car evacuation method also includes horizontal evacuation driving and vertical evacuation driving.

[0023] In some embodiments of the first technical solution, the evacuation data includes personnel distribution data, road distribution data and shelter distribution data.

[0024] In some embodiments of the first technical solution, the evacuation data also includes parameters of the shortest time required for evacuees to prepare and the distribution of evacuation time.

[0025] In the second technical solution, the present invention provides an emergency evacuation simulation system, comprising:

[0026] Construction module, used to build evacuation models;

[0027] An acquisition module, used to acquire evacuation data;

[0028] A first calculation module is used to determine the proportion of crowd evacuation methods and the speed of crowd evacuation methods according to the evacuation data, wherein the crowd evacuation methods at least include car evacuation;

[0029] A second calculation module is used to determine the vehicle sensitivity according to the vehicle following model, and determine the vehicle acceleration and the vehicle deceleration based on the vehicle sensitivity;

[0030] The third calculation module is used to input the evacuation data, the proportion of the crowd evacuation method, the speed of the crowd evacuation method, the car acceleration, and the car deceleration into the evacuation model to obtain a simulation result.

[0031] The beneficial effects of the present invention are as follows:

[0032] Since this solution introduces vehicle sensitivity when calculating the vehicle evacuation speed, and uses vehicle sensitivity to determine vehicle acceleration and deceleration, it takes into account the situation that the driver's perception reaction time is shorter than usual in an emergency, thereby more realistically simulating driving behavior and vehicle movement in an emergency; after inputting evacuation data, the proportion of evacuation transportation modes, the speed of evacuation transportation modes, vehicle acceleration, and vehicle deceleration into the evacuation model, the evacuation routes of the affected people can be simulated in real time, and the number of people who have arrived at the refuge point and the evacuation rate at each moment can be provided, which will help emergency management departments to better make emergency refuge arrangements and reduce the loss of life and property caused by disasters. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 It is a schematic diagram of the overall steps provided by the preferred embodiment of the present invention;

[0035] Figure 2 It is an ArcGIS preliminary data map provided by a preferred embodiment of the present invention;

[0036] Figure 3 is a NetLogo parameter setting diagram provided by a preferred embodiment of the present invention;

[0037] Figure 4 is a graph showing changes in evacuation rate over time obtained by simulation in a preferred embodiment of the present invention;

[0038] Figure 5 It is a histogram of evacuation time distribution obtained by simulation in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0040] In order to solve the above problems, this solution provides an emergency evacuation simulation method, please refer to Figure 1 , specifically including the following steps:

[0041] S1, obtaining evacuation data, wherein the evacuation data includes personnel distribution data, road distribution data, shelter distribution data and field survey data. After these parameters are collected, these parameters can be used as construction environment parameters of the Netlogo model.

[0042] Preferably, step S1 comprises the following steps:

[0043] S10. Conduct field surveys on the distribution of permanent residents in the research area and produce the corresponding shp file;

[0044] S11. Use satellite maps and other means to observe the road network in the study area and produce the corresponding shp file;

[0045] S12. Field survey the location of shelters in the study area and produce the corresponding shp file;

[0046] S13. Conduct a field survey on the number of people and vehicles in the study area to determine the proportion of evacuation methods later.

[0047] like Figure 2 As shown in the figure, this is a preliminary data map prepared on ArcGIS software, in which dark small dots represent disaster victims, lines represent road networks, and light large dots represent shelters.

[0048] S2, according to the evacuation data, determines the proportion of crowd evacuation methods and the speed of crowd evacuation methods. Crowd evacuation methods include at least car evacuation and walking evacuation. After adopting this setting method, the evacuation methods of evacuees at each moment can be paid attention to, and the time required for the affected people to reach the shelter can be paid attention to in time, so as to reflect the number of evacuees and the evacuation rate at each moment.

[0049] In this embodiment, the default walking speed during evacuation is set to 1.2 m / s (corresponding to 4 ft / s), the maximum speed of the vehicle during evacuation is 56.3 km / h (corresponding to 35 mph), and the number and proportion of evacuation methods can be adjusted according to actual conditions through field investigation.

[0050] In some embodiments of the present application, the default evacuation method for disaster-stricken people is horizontal evacuation and vertical evacuation, including horizontal evacuation walking, horizontal evacuation driving, vertical evacuation walking, and vertical evacuation driving. The respective proportions can be adjusted according to actual conditions. In this example, the preferred proportion is 25% each.

[0051] S3, determines the vehicle sensitivity according to the vehicle following model, and determines the vehicle acceleration and vehicle deceleration based on the vehicle sensitivity. After adopting this setting method, in an emergency, the perception reaction time is shorter than usual. After adding the vehicle sensitivity, it can reflect the driver's alertness and reaction level, because if the driver is aware of the upcoming threat, they tend to be more alert and reactive.

[0052] Preferably, step S3 specifically includes the following steps:

[0053] S30, substituting the boundary condition state into the vehicle following model to obtain a sensitivity function.

