Mine underground roadway fire escape simulation method

Abstract

The application provides a mine underground roadway fire hazard simulation method, steps comprising: importing an underground roadway three-dimensional model into Unity software, building a three-dimensional scene in the Unity software; preparing a prefabricated body for dynamically generating objects, instantiating a personnel prefabricated body or a flame prefabricated body; simulating a smoke diffusion process; baking a navigation mesh, and enabling the personnel prefabricated body to walk on the navigation mesh; dynamically adjusting an escape route, and enabling the personnel to navigate and move according to the escape route; according to wind path navigation calculation, drawing a line segment indicating a wind path, performing ray detection on the line segment, comparing a ray direction with an attribute of a smoke object, and according to a comparison result, destroying or accelerating smoke diffusion. The method can specify personnel distribution and a fire starting position, plan an optimal escape path between each personnel position and each escape exit by comprehensively considering various factors, simultaneously, simulate a smoke diffusion process in real time, and recompute and adjust an escape path of each personnel of each mining level in real time.

Description

Technical Field

[0001] This invention belongs to the field of underground mine disaster prevention technology, specifically a method for simulating fire avoidance in underground mine roadways. Background Technology

[0002] Underground mine tunnels are complex, making it difficult to quickly plan the optimal escape route after a fire. Existing simulation software primarily focuses on escape drills, using VR or first-person perspectives to simulate fires at fixed locations. The drills involve autonomously executing standardized emergency actions step-by-step based on UI prompts, such as correctly donning protective gear, using fire extinguishers, and operating alarm devices or closing valves. While this method emphasizes standardized procedures and is generally applicable, it only simulates fires in fixed locations. It lacks flexibility for different personnel distributions and fire origin locations, and cannot plan escape routes for all personnel in specific mines with unique underground tunnel layouts and potential fire locations. Summary of the Invention

[0003] To overcome the shortcomings of existing simulation software in planning escape routes for all personnel in specific mine underground roadways and potential fire locations, this invention provides a mine underground roadway fire avoidance simulation method. This method allows for the specification of personnel distribution and fire location, and the planning of the optimal escape path from each personnel location to each escape exit by integrating multiple factors. Simultaneously, it simulates the smoke diffusion process in real time, and then recalculates and adjusts the escape path for each personnel at each mining level in real time.

[0004] The technical solution adopted by this invention to solve its technical problem is as follows:

[0005] A method for simulating fire avoidance in underground mine roadways, comprising the following steps:

[0006] Create a 3D model of the underground tunnel and import it into Unity software to build a 3D scene.

[0007] Create prefabricated bodies for dynamically generating objects, the prefabricated bodies including personnel prefabricated bodies, flame prefabricated bodies, smoke prefabricated bodies, and fan model prefabricated bodies;

[0008] Generate personnel and flames: A ray is emitted from the camera toward the mouse position, and personnel or flame prefabs are instantiated at the points where the ray collides with the 3D model of the alleyway in the 3D scene.

[0009] Simulate the smoke diffusion process;

[0010] Baking the navigation grid and enabling personnel prefabs to walk on it;

[0011] Intelligent pathfinding for personnel: dynamically adjusts escape routes, allowing personnel to navigate and move according to these routes;

[0012] Wind and Smoke Interaction: Based on wind path navigation calculations, draw line segments to indicate the wind path, perform ray detection on the line segments and compare the ray direction with the attributes of the smoke object, and destroy or accelerate the smoke diffusion based on the comparison results.

[0013] Based on the above scheme, the dynamic generation of prefabricated structures allows for the real-time generation of objects such as personnel, flames, and smoke in the simulation, enhancing its realism. Simulating the smoke diffusion process provides a better understanding of fire spread, aiding in the development of more effective escape strategies. Baking the navigation grid and employing intelligent pathfinding algorithms enables personnel prefabricated structures to walk on the grid and navigate according to escape routes. Calculating airflow paths, drawing line segments, and using ray detection achieves interactive effects between wind and smoke, helping to determine the direction of smoke diffusion. This method for simulating fire avoidance in underground mine roadways provides a more realistic and visualized fire simulation, helping to better understand fire spread and develop effective escape strategies.

[0014] Furthermore, the method for creating the wind turbine model prefabricated body is as follows: obtain the wind turbine equipment model using modeling software, load the wind turbine equipment model in Unity software and render it, add a script and specify the collision range of the wind turbine equipment model, add two empty objects to the wind turbine equipment model as wind path position markers, and add Transform components to the two empty objects to obtain the wind turbine model prefabricated body; then, instantiate the wind turbine model prefabricated body as an object in the 3D scene according to the position of the wind turbine in the alley.

