Low-altitude aircraft detection and avoidance method

Abstract

The invention relates to the technical field of aircraft navigation and control, in particular to a low-altitude aircraft detection and avoidance method, which comprises the following steps: configuring DAA parameters and dividing an airspace; defining an adaptive net airspace of the flight stage and obtaining an adaptive net airspace detection result; acquiring a maneuvering conflict belt, a maneuvering guide belt and a maneuvering recovery belt; and carrying out intrusion alarm and obtaining the optimal maneuvering mode and direction of the aircraft for avoiding the invading aircraft. The method is used for effectively identifying possible threats of the airspace in which the aircraft is located in a complex low-altitude flight environment, and provides an optimal avoidance strategy with relatively high adaptability.

Description

Technical Field

[0001] This invention relates to the field of aircraft navigation and control technology, specifically to a method for detecting and avoiding low-altitude aircraft. Background Technology

[0002] Although the development of low-altitude aircraft collision avoidance systems is still a relatively new project, countries around the world have long conducted in-depth research on the problem of large aircraft collision avoidance. Large aircraft collision avoidance systems such as Air Traffic Detection, TCAS, and ACASX (Airborne Collision Avoidance System X) all use algorithms based on geometric rules to predict the approach time and distance between aircraft that may be colliding in potential airspace, and then provide traffic warnings and decision warnings to guide pilots to maintain or increase vertical separation. Therefore, the thinking on aircraft collision avoidance is consistent with the ideas and models established for detecting threats in the air for large aircraft.

[0003] The definition of the airspace is crucial for establishing collision avoidance models and is the foundation for realizing the self-separation function of aircraft collision avoidance. Realizing the collision avoidance function of aircraft involves three key stages: situational awareness, conflict prediction, and conflict resolution. Many scholars have conducted research on this. Through situational awareness and conflict prediction, relatively accurate flight status information of other aircraft in the airspace over a future period can be obtained. Currently, probabilistic analysis and geometric analysis methods are mainly used.

[0004] Probabilistic analysis first establishes a probabilistic conflict model for the aircraft, using this model to determine whether a conflict will occur within a certain forward timeframe. Short-term conflict models are designed based on different forward timeframes, using these models to determine if a conflict threat exists within a short period, i.e., a few seconds to a few minutes. If a conflict is predicted, appropriate collision avoidance maneuvers should be taken to prevent a collision. However, due to the excessive computational load of probabilistic analysis in practical applications, it cannot meet the requirements for real-time prediction. Therefore, geometric methods are more commonly used for prediction. Research on geometric methods mainly focuses on the modeling of aircraft collision zones. For example, a three-dimensional cylinder is defined based on the minimum safe flight separation standard. A spherical protection zone is defined based on a fixed time or distance, and this type of protection zone is unaffected by the aircraft's speed or direction. An ellipsoidal protection zone incorporates uncontrollable factors during flight and errors caused by equipment into the model building, using Kalman filtering to predict the aircraft's trajectory and directly excluding aircraft that are unlikely to collide, thus greatly reducing the computational load. Some researchers have also proposed different collision avoidance planning models based on the static protection zone of an aircraft cylinder to provide early warning of aerial threat situations.

[0005] When an aircraft anticipates a potential conflict threat, it must immediately initiate conflict avoidance. For cooperative targets in two-dimensional space, path planning can be categorized into global path planning and local path planning, with the algorithm being crucial. Global path planning is typically used for cooperative aircraft targets because the surrounding environment is known, and precise state information in the airspace is obtained, allowing for global collision avoidance path planning with minimal maneuvering costs. Researchers have combined the advantages of genetic algorithms and particle swarm optimization to solve the problem of multi-aircraft flight conflicts. Other researchers have proposed a novel conflict detection algorithm using ADS-B, which leverages enhanced surveillance information to achieve better warning performance in challenging environments.

[0006] Local path planning can be broadly categorized into potential field methods, geometric methods, and dynamic programming methods. The potential field method models each aircraft as a positively charged particle and the target point as a negatively charged particle. By solving electrostatic equations, the aircraft can quickly reach the target point without collision. Researchers derived gravitational and repulsive functions based on velocity vectors, improving the potential field function and enabling the aircraft to quickly avoid obstacles and reach the designated location. Several velocity field models were also established to dynamically plan the aircraft's course in two-dimensional space. In dynamic programming, if the time window is extended to infinity, the local algorithm becomes a global algorithm. The geometric method for the aircraft draws inspiration from RTCADO-185B. A collision risk model is first defined, ensuring that the tangent from the spherical protection zone to the aircraft forms a collision cone. The optimal escape route for the aircraft can then be solved. Since the current safety separation standards have a much larger horizontal separation standard than the vertical separation standard, the sphere is not realistic; therefore, a cylindrical model yielded better results. However, a standalone collision risk model cannot best represent the process from approach to collision of an aircraft. Therefore, combining a defined model can provide more complete guidance to aircraft operators.

[0007] In summary, existing technologies are insufficient for accurately and efficiently detecting and avoiding low-altitude aircraft intrusions. Therefore, a method for detecting and avoiding low-altitude aircraft is needed to address these issues. Summary of the Invention

[0008] To achieve low-altitude aircraft intrusion detection and avoidance, this invention provides a method for low-altitude aircraft detection and avoidance to solve existing problems.