[0054] Specifically, the motion of the vehicle is controlled by the classic car following model, the general car model, whose equation is as follows:

[0055]

[0056] in: is the position of the leading vehicle at time t, is the speed of the leading vehicle at time t, is the position of the following vehicle at time t, is the speed of the following vehicle at time t, l is the headway index (ranging from -1 to +4), m is the speed index (ranging from -2 to +2), α l,m is the sensitivity coefficient, and δt is the perception reaction time.

[0057] Conservatively speaking, in emergency situations, the perception-reaction time is assumed to be fairly close to zero, the headway l is 2, the speed m is 0, the perception-reaction time is 0, and the following sensitivity α function is derived:

[0058]

[0059]

[0060]

[0061]

[0062] make Then we can get:

[0063]

[0064]

[0065]

[0066]

[0067]

[0068] Substituting the boundary conditions, the boundary conditions are preferably the boundary conditions of the blocked state and the free flow state, and there are:

[0069] αK j =c

[0070] c=V f

[0071]

[0072] In the above formula, V f is the maximum speed during evacuation; K j is the blocking density.

[0073] S31, determine the sensitivity of the vehicle according to the sensitivity function, that is, assume that the free flow speed V f Equal to 35 miles per hour, the congestion density K j Equal to 250vpm, the car sensitivity is as follows:

[0074]

[0075] S32, determine the range of the speed change rate according to the sensitivity of the vehicle, and obtain the following model parameter of 0.14 by assuming the movement of the simulated vehicle. The following model parameter of 0.14 will result in a speed change rate of 5 ft / s 2 Up to 10ft / s 2 On the other hand, deceleration will result in an acceleration of 10 ft / s 2 Up to 25ft / s 2 Unequal acceleration.

[0076] S33, the acceleration and deceleration are determined based on the maximum value of the range of velocity change rate. According to the literature, considering this range of acceleration and deceleration, it can well represent the empirical data. Since the acceleration and deceleration are often higher in evacuation situations, the default acceleration and deceleration are set to 5 ft / s. 2 and 25ft / s 2 .

[0077] To summarize step S3, vehicle sensitivity is introduced when calculating the vehicle evacuation speed, and the vehicle acceleration and vehicle deceleration are determined using the vehicle sensitivity, taking into account the fact that the driver's perception reaction time in an emergency is shorter than usual, thereby more realistically simulating the driving behavior and vehicle movement in an emergency.

[0078] S4, based on the field survey data, determine the shortest preparation time required for evacuees and the parameters of the evacuation time distribution. τ represents the shortest preparation time required for evacuees, and σ represents the parameters of the evacuation time distribution. They indicate that when a disaster occurs, people panic out of fear, and the crowd will be crowded and disorderly, making it impossible to go to the shelter in an orderly manner in the first place. τ and σ both obey the Rayleigh distribution. The increase of τ and σ will reduce the final number of evacuees and the evacuation rate.

[0079] S5, constructing an evacuation model. Preferably, the evacuation model preferably adopts a Netlogo model.

[0080] Among them, NetLogo is a modeling language for the general public launched by the University of Illinois at Urbana–Champaign. NetLogo can help us describe and analyze social force models in a relatively simple way, so as to help people better understand the evacuation process. The entities in NetLogo are called "agents". In NetLogo, agents can interact with other agents, such as sensing the positions of other agents and following them. Through custom functions, NetLogo can add degrees of freedom to create more realistic social scenarios; in NetLogo, in addition to setting the behavior rules of agents, you can also set initial conditions, environments, and corresponding motion rules; when agents are affected by various forces as mentioned above, NetLogo will automatically calculate the next action of each agent according to the motion rules. NetLogo provides a very simple and easy-to-use modeling language that can help us quickly create evacuation scenarios, simulate and explore, and provide a new and effective means to solve practical problems.

[0081] The permanent population distribution data, the road network of the study area, and the location of shelters are imported into NetLogo to obtain the evacuation scenario environment constructed by NetLogo.

[0082] S6, define the agents in the scene, that is, import the data of horizontal evacuation walking, horizontal evacuation driving, vertical evacuation walking, vertical evacuation driving, walking speed, normal distribution parameters related to walking speed, vehicle maximum speed, vehicle acceleration, vehicle deceleration, vehicle sensitivity, τ and σ under horizontal evacuation walking, τ and σ under horizontal evacuation driving, τ and σ under vertical evacuation walking, and τ and σ under vertical evacuation driving into the NetLogo model. After adopting this setting method, for example, each person's characteristics, position, expected acceleration to reach the target position, and interaction force with others, that is, Figure 3 The middle represents the type of parameters that need to be set, from top to bottom, respectively representing: horizontal evacuation walking, horizontal evacuation driving, vertical evacuation walking, the respective proportions of vertical evacuation driving, walking speed, normal distribution parameters related to walking speed, maximum vehicle speed, vehicle acceleration, vehicle deceleration, following model parameters, τ and σ under horizontal evacuation walking, τ and σ under horizontal evacuation driving, τ and σ under vertical evacuation walking, and τ and σ under vertical evacuation driving.

