Hierarchical conflict detection and solution method based on ADS-B data validity

Abstract

The invention discloses a layered conflict detection and solution method based on ADS-B data validity, which relates to the technical field of automatic flight avionics and comprises the steps of ADS-B data validity analysis, alarm hierarchy design, danger alarm area (HAZ) definition, non-danger area (NHZ) definition, danger table and alarm device and algorithm implementation. The algorithm implementation comprises geometric agreement, safety distance violation judgment logic, detection logic, guidance processing logic and a universal conflict band calculation method, and the algorithm implementation uses received state information provided by an ADS-B of an invading aircraft as input; the invention provides a predictive method for detecting safety distance conflicts, potential and experienced safety distance conflicts can be detected, corresponding operation guidance can be given according to the detection condition, the detection method used by the invention is autonomous detection of an aircraft, and compared with a centralized detection anti-collision strategy, the method has the advantages that the safety distance conflicts can be detected more accurately, and the detection efficiency is improved. The method belongs to a non-centralized detection anti-collision strategy.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic flight avionics equipment, and in particular to a hierarchical conflict detection and resolution method based on ADS-B data validity. Background Art

[0002] The vigorous development of the low-altitude economy for small aircraft is a trend. In the future, the number of low-altitude aircraft will increase, and it will become particularly important for aircraft to maintain a safe distance. Currently, aircraft maintain a safe distance in the air mainly through air traffic control instructions. Air traffic control issues air traffic control instructions based on monitoring information (radar and ADS-B information reception, etc.) and coordination between pilots and air traffic control. Pilots control the flight of aircraft according to air traffic control instructions. Aircraft do not have the ability to autonomously detect (predict) and provide solutions to maintain a safe distance. With the increase in the density of low-altitude drones in the future, the traditional method of relying on air traffic control instructions to maintain a safe distance will become more complex, and the decision-making efficiency will be reduced due to the use of centralized monitoring. An effective method for autonomous detection and maintenance of safe distances by aircraft is needed to meet this demand.

[0003] The existing technology has the following deficiencies:

[0004] The current technology for maintaining a safe distance in the air is that air traffic control uses various systems to collect environmental conditions on the ground and in the air, such as status data of aircraft in flight, and aggregates the information into the air traffic control system for centralized monitoring, calculation and analysis, and centralized scheduling to provide air traffic control instructions for aircraft. Current technology has high requirements for air traffic control. When the density of low-altitude aircraft increases and the complexity of the low-altitude flight environment increases, the difficulty and cost of air traffic control decisions increase significantly. It may even be impossible to efficiently detect and provide solutions for a large number of aircraft according to their current status. Summary of the invention

[0005] The purpose of the present invention is to provide a low-cost, high-real-time detection and solution based on receiving ADS-B data to maintain a safe distance between aircraft in the future low-altitude industry and scenarios with increased aircraft density. The method provides different levels of detection, representing different degrees of severity of loss of safe distance, and outputs the detection results in the form of alarms and operation instructions. The alarm is used to remind pilots (including remote control pilots of drones) to pay attention to the surrounding environment of the aircraft, and the instruction is used to provide pilots with operational references for maintaining a safe distance. The method is a distributed method based on autonomous detection and analysis of aircraft, which can provide services for safe and efficient flight of aircraft and enhance the autonomous flight capability of aircraft.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention is a hierarchical conflict detection based on ADS-B data validity, comprising:

[0008] ADS-B data validity analysis, warning level design, definition of danger warning zone (HAZ), definition of non-dangerous zone (NHZ), danger table and warning device, algorithm implementation, the algorithm implementation includes geometric convention, safety distance violation judgment logic, detection logic, guidance processing logic, general conflict zone calculation method, the algorithm implementation is to perform conflict detection calculation by using the status information provided by the ADS-B received from the intruder aircraft, and the output is divided into two parts: warning and guidance;

[0009] In the geometric convention algorithm, it is assumed that the Euclidean three-dimensional coordinate system is used. Moreover, if wind information is provided, it is assumed that the aircraft speed is relative to the wind. The calculation formula uses a relative coordinate system, with the invading aircraft as the origin, and the own aircraft moves relative to the invading aircraft. The subscript "o" is the own aircraft, and the subscript "i" is the invading aircraft, such as: relative horizontal distance is a two-dimensional vector; relative vertical distance s z =s oz –s iz ; Relative horizontal speed is a two-dimensional vector; relative vertical velocity v z =v oz –v iz ; If agreed and is a two-dimensional vector, then for The norm of for and The dot product of Represents a scalar Representation vector Rotate 90 degrees to the right;

[0010] In the safety distance violation judgment logic, the following function is used to judge whether the safety distance is violated: Function Input is the horizontal distance vector, is the horizontal velocity vector, is the vertical distance, is the vertical speed. When the judgment result is that the safety distance is violated, the function returns TRUE, otherwise it returns FALSE.

[0011] The detection logic is implemented through a function. The input of the function is the relative position and relative speed between the own aircraft and the intruder aircraft and a forward-looking time period [B, T] for prediction. The function calculates the safety distance at a constant speed according to a certain time step within the time period [B, T] and returns a time period [t in ,t out ], if t in ≤t out , then t in Indicates the moment when the safety distance is lost for the first time, t out Indicates the moment when the safety distance was last lost (i.e., when the state of "losing safety distance" was exited); if t in >t out , it means that there is no loss of safety distance in the time period [B, T]. Usually B is taken as 0, which means that the detection calculation starts from the current moment. The value of T can be set by configuring parameters;

[0012] In the guidance processing logic, a safety distance guidance processing function is designed to calculate the operation guidance band. The guidance processing function performs guidance calculation on each danger table of the active alarm whose setting area is FAR, MID or NEAR. The guidance calculation result is output in the form of "guidance band" and will be marked as NONE, FAR, MID or NEAR. Adjacent guidance bands of the same type will be merged, the NEAR guidance band will be superimposed on the MID guidance band, and the NEAR and MID guidance bands will be superimposed on the FAR guidance band.