[0009] The low-altitude aircraft detection and avoidance method of the present invention adopts the following technical solution, including: Configure the corresponding DAA parameters according to the current flight phase of the aircraft, and divide the airspace according to the DAA parameters; Establish a relative coordinate system between the aircraft and the intruding aircraft, define the adaptive airspace during the flight phase according to the DAA configuration parameters, and then conduct adaptive airspace detection. Based on the configured DAA parameters and adaptive airspace detection results, obtain the maneuvering conflict zone, maneuvering guidance zone and maneuver recovery zone corresponding to the heading, horizontal speed and vertical speed; The system issues an intrusion warning and, based on the flight phase, warning level, and the aircraft's own maneuverability limitations, determines the optimal maneuvering method and direction for the aircraft to avoid the intruding aircraft.

[0010] A further technical solution of the present invention is that the flight phase includes the takeoff and climb phase, the cruise phase, and the approach and landing phase; when the preceding flight phase is the cruise phase, the airspace is divided into NONE airspace, FAR airspace, MID airspace, and NEAR airspace according to the DAA parameters configured in Table 1; when the current flight phase is the takeoff and climb or approach and landing phase, the airspace is divided into NONE airspace, MID airspace, and NEAR airspace according to the DAA parameters configured in Table 1.

[0011] Table 1

[0012] A further technical solution of the present invention, wherein the steps for defining the adaptive airspace during the flight phase according to the DAA configuration parameters are as follows:

[0013] In the formula, Indicates adaptive airspace; Indicates the adaptive level of net airspace; Indicates adaptive vertical airspace; This represents the position vector of the aircraft. Represents the position vector of the intruding aircraft; This represents the velocity vector of the aircraft. Represents the velocity vector of the intruding aircraft; This represents the horizontal component of the aircraft's position vector; This represents the horizontal component of the intruding aircraft's position vector; This represents the horizontal component of the velocity vector of this aircraft. This represents the horizontal component of the velocity vector of the intruding aircraft. This represents the vertical component of the aircraft's position vector; Represents the vertical component of the intruding aircraft's position vector; This represents the vertical component of the velocity vector of this aircraft. Represents the vertical component of the velocity vector of the intruding aircraft; Indicates the horizontal distance threshold. Indicates the vertical distance threshold. This indicates the correction of the horizontal time threshold. Indicates the vertical time threshold; This indicates the distance between the point where this aircraft is closest to the intruding aircraft in horizontal direction; This represents the corrected state-time function; This indicates the time when the aircraft and the intruding aircraft intersect perpendicularly.

[0014] A further technical solution of the present invention provides the following expressions for the distance between the horizontal closest point of the aircraft and the intruding aircraft, the corrected state-time function, and the vertical intersection time between the aircraft and the intruding aircraft: .

[0015] A further technical solution of the present invention includes the following steps for adaptive airspace detection: Based on the position and velocity vectors of the aircraft and the intruding aircraft, under the set constant velocity condition, it is determined within the look-ahead time interval. Whether an intrusion will occur, and output the time interval when the intrusion occurs; where the upper bound of the look-ahead time interval is equal to the advance warning time. ; Obtain adaptive vertical airspace clearance detection results and adaptive horizontal airspace clearance detection results, and obtain adaptive airspace clearance detection results based on the adaptive vertical airspace clearance detection results and adaptive horizontal airspace clearance detection results; The steps for obtaining adaptive vertical airspace detection results are as follows: 1) If and If a vertical intrusion occurs and remains in an intrusive state for the duration of the time interval, then the time interval will be... As a result of adaptive vertical airspace detection; 2) If and If the time interval is specified, it indicates that no vertical intrusion will occur within that time interval. As an adaptive vertical airspace detection result, the time interval is included. An empty time interval; 3) If conditions 1) and 2) are not met, then the target time interval is calculated as follows:

[0016] The target time interval will be used as the result of adaptive vertical airspace detection. The steps for obtaining adaptive level airspace detection results are as follows: 4) If and If this is the case, it indicates that a horizontal intrusion has occurred, and the time interval will be specified. As a result of adaptive level airspace detection; 5) If and Then the time interval As a result of adaptive level airspace detection; 6) If the conditions in steps 4) and 5) are not met, and or Then the time interval As a result of adaptive level net airspace detection, among which: ; 7) If the conditions in steps 4), 5), and 6) are not met, and Then the time interval As the result of adaptive level airspace detection, otherwise, the time interval will be used. As a result of adaptive level airspace detection; The steps for obtaining adaptive airspace detection results based on adaptive vertical airspace detection results and adaptive horizontal airspace detection results are as follows: 8) Results of adaptive vertical airspace detection ; 9) If Then the time interval As a result of adaptive airspace detection; 10) If and Then the time interval As a result of adaptive airspace detection; 11) If And not Then the time interval As a result of adaptive airspace detection; 12) If the conditions in steps 9), 10), and 11) are not met, let the detection results of the adaptive level airspace be... Then the time interval As a result of adaptive airspace detection; in, For the state of the aircraft Adaptive level of airspace at that time; For the state of the aircraft The adaptive net airspace detection results at that time; if the time interval of the adaptive net airspace detection results is empty, it indicates that in the look-ahead time interval... No intrusion occurred.