[0015] Furthermore, the method for creating the personnel prefab is as follows: obtain the worker model using modeling software, create the worker information visualization primitive prefab in the Unity software editor, load the worker model in Unity software, render the worker model, add a script and specify the collision range of the worker model, add navigation and movement functions to the worker model, and add the worker information visualization primitive prefab as a child object under the worker model to complete the creation of the personnel prefab.

[0016] Furthermore, the method for creating the flame prefab is as follows: create an empty object in Unity software, add particle effects to it, adjust the particle-related parameters to achieve the flame effect, and add a navigation mesh obstacle to the object.

[0017] Furthermore, the method for creating the smoke prefab is as follows: create an empty object in Unity software, add particle effects to it, adjust the particle-related parameters to achieve the smoke effect, add navigation mesh obstacles to the object, and add a script to the object to control the diffusion behavior of the smoke.

[0018] Furthermore, the simulated smoke diffusion process is specifically as follows: triggered from the center of the flame, fixed-length line segments are launched in eight horizontal directions. The collision between each line segment and the three-dimensional model of the tunnel is determined by ray detection. If there is no collision, a new smoke preform is generated at the end of the line segment. When the new smoke preform is generated, the direction vector from the previous generation point to the current generation point is recorded as the smoke diffusion direction. Then, line segments in eight directions are launched from the current generation point to repeat the above detection and generation steps to realize the simulation of the smoke diffusion process.

[0019] Furthermore, the baking navigation mesh specifically involves: adding a MeshCollider component to the 3D model of the alleyway and performing a Bake operation in the Navigation panel to generate a navigation mesh; adding a NavMeshAgent component to the personnel prefab to enable it to walk on the navigation mesh, and setting its walkable navigation layer.

[0020] Furthermore, the wind and smoke interaction specifically involves the following: During the execution of the 3D scene, wind is generated at the intersection of the intake shaft and each horizontal tunnel, and behind each fan. The wind is used to navigate to the outlet shaft and each horizontal intersection point via the fans, but it does not navigate to move. After obtaining each navigation path point, a graphic is drawn along these points to indicate the wind path. Starting from each navigation path point, a line segment is drawn towards its next point and ray detection is performed. If the line segment collides with and detects a smoke object, the ray direction is compared with the diffusion direction attribute of the smoke object. If they are opposite, the smoke object is destroyed; if they are in the same direction, the smoke diffusion speed is increased.

[0021] The beneficial effects of this invention include:

[0022] By creating 3D models of underground mine tunnels and building 3D scenes using Unity software, a realistic simulation of the fire escape process in mine tunnels can be achieved. Simulating the smoke diffusion process allows for a better understanding of smoke propagation patterns within the tunnels, helping to guide personnel escape actions during fires and improve escape efficiency. The navigation mesh and personnel prefab navigation functions enable intelligent pathfinding in fire scenarios, providing guidance for escape routes. Simulating wind and smoke interaction provides a better understanding of the impact of wind on smoke diffusion, helping to guide personnel in choosing escape routes and avoiding smoke-filled areas. Based on these solutions, a realistic and dynamic simulation environment for fire escape in underground mine tunnels can be provided, helping to improve fire escape awareness and response capabilities, and increasing escape efficiency and success rates. Attached Figure Description

[0023] Figure 1 This is a schematic diagram illustrating the smoke diffusion process simulated by this method;

[0024] Figure 2 This is a schematic diagram of the baking navigation grid for this method;

[0025] Figure 3 This is a schematic diagram of intelligent pathfinding for personnel using this method. Detailed Implementation

[0026] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] This invention provides a method for simulating fire avoidance in underground mine roadways, comprising:

[0029] 1. Underground tunnel modeling: Import the dwg format tunnel centerline drawing and tunnel cross-section drawing into 3ds Max software, and generate an FBX format 3D model of the underground tunnel using the lofting command.

[0030] 2. 3D Scene Construction: Import the 3D model file of the underground tunnel into Unity software, create a new scene in Unity software, drag the model file into the scene, apply textures to different positions of the 3D model of the underground tunnel, and, according to display needs, shift the overlapping horizontal tunnels to separate them.

