Aircraft anti-collision warning method

Abstract

The present invention provides an aircraft anti-collision warning method, which belongs to the field of flight management system design. The method comprises the following steps: obtaining plane latitude and longitude information of waypoints of two aircraft; converting the latitude and longitude information into a spherical coordinate system and solving the intersection latitude and longitude information through three-point coplanar simultaneous equations; and calculating the arrival distance and time factor in combination with the aircraft position information and the intersection latitude and longitude information, and providing an alarm judgment in combination with a time threshold value.

Description

Technical Field

[0001] The present invention belongs to the field of airborne flight management systems, and in particular relates to an aircraft anti-collision warning method. Background Art

[0002] A flight management system (FMS) generally consists of two major components: a horizontal navigation system and a vertical performance management system. The horizontal navigation system, in turn, includes a series of subsystems, such as radio navigation, route management, navigation performance calculation, and guidance. Collision warning is part of flight management. Civilian airliners typically fly in segments. When aircraft at the same altitude fly, their segments may intersect, potentially leading to a collision. The longitude and latitude of the segment intersection point must be calculated. This information, combined with the aircraft's current flight speed, is then used to determine the likelihood of a collision and issue a warning.

[0003] Traditional large civil airliners are typically equipped with a Traffic Collision Avoidance System (TCAS) for collision avoidance. Small aircraft, due to cost constraints, generally do not have TCAS installed. TCAS alerts pilots to potential collisions and instructs them to maneuver. However, drones, general aviation aircraft, and small, low-altitude aircraft generally lack such systems. Therefore, it is crucial for these small general aviation aircraft to incorporate a collision avoidance feature into their flight management systems. Summary of the Invention

[0004] In view of this, the present invention discloses an aircraft anti-collision warning method, which is an auxiliary anti-collision method and can further improve the safety of aircraft flight.

[0005] An aircraft anti-collision warning method, the method comprising:

[0006] Obtain the longitude and latitude information of the waypoint planes of at least two target aircraft;

[0007] All longitude and latitude information are converted to spherical coordinate system;

[0008] By solving the three-point coplanar simultaneous equations, the longitude and latitude information of the intersection points of all target aircraft paths are solved;

[0009] According to the target aircraft's position information and the intersection's longitude and latitude information, the distance and time factors for the target aircraft to reach the intersection are determined, and according to the set time threshold, whether to send an alarm is determined.

[0010] Beneficial effects

[0011] 1. Based on the longitude and latitude plane coordinates, the present invention converts the longitude and latitude information into spherical coordinates, calculates the longitude and latitude of the intersection point through three - point coplanarity, and combines the longitude and latitude information of the intersection point with the aircraft position to further calculate the aircraft anti - collision warning. The algorithm is effective and can be applied to eVTOL or other types of aircraft. It has the characteristics of stable and reliable method, strong versatility, and does not require professional equipment such as TCAS, with low cost. This method uses other aircraft data for indirect anti - collision calculation and can be embedded in the aircraft avionics system as a low - cost auxiliary anti - collision method.

[0012] 2. The method proposed by the present invention is not only applicable to the situation of two aircraft, but also applicable to the situation of n aircraft that may collide with more than two aircraft. Only by calling this method and performing permutations and combinations can it be applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments, the following will briefly introduce the drawings required for the embodiments. Obviously, the drawings in the following description are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0014] Figure 1 Flowchart of the anti - collision algorithm;

[0015] Figure 2 Anti - collision simulation diagram. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] The following will describe the embodiments of the present disclosure in detail with reference to the drawings.

[0017] The following illustrates the implementation manners of the present disclosure through specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present disclosure without creative efforts belong to the scope of protection of the present disclosure.

[0018] It should be noted that the following description pertains to various aspects of embodiments within the scope of the appended claims. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of the aspects set forth herein can be used to implement a device and / or practice a method. Additionally, this device can be implemented and this method can be practiced using other structures and / or functionality in addition to one or more of the aspects set forth herein.