[0017] A further technical solution of the present invention includes the following steps for obtaining the mobile conflict zone: 1) Initialization ; 2) Based on the aircraft's status Adaptive airspace detection results Determine if an intrusion has occurred. If the adaptive airspace detection result indicates an intrusion has occurred, update... If the adaptive airspace detection result indicates no intrusion, then the aircraft's status will be as follows: Time range The corresponding adaptive airspace detection results Determine if an empty time interval is returned. If not, update the maneuver conflict zone. If an empty time range is returned, then update the time. Update the mobility The aircraft's position is updated based on a trajectory prediction function based on aircraft maneuvers: ; 3) If and (Execute step 2); otherwise, initialize. ; 4) Based on the results of the adaptive airspace assessment Determine if an intrusion has occurred; if so, update the mobile conflict zone. Otherwise, according to Determine if an empty time interval is returned. If not, update the maneuver conflict zone. If an empty time range is returned, then update the time. Update the mobility The aircraft's position is updated based on a trajectory prediction function based on aircraft maneuvers: ; 5) If and Execute step 4); otherwise, output the maneuvering conflict zone. ; The upper bound of the forward time interval is equal to the warning time, i.e. , This indicates the current maneuverability value of the aircraft. This indicates the current rate of change of maneuver of the aircraft. This indicates the maximum maneuverability of this aircraft; This indicates the minimum maneuverability of this aircraft. Indicates the time step. This represents the change in the maneuver value within the predicted time step. This indicates the aircraft's heading, horizontal speed, and vertical speed in the initial state. and constant rate of change of maneuver The position function corresponding to the condition; This indicates the aircraft's heading, horizontal speed, and vertical speed in the initial state. and constant rate of change of maneuver The velocity function corresponding to the given conditions. This indicates the range of maneuvers that led to the intrusion, i.e., the maneuver conflict zone; when there is air... When an intruding aircraft is attacked, the maneuvering conflict zone corresponding to the aircraft and each intruding aircraft is calculated separately. Then, the union of all maneuvering conflict zones is taken as the maneuvering conflict zone of the aircraft against multiple intruding aircraft.

[0018] A further technical solution of the present invention includes the following steps for obtaining the maneuvering guidance belt: When adaptive airspace detection results In order to detect a conflict, the maneuvering range of this aircraft will be adjusted. Conflict zone with motor Obtain by taking the difference set This refers to the maneuvering guidance strip designed to prevent intrusion, which consists of several sub-sections. By traversing the sub-intervals, we find the two sub-intervals that are closest to the current maneuver value. We then take the two boundary values ​​of the two sub-intervals that are closest to the current maneuver value as the upper and lower bounds of the current maneuver guidance zone, and thus obtain the maneuver guidance zone.

[0019] A further technical solution of the present invention includes the following steps for obtaining the motor recovery strip: 1) Initialize the starting value of the time interval ; 2) Obtain the maneuver conflict zone based on the initial value of the time interval; 3) If If the above steps are not executed, proceed to step 4; otherwise, proceed to step 5. 4) Update the starting value of the time interval. Execute step 2). 5) Then output ; in, In For mobile recovery zone, This refers to the recovery time.

[0020] A further technical solution of the present invention is as follows: the intrusion alarm steps are as follows: according to the airspace danger level NONE airspace < FAR airspace < MID airspace < NEAR airspace, the alarm priority is defined as no alarm < prevention level alarm < correction level alarm < warning level alarm; if the adaptive net airspace detection results of various types of airspace are not empty within a time interval, then alarms are issued according to the priority from high to low.

[0021] A further technical solution of the present invention, the steps for obtaining the optimal maneuvering method and direction for the aircraft to avoid the intruding aircraft are as follows: 1) Obtain the maneuver recovery zone corresponding to the heading, horizontal speed, and vertical speed respectively. ; 2) According to If the maneuver conflict zones corresponding to the heading, horizontal speed and vertical speed are obtained respectively, then the maneuver values ​​of the heading, horizontal speed and vertical speed of this aircraft must be in the sub-interval of its corresponding maneuver conflict zone; 3) Traverse the maneuvering conflict zones by heading, horizontal speed, and vertical speed respectively. Find the sub-interval where the current maneuver value is located, i.e. , The sub-interval number is the upper and lower bounds of which are the maneuver values ​​closest to the recovery zone. 4) Through The heading, horizontal speed, and vertical speed correspond to the two maneuvering targets above and below, respectively. 5) If the current flight phase is the takeoff and climb phase or the approach and landing phase, and the alarm level is the correction level alarm, select vertical speed as the optimal maneuvering mode. Based on the positive and negative maximum vertical acceleration of the aircraft's maneuvering characteristics, calculate the minimum time required to reach the corresponding upper and lower maneuvering targets from the current vertical speed. The maneuvering direction corresponding to the minimum time is the optimal maneuvering direction. 6) If the current flight phase is the cruise phase and the alarm level is the preventive alarm, select the horizontal speed as the optimal maneuver. Based on the positive and negative maximum horizontal acceleration of the aircraft's maneuver characteristics, calculate the minimum time required to reach the corresponding upper and lower maneuver targets from the current horizontal speed. The maneuver direction corresponding to the minimum time is the optimal maneuver direction. 7) If it is not the case of steps 5) and 6), then the maneuverability characteristics of this aircraft, including the maximum rate of change of heading, positive and negative maximum horizontal acceleration, and positive and negative maximum vertical acceleration, are used to calculate the minimum time required to reach the corresponding upper and lower maneuver targets from the current heading, horizontal speed and vertical speed. The maneuver mode and maneuver direction corresponding to the minimum time are the optimal maneuver mode and direction.