[0031] 3. Create prefabricated objects for dynamic object generation, including personnel prefabricated objects, flame prefabricated objects, smoke prefabricated objects, and fan model prefabricated objects.

[0032] 4. Click to generate personnel and flames: When the left mouse button is clicked, a ray is emitted from the camera to the mouse position, and personnel or flame prefabs are instantiated at the point where the ray collides with the alleyway model in the scene.

[0033] 5. Simulate the smoke diffusion process: Triggered from the center of the flame, fixed-length line segments are launched in eight horizontal directions. The collision between each line segment and the tunnel model is determined by ray detection. If there is no collision, a new smoke preform is generated at the end of the line segment. When a new smoke is generated, the direction vector from the previous generation point to the current generation point is recorded as the smoke diffusion direction. Then, line segments in eight directions are launched from the current generation point to repeat the above detection and generation steps to realize the simulation of the smoke diffusion process.

[0034] 6. Baking the Navigation Mesh: Add a MeshCollider component to the 3D model of the underground tunnel and perform a Bake operation in the Navigation panel to generate the navigation mesh. Add a NavMeshAgent component to the personnel prefab to enable it to walk on the navigation mesh and set its walkable navigation layer.

[0035] 7. Intelligent Personnel Pathfinding Function: Personnel monitor fire events. After a fire breaks out, personnel calculate their distance to each escape exit along the navigation grid every 2 seconds, selecting the shortest path as their escape target and navigating accordingly. The NavMeshObstacle component of smoke instances alters the navigation grid, affecting the accessibility of the current escape path and thus changing the result of the next path calculation, dynamically adjusting the escape path. Smoke diffusion and continuous personnel path calculation are synchronized, enabling dynamic adjustment of escape routes. When all escape routes are obscured by smoke, the accessibility level of the personnel's NavMeshAgent component is changed to replan the escape path according to a new rule that ignores smoke obstruction. Simultaneously, the personnel begin consuming their breathing apparatus reserves, which are displayed in real-time in the UI.

[0036] 8. Smoke and Air Interaction Function: During scene execution, wind is generated at the intersection of the intake shaft and each horizontal tunnel, and behind each fan. The wind is used to navigate to the outlet shaft and each horizontal intersection point via the fans (but does not navigate to move). After obtaining each navigation path point, a graphic is drawn along these points to indicate the wind path. Starting from each navigation point, a line segment is drawn to the next point and ray detection is performed. If the line segment collides with and detects a smoke object, the ray direction is compared with the diffusion direction attribute of the smoke object. If they are opposite, the smoke object is destroyed; if they are in the same direction, the smoke diffusion speed is increased.

[0037] Example 1

[0038] Modeling of S1 underground tunnel:

[0039] S11 creates a three-dimensional model of the underground tunnel by importing the dwg format tunnel centerline design drawings and tunnel cross-section design drawings into 3DS Max software. The three-dimensional model includes ramps, tunnels, main shafts, auxiliary shafts, intake shafts, exhaust shafts, and transport horizontal tracks.

[0040] S12 loads a 3D model of the underground tunnel in Unity, renders the 3D model, opens relevant properties of the 3D model by adding scripts, obtains a 3D model prefab of the underground tunnel, and adds a MeshCollider component to the 3D model prefab of the underground tunnel.

[0041] In the Unity editor, S13 instantiates a 3D model prefab of the underground tunnel as a tunnel model object. The tunnel model object is then moved so that its center point coincides with the origin of the 3D scene, serving as the base map for the 3D scene. Empty objects and labels are added at the entrances of the ramps and the connection points between the main shaft and each horizontal shaft in the 3D scene to record the location information of these escape points.

[0042] S2 creates prefabs for dynamically generating objects:

[0043] S21 uses the modeling software 3DS MAX to create models based on the characteristics of the wind turbine equipment and operators, resulting in wind turbine equipment models and operator models.

[0044] S22 loads the wind turbine equipment model in Unity, renders the wind turbine equipment model, opens the relevant properties of the wind turbine equipment model by adding a script, specifies the collision range of the model by adding a BoxCollier component, adds empty child objects named WindIn and WindOut to the wind turbine equipment model as wind path position markers, and adds Transform components to the two child objects to obtain the wind turbine model prefab.

[0045] In the 3D scene, S23 instantiates the fan model prefab as a fan equipment object based on the position of the fans in the alley at each production level.