[0019] As Figure 1 shown, the aircraft collision avoidance warning method is applicable to path planning or warning of small aircraft, and the method includes:

[0020] S101: Obtain the longitude and latitude information of the waypoints of the target aircraft in the plane. Specifically,

[0021] There are two target aircraft equipped with navigation systems, including the first aircraft and the second aircraft. Obtaining the longitude and latitude information of the waypoints of the target aircraft includes:

[0022] Obtain the longitude and latitude information of the first aircraft and the second aircraft through the navigation system, satisfying:

[0023] As Figure 2 shown, the longitude and latitude of the two endpoints on the flight path segment of the first aircraft are respectively and and the current position longitude and latitude is Airplane1 (N1, E1). The longitude and latitude of the two ends on the flight path segment of the first aircraft are respectively and The current position longitude and latitude is Airplane2 (N2, E2). The intersection point is set with the longitude and latitude set to ;

[0024] When it is necessary to give a collision avoidance warning for the first aircraft and the second aircraft, then take the current aircraft position as the starting point position of the flight segment, then satisfy:

[0025] , ;

[0026] S102: Convert all longitude and latitude information to the spherical coordinate system. Specifically,

[0027] A spherical coordinate system is established for the Earth, where the center of the Earth is the origin and the O-XYZ coordinate system is established. The equator is the base plane, and the axis perpendicular to the equator and passing through the center of the Earth is called the Z axis, with the axis pointing to the North Pole being positive. The axis where the prime meridian coincides with the equatorial plane is called the X axis, with the axis pointing east being positive. The Y axis is perpendicular to the XZ plane, forming the right-hand rule.

[0028] The distinction criteria when converting spherical coordinates are: north latitude and east longitude are positive, and south latitude and west longitude are negative;

[0029] The spherical coordinate transformations corresponding to the longitudes and latitudes of the two endpoints on the first aircraft segment, the two endpoints on the second aircraft segment, and the possible intersection point are recorded as: and , then further, perform spherical coordinate transformation: Convert the latitude information of the first aircraft starting point into the latitude information under spherical coordinates, The longitude information of the first aircraft starting point is converted into the longitude information in spherical coordinates and satisfies:

[0030] , and (1), that is,

[0031] The longitude and latitude information of the two end points on the first aircraft segment path are converted into spherical coordinates. The latitude information in spherical coordinates is (( )、( )); The longitude and latitude information of the two end points on the second aircraft segment are converted into spherical coordinates. The latitude information in spherical coordinates is (( )、( )), in the three-dimensional spherical coordinate system (( )、( ))and(( )、( )) The longitude and latitude information of the point where a collision may occur is expressed as ( ), and satisfy:

[0032] , and (1).

[0033] S103: Solve the longitude and latitude information of the intersection points of all target aircraft paths through the three-point coplanar simultaneous equations. Specifically,

[0034] A1, let the radius of the earth be R, then The vector radius of the point satisfies:

[0035] P 11 The vector radius is represented by r 11 , P12 The vector radius is represented by r 12 , P 21 The vector radius is represented by r 21 , P 22 The vector radius is represented by r 22 , r is the vector radius of point P;

[0036] B1, project the vector radius of each point in the spherical coordinate system onto the spherical coordinate axis. The unit vectors on the X, Y, and Z axes are i, j, and k, then,

[0037]

[0038] C1, predicts the intersection point P by vector difference multiplication, including:

[0039] The three vectors are coplanar 、 、 and 、 、 The coplanarity condition simultaneous equations give

[0040]

[0041] Substituting formula (2) into formula (3), we can get:

[0042]

[0043]

[0044] D1, further organize formulas (4) and (5) into the following form:

[0045]

[0046] E1, combining the intermediate variables in formulas (6) and (7), can be used to obtain the longitude of the collision point:

[0047]

[0048] When calculated When , take the value of 0° to 90° or 180° to 270° east longitude, otherwise Take values from 90° to 180° or 270° to 360°;

[0049] Calculate the longitude of the intersection After the value is obtained, it is further brought into formula (6) to calculate the latitude value of the intersection point.

[0050] .

[0051] Further, the intermediate variables are A1, A2, B1, B2, C1, and C2, and they satisfy:

[0052] .

[0053] It should be noted here that further screening of the longitude and latitude values of the intersection point P is required:

[0054] The longitude of the intersection point P The value needs to be between and 、 and ; and the latitude needs to be between and 、 and ; therefore,

[0055] When The calculated angle is between 0° and 180°, it represents east longitude;

[0056] When The calculated angle is between 180° and 360°, then when The value should be 360° - , representing west longitude. Similarly, After calculating the intersection point latitude value, it should be taken as , and a positive intersection point latitude value represents north latitude, and a negative value represents south latitude.