[0022] The beneficial effects of this invention are: This invention enables aircraft to effectively identify potential threats in complex low-altitude flight environments and provides highly adaptive avoidance strategies. Furthermore, the low-altitude aircraft detection method designed in this invention determines the likelihood of intrusion through horizontal and vertical detection, while simultaneously calculating the time required to enter and leave the adaptive airspace, making it more predictive. The designed avoidance method can obtain the maneuver conflict zone, maneuver guidance zone, and maneuver recovery zone corresponding to various maneuvers, providing greater guidance and intuitiveness. Finally, based on the aircraft's maneuverability, the avoidance time required for various maneuvers can be calculated, thereby adaptively selecting the optimal avoidance strategy. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a flowchart of a low-altitude aircraft detection and avoidance method according to the present invention; Figure 2 This is a schematic diagram of the process for obtaining the maneuvering conflict zone in a specific embodiment of the present invention; Figure 3 This is a schematic diagram of the intrusion alarm process in a specific embodiment of the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] An embodiment of the low-altitude aircraft detection and avoidance method of the present invention, such as... Figure 1 As shown, it includes: S1. Configure DAA parameters and divide the spatial domain; Specifically, based on the current flight phase of the aircraft, the corresponding DAA parameters are configured, and the airspace is divided according to the DAA parameters.

[0027] For example, in one specific embodiment, the flight phase includes the takeoff and climb phase, the cruise phase, and the approach and landing phase; the airspace around the aircraft is divided into NONE airspace, FAR airspace, MID airspace, and NEAR airspace according to the DAA parameters, wherein the flight phase and airspace are shown in Table 1. The flight phase includes the takeoff and climb phase, the cruise phase, and the approach and landing phase; when the previous flight phase is the cruise phase, the airspace is divided into NONE airspace, FAR airspace, MID airspace, and NEAR airspace according to the DAA parameters configured in Table 1; when the current flight phase is the takeoff and climb or approach and landing phase, the airspace is divided into NONE airspace, MID airspace, and NEAR airspace according to the DAA parameters configured in Table 1.

[0028] Table 1

[0029] Among them, Table 1 Indicates the horizontal distance threshold. Indicates the vertical distance threshold. This indicates the correction of the horizontal time threshold. Indicates the vertical time threshold; This indicates the advance warning time.

[0030] S2. Define the adaptive airspace during the flight phase and obtain the adaptive airspace detection results; Specifically, a relative coordinate system is established between the aircraft and the intruding aircraft, and an adaptive airspace is defined for the flight phase based on the DAA configuration parameters. Then, adaptive airspace detection is performed to obtain the adaptive airspace detection results.

[0031] For example, in one specific embodiment, the step of defining the adaptive airspace for a flight phase according to DAA configuration parameters is as follows:

[0032] In the formula, Indicates adaptive airspace; Indicates the adaptive level of net airspace; Indicates adaptive vertical airspace; This represents the position vector of the aircraft. Represents the position vector of the intruding aircraft; This represents the velocity vector of the aircraft. Represents the velocity vector of the intruding aircraft; This represents the horizontal component of the aircraft's position vector; This represents the horizontal component of the intruding aircraft's position vector; This represents the horizontal component of the velocity vector of this aircraft. This represents the horizontal component of the velocity vector of the intruding aircraft. This represents the vertical component of the aircraft's position vector; Represents the vertical component of the intruding aircraft's position vector; This represents the vertical component of the velocity vector of this aircraft. Represents the vertical component of the velocity vector of the intruding aircraft; Indicates the horizontal distance threshold. Indicates the vertical distance threshold. This indicates the correction of the horizontal time threshold. Indicates the vertical time threshold; This indicates the distance between the point where this aircraft is closest to the intruding aircraft in horizontal direction; This represents the corrected state-time function; This indicates the time when the aircraft and the intruding aircraft intersect perpendicularly.

[0033] In this embodiment, the expressions for the horizontal closest point distance between the aircraft and the intruding aircraft, the corrected state-time function, and the vertical intersection time between the aircraft and the intruding aircraft are as follows: .

[0034] For example, in one specific embodiment, the step of obtaining adaptive airspace detection results through adaptive airspace detection is as follows: based on the position vectors and velocity vectors corresponding to the local aircraft and the intruding aircraft, under a set constant velocity condition, it is determined that within the look-ahead time interval... Whether an intrusion will occur internally, and output the time interval when an intrusion occurs; where the upper bound of the look-ahead time interval is equal to the advance warning time. ,in,( ); among them, adaptive airspace detection results Including adaptive vertical airspace detection results and adaptive horizontal airspace detection results, in this embodiment, S21, obtain adaptive vertical airspace detection results, S22, obtain adaptive horizontal airspace detection results, and S23, obtain adaptive airspace detection results based on adaptive vertical airspace detection results and adaptive horizontal airspace detection results.