[0046] In the Unity editor, S24 creates a prefab for visualizing worker information. The visual content includes a display panel for worker information and multiple attribute text components.

[0047] S25 loads the worker model in Unity, renders the worker model, opens the relevant properties of the worker model by adding scripts, specifies the collision range of the model by adding the CapsuleCollider component, adds the NavMeshAgent component to the worker model to add navigation and movement functions, adds a worker information visualization primitive prefab as a child object under the worker model, configures fields according to the visualization effect, and visualizes the worker information to complete the production of the worker prefab.

[0048] In Unity, create an empty object named Fire, add the ParticleSystem component to it, and adjust the particle's texture, color, emission speed, emission amount, duration, and other parameters to achieve a fire effect. Then, add the NavMeshObstacle component to the object so that it can block the movement of navigation objects in the navigation mesh.

[0049] In Unity, create an empty object named Smoke, add the ParticleSystem component to it, and adjust the particle texture, color, emission speed, emission amount, and duration to achieve a smoke effect. Add a NavMeshObstacle component to this object so it can block the movement of navigation objects within the navigation mesh. Add a script named Smoke to the Smoke object to control the smoke's diffusion behavior.

[0050] The steps for generating S3 wind, fire, and smoke:

[0051] S31 wind formation

[0052] In the pre-created 3D scene in Unity, add an empty object named LevelWindIn at the junction of the air intake shaft and each horizontal aisle, and add a Transform component to this object to obtain its position coordinates, which will serve as the main air intake position identifier for each horizontal aisle; add an empty object named LevelWindOut at the junction of the return air shaft and each horizontal aisle, and add a Transform component to this object to obtain its position coordinates, which will serve as the main return air position identifier for each horizontal aisle; and add an empty object named WindPoint at each of the main air paths within each horizontal aisle to represent the path points that the wind must pass through.

[0053] S312 takes a horizontal tunnel as an example. An empty object named WindCreator is created under the horizontal tunnel model object. A Line Renderer component is added to it, and the properties of the Line Renderer component are adjusted, setting the wind's display color, width, length, and texture appearance. The LineRenderer component is obtained through a script, and the aforementioned LevelWindIn, WindPoint, and WindPoint objects are also obtained and saved. A NavMeshAgent component is added to each object. The agent.CalculatePath method is used to calculate the navigation paths and path points (path.corners) between LevelWindIn and each WindPoint, between each WindPoint and LevelWindOut, and between LevelWindIn and LevelWindOut. These path points are then set to the keypoint properties of the LineRenderer component using the LineRenderer.SetPosition method, thus realizing the drawing of the wind path. After setting, the main wind path between the intake and return air shafts in this horizontal tunnel is generated.

[0054] S32 Flame and Smoke Generation

[0055] To simulate fires at any location and allow users to generate flames in real time at the mouse click location, the S321 uses the Resources.Load() method to dynamically load flame prefabs. After the flames are generated, particle effects are automatically played, and the navigation grid can be blocked, allowing personnel to actively bypass this area when calculating escape routes.

[0056] When the user clicks the left mouse button, the Physics.Raycast() method provided by the Unity physics engine is called to emit a ray from the camera to the mouse position. At the point where the ray collides with the alleyway model in the 3D scene, an instance of a Fire and an instance of a Smoke prefab are instantiated.

[0057] S4 simulates smoke diffusion

[0058] Once the S41 Smoke object is created in the scene, its Smoke script component begins to run. It first obtains the Smoke prefab through the Resources.Load() method, which is used for the subsequent generation of the smoke object.

[0059] The S42 program starts a coroutine that runs the Spread() method at specified time intervals. This method starts at the location of the Smoke object and emits detection segments, each 5m long, in eight horizontal directions at 45° intervals, performing collision detection on each segment. The 5m length of the detection segments is taken as the width of the tunnel.

[0060] S43 If no collision occurs with the detection line segment, launch a 4m long ground detection line downwards from the end of the detection line segment. If the ground detection line collides with the tunnel model, it means that the end of the detection line is located inside the tunnel. Record this point and generate an instance of the prefab Smoke 1.5m above this point.

[0061] While generating smoke instances, S44 saves the direction vector smokeDir from the start position to the end position of the detection line in Vector3 format. This attribute records the direction of smoke generation.

[0062] If S45 detects a collision between a line segment and the colliding object is a tunnel model, it means that the front is a tunnel wall or end, not a tunnel passage, and a Smoke instance is not created at the collision point.