[0013] In the generic conflict band calculation method, the conflict band represents the predicted horizontal and vertical operating range that will lead to a violation of the danger warning zone. The conflict band is represented by a pair of numerical values. A method is designed to calculate the conflict band of each intruding aircraft relative to its own aircraft and merge them. A generic function GenericBands_1x1 that returns a pair of numerical values ​​and is used to calculate the horizontal and vertical conflict bands that lead to a violation of the danger warning zone HAZ is used to calculate the conflict band.

[0014] As a further solution of the present invention: the ADS-B data validity analysis is that after the aircraft receives the ADS-B message of the invading aircraft, the following status information of the invading aircraft is extracted according to the message protocol: longitude, latitude, altitude, horizontal speed, vertical speed, and the received ADS-B data needs to be verified and checked. The ADS-B data in the following cases will be regarded as invalid data: the horizontal acceleration calculated by the received horizontal speed exceeds 1.5g; the horizontal acceleration value in any direction calculated by the received horizontal position exceeds 1.5g; the vertical rate calculated by the received vertical height exceeds 10000fpm; the ADS-B trajectory data used to calculate warning guidance must be verified by additional measuring devices, such as active monitoring devices, air-to-air radars, optoelectronic / infrared sensors, etc. If the ADS-B data passes the verification, it will be marked as valid, otherwise, no further processing will be performed.

[0015] As a further solution of the present invention: the alarm level design is to divide the conflict alarm into three levels: preventive alarm, corrective alarm and warning alarm. The detection methods of the above three levels of alarms are the same, but the calculation parameters and thresholds for triggering alarms are different;

[0016] Preventive warnings are used to remind pilots that if they continue with the current control status, corrective warnings or warning warnings may be triggered. Preventive warnings are reminder-level warnings and must last for at least 4 seconds after they are issued, unless a higher-level warning occurs.

[0017] Corrective alerts are the earliest alerts that the pilot is expected to start maneuvering to maintain a safe distance. The purpose is to attract the pilot's attention and remind the pilot that he needs to participate in the maneuver or coordinate with air traffic control. Corrective alerts are reminder-level alerts and must last for at least 4 seconds after being issued, unless a higher-level alert occurs.

[0018] Warning alerts are used to inform pilots that they need to take immediate action to maintain a safe distance. Warning alerts are warning-level alerts and must last for at least 4 seconds after a corrective alert is issued.

[0019] The alarm priority stipulates that at the same time, there can be only one alarm status for each intruding aircraft. If an intruding aircraft triggers more than one alarm condition, it is set to select the highest alarm level output in the following order: warning alarm, corrective alarm, and preventive alarm.

[0020] As a further solution of the present invention: the HAZ definition defines a HAZ and a non-HAZ for each alert level of conflict detection. For a given alert level, the definition of an intruder aircraft in the HAZ is as follows:

[0021] [r≤S * ] AND [HMD p ≤HMD * ] AND [d h ≤h * ] == TRUE.

[0022] As a further aspect of the present invention, the non-hazardous zone (NHZ) is defined as follows: for a given alert level, an intruder aircraft is located in the HAZ:

[0023] [r > S * ] OR [HMD p > HMD * ] OR [d h > V * ] == TRUE.

[0024] As a further solution of the present invention: the danger table and the alarm are provided with a group of danger tables for realizing detection and guidance calculation, each danger table contains a set of parameters for defining a safety distance: horizontal range threshold (DMOD), vertical range threshold (ZTHR), modified conflict time threshold (TAUMOD), time threshold for reaching the same height (TCOA), alarm time point and earliest alarm time point.

[0025] A solution to hierarchical conflict detection based on ADS-B data validity, including: recovery guidance, horizontal and vertical guidance, warning logic, conflict warning and conflict guidance display; the recovery guidance is when the conflict band calculated by a certain warning level is a saturated conflict band, that is, when the system predicts that it is inevitable to enter the corresponding danger warning area, the operating range that can quickly leave the danger warning area is the recovery guidance.

[0026] As a further solution of the present invention: the horizontal and vertical guidance utilizes the previous calculation of the conflict band and recovery guidance to calculate the horizontal azimuth guidance, horizontal speed guidance and vertical rate guidance under a given look-ahead time T, minimum horizontal spacing and minimum vertical spacing.

[0027] As a further solution of the present invention: the alarm logic is designed to implement an alarm based on a method that predicts the loss of the safety distance between the aircraft itself and the invading aircraft. For a specific alarm, detection calculations are performed according to the danger parameter table corresponding to its different alarm levels. Detection starts from the highest alarm level until the lowest level detection is completed. The designed function returns the triggered alarm level. If it returns 0, it means there is no alarm.