[0035] Among them, such as Figure 2 As shown, in this embodiment, S21, obtain the adaptive vertical airspace detection results. The steps are as follows: S211, if and If a vertical intrusion occurs and remains in an intrusive state for the duration of the time interval, then the time interval will be... As a result of adaptive vertical airspace detection; S212, if and If the time interval is specified, it indicates that no vertical intrusion will occur within that time interval. As an adaptive vertical airspace detection result, the time interval is included. An empty time interval; S213. If the conditions in steps S211 and S212 are not met, then the target time interval is calculated as follows:

[0036] The target time interval is used as the result of adaptive vertical airspace detection.

[0037] In this embodiment, S22, obtaining the adaptive horizontal airspace detection results. The steps are as follows: S221, if and If this is the case, it indicates that a horizontal intrusion has occurred, and the time interval will be specified. As a result of adaptive level airspace detection; S222, if and Then the time interval As a result of adaptive level airspace detection; S223. If the conditions of steps S221 and S222 are not met, and or Then the time interval As a result of adaptive level net airspace detection, among which: ; S224. If the conditions of steps S222, S221, and S223 are not met, and Then the time interval As the result of adaptive level airspace detection, otherwise, the time interval will be used. As a result of adaptive level airspace detection.

[0038] In this embodiment, step S23, obtaining the adaptive airspace detection result based on the adaptive vertical airspace detection result and the adaptive horizontal airspace detection result, is as follows: S231, Results of Adaptive Vertical Clearance Detection ; S232, if Then the time interval As a result of adaptive airspace detection; S233, if and Then the time interval As a result of adaptive airspace detection; S234, if And not Then the time interval As a result of adaptive airspace detection; S235. If the conditions of steps S232, S233, and S234 are not met, let the detection results of the adaptive level airspace be... Then the time interval As a result of adaptive airspace detection; in, For the state of the aircraft Adaptive level of airspace at that time; For the state of the aircraft The adaptive airspace clearance detection results are defined as time intervals in this embodiment. ; This indicates entry into the adaptive airspace; This indicates the time of departure from the adaptive net airspace. If the time interval of the adaptive net airspace detection result is empty, it indicates that the time interval is within the look-ahead time interval. No intrusion occurred.

[0039] Thus, the adaptive airspace detection results were obtained.

[0040] S3, acquire maneuver conflict zone, maneuver guidance zone and maneuver recovery zone; Specifically, based on the configured DAA parameters and adaptive airspace detection results, the maneuvering conflict zone, maneuvering guidance zone, and maneuver recovery zone corresponding to the heading, horizontal speed, and vertical speed are obtained; For example, in one specific embodiment, step S31, the step of obtaining the maneuvering conflict zone, is as follows: S311, Initialization ; S312. Obtain the aircraft's status according to step S2. Adaptive airspace detection results Determine if an intrusion has occurred. If the adaptive airspace detection result indicates an intrusion has occurred, update... If the adaptive airspace detection result indicates no intrusion, then the aircraft's status will be as follows: Time range The corresponding adaptive airspace detection results Determine if an empty time interval is returned. If not, update the maneuver conflict zone. If an empty time range is returned, then update the time. Update the mobility The aircraft's position is updated based on a trajectory prediction function based on aircraft maneuvers:

[0041] S313, if and Execute step S312; otherwise, initialize. ; S314. Obtain the adaptive airspace assessment result based on step S2. And determine if an intrusion has occurred; if so, update the mobile conflict zone. Otherwise, according to Determine if an empty time interval is returned. If not, update the maneuver conflict zone. If an empty time range is returned, then update the time. Update the mobility The aircraft's position is updated based on a trajectory prediction function based on aircraft maneuvers:

[0042] S315, if and Execute step S314; otherwise, output the motor conflict zone. ; The upper bound of the forward time interval is equal to the warning time, i.e. , This indicates the current maneuverability value of the aircraft. This indicates the current rate of change of maneuver of the aircraft. This indicates the maximum maneuverability of this aircraft; This indicates the minimum maneuverability of this aircraft. Indicates the time step. This represents the change in the maneuver value within the predicted time step. This indicates the aircraft's heading, horizontal speed, and vertical speed in the initial state. and constant rate of change of maneuver The position function corresponding to the condition; This indicates the aircraft's heading, horizontal speed, and vertical speed in the initial state. and constant rate of change of maneuver The velocity function corresponding to the given conditions. Indicates the range of maneuvers that led to the intrusion, i.e., when there is airborne... When an intruding aircraft is deployed, the collision zone between this aircraft and each intruding aircraft should be calculated separately. Then take the union. This yields the conflict zone targeting multiple intruding aircraft. .

[0043] For example, in one specific embodiment, the maneuvering guidance belt is acquired. The steps are as follows: when the adaptive airspace detection results In order to detect a conflict, the maneuvering range of this aircraft will be adjusted. Conflict zone with motor Obtain by taking the difference set This refers to the maneuvering guidance strip designed to prevent intrusion, which consists of several sub-sections. By traversing the sub-intervals, we find the two sub-intervals that are closest to the current maneuver value. We then take the two boundary values ​​of the two sub-intervals that are closest to the current maneuver value as the upper and lower bounds of the current maneuver guidance zone, and thus obtain the maneuver guidance zone.