[0057] S104: Determine the arrival distance and time factor based on the target aircraft position information and the intersection point longitude and latitude information, and determine whether to send an alarm according to the set time threshold. Specifically,

[0058] After calculating the longitude and latitude of the intersection point , calculate the distances from the current positions of the first aircraft Airplane1 (N1, E1) and the second aircraft Airplane2 (N2, E2) to the intersection point respectively, and use the great circle route distance calculation method to calculate the distances from the current first aircraft and the second aircraft to the intersection point. Among them:

[0059] Let the distance from the current position of the first aircraft Airplane1 (N1, E1) to the intersection point be , and the true airspeed during flight in this flight segment is ;

[0060] Let the distance from the current position of the second aircraft Airplane2 (N2, E2) to the intersection point be The true airspeed during flight in this leg is ;

[0061] Let the times for the first aircraft and the second aircraft to reach the intersection point be set as and ;

[0062] Let the time threshold be , then:

[0063]

[0064] Take the difference between the time when the first aircraft reaches the intersection point and the time , take the absolute value, and make a judgment according to formula (12):

[0065]

[0066] When it is less than a certain threshold (the threshold is determined according to the performance parameters of the aircraft. For example, for a helicopter, the threshold is small; for a civil aircraft), it is regarded as a risk of collision and an alarm is issued. When it is greater than the threshold, it is regarded as no risk of collision. When it is less than the threshold, an alarm message is issued.

[0067] The method of this law is determined through simulation integration as follows:

[0068] Select a set of data on the Jeppesen chart. Leg 1: The position (Chaoyang) of aircraft 1 has latitude and longitude N41°32.3′, E120°25.9′, and the end point (Kaiyuan) has latitude and longitude N42°34.2′, E124°0.4′. The starting position of aircraft 2 in leg 2 has latitude and longitude N41°38.3′, E122°7.7′, and the end point has latitude and longitude N42°10.5′, E122°34.8′; Substitute the data into the algorithm model, and calculate that the latitude and longitude of the intersection point is N42°10.0′, E122°34.8′. The actually marked intersection point on the Jeppesen chart is N42°9.7′, E122°34.9′. Verify that the algorithm of the intersection point solution model is effective.

[0069] Furthermore, substitute it into the distance calculation model. The distance of aircraft 1 from the intersection point: D1 = 191.08 KM;

[0070] The distance of aircraft 2 from the intersection point: D2 = 69.61 KM;

[0071] Set the flight speed of the first aircraft: V1 = 600 KM / h, the flight speed of the second aircraft: V2 = 600 Km / h, and the threshold value is set to 10S. The alarm output should be FALSE, which is consistent with the simulation results.

[0072] Set the flight speed of the first aircraft: V1 = 1147 KM / h, the flight speed of the second aircraft: V2 = 257 Km / h, the limit value is set to 10S, calculate T1 = 982.28S, T2 = 974.94S, which is less than the 10s threshold value. The output should be TURE, which is consistent with the simulation result, and the anti-collision warning is activated. The simulation result is consistent with the derived result.

[0073] As described above, it is only the specific implementation manner of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present disclosure should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. An aircraft anti-collision warning method, applicable to the calculation of the intersection points of multiple small aircraft, characterized in that, The method includes: Obtaining the longitude and latitude information of the waypoints of the target aircraft in the plane; Converting all the longitude and latitude information to the spherical coordinate system; Solving the longitude and latitude information of the intersection points of all the paths of the target aircraft through the co-planar simultaneous equations of three points; Based on the target aircraft position information and the longitude and latitude information of the intersection point, determine the arrival distance and time factors, and determine whether to send an alarm according to the set time threshold value. Among them, define the intermediate variables as A1, A2, B1, B2, C1, and C2, and the longitude and latitude information of the possible collision point is expressed as ( ), and satisfy: ； Obtaining the longitude value of the collision point according to the intermediate variable, and the expression is: ； When calculated take the value from 0° to 90° or 180° to 270° east longitude, otherwise take the value from 90° to 180° or 270° to 360°; Calculate the longitude of the intersection point After obtaining the value and determining the latitude value of the intersection point, the expression is: Intersection point After the longitude and latitude are calculated, it is necessary to calculate the distances between the current position of the first aircraft Airplane1 (N1, E1) and the current position of the second aircraft Airplane2 (N2, E2) from the intersection point respectively Distances. Using the great circle route distance calculation method, calculate the distances of the current first aircraft and the second aircraft from the intersection point respectively. Among them, let the distance between the current position of the first aircraft Airplane1 (N1, E1) and the intersection point be , and the true airspeed during flight in this flight segment is ; let the distance between the current position of the second aircraft Airplane2 (N2, E2) and the intersection point be , and the true airspeed during flight in this flight segment is ; then the times for the first aircraft and the second aircraft to fly to the intersection point are set as and ; calculate the times of each aircraft from the collision point according to the speeds respectively, and set the time threshold as , then: The time for the first aircraft to reach the intersection point is subtracted from the time and the absolute value is taken, and the judgment is made according to formula (12): When it is less than a certain threshold it is regarded as being at risk of collision and an alarm is issued. When it is greater than the threshold, it is regarded as not being at risk of collision. When it is less than the threshold, an alarm message is issued.