[0028] As a further solution of the present invention: the conflict warning and conflict guidance display include: conflict warning display, conflict guidance display, the conflict warning is displayed on the display screen on the aircraft or the display screen of the UAV ground station, the conflict warning is displayed at the warning level, and the ID of the aircraft causing the warning is displayed, and the aircraft icon or ID is filled with different colors and flashes to indicate the corresponding warning level; the conflict guidance is displayed on the display screen on the aircraft or the display screen of the UAV ground station, the conflict guidance is displayed in the form of a guidance band, wherein the horizontal direction guidance band is displayed as a (segmented) arc; the horizontal speed guidance band, the vertical speed guidance band, and the altitude guidance band are displayed as "ruler"-shaped indicator bands.

[0029] Compared with the prior art, the present invention has the following beneficial effects: Safety distance conflict detection is performed based on the ADS-B data received from the cooperating aircraft. Since ADS-B is a commonly used device in aviation, the cost of using the information provided by the device for detection is low, especially when large-scale low-altitude aircraft are put into operation, the cost advantage is more obvious. The present invention provides a method for detecting safety distance conflicts with predictiveness, which can detect potential and ongoing safety distance conflicts, and can provide corresponding operation instructions based on the detection situation. Since the detection method used in the invention is autonomous detection by aircraft, it is a decentralized detection and collision avoidance strategy. Compared with the centralized detection and collision avoidance strategy, the method is efficient and easy to deploy. The method uses a layered (hierarchical) warning strategy, which can provide graded warnings and guidance to remote control pilots according to the severity of potential conflicts. The method used in the invention can also be used in auxiliary systems for autonomous flight of future drones. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of a process flow of a hierarchical conflict detection and resolution method based on ADS-B data validity according to the present invention;

[0031] Figure 2 An example diagram of a horizontal direction guidance band displayed for conflict warning and conflict guidance of the present invention;

[0032] Figure 3 An example diagram of the altitude guidance displayed for the conflict warning and conflict guidance of the present invention. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0034] See also Figure 1-Figure 2In an embodiment of the present invention, a hierarchical conflict detection based on ADS-B data validity includes: ADS-B data validity analysis, warning level design, danger warning zone (HAZ) definition, non-danger zone (NHZ) definition, danger table and alarm, algorithm implementation, the algorithm implementation includes geometric convention, safety distance violation judgment logic, detection logic, guidance processing logic, and general conflict zone calculation method, the algorithm implementation performs conflict detection calculation by using the status information provided by the ADS-B received from the intruding aircraft, and the output is divided into two parts: warning and guidance;

[0035] The validity analysis of ADS-B data lies in that after the aircraft receives the ADS-B message from the invading aircraft, the following status information of the invading aircraft is extracted according to the message protocol: longitude, latitude, altitude, horizontal speed, and vertical speed. The received ADS-B data needs to be verified and checked. The ADS-B data in the following cases will be regarded as invalid data: the horizontal acceleration calculated by the received horizontal speed exceeds 1.5g; the horizontal acceleration value in any direction calculated by the received horizontal position exceeds 1.5g; the vertical rate calculated by the received vertical altitude exceeds 10,000fpm; the ADS-B trajectory data used to calculate warning guidance must be verified by additional measuring devices, such as active monitoring devices, air-to-air radars, optoelectronic / infrared sensors, etc. If the ADS-B data passes the verification, it will be marked as valid, otherwise, no further processing will be performed.

[0036] The alarm level design is to divide the conflict alarm into three levels: preventive alarm, corrective alarm and warning alarm. The detection methods of the above three levels of alarms are the same, but the calculation parameters and thresholds for triggering alarms are different;

[0037] Preventive warnings are used to remind pilots that if they continue with the current control status, corrective warnings or warning warnings may be triggered. Preventive warnings are reminder-level warnings and must last for at least 4 seconds after they are issued, unless a higher-level warning occurs.

[0038] Corrective alerts are the earliest alerts that the pilot is expected to start maneuvering to maintain a safe distance. The purpose is to attract the pilot's attention and remind the pilot that he needs to participate in the maneuver or coordinate with air traffic control. Corrective alerts are reminder-level alerts and must last for at least 4 seconds after being issued, unless a higher-level alert occurs.

[0039] Warning alerts are used to inform pilots that they need to take immediate action to maintain a safe distance. Warning alerts are warning-level alerts, and the corrective alert must last for at least 4 seconds after it is issued;

[0040] Alarm priority. At the same time, there can be only one alarm status for each intruding aircraft. If an intruding aircraft triggers more than one alarm condition, it is set to the highest alarm level applicable in the following order: warning alarm, corrective alarm, and preventive alarm.

[0041] The HAZ definition defines HAZs and non-HAZs for conflict detection at each alert level;

[0042] For a given alert level, the HAZ for an intruder aircraft is defined as follows: [r≤S * ] AND [HMD p ≤HMD * ] AND [d h ≤h * ] == TRUE (1)

[0043] The meanings of the parameters in the formula are as follows: r is the current horizontal distance between the own aircraft and the invading aircraft, S * is the horizontal size of the HAZ corresponding to the warning level (the safe distance τ through time * mod computing), HMD p is the horizontal offset distance of the predicted closest approach point, HMD * is the horizontal offset distance threshold corresponding to the alarm level, d h is the current vertical spacing, h * is the vertical spacing corresponding to the alarm level;

[0044] When all three conditions in equation (1) are true at a given time point, the HAZ is violated.

[0045] The horizontal distance r is defined as follows: r = (2),

[0046] in: d x = x2 – x1, which is the current horizontal spacing in the x direction; d y = y2 – y1, which is the current horizontal spacing in the y direction.