[0044] For example, in one specific embodiment, step S32, obtaining the motor recovery strip, is as follows: The maneuver recovery zone is when the maneuver conflict zone is... When this occurs, it indicates that there are no more maneuvers to avoid the intrusion. The maneuverability to escape the intrusion state should be calculated, i.e., the maneuver recovery zone. For: When adaptive airspace detection results In order to detect a conflict, the maneuvering range of this aircraft will be adjusted. Conflict zone with motor Obtain by taking the difference set This refers to the maneuvering guidance strip designed to prevent intrusion, which consists of several sub-sections. By traversing the sub-intervals, we find the two sub-interval boundary values ​​that are closest to the current maneuver value. We then use the two boundary values ​​of the two sub-intervals that are closest to the current maneuver value as the upper and lower bounds of the current maneuver guidance zone, and thus obtain the maneuver guidance zone.

[0045] Step S321: Initialize the starting value of the time interval ; Step S322: Obtain the maneuver conflict zone based on the initial value of the time interval; Step S323, if If the condition is met, proceed to step S324; otherwise, proceed to step S325. Step S324: Update the starting value of the time interval. Execute step S322; Step S325 Then output ; in, In For mobile recovery zone, This refers to the recovery time.

[0046] Thus, the maneuver recovery zone, the maneuver conflict zone, and the maneuver guidance zone were obtained.

[0047] S4. Obtain the optimal maneuvering method and direction for this aircraft to avoid the intruding aircraft; Specifically, based on the flight phase, alarm level, and the aircraft's own maneuverability limitations, the optimal maneuvering method and direction for the aircraft to avoid the intruding aircraft are obtained.

[0048] For example, in one specific embodiment, the present invention further includes: an intrusion alarm, wherein the intrusion alarm step is as follows: according to the airspace hazard level NONE airspace < FAR airspace < MID airspace < NEAR airspace, the alarm priority is defined as no alarm < preventive alarm < corrective alarm < warning alarm; if the adaptive net airspace detection results for each type of airspace are not empty within a time interval, then an alarm is issued according to the priority from high to low. Wherein, for example... Figure 3 As shown, the aircraft is in the cruise flight phase. At that moment, the intrusion aircraft was in NONE airspace, and there were no alarms. At that moment, the intruding aircraft was in FAR airspace, triggering a preventative warning and generating a directional maneuvering conflict zone; the remaining directional maneuvers served as guidance zones. At that moment, the intruding aircraft was in the MID airspace, triggering a correction-level warning and generating a directional maneuvering conflict zone; the remaining directional maneuvers served as guidance zones. At that moment, the intruding aircraft was in the NEAR airspace, triggering a warning-level alert and generating a heading maneuver conflict zone. The remaining heading maneuvers were maneuver recovery zones.

[0049] For example, in one specific embodiment, the steps for obtaining the optimal maneuvering method and direction for the aircraft to avoid the intruding aircraft are as follows: S41. Obtain the maneuver recovery zones corresponding to heading, horizontal speed, and vertical speed respectively through step S32. ; S42, according to If the maneuver conflict zones corresponding to the heading, horizontal speed and vertical speed are obtained respectively, then the maneuver values ​​of the heading, horizontal speed and vertical speed of this aircraft must be in the sub-interval of its corresponding maneuver conflict zone; S43, Traversing the maneuvering conflict zone by heading, horizontal speed, and vertical speed respectively. Find the sub-interval where the current maneuver value is located, i.e. , The sub-interval number is the upper and lower bounds of which are the maneuver values ​​closest to the recovery zone. S44, Through The heading, horizontal speed, and vertical speed correspond to the two maneuvering targets above and below, respectively. S45. If the current flight phase is the takeoff and climb phase or the approach and landing phase, and the alarm level is the correction level alarm, select vertical speed as the optimal maneuvering mode. Based on the positive and negative maximum vertical acceleration of the aircraft's maneuvering characteristics, calculate the minimum time required to reach the corresponding upper and lower maneuvering targets from the current vertical speed. The maneuvering direction corresponding to the minimum time is the optimal maneuvering direction.

[0050] S46. If the current flight phase is the cruise phase and the alarm level is the preventive level alarm, select the horizontal speed as the optimal maneuver. Based on the positive and negative maximum horizontal acceleration of the aircraft's maneuver characteristics, calculate the minimum time required to reach the corresponding upper and lower maneuver targets from the current horizontal speed. The maneuver direction corresponding to the minimum time is the optimal maneuver direction.

[0051] S47. If it is not the case of steps 45) and 46), then the maneuverability characteristics of this aircraft, including the maximum rate of change of heading, positive and negative maximum horizontal acceleration, and positive and negative maximum vertical acceleration, are used to calculate the minimum time required to reach the corresponding upper and lower maneuver targets from the current heading, horizontal speed and vertical speed. The maneuver mode and maneuver direction corresponding to the minimum time are the optimal maneuver mode and direction.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for detecting and avoiding low-altitude aircraft, characterized in that, include: Configure the corresponding DAA parameters according to the current flight phase of the aircraft, and divide the airspace according to the DAA parameters; Establish a relative coordinate system between the aircraft and the intruding aircraft, define the adaptive airspace during the flight phase according to the DAA configuration parameters, and then conduct adaptive airspace detection. Based on the configured DAA parameters and adaptive airspace detection results, obtain the maneuvering conflict zone, maneuvering guidance zone and maneuver recovery zone corresponding to the heading, horizontal speed and vertical speed; The system issues an intrusion warning and, based on the flight phase, warning level, and the aircraft's own maneuverability limitations, determines the optimal maneuvering method and direction for the aircraft to avoid the intruding aircraft.