2. The method according to claim 1, characterized in that, The number of the target aircraft is two and they are equipped with navigation systems, including a first aircraft and a second aircraft. Obtaining the longitude and latitude information of the waypoints of the target aircraft includes: Obtaining the longitude and latitude information of the first aircraft and the second aircraft through the navigation system, satisfying: The latitudes and longitudes of the two endpoints on the flight path of the first aircraft are respectively and And the current position has latitude and longitude of Airplane1 (N1, E1). The latitudes and longitudes of the two endpoints on the flight path of the first aircraft are respectively and The current position has latitude and longitude of Airplane2 (N2, E2). The intersection point is set with latitude and longitude as ; When it is necessary to give a collision avoidance warning for the first aircraft and the second aircraft, take the current aircraft position as the starting point position of the flight segment, then it satisfies: Airplane1 (N1, E1) = P 11 (N 11 , E 11 ), Airplane2 (N2, E2) = P 21 (N 21 , E 21 )。 3. The method according to claim 2, wherein First, convert all the longitude and latitude information to the spherical coordinate system, including: Establish a spherical coordinate system for the earth. Among them, with the center of the earth as the origin, establish an O-XYZ coordinate system, and take the equator as the basic plane. An axis perpendicular to the equatorial basic plane and passing through the center of the earth is called the Z axis, and the north pole direction is positive; the axis where the prime meridian plane coincides with the equatorial plane is called the X axis, and the east direction is positive; the Y axis is perpendicular to the XZ plane to form the right-hand rule. The discrimination criterion for converting spherical coordinates is: north latitude and east longitude are positive, and south latitude and west longitude are negative; Perform spherical coordinate conversion on the longitude and latitude information of the two endpoints on the path of the first flight segment. The latitude information in spherical coordinates is (( ), ( )); Perform spherical coordinate conversion on the longitude and latitude information of the two endpoints on the second flight segment. The latitude information in spherical coordinates is (( ), ( )); In the three-dimensional spherical coordinate system (( ), ([[]] )) and (( ), ([[]] ))), the longitude and latitude information of the possible collision points is expressed as ( ), and satisfies: , and (1).

4. The method according to claim 3, wherein Respectively perform spherical coordinate system conversion on each waypoint and intersection point. After converting to the spherical coordinate system, solve the longitude and latitude information of the intersection points of the paths of the two aircraft through the co-planar simultaneous equations in the form of vector radii. The operation steps include: Assume the radius of the Earth is R, then The vector radius of the point satisfies: P 11 where the vector radius is represented by r 11 , P 12 where the vector radius is represented by r 12 , P 21 where the vector radius is represented by r 21 , P 22 where the vector radius is represented by r 22 , and r is the vector radius of point P; Project the vector radii of each point in the spherical coordinate system onto the spherical coordinate axes. The unit vectors on the X, Y, and z axes are i, j, and k, then, Further solve the longitude and latitude coordinates of the intersection point P through the vector cross product simultaneous formula, including: The three vectors are coplanar 、 、 and 、 、 The coplanarity condition simultaneous equations give Substitute formula (2) into formula (3) and organize to get, Further organize formulas (4) and (5) into the following form, 。 5. The method according to claim 4, characterized in that, It also includes the screening of the intersection point P, and the longitude of the intersection point P needs to be between and , and , and the latitude needs to be between and , and . Therefore, When the calculated angle is between 0° and 180°, it is expressed as east longitude; When When the calculated angle value is between 180° and 360°, then it is expressed as west longitude, and its actual value is 360° - ; When the calculated value of is negative, it represents south latitude, and when the calculated value of is positive, it represents north latitude, and its actual value is

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