[0047] The size of the HAZ corresponding to a given warning level is used to compare with the horizontal spacing r. is defined as follows:

[0048] = (3)

[0049] in:

[0050] DMOD is the time safety interval τ used to calculate the correction mod The distance correction value of

[0051] , is the horizontal relative speed between the own aircraft and the intruder aircraft (negative values ​​indicate that the distance is decreasing);

[0052] , is the horizontal relative velocity in the x direction;

[0053] , is the horizontal relative velocity in the y direction;

[0054] τ * mod It is the threshold of the corrected time safety interval used to determine the alarm.

[0055] In all cases, the horizontal offset distance threshold HMD is taken * =DMOD.

[0056] Predicted horizontal stagger distance HMD p The definition is as follows:

[0057] (4)

[0058] in

[0059] max (5)

[0060] Horizontal stagger distance threshold HMD corresponding to a given alarm level * For use with HMD p Make a comparison.

[0061] The current vertical distances are defined as follows:

[0062] (6)

[0063] The vertical distance threshold h corresponding to a given alarm level * Used to compare with the current vertical distance.

[0064] The non-hazard zone (NHZ) definition, for a particular alert level, where an intruder aircraft is located in the HAZ is defined as follows: [r > S * ] OR [HMD p > HMD * ] OR [d h > V *] == TRUE;

[0065] All parameters with the same names as those in HAZ are defined in the same way as those in HAZ, but with different values. In addition, the parameter V is added. * .

[0066] Vertically approaching the threshold V * is defined as follows:

[0067] = max(VMOD, VMOD- ) (7)

[0068] in

[0069] VMOD is used to calculate the corrected time safety distance τ in the vertical direction mod distance;

[0070] is the vertical closing rate between the two aircraft.

[0071] Vertical Closure Rate The definition is as follows:

[0072] = - (8)

[0073] in Negative values ​​indicate that the distance is decreasing.

[0074] The hazard table and alarm device set a set of hazard tables for realizing detection and guidance calculation. Each hazard table contains a set of parameters for defining a safety distance: horizontal range threshold (DMOD), vertical range threshold (ZTHR), modified conflict time threshold (TAUMOD), time threshold to reach the same height (TCOA), alarm time point and earliest alarm time point;

[0075] Different alarms are set according to different scenarios (such as normal cruising, approach or flight in the airport landing area). Each alarm corresponds to a danger table and is assigned a guidance area (possibly NONE, FAR, MID, NEAR). The alarm level is associated with the guidance area. NONE or FAR corresponds to preventive alarms, MID corresponds to corrective alarms, and NEAR corresponds to warning alarms. Examples of danger tables and alarms are shown in Table 1, which lists the danger tables of the three alarms ER1, ER2, and ER3.

[0076]

[0077] In the geometric convention algorithm, it is assumed that the Euclidean three-dimensional coordinate system is used. Moreover, if wind information is provided, it is assumed that the aircraft speed is relative to the wind. The calculation formula uses a relative coordinate system, with the invading aircraft as the origin, and the own aircraft moves relative to the invading aircraft. The subscript "o" is the own aircraft, and the subscript "i" is the invading aircraft, such as: relative horizontal distance , is a two-dimensional vector; relative vertical distance s z = s oz –s iz ; Relative horizontal speed , is a two-dimensional vector; relative vertical velocity v z = v oz –v iz ; If agreed and is a two-dimensional vector, then || || for The norm of for and The dot product of Represents a scalar , Representation vector Rotate 90 degrees to the right;

[0078] The formula for calculating the horizontal distance is as follows: r(t) = || || =

[0079] Time t to reach the closest horizontal point cpa : ,

[0080] t cpa Horizontal distance between time points: ,

[0081] Vertical distance at time t: ,

[0082] Time to reach equal height ,

[0083] Corrected : .

[0084] In the safety distance violation judgment logic, the following function is used to judge whether the safety distance is violated: Function Input is the horizontal distance vector, is the horizontal velocity vector, is the vertical speed, is the vertical speed. When the judgment result is that the safety distance is violated, the function returns TRUE, otherwise it returns FALSE;

[0085] in The function for judging whether the horizontal direction violates the safety distance is defined as follows: , ,

[0086] The function for judging whether the horizontal direction violates the safety distance is defined as follows: .

[0087] The safety distance detection logic is implemented by a function. The input of the function is the relative position and relative speed between the own aircraft and the intruder aircraft and a forward-looking time period [B, T] for prediction. The function calculates the safety distance at a certain time step and a constant speed within the time period [B, T] and returns a time period [t in , t out ], if t in ≤t out , then tin represents the moment when the safety distance is first lost, t out Indicates the moment when the safety distance is last lost (i.e., no longer lost); if t in >t out , it means that there is no loss of safety distance in the time period [B, T]. Usually B is taken as 0, which means that the detection calculation starts from the current moment. The value of T can be set by configuring parameters;

[0088] The detection function is defined as follows:

[0089]

[0090] let [t1, t2] =

[0091] if t1> t2 then return [T, B]

[0092] elseif t1= t2 and then return [t1, t2]

[0093] elseif t1= t2 then return [T, B]

[0094] else let [t in , t out ] = in [t in +t1,t out +t1]

[0095] endif

[0096] in, It is a vertical safety distance detection function, which returns a time period [t in , t out ], the return value has the same meaning as above, and the function is defined as follows:

[0097]

[0098] if and then return [B, T]

[0099] elseif then return [T, B]

[0100] else let [t1, t2] = in

[0101] if T < t1 or t2 < B then return [T, B]

[0102] else return [max(B, t1), min(T, t2)]

[0103] endif

[0104] endif

[0105] in, The definition is as follows

[0106]

[0107] let H =

[0108] return

[0109] Horizontal safety distance detection function The definition is as follows:

[0110]

[0111] let a = ,

[0112] b = ,

[0113] c =

[0114] if a = 0 and then return [0, T]

[0115] elseif then return [0, min ]

[0116] elseif or then return [T, 0]

[0117] else let t =

[0118] if and t≤T then return [max(0, t), min ]

[0119] else return [T, 0]

[0120] endif

[0121] endif

[0122] in,

[0123]

[0124] .