2. The method for detecting and avoiding low-altitude aircraft according to claim 1, characterized in that, Flight phases include takeoff and climb, cruise, and approach and landing. When the preceding flight phase is cruise, the airspace is divided into NONE, FAR, MID, and NEAR airspace according to DAA parameters. When the current flight phase is takeoff and climb or approach and landing, the airspace is divided into NONE, MID, and NEAR airspace according to DAA parameters.

3. The method for detecting and avoiding low-altitude aircraft according to claim 1, characterized in that, The steps for defining the adaptive airspace for the flight phase based on DAA configuration parameters are as follows: In the formula, Indicates adaptive airspace; Indicates the adaptive level of net airspace; Indicates adaptive vertical airspace; This represents the position vector of the aircraft. Represents the position vector of the intruding aircraft; This represents the velocity vector of the aircraft. Represents the velocity vector of the intruding aircraft; This represents the horizontal component of the aircraft's position vector; This represents the horizontal component of the intruding aircraft's position vector; This represents the horizontal component of the velocity vector of this aircraft. This represents the horizontal component of the velocity vector of the intruding aircraft. This represents the vertical component of the aircraft's position vector; Represents the vertical component of the intruding aircraft's position vector; This represents the vertical component of the velocity vector of this aircraft. Represents the vertical component of the velocity vector of the intruding aircraft; Indicates the horizontal distance threshold. Indicates the vertical distance threshold. This indicates the correction of the horizontal time threshold. Indicates the vertical time threshold; This indicates the distance between the point where this aircraft is closest to the intruding aircraft in horizontal direction; This represents the corrected state-time function; This indicates the time when the aircraft and the intruding aircraft intersect perpendicularly.

4. The method for detecting and avoiding low-altitude aircraft according to claim 3, characterized in that, The expressions for the horizontal closest point distance between this aircraft and the intruding aircraft, the corrected state-time function, and the vertical intersection time between this aircraft and the intruding aircraft are as follows: 。 5. The method for detecting and avoiding low-altitude aircraft according to claim 3, characterized in that, The steps of adaptive airspace detection are as follows: Based on the position and velocity vectors of the aircraft and the intruding aircraft, under the set constant velocity condition, it is determined within the look-ahead time interval. Whether an intrusion will occur within the system, and output the time interval at which the intrusion will occur; where the upper bound of the look-ahead time interval is equal to the warning time. ; Obtain adaptive vertical airspace clearance detection results and adaptive horizontal airspace clearance detection results, and obtain adaptive airspace clearance detection results based on the adaptive vertical airspace clearance detection results and adaptive horizontal airspace clearance detection results; The steps for obtaining adaptive vertical airspace detection results are as follows: 1) If and If a vertical intrusion occurs and remains in an intrusive state for the duration of the time interval, then the time interval will be... As a result of adaptive vertical airspace detection; 2) If and If the time interval is specified, it indicates that no vertical intrusion will occur within that time interval. As an adaptive vertical airspace detection result, the time interval is included. An empty time interval; 3) If conditions 1) and 2) are not met, then the target time interval is calculated as follows: The target time interval will be used as the result of adaptive vertical airspace detection. The steps for obtaining adaptive level airspace detection results are as follows: 4) If and If this is the case, it indicates that a horizontal intrusion has occurred, and the time interval will be specified. As a result of adaptive level airspace detection; 5) If and Then the time interval As a result of adaptive level airspace detection; 6) If the conditions in steps 4) and 5) are not met, and or Then the time interval As a result of adaptive level net airspace detection, among which: ； 7) If the conditions in steps 4), 5), and 6) are not met, and Then the time interval As the result of adaptive level airspace detection, otherwise, the time interval will be used. As a result of adaptive level airspace detection; The steps for obtaining adaptive airspace detection results based on adaptive vertical airspace detection results and adaptive horizontal airspace detection results are as follows: 8) Results of adaptive vertical airspace detection ; 9) If Then the time interval As a result of adaptive airspace detection; 10) If and Then the time interval As a result of adaptive airspace detection; 11) If And not Then the time interval As a result of adaptive airspace detection; 12) If the conditions in steps 9), 10), and 11) are not met, let the detection results of the adaptive level airspace be... Then the time interval As a result of adaptive airspace detection; in, For the state of the aircraft Adaptive level of airspace at that time; For the state of the aircraft The adaptive net airspace detection results at that time; if the time interval of the adaptive net airspace detection results is empty, it indicates that in the look-ahead time interval... No intrusion occurred.