[0083] S7, after defining the scenario and agent, you can use NetLogo's simulation function to simulate and deduce. That is, after NetLogo builds the scenario environment and imports the research data, you can perform evacuation simulation. When the model simulation output is completed, you can see the specific location of the victims at every moment when they go to the shelter in real time, which is presented in the form of animation. In addition, you can also wait for the histogram of the number of evacuees, evacuation rate and evacuation time that changes over time. Figure 4 and Figure 5 This is the final result of the emergency evacuation simulation based on a certain area in a certain city. Figure 4 is the graph of evacuation rate changing over time, Figure 5 is the evacuation time distribution histogram.

[0084] Through the above steps, the present invention can simulate the real-time emergency evacuation routes of disaster victims to refuge points when a disaster occurs; on the premise that the disaster victims all go to the refuge points closest to them, the refuge routes of the disaster victims are simulated in real time, and the local government can take precautions in advance for places where congestion and chaos may occur; at the same time, it can provide the number of people who have arrived at the refuge point and the evacuation rate at each moment, which helps the emergency management department to better make emergency refuge arrangements and reduce the loss of life and property caused by disasters.

[0085] As can be seen from the above, the basic process and steps of this solution will be described below in conjunction with a specific application system. In this embodiment, an emergency evacuation simulation system is provided, including: a construction module, an acquisition module, a first calculation module, a second calculation module, and a third calculation module;

[0086] As for the building modules, the building modules are used to build the evacuation model;

[0087] As for the acquisition module, the acquisition module is used to acquire evacuation data;

[0088] For the first calculation module, the first calculation module is used to determine the proportion of crowd evacuation methods and the speed of crowd evacuation methods according to the evacuation data, and the crowd evacuation methods at least include car evacuation;

[0089] For the second calculation module, the second calculation module is used to determine the vehicle sensitivity according to the vehicle following model, and determine the vehicle acceleration and the vehicle deceleration based on the vehicle sensitivity;

[0090] As for the third calculation module, the third calculation module is used to input the evacuation data, the proportion of crowd evacuation methods, the speed of crowd evacuation methods, the acceleration of the car, and the deceleration of the car into the evacuation model to obtain the simulation results.

[0091] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An emergency evacuation simulation method, characterized in that: The following steps are involved: Obtain evacuation data; Constructing evacuation models; Determine the proportion of crowd evacuation methods and the speed of crowd evacuation methods according to the evacuation data, wherein the crowd evacuation methods at least include car evacuation; Determine the vehicle sensitivity according to the vehicle following model, and determine the vehicle acceleration and the vehicle deceleration based on the vehicle sensitivity; Inputting the evacuation data, the proportion of the crowd evacuation method, the speed of the crowd evacuation method, the car acceleration, and the car deceleration into the evacuation model to obtain a simulation result; In the step of determining the vehicle sensitivity according to the vehicle following model, and determining the vehicle acceleration and the vehicle deceleration based on the vehicle sensitivity, the following steps are included: Substituting the boundary condition state into the car following model to obtain a sensitivity function; Determining the vehicle sensitivity according to a sensitivity function; Determining a range of speed change rate according to the vehicle sensitivity; Determining acceleration and deceleration according to a maximum value of the range of speed change rates; The sensitivity function is: In the above formula, V f is the maximum speed during evacuation; K j is the blocking density; The simulation results include the number of people who have arrived at the shelter at each moment and the evacuation rate.

2. The method for simulating emergency evacuation according to claim 1, characterized in that: The boundary condition states include a blocked state and a free flow state.

3. The method for simulating emergency evacuation according to claim 1, characterized in that: The crowd evacuation method also includes walking.

4. The method for simulating emergency evacuation according to claim 3, characterized in that: The walking evacuation mode also includes horizontal evacuation walking and vertical evacuation walking; The evacuation mode of the automobile also includes horizontal evacuation driving and vertical evacuation driving.

5. The method for simulating emergency evacuation according to claim 1, characterized in that: The evacuation data includes personnel distribution data, road distribution data and shelter distribution data.

6. The method for simulating emergency evacuation according to claim 1, characterized in that: The evacuation data also includes parameters of the shortest preparation time required for evacuees and the evacuation time distribution.

7. An emergency evacuation simulation system, characterized in that: Used to execute the emergency evacuation simulation method according to claim 1, comprising: Construction module, used to build evacuation models; An acquisition module, used to acquire evacuation data; A first calculation module is used to determine the proportion of crowd evacuation methods and the speed of crowd evacuation methods according to the evacuation data, wherein the crowd evacuation methods at least include car evacuation; A second calculation module is used to determine the vehicle sensitivity according to the vehicle following model, and determine the vehicle acceleration and the vehicle deceleration based on the vehicle sensitivity; The third calculation module is used to input the evacuation data, the proportion of the crowd evacuation method, the speed of the crowd evacuation method, the car acceleration, and the car deceleration into the evacuation model to obtain a simulation result.

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