Avoidance path design method and device for low-altitude cross route

Abstract

The invention provides an evasion path design method and device for a low-altitude cross route, and the technical key points are as follows: according to the type of an aircraft and the navigational speed, dividing route planes in a layered manner, and determining the minimum sailing safety distance D of each plane; on the basis of the principle of shortest linear distance, keeping respective heading of the aircrafts unchanged before and after passing through the route intersection; in the process of passing through the air route intersection, measuring the navigational speed vector of the opposite aircraft by adopting a two-point positioning speed measurement method, and judging whether the two aircrafts have the risk of being too close to each other or colliding with each other; and if the risk of too close distance or collision exists, constructing a virtual 3D roundabout, and determining respective avoidance routes along the surface of the 3D roundabout according to the navigational speed vectors of the aircrafts.

Description

Technical Field

[0001] This application relates to the field of low-altitude transportation technology, and in particular to a method and apparatus for designing avoidance paths for low-altitude intersecting air routes. Background Technology

[0002] Low-altitude intersecting routes refer to a set of low-altitude routes that intersect at the same altitude plane. Under certain circumstances, there is a risk of aircraft being too close together or even colliding at the route intersections. Currently, to address this risk, most low-altitude aircraft adopt traditional avoidance methods based on manual commands. This involves changing flight altitude, temporarily adjusting flight paths, or coordinating speed adjustments to achieve avoidance between aircraft based on manual commands.

[0003] However, aircraft avoidance methods based on manual commands suffer from drawbacks such as low airspace utilization and high labor costs, making them difficult to fully apply to low-altitude traffic scenarios with limited airspace and complex flight conditions. Currently, research on aircraft avoidance methods adapted to low-altitude intersecting routes is relatively lacking. Summary of the Invention

[0004] Exemplary embodiments of this application provide a method and apparatus for designing obstacle avoidance paths for low-altitude intersecting routes, so as to achieve the technical effect of obstacle avoidance for aircraft without affecting traffic efficiency and maximizing the utilization of low-altitude airspace.

[0005] Exemplary embodiments of this application provide a method for designing avoidance paths for low-altitude intersecting air routes, including the following steps:

[0006] Based on the aircraft type and speed, the flight path planes are divided into layers and the minimum safe distance D0 for each plane is determined.

[0007] Based on the principle of the shortest straight distance, each aircraft maintains its own course and travels in a straight line with constant power before and after passing through the route intersection;

[0008] During the passage through the crossroads, the two-point positioning speed measurement method is used to determine the speed vector of the other aircraft and to determine whether there is a risk of the two aircraft being too close or colliding.

[0009] If there is a risk of getting too close or colliding, a virtual 3D roundabout is constructed, and the avoidance routes along the surface of the 3D roundabout are determined based on the aircraft's speed vector.

[0010] According to another aspect of this application, an optimization device based on dynamic point clouds and visually assisted loop closure, applying any of the above methods, includes:

[0011] The distance calculation module is configured to divide the flight path plane into layers based on the aircraft type and speed, and determine the minimum safe distance D0 for each plane.

[0012] The route determination and maintenance module is configured to maintain its course and travel in a straight line with constant power before and after passing through the route intersection, based on the principle of the shortest straight distance, in the absence of emergencies.

[0013] The risk assessment module is configured to use a two-point positioning speed measurement method to determine the speed vector of the other aircraft during the passage through the airway intersection, and to determine whether there is a risk of the two aircraft being too close or colliding.

[0014] The route determination module is configured to construct a virtual 3D roundabout if there is a risk of being too close or colliding, and determine the avoidance route along the surface of the 3D roundabout based on the aircraft's speed vector.

[0015] This application has the following beneficial effects:

[0016] This invention presents a path avoidance design method for low-altitude intersecting air routes that differs from traditional aviation obstacle avoidance methods based on manual commands. Its key advantage lies in its ability to achieve obstacle avoidance for aircraft without requiring manual commands or wireless communication, while maximizing low-altitude airspace utilization and maintaining traffic efficiency. This invention creatively proposes a two-point positioning and velocity measurement method to quickly obtain the heading and speed of aircraft on intersecting air routes, predicting the risk of collisions at the intersection points. It also creatively introduces the concept of a virtual 3D roundabout and designs obstacle avoidance routes for each aircraft based on this concept. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0018] Figure 1 This is a schematic diagram of the overall process of this application;

[0019] Figure 2 This is a schematic diagram of the two-point positioning speed measurement method;

[0020] Figure 3 This is a schematic diagram of an aircraft's flight path based on a virtual 3D roundabout.