[0125] In the guidance processing logic, a safety distance guidance processing function is designed to calculate the operation guidance band. The guidance processing function performs guidance calculation for each danger table of the active alarm whose area is set to FAR, MID, or NEAR. The calculation result of the guidance is output in the form of a "guidance band" and will be marked as NONE, FAR, MID, or NEAR. Guidance bands of the same type will be merged, the NEAR guidance band will be superimposed on the MID guidance band, and the NEAR and MID guidance bands will be superimposed on the FAR guidance band.

[0126] This method provides guidance bands in four dimensions: (1) horizontal orientation guidance band; (2) horizontal speed guidance band; (3) vertical rate guidance band; and (4) altitude guidance band.

[0127] In the generic conflict band calculation method, the conflict band represents the predicted horizontal and vertical operating range that will lead to violation of the danger warning zone. The conflict band is represented by a pair of numerical values. A method is designed to calculate the conflict band of each intruding aircraft relative to the own aircraft and merge them. A generic function GenericBands_1x1 that returns a pair of numerical values ​​and is used to calculate the conflict band between an intruding aircraft and the own aircraft is used to calculate the horizontal and vertical conflict bands that lead to violation of the danger warning zone HAZ; the function algorithm is implemented as follows:

[0128] GenericBands_1x1( , , B,T,cval,min,max,step,accel,D,H,Pos,Vel)

[0129] List

[0130] tstep := step / accel;

[0131] t := 0;

[0132] val := cval;

[0133] bands := EmptyList <doubleinterval>;

[0134] while val < max and t < T do

[0135] := Pos( , , accel, t);

[0136] := Vel( , , accel, t);

[0137] if t < B then

[0138] if || || < D and | | < H then

[0139] bands := Union(bands,[val,max]);

[0140] val := max;

[0141] endif

[0142] elseif WCV( ) then

[0143] bands := Union(bands,[val,max]);

[0144] val := max;

[0145] elseif not IsEmptyInterval(WCD( )) then

[0146] bands := Union(bands,[val,val+step]);

[0147] val := val+step;

[0148] endif

[0149] t := t+tstep;

[0150] endwhile

[0151] t := 0;

[0152] val := cval;

[0153] while val > min and t < T do

[0154] := Pos( , , -accel,t);

[0155] := Vel( , , -accel,t);

[0156] if t < B then

[0157] if || || < D and | | < H then

[0158] bands := Union(bands,[min,val]);

[0159] val := min;

[0160] endif

[0161] elseif WCV( ) then

[0162] bands := Union(bands,[min,val]);

[0163] val := min;

[0164] elseif not IsEmptyInterval(WCD( )) then

[0165] bands := Union(bands,[val-step,val]);

[0166] val:= val-step;

[0167] endif

[0168] t := t+tstep;

[0169] endwhile

[0170] return bands

[0171] In the above function, the EmptyInterval function determines whether the interval returned by WCD is empty. If it is not empty, it means there is a conflict. By calling GenericBands_1x1, the conflict band between the multiple invading aircraft lists and the own aircraft can be calculated according to the following function GenericBands(ownship,traffic,B,T,cval,min,max,step,accel,D,H,Pos,Vel):

[0172] GenericBands(ownership,traffic,B,T,cval,min,max,step,accel,D,H,Pos,Vel):

[0173] List <doubleinterval>

[0174] bands:= EmptyList <doubleinterval>;

[0175] foreach intruder in traffic do

[0176] ( ):= Position(ownership)-Position(intruder);

[0177] ( ):= Velocity(ownership)-Velocity(intruder);

[0178] bands:=Union(bands,GenericBands_1x1( , , B,T,cval,min,max,step,accel,D,H,Pos,Vel));

[0179] endforeach

[0180] return bands.

[0181] See also Figure 1-Figure 3 In an embodiment of the present invention, a solution for hierarchical conflict detection based on ADS-B data validity includes: recovery guidance, horizontal and vertical guidance, warning logic, conflict warning and conflict guidance display; when the conflict band calculated for a certain warning level is a saturated conflict band, that is, when the system predicts that it is inevitable to enter the corresponding danger warning area, the operation range provided for quickly leaving the danger warning area is the recovery guidance;

[0182] This method provides a general recovery guidance calculation algorithm. It assumes that the general conflict band calculation function returns a saturated conflict band, that is, the conflict band is a single occupied interval [min, max]. A recovery conflict band calculation function RecoveryBands is defined. This function tries to find a non-saturated conflict band in a certain time interval. If found, it returns the first occurrence of this type of conflict band and the time of occurrence. Its input is: the state of the own aircraft, the state of all other invading aircraft, the look-ahead time T, the current control value cval of the own aircraft, the minimum value min and the maximum value max, the control change step step, the constant acceleration accel, the horizontal distance D and the vertical distance H. The function returns the spacing (conflict band) and recovery time represented by a list. The function is defined as follows:

[0183] RecoveryBands(ownship,traffic,T,cval,min,max,step,accel,D,H,Pos,Vel):Pair<List <doubleinterval>,RecoveryTime>

[0184] B := 0;

[0185] repeat

[0186] B := B+1;

[0187] bands := GenericBands(ownership,traffic,B,T,cval,min,max,step,accel,D,H,Pos,Vel); until not [min,max] in bands;

[0188] return (bands,B);

[0189] The spacing returned by the RecoveryBands function is equivalent to the conflict bands that will cause HAZ violations. The complement of these conflict bands within [min, max] is the recovery guidance band.