6. The method for detecting and avoiding low-altitude aircraft according to claim 1, characterized in that, The steps to obtain the maneuver conflict zone are as follows: 1) Initialization ; 2) Based on the aircraft's status Adaptive airspace detection results Determine if an intrusion has occurred. If the adaptive airspace detection result indicates an intrusion has occurred, update... If the adaptive airspace detection result indicates no intrusion, then the aircraft's status will be as follows: Time range The corresponding adaptive airspace detection results Determine if an empty time interval is returned. If not, update the maneuver conflict zone. If an empty time range is returned, then update the time. Update the mobility The aircraft's position is updated based on a trajectory prediction function based on aircraft maneuvers: ； 3) If and (Execute step 2); otherwise, initialize. ; 4) Based on the results of the adaptive airspace assessment Determine if an intrusion has occurred; if so, update the mobile conflict zone. Otherwise, according to Determine if an empty time interval is returned. If not, update the maneuver conflict zone. If an empty time range is returned, then update the time. Update the mobility The aircraft's position is updated based on a trajectory prediction function based on aircraft maneuvers: ； 5) If and Execute step 4); otherwise, output the maneuvering conflict zone. ; The upper bound of the look-ahead time interval is equal to the warning time, i.e. , This indicates the current maneuverability value of the aircraft. This indicates the current rate of change of maneuver of the aircraft. This indicates the maximum maneuverability of this aircraft; This indicates the minimum maneuverability of this aircraft. Indicates the time step. This represents the change in the maneuver value within the predicted time step. This indicates the aircraft's heading, horizontal speed, and vertical speed in the initial state. and constant rate of change of maneuver The position function corresponding to the condition; This indicates the aircraft's heading, horizontal speed, and vertical speed in the initial state. and constant rate of change of maneuver The velocity function corresponding to the given conditions. This indicates the range of maneuvers that led to the intrusion, i.e., the maneuver conflict zone; when there is air... When an intruding aircraft is attacked, the maneuvering conflict zone corresponding to the aircraft and each intruding aircraft is calculated separately. Then, the union of all maneuvering conflict zones is taken as the maneuvering conflict zone of the aircraft against multiple intruding aircraft.

7. The method for detecting and avoiding low-altitude aircraft according to claim 1, characterized in that, The steps to obtain the maneuvering guidance belt are as follows: When adaptive airspace detection results In order to detect a conflict, the maneuvering range of this aircraft will be adjusted. Conflict zone with motor Obtain by taking the difference set This refers to the maneuvering guidance strip designed to prevent intrusion, which consists of several sub-sections. By traversing the sub-intervals, we find the two sub-intervals that are closest to the current maneuver value. We then take the two boundary values ​​of the two sub-intervals that are closest to the current maneuver value as the upper and lower bounds of the current maneuver guidance zone, and thus obtain the maneuver guidance zone.

8. The method for detecting and avoiding low-altitude aircraft according to claim 1, characterized in that, The steps to obtain a motor recovery belt are as follows: 1) Initialize the starting value of the time interval ; 2) Obtain the maneuver conflict zone based on the initial value of the time interval; 3) If If the above steps are not executed, proceed to step 4; otherwise, proceed to step 5. 4) Update the starting value of the time interval. Execute step 2). 5) Then output ; in, In For mobile recovery zone, This refers to the recovery time.

9. A method for detecting and avoiding low-altitude aircraft according to claim 2, characterized in that, The intrusion alarm steps are as follows: Based on the airspace hazard level, NONE airspace < FAR airspace < MID airspace < NEAR airspace, the alarm priority is defined as no alarm < preventive alarm < corrective alarm < warning alarm; If the adaptive net airspace detection results for various airspaces are not empty within a given time interval, then an alarm will be issued according to priority from high to low.

10. A method for detecting and avoiding low-altitude aircraft according to claim 9, characterized in that, The steps to obtain the optimal maneuvering method and direction for this aircraft to avoid the intruding aircraft are as follows: 1) Obtain the maneuver recovery zone corresponding to the heading, horizontal speed, and vertical speed respectively. ; 2) According to If the maneuver conflict zones corresponding to the heading, horizontal speed and vertical speed are obtained respectively, then the maneuver values ​​of the heading, horizontal speed and vertical speed of this aircraft must be in the sub-interval of its corresponding maneuver conflict zone; 3) Traverse the maneuvering conflict zones by heading, horizontal speed, and vertical speed respectively. Find the sub-interval where the current maneuver value is located, i.e. , The sub-interval number is the upper and lower bounds of which are the maneuver values ​​closest to the recovery zone. 4) Through The heading, horizontal speed, and vertical speed correspond to the two maneuvering targets above and below, respectively. 5) If the current flight phase is the takeoff and climb phase or the approach and landing phase, and the alarm level is the correction level alarm, select vertical speed as the optimal maneuvering mode. Based on the positive and negative maximum vertical acceleration of the aircraft's maneuvering characteristics, calculate the minimum time required to reach the corresponding upper and lower maneuvering targets from the current vertical speed. The maneuvering direction corresponding to the minimum time is the optimal maneuvering direction. 6) If the current flight phase is the cruise phase and the alarm level is the preventive alarm, select the horizontal speed as the optimal maneuver. Based on the positive and negative maximum horizontal acceleration of the aircraft's maneuver characteristics, calculate the minimum time required to reach the corresponding upper and lower maneuver targets from the current horizontal speed. The maneuver direction corresponding to the minimum time is the optimal maneuver direction. 7) If it is not the case of steps 5) and 6), then the maneuverability characteristics of this aircraft, including the maximum rate of change of heading, positive and negative maximum horizontal acceleration, and positive and negative maximum vertical acceleration, are used to calculate the minimum time required to reach the corresponding upper and lower maneuver targets from the current heading, horizontal speed and vertical speed. The maneuver mode and maneuver direction corresponding to the minimum time are the optimal maneuver mode and direction.

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