[0021] Figure 4 This is a schematic diagram of the virtual 3D roundabout and avoidance route for Example 1. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] like Figures 1-2 As shown in the exemplary embodiments of this application, a method for designing avoidance paths for low-altitude intersecting air routes is provided, including the following steps:

[0024] S102, based on the type of aircraft and its speed, divide the route plane into layers and determine the minimum safe distance D0 for each plane;

[0025] S104, based on the principle of the shortest straight distance, each aircraft maintains its own course and travels in a straight line with constant power before and after passing through the route intersection;

[0026] S106, during the passage through the crossroads, the two-point positioning speed measurement method is used to determine the speed vector of the other aircraft and to determine whether there is a risk of the two aircraft being too close or colliding;

[0027] S108 If there is a risk of being too close or colliding, a virtual 3D roundabout is constructed, and the avoidance route along the surface of the 3D roundabout is determined according to the aircraft's speed vector.

[0028] It should be noted that, based on the principle of the shortest straight distance, unless there are sudden weather disasters, temporary equipment problems or other emergencies, the aircraft will always maintain constant power and travel in a straight line; all aircraft in the same airway plane will maintain their own course before and after passing through airway intersections.

[0029] In one embodiment, step S106 includes:

[0030] S1, Set the obstacle detection range for the aircraft;

[0031] S2, when aircraft A approaches the route intersection, aircraft B appears within the detection range and the position vector from A to B changes from s0=(Δx0,Δy0,0) to s1=(Δx1,Δy1,0) within the time interval Δt;

[0032] S3, Given a geographic three-dimensional coordinate system with east as the X-axis, north as the Y-axis, and above as the Z-axis, the heading deflection angle of aircraft A is α, and its speed vector is u. a =(|u a |cosα,|u a The velocity vector u of aircraft B can be measured using the two-point positioning velocity measurement method, given |sinα,0). band heading deflection angle β:

[0033]

[0034] S4, based on the speed vectors of the two aircraft, if there exists Make |s1+(u b -u a If t|≤D0, then the two aircraft are at risk of being too close to each other or colliding, and their routes need to be adjusted to avoid collision; otherwise, normal navigation is fine.

[0035] In this system, the defined geographic 3D coordinate system uses east as the X-axis, north as the Y-axis, and directly above as the Z-axis. s0 and s1 represent the position vectors from A to B in the geographic 3D coordinate system, and their values ​​are equal to the difference between the current position coordinates of B and A. Δt is the time taken for the position vector from A to B to change from s0 to s1, which is usually manually set based on the aircraft's radar detection frequency. a ,u b These are the velocity vectors of aircraft A and aircraft B in the geographic three-dimensional coordinate system, |u a |,|u b | represents the speed scalars of aircraft A and aircraft B, respectively. α and β represent the heading deflection angles of aircraft A and aircraft B, respectively, which are the degrees of counterclockwise rotation from the positive X-axis in the XY top-view plane of the geographic three-dimensional coordinate system, with values ​​ranging from [0, 2π).

[0036] refer to Figure 3 In one embodiment, S108 includes:

[0037] S1. Construct a virtual 3D roundabout with the route intersection as the center and d as the diameter, and establish a 3D roundabout spatial coordinate system with the center as the origin, east as the X-axis, north as the Y-axis, and the top as the Z-axis; where d takes a value greater than or equal to D0.

[0038] S2, the maximum relative deflection angle of the avoidance route does not exceed δ, determine the distance S from the starting point of the avoidance route to the route intersection point:

[0039]

[0040] S3, determine the avoidance routes for aircraft A and B in the 3D island-shaped spatial coordinate system:

[0041]

[0042] The route intersection point refers to the point where the trajectories of aircraft A and aircraft B intersect when they travel in a straight line along their respective predetermined headings. The maximum relative deflection angle of the avoidance route refers to the maximum angle between the aircraft's heading and the original navigation plane (the XY plane in the 3D island coordinate system) when the aircraft travels along the avoidance route. The starting points of the avoidance route refer to the coordinate points where the aircraft leaves and returns to the original route plane, respectively. (x, y, z) are the coordinate values ​​of the aircraft in the 3D island coordinate system. Aircraft A and aircraft B only need to determine their respective avoidance routes based on the magnitudes of their respective heading deflection angles α and β.

[0043] In one embodiment, the obstacle detection range of the aircraft is set to eight times the minimum safe distance for navigation, D0.