[0190] Assuming that the current control value is within the conflict zone, the upper and lower boundaries of the conflict zone are the closest points that can be controlled to escape the conflict zone (except when the boundary is min or max, in which case the corresponding side of the boundary cannot escape the conflict). A function Resolutions is designed to calculate the upper and lower boundary values ​​that can escape the conflict zone. If the value is 0, it means that there is no solution to escape the conflict on that side. The function is implemented as follows:

[0191] Resolutions(ownership,traffic,T,cval,min,max,step,accel,D,H,Pos,Vel):

[0192] Pair

[0193] L := 0;

[0194] U := 0;

[0195] Bands :=RecoveryBands(ownership,traffic,T,cval,min,max,step,accel,D,H,Pos,Vel)[1]

[0196] for i <length(Bands)

[0197] if Bands[i][0] <cval and cval<Bands[i][1] then

[0198] if Bands[i][0]>min then

[0199] L:=Bands[i][0];

[0200] endif

[0201] If Bands[i][1] <max then

[0202] U:=Bands[i][1];

[0203] endif

[0204] endif

[0205] return (L, U)

[0206] In the above function, L and U are the upper and lower boundaries respectively. RecoveryBands(ownship, traffic, T, cval, min, max, step, accel, D, H, Pos, Vel)[1] represents the first part of the Pair type returned by the function, namely the bands part. Bands is a set of conflict bands, represented in the form of a two-dimensional array. Bands[i][0] represents the lower boundary of the i-th conflict band, and Bands[i][1] represents the upper boundary of the i-th conflict band.

[0207] The horizontal and vertical guidance is based on the calculation of the conflict zone and the recovery guidance, and the following functions are defined to calculate the horizontal azimuth guidance, the horizontal speed guidance and the vertical rate guidance under the given look-ahead time T, the minimum horizontal spacing and the minimum vertical spacing;

[0208] The guidance content lists all sub-intervals (bands) in the range of [min, max] and identifies their types. The non-conflicting band is identified as NONE, the recovery guidance band in the non-conflicting band is identified as RECOVERY, and the conflicting band is identified as MID or NEAR; the guidance content also includes the time of recovery.

[0209] HorizontalDirBands(ownership,traffic,T,D,H):

[0210] Pair<HorizontalDirRegions, RecoveryTime>

[0211] ColorBands(ownership,traffic,T,HorizontalDir(ownership),- , ,TurnStep,TurnRate,D,H, TurnRatePos,TurnRateVel)),

[0212] HorizontalSpeedBands(ownership,traffic,T,D,H):

[0213] Pair<HorizontalSpeedRegions,RecoveryTime>

[0214] ColorBands(ownership,traffic,T,HorizontalSpeed(ownership),MinHorizontalSpeed,MaxHorizontalSpeed,HorizontalSpeedStep,HorizontalAcceleration,D,H,HorizontalAccelPos,HorizontalAccelVel),

[0215] VerticalSpeedBands(ownership,traffic,T,D,H):

[0216] Pair<VerticalSpeedRegions,RecoveryTime>

[0217] ColorBands(ownership,traffic,T,VerticalSpeed(ownership),MinVerticalSpeed,MaxVerticalSpeed,VerticalSpeedStep,VerticalAcceleration,D,H,VerticalAccelPos,VerticalAccelVel),

[0218] The ColorBands(ownship,traffic,T,cval,min,max,step,accel,D,H,Pos,Vel) function is used to calculate all "bands" and identify the types of all sub-bands in the range [min, max]. The function is implemented as follows;

[0219] ColorBands(ownership,traffic,T,cval,min,max,step,accel,D,H,Pos,Vel):Pair <Pair<List <double>,List <bandstypes>>,RecoveryTime>

[0220] bands :=GenericBands(ownship,traffic,0,T,cval,min,max,step,accel,0,0,Pos,Vel);

[0221] noconflictband := NONE;

[0222] recovery_time := 0;

[0223] if [min,max] in bands then

[0224] noconflictband := RECOVERY;

[0225] (bands,recovery_time):=RecoveryBands(ownship,traffic,T,cval,min,max,step,accel,D,H,Pos,Vel);

[0226] endif

[0227] intervals := EmptyList <doubleinterval>;

[0228] types := EmptyList <bandstype>;

[0229] prev := min;

[0230] foreach [low,up] in bands do

[0231] if prev < low then

[0232] intervals :=Add(intervals,[prev,low]);

[0233] types := Add(types,noconflictband);

[0234] endif

[0235] intervals :=Add(intervals,[low,up]);

[0236] types := Add(types,CONFLICT);

[0237] prev := up;

[0238] endforeach

[0239] if prev < max then

[0240] intervals :=Add(intervals,[prev,max]);

[0241] types := Add(types,noconflict);

[0242] endif

[0243] return ((intervals,types),recovery_time).