[0063] S46 further considers the situation where there are ups and downs in the tunnel. When the detection ray collides with the tunnel model, it may collide with the tunnel floor or top surface of the slope. In this case, smoke should continue to be generated along the slope direction. Therefore, when the detection ray collides with the tunnel model, a longitudinal detection line with a length of half the tunnel height is created upwards and downwards from the collision point.

[0064] S47 If only the upward detection line collides with the roadway model, while the downward detection line does not, it is determined to be an uphill slope; if only the downward detection line collides with the roadway model, while the upward detection line does not, it is determined to be a downhill slope; if both the upward and downward detection lines collide, the distance between the collision points is further determined. If the collision point of the upward detection line is farther away, it is determined to be an uphill slope; otherwise, it is determined to be a downhill slope.

[0065] If the road ahead is uphill, create smoke 1.5m above the point where the horizontal detection line collides with the roadway model (ground); if the road ahead is downhill, create smoke 3m below the point where the horizontal detection line collides with the roadway model (ground). The height of the smoke position depends on the height of the roadway.

[0066] When a new Smoke instance is created, the Smoke script attached to the new instance runs, repeating the above detection process to achieve the effect of continuous smoke diffusion along the alley.

[0067] To avoid system resource consumption and performance lag when there are too many smoke instances, the S410 uses a script to centrally hold all newly generated Smoke objects. When the number of smoke instances exceeds 100, it reclaims even-numbered instances in an object pool according to the order in which the smoke was generated and then reorders them. This releases system resources without affecting the observation of the distribution of smoke in the alley.

[0068] Implementation of S5 Smoke Interaction Function

[0069] S51 starts from each path point (path.corners) saved in the Wind object script and emits detection lines to its next path point using the Physics.Raycast method. Simultaneously, it saves the direction vector `windDir` from the start to the end point of the detection line in Vector3 format; this attribute records the wind generation direction. If the detection line collides with a smoke object, it calculates the angle between `winDir` and `smokeDir`. If this angle is greater than 120°, it indicates that the wind direction is opposite to the smoke direction, and the smoke object is destroyed, achieving the effect of no smoke diffusion in the upwind direction.

[0070] S6 Intelligent Personnel Navigation Function

[0071] S61 adds a MeshCollider component to the alleyway model and performs a Bake operation in the Navigation panel to generate a navigation mesh.

[0072] S62 adds the NavMeshAgent component to the personnel prefab, enabling it to walk on the navigation mesh, and sets the navigation layer it can walk on.

[0073] When the user clicks the mouse and generates a flame, the S63 script broadcasts a fire event to all personnel instances. The personnel instances respond to the fire event and use the NavMeshAgent.SetDestination() method in Unity's NavMesh algorithm to calculate the navigation paths to various escape exits, such as the ramp exit and the cage entrance at the current level.

[0074] S64 compares the lengths of each navigation path and selects the shortest, passable path as the optimal route. Personnel then navigate along this route. If all paths are impassable, the shortest path is selected as the optimal route, personnel wear self-contained breathing apparatus (SCBA), and the SCBA's remaining energy timer begins.

[0075] The S65 displays each person's current escape goal, path length, and remaining air respirator capacity on the personnel UI panel.

[0076] S66 uses the LineRender component to draw and display the escape path of personnel in the scene.

[0077] This method uses 3D modeling based on underground tunnel design drawings to recreate the real-world scene of each mine. Operators can specify personnel distribution and fire location. After a fire starts, the software comprehensively analyzes path distance, path safety, and remaining air respirator capacity from each personnel location to each escape exit to plan the optimal escape route. Simultaneously, it simulates the smoke diffusion process in real time, taking into account the impact of wind direction and tunnel distribution on fire changes. The escape routes for each person at each mining level are then recalculated and adjusted in real time. It has the following advantages:

[0078] 1. Realistically recreate the distribution of underground tunnels in a specific mine;

[0079] 2. Allows users to specify (or batch import from documents) personnel work locations, fan locations, and ignition points;

[0080] 3. Plan the escape route by comprehensively considering factors such as the length of the escape path, whether it passes through smoke, and the remaining capacity of the air respirator;

[0081] 4. The smoke diffusion process can be simulated by combining the distribution of alleyways and the influence of wind direction, and the escape route of each person can be updated in real time accordingly;

[0082] 5. It can display in real time information such as the current escape target, path length, remaining breathing apparatus capacity, and whether there is a possibility of escape for each worker, as well as statistical information such as the total number of people underground, the number of people who are safe, and the number of people who are trying to escape.