[0044] In one embodiment, step S102 includes:

[0045] S1, based on aircraft type and speed, divides the low-altitude region below 1000 meters into several flight paths, including dedicated flight paths for manned helicopters, low-to-medium speed flight paths for unmanned aerial vehicles (UAVs), high-speed flight paths for UAVs, and emergency flight paths. Using computational fluid dynamics simulation software or wind tunnel testing, the shortest distance d unaffected by airflow interference from parallel aircraft is determined. f ;

[0046] S2, calculate the emergency braking distance and the equipment reaction distance to determine the shortest distance d at which the two aircraft will not collide. v ;

[0047] S3, according to the formula D0=max{d f ,d v Determine the minimum safe distance;

[0048] Where, d f The shortest distance, unaffected by airflow interference from parallel aircraft, is determined using computational fluid dynamics simulation software or wind tunnel testing; d v It is the shortest distance at which two aircraft will not collide, including emergency braking distance and equipment reaction distance.

[0049] According to another aspect of this application, an optimization device based on dynamic point clouds and visually assisted loop closure, applying any of the above methods, includes:

[0050] The distance calculation module is configured to divide the flight path plane into layers based on the aircraft type and speed, and determine the minimum safe distance D0 for each plane.

[0051] The route determination and maintenance module is configured to maintain its course and travel in a straight line with constant power before and after passing through the route intersection, based on the principle of the shortest straight distance, in the absence of emergencies.

[0052] The risk assessment module is configured to use a two-point positioning speed measurement method to determine the speed vector of the other aircraft during the passage through the airway intersection, and to determine whether there is a risk of the two aircraft being too close or colliding.

[0053] The route determination module is configured to construct a virtual 3D roundabout if there is a risk of being too close or colliding, and determine the avoidance route along the surface of the 3D roundabout based on the aircraft's speed vector.

[0054] refer to Figure 4 The following example will illustrate this point.

[0055] A certain consumer-grade drone has an average speed of 70 km / h and is used for short-distance commercial delivery. Therefore, the applicable flight path is determined to be a low-to-medium speed flight path for the drone, and the minimum safe distance for navigation is D0 = max{d f ,d v} = 10m.

[0056] The weather was sunny and breezy that day; the drone equipment was in good condition during the delivery process, and there were no external emergencies. Based on the principle of the shortest straight distance, the drone traveled at 70 km / h (19.44 m / s) in a straight line at 45° north of west.

[0057] During flight, a similar drone X was detected at a horizontal distance of 80m, and within 0.1 seconds, the drone's position vector from itself to X changed from s... x0 =(20.7,77.3,0) becomes s x1 = (19.8, 74.0, 0). In a geographic three-dimensional coordinate system with east as the X-axis, north as the Y-axis, and above as the Z-axis, its own heading deflection angle is 135°, and its speed vector is u0 = (-13.75, 13.75, 0). The speed vector u of aircraft B can be measured using the two-point positioning speed measurement method. x and heading deflection angle β:

[0058]

[0059] because Make |s x1 +(u x -u a If t|=|(19.8-9×2.3,74.0-33×2.3,0)|=2.1≤D0=10, then the two aircraft are at risk of being too close to each other and need to adjust their routes to avoid this.

[0060] A virtual 3D roundabout with a diameter of 10m and centered at the route intersection is constructed. A 3D roundabout spatial coordinate system is established with the center as the origin, east as the X-axis, north as the Y-axis, and above as the Z-axis. Considering factors such as navigation safety (maintaining a safe distance at all times), aircraft performance (maximum relative deflection angle of the avoidance route not exceeding 25°), and low-altitude airspace (minimizing the impact range of the route intersection), the distance from the starting point of the avoidance route to the route intersection is:

[0061]

[0062] The avoidance route in the 3D island spatial coordinate system is:

[0063]

[0064] Correspondingly, aircraft X also uses the same method to determine the avoidance route in the 3D island-circling spatial coordinate system:

[0065]

[0066] The above description is merely a preferred embodiment of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

[0067] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications based on these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of this application.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for designing avoidance paths for low-altitude intersecting air routes, characterized in that, Includes the following steps: Based on the aircraft type and speed, the flight path planes are divided into layers and the minimum safe distance D0 for each plane is determined. Based on the principle of the shortest straight distance, each aircraft maintains its own course and travels in a straight line with constant power before and after passing through the route intersection; During the passage through the crossroads, the two-point positioning speed measurement method is used to determine the speed vector of the other aircraft and to determine whether there is a risk of the two aircraft being too close or colliding. If there is a risk of getting too close or colliding, a virtual 3D roundabout is constructed, and the avoidance routes along the surface of the 3D roundabout are determined based on the aircraft's speed vector.