[0244] The alarm logic is designed to implement an alarm based on a method for predicting the loss of the safety distance between the aircraft itself and the intruder aircraft. For a specific alarm, detection calculation is performed according to the danger parameter table corresponding to its different alarm levels. Detection starts from the highest alarm level until the lowest level detection is completed. The designed function returns the triggered alarm level. If it returns 0, it means there is no alarm.

[0245] The function definition is as follows:

[0246] AlertLevel

[0247] i := length(Alerter);

[0248] while i≥1 do

[0249] HazTable := Alerter(i);

[0250] if not EmptyInterval( ) then

[0251] return i;

[0252] else

[0253] i := i-1;

[0254] endif

[0255] endwhile

[0256] return i;

[0257] In the above function, Alerter represents the selected alarm; Alerter(i) represents the danger parameter table of the i-th level alarm of the alarm; the EmptyInterval function determines whether the interval returned by WCD is empty. If it is not empty, it means that there is a conflict.

[0258] The conflict warning and conflict guidance display include: conflict warning display and conflict guidance display. The conflict warning is displayed on a display screen on an aircraft or a display screen of an unmanned aerial vehicle ground station. The conflict warning is displayed at a warning level, and the ID of the aircraft causing the warning is displayed. At the same time, the aircraft icon or ID is filled with different colors and flashes to indicate the corresponding warning level; the conflict guidance is displayed on a display screen on an aircraft or a display screen of an unmanned aerial vehicle ground station. The conflict guidance is displayed in the form of a guidance belt, wherein the horizontal direction guidance belt is displayed in a (segmented) arc; the horizontal speed guidance belt, the vertical speed guidance belt, and the altitude guidance belt are displayed in a "ruler"-shaped indicator belt;

[0259] Figure 2 This is an example of a horizontal heading guidance tape. The figure shows a circle centered on the own aircraft. AC01 represents the intruder aircraft. The arc is divided into several segments, which represent the conflict situations when the own aircraft flies in different horizontal headings. The thin line part represents NONE or FAR. The thick arc on the right is displayed in yellow, indicating MID, and the thick arc on the left is displayed in red, indicating NEAR. Figure 3 The right half is an example of altitude guidance. The figure shows a circle centered on the aircraft itself. AC01 and AC02 represent intruding aircraft. The numbers below AC01 and AC02 represent vertical speeds. The meaning of the guidance band color is the same as that of the horizontal heading guidance band. If a recovery guidance band exists, it is represented by a thicker dotted line segment.

[0260] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.< / bandstype> < / doubleinterval> < / bandstypes> < / double> < / doubleinterval> < / doubleinterval> < / doubleinterval> < / doubleinterval>

Claims

1. A hierarchical conflict detection based on ADS-B data validity, characterized in that: include: ADS-B data validity analysis, warning level design, definition of danger warning zone (HAZ), definition of non-dangerous zone (NHZ), danger table and alarm, algorithm implementation, the algorithm implementation includes geometric convention, safety distance violation judgment logic, detection logic, guidance processing logic, and general conflict zone calculation method. The algorithm implementation uses the status information provided by the ADS-B received from the intruder aircraft and the status information of the aircraft itself as input to perform conflict detection calculation, and the output is divided into two parts: warning and guidance; In the geometric conventions described, the Euclidean three-dimensional coordinate system is assumed to be used. Furthermore, if wind information is provided, it is assumed that the aircraft speed is relative to the wind. The calculation formula uses a relative coordinate system, with the intruder aircraft as the origin, and the own aircraft moves relative to the intruder aircraft. The subscript "o" is the own aircraft, and the subscript "i" is the intruder aircraft, such as: relative horizontal distance , is a two-dimensional vector; relative vertical distance s z = s oz –s iz ; Relative horizontal speed , is a two-dimensional vector; relative vertical velocity v z = v oz –v iz ; If agreed and is a two-dimensional vector, then || || for The norm of for and The dot product of Represents a scalar , Representation vector Rotate 90 degrees to the right; In the safety distance violation judgment logic, the following function is used to judge whether the safety distance is violated: , function input is the horizontal distance vector, is the horizontal velocity vector, is the vertical distance, is the vertical speed. When the judgment result is that the safety distance is violated, the function returns TRUE, otherwise it returns FALSE. The detection logic is implemented through a function. The input of the function is the relative position and relative speed between the own aircraft and the intruder aircraft and a forward-looking time period [B, T] for prediction. The function calculates the safety distance at a constant speed according to a certain time step within the time period [B, T] and returns a time period [t in ,t out ], if t in ≤t out , then t in Indicates the moment when the safety distance is lost for the first time, t out Indicates the moment when the safety distance was last lost (i.e., when the state of "losing safety distance" was exited); if t in >t out , it means that there is no loss of safety distance in the time period [B, T]. Usually B is taken as 0, which means that the detection calculation starts from the current moment. The value of T can be set by configuring parameters; In the guidance processing logic, a safety distance guidance processing function is designed to calculate the operation guidance band. The guidance processing function performs guidance calculation on each danger table of the active alarm whose setting area is FAR, MID or NEAR. The guidance calculation result is output in the form of "guidance band" and will be marked as NONE, FAR, MID or NEAR. Adjacent guidance bands of the same type will be merged, the NEAR guidance band will be superimposed on the MID guidance band, and the NEAR and MID guidance bands will be superimposed on the FAR guidance band. In the generic conflict band calculation method, the conflict band represents the detected operating range in the horizontal and vertical directions that will lead to violation of the danger warning zone. The conflict band is represented by a pair of numerical values. A method is designed to calculate the conflict band of each intruding aircraft relative to its own aircraft and merge them. A generic function GenericBands_1x1 that returns a pair of numerical values ​​and is used to calculate the horizontal and vertical conflict bands that lead to violation of the danger warning zone HAZ is used to calculate the conflict bands.