[0083] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A mine underground roadway fire refuge simulation method, its characteristic steps are include: Create a 3D model of the underground tunnel and import it into Unity software to build a 3D scene. Create prefabricated bodies for dynamically generating objects, the prefabricated bodies including personnel prefabricated bodies, flame prefabricated bodies, smoke prefabricated bodies, and fan model prefabricated bodies; Generate personnel and flames: A ray is emitted from the camera toward the mouse position, and personnel or flame prefabs are instantiated at the points where the ray collides with the 3D model of the alleyway in the 3D scene. Simulate the smoke diffusion process; Baking the navigation grid and enabling personnel prefabs to walk on it; Intelligent pathfinding for personnel: dynamically adjusts escape routes, allowing personnel to navigate and move according to these routes; Wind and Smoke Interaction: Based on wind path navigation calculations, draw line segments to indicate the wind path, perform ray detection on the line segments and compare the ray direction with the attributes of the smoke object, and destroy or accelerate the smoke diffusion based on the comparison results; The wind and smoke interaction is as follows: During the execution of the three-dimensional scene, wind is generated at the intersection of the air intake shaft and each horizontal tunnel, and behind each fan. The wind is used to navigate to the air outlet shaft and each horizontal intersection point via the fans, but it does not navigate to move. After obtaining each navigation path point, a graphic is drawn along these points to indicate the wind path. Starting from each navigation path point, a line segment is drawn to the next point and ray detection is performed. If the line segment collides with and detects a smoke object, the ray direction is compared with the diffusion direction attribute of the smoke object. If they are opposite, the smoke object is destroyed; if they are in the same direction, the smoke diffusion speed is increased.

2. The method for simulating fire avoidance in underground mine roadways according to claim 1, characterized in that, The method for creating the prefabricated wind turbine model is as follows: a wind turbine equipment model is obtained using modeling software, the wind turbine equipment model is loaded and rendered in Unity software, a script is added and the collision range of the wind turbine equipment model is specified, two empty objects are added to the wind turbine equipment model as wind path location markers, and Transform components are added to the two empty objects to obtain the prefabricated wind turbine model; then, the prefabricated wind turbine model is instantiated as an object in the 3D scene according to the position of the wind turbine in the alley.

3. The method for simulating fire avoidance in underground mine roadways according to claim 1, characterized in that, The method for creating the personnel prefab is as follows: obtain the worker model using modeling software, create the worker information visualization primitive prefab in the Unity software editor, load the worker model in Unity software, render the worker model, add a script and specify the collision range of the worker model, add navigation and movement functions to the worker model, and add the worker information visualization primitive prefab as a child object under the worker model to complete the creation of the personnel prefab.

4. The method for simulating fire avoidance in underground mine roadways according to claim 1, characterized in that, The method for creating the flame prefab is as follows: create an empty object in Unity software, add particle effects to it, adjust the particle-related parameters to achieve the flame effect, and add a navigation mesh obstacle to the object.

5. The method for simulating fire avoidance in underground mine roadways according to claim 1, characterized in that, The method for creating the smoke prefab is as follows: create an empty object in Unity software, add particle effects to it, adjust the particle-related parameters to achieve the smoke effect, add navigation mesh obstacles to the object, and add a script to the object to control the diffusion behavior of the smoke.

6. The method for simulating fire avoidance in underground mine roadways according to claim 1 or 5, characterized in that, The simulated smoke diffusion process is as follows: triggered from the center of the flame, fixed-length line segments are launched in eight horizontal directions. The collision between each line segment and the three-dimensional model of the tunnel is determined by ray detection. If there is no collision, a new smoke preform is generated at the end of the line segment. When the new smoke preform is generated, the direction vector from the previous generation point to the current generation point is recorded as the smoke diffusion direction. Then, line segments in eight directions are launched from the current generation point to repeat the above detection and generation steps to realize the simulation of the smoke diffusion process.

7. The method for simulating fire avoidance in underground mine roadways according to claim 1, characterized in that, The baking navigation mesh is specifically achieved by: adding a MeshCollider component to the 3D model of the tunnel and performing a Bake operation in the Navigation panel to generate the navigation mesh; adding a NavMeshAgent component to the personnel prefab to enable it to walk on the navigation mesh, and setting the navigation layer that it can walk on.

Images