2. The method for designing avoidance paths for low-altitude intersecting air routes according to claim 1, characterized in that, The step of determining the speed vector of the other aircraft using a two-point positioning speed measurement method during the passage through an airway intersection, and judging whether there is a risk of the two aircraft being too close or colliding, includes: Set the obstacle detection range for the aircraft; When aircraft A approaches the route intersection, aircraft B appears within the detection range and the position vector from A to B changes from s0=(Δx0,Δy0,0) to s1=(Δx1,Δy1,0) within the time interval Δt. In a geographic three-dimensional coordinate system with east as the X-axis, north as the Y-axis, and above as the Z-axis, the heading deflection angle of aircraft A is α, and its speed vector is u. a =(|u a |cosα,|u a The velocity vector u of aircraft B can be measured using the two-point positioning velocity measurement method, given |sinα,0). b and heading deflection angle β: Based on the velocity vectors of the two aircraft, if there exists t∈(0,+∞) such that |s1+(u b -u a If t|≤D0, then the two aircraft are at risk of being too close to each other or colliding, and their routes need to be adjusted to avoid collision; otherwise, normal navigation is fine. In this system, the geographic 3D coordinate system is defined with east as the X-axis, north as the Y-axis, and directly above as the Z-axis; s0 and s1 represent the position vectors from A to B in the geographic 3D coordinate system, and their values ​​are equal to the difference between the position coordinates of B and A at the current moment; Δt is the time taken for the position vector from A to B to change from s0 to s1; u a ,u b These are the velocity vectors of aircraft A and aircraft B in the geographic three-dimensional coordinate system, |u a |,|u b | represents the speed scalars of aircraft A and aircraft B, respectively; α and β represent the heading deflection angles of aircraft A and aircraft B, respectively.

3. The method for designing avoidance paths for low-altitude intersecting air routes according to claim 2, characterized in that, If there is a risk of being too close or colliding, the steps of constructing a virtual 3D roundabout and determining the avoidance path along the surface of the 3D roundabout based on the aircraft's speed vector specifically include: Construct a virtual 3D roundabout with the route intersection as the center and d as the diameter, and establish a 3D roundabout spatial coordinate system with the center as the origin, east as the X-axis, north as the Y-axis, and the top as the Z-axis; where d takes a value greater than or equal to D0; The maximum relative deflection angle of the avoidance route does not exceed δ. Determine the distance S from the starting point of the avoidance route to the route intersection point: Determine the avoidance routes for aircraft A and B in the 3D island-shaped spatial coordinate system: Among them, the route intersection point refers to the intersection point of the routes of aircraft A and aircraft B when they travel in a straight line along their respective predetermined headings; the maximum relative deflection angle of the avoidance route refers to the maximum angle between the heading and the original navigation plane when the aircraft travels along the avoidance route; the starting point of the avoidance route refers to the coordinate point where the aircraft leaves the original route plane and returns to the original route plane, respectively; (x,y,z) are the coordinate values ​​of the aircraft in the 3D island space coordinate system. Aircraft A and aircraft B only need to determine their respective avoidance routes based on the magnitude of their respective heading deflection angles α and β.

4. The method for designing avoidance paths for low-altitude intersecting air routes according to claim 2, characterized in that, The obstacle detection range of the aircraft is set to eight times the minimum safe distance for navigation, D0.

5. The method for designing avoidance paths for low-altitude intersecting air routes according to claim 1, characterized in that, The steps of dividing the flight path planes into layers based on aircraft type and speed, and determining the minimum safe distance for each plane, include the following: Based on aircraft type and speed, the low-altitude region below 1000 meters is divided into several flight paths, including dedicated flight paths for manned helicopters, low-to-medium speed flight paths for unmanned aerial vehicles (UAVs), high-speed flight paths for UAVs, and emergency flight paths. Computational fluid dynamics simulation software or wind tunnel tests are used to determine the shortest distance d that is unaffected by airflow interference from parallel aircraft. f ; Calculate the emergency braking distance and equipment reaction distance to determine the shortest distance d that will prevent a collision between the two aircraft. v ; According to the formula D0=max{d f ,d v Determine the minimum safe distance; Where, d f The shortest distance, unaffected by airflow interference from parallel aircraft, is determined using computational fluid dynamics simulation software or wind tunnel testing; d v It is the shortest distance at which two aircraft will not collide, including emergency braking distance and equipment reaction distance.

6. A method and apparatus for designing avoidance paths for low-altitude intersecting air routes, applying any one of the methods in claims 1-5 above, characterized in that, include: The distance calculation module is configured to divide the flight path plane into layers based on the aircraft type and speed, and determine the minimum safe distance D0 for each plane. The route determination and maintenance module is configured to maintain its course and travel in a straight line with constant power before and after passing through the route intersection, based on the principle of the shortest straight distance, in the absence of emergencies. The risk assessment module is configured to use a two-point positioning speed measurement method to determine the speed vector of the other aircraft during the passage through the airway intersection, and to determine whether there is a risk of the two aircraft being too close or colliding. The route determination module is configured to construct a virtual 3D roundabout if there is a risk of being too close or colliding, and determine the avoidance route along the surface of the 3D roundabout based on the aircraft's speed vector.

Images