2. The hierarchical conflict detection based on ADS-B data validity according to claim 1, characterized in that: The validity analysis of ADS-B data lies in that after the aircraft receives the ADS-B message from the invading aircraft, the following status information of the invading aircraft is extracted according to the message protocol: longitude, latitude, altitude, horizontal speed, and vertical speed. The received ADS-B data needs to be verified and checked. The ADS-B data in the following cases will be regarded as invalid data: the horizontal acceleration calculated by the received horizontal speed exceeds 1.5g; the horizontal acceleration value in any direction calculated by the received horizontal position exceeds 1.5g; the vertical rate calculated by the received vertical altitude exceeds 10,000fpm; the ADS-B trajectory data used to calculate warning guidance must be verified by additional measuring devices, such as active monitoring devices, air-to-air radars, optoelectronic / infrared sensors, etc. If the ADS-B data passes the verification, it will be marked as valid, otherwise, no further processing will be performed.

3. The hierarchical conflict detection based on ADS-B data validity according to claim 1, characterized in that: The alarm level design is to divide the conflict alarm into three levels: preventive alarm, corrective alarm and warning alarm. The detection methods of the above three levels of alarms are the same, but the calculation parameters and thresholds for triggering alarms are different; Preventive warnings are used to remind pilots that if the current control state is continued, corrective warnings or warning warnings may be triggered. Preventive warnings are reminder-level warnings and must last for at least 4 seconds after being issued, unless a higher-level warning occurs. Corrective alerts are the earliest alerts that the pilot is expected to start maneuvering to maintain a safe distance. The purpose is to attract the pilot's attention and remind the pilot that he needs to participate in the maneuver or coordinate with air traffic control. Corrective alerts are warning-level alerts and must last for at least 4 seconds after being issued, unless a higher-level alert occurs. Warning alerts are used to inform pilots that they need to take immediate action to maintain a safe distance. Warning alerts are warning-level alerts and must last for at least 4 seconds after being issued. At the same time, there can be only one alarm state for each intruding aircraft. If an intruding aircraft triggers more than one alarm, it is set to select the highest alarm level output in the following order: warning alarm, corrective alarm, and preventive alarm.

4. The hierarchical conflict detection based on ADS-B data validity according to claim 1, characterized in that: Dangerous alert zones and non-dangerous alert zones are defined for conflict detection at each alert level. The definition of the dangerous alert zone (HAZ) is as follows: [r≤S * ] AND [HMD p ≤HMD * ] AND[d h ≤h * ] == TRUE.

5. The hierarchical conflict detection based on ADS-B data validity according to claim 1, characterized in that: The non-hazard zone (NHZ) definition, for a particular alert level, where an intruder aircraft is located in the NHZ is defined as follows: [r > S * ]OR [HMD p > HMD * ] OR [d h > V * ] == TRUE.

6. The hierarchical conflict detection based on ADS-B data validity according to claim 1, characterized in that: The danger table and alarm set a group of danger tables for realizing detection and guidance calculation, each danger table contains a set of parameters for defining a safety distance: horizontal range threshold (DMOD), vertical range threshold (ZTHR), modified conflict time threshold (TAUMOD), time threshold to reach the same height (TCOA), alarm time point and earliest alarm time point.

7. A solution to layered conflict detection based on ADS-B data validity, characterized in that: include: Recovery guidance, horizontal and vertical guidance, warning logic, conflict warning and conflict guidance display; The recovery guide is an operation range that can quickly leave the danger warning zone when the conflict zone calculated by a certain alarm level is a saturated conflict zone, that is, the system predicts that it is inevitable to enter the corresponding danger warning zone.

8. A method for solving layered conflict detection based on ADS-B data validity according to claim 7, characterized in that: The horizontal and vertical guidance utilizes the calculation of the conflict zone and the recovery guidance to design a function for calculating the horizontal azimuth guidance, horizontal speed guidance and vertical rate guidance under a given look-ahead time T, minimum horizontal spacing and minimum vertical spacing.

9. A method for solving hierarchical conflict detection based on ADS-B data validity according to claim 7, characterized in that: The alarm logic is designed to implement an alarm based on a method that predicts the loss of the safety distance between the aircraft itself and the invading aircraft. For specific alarms, detection calculations are performed according to the danger parameter table corresponding to different alarm levels. Detection starts from the highest alarm level until the lowest level detection is completed. A function is designed to return the triggered alarm level. If it returns 0, it means there is no alarm.

10. A method for solving layered conflict detection based on ADS-B data validity according to claim 7, characterized in that: The conflict warning and conflict guidance display include: conflict warning display and conflict guidance display. The conflict warning is displayed on a display screen on an aircraft or a display screen of an unmanned aerial vehicle ground station. The conflict warning is displayed at a warning level, and the ID of the aircraft causing the warning is displayed. At the same time, the aircraft icon or ID is filled with different colors and flashes to indicate the corresponding warning level; the conflict guidance is displayed on a display screen on an aircraft or a display screen of an unmanned aerial vehicle ground station. The conflict guidance is displayed in the form of a guidance belt, wherein the horizontal direction guidance belt is displayed as a (segmented) arc; the horizontal speed guidance belt, the vertical speed guidance belt, and the altitude guidance belt are displayed as "ruler"-shaped indicator belts.

Images