KR102096376B1 - Closest Point of Approach Based Aircraft Collision Avoidance Method with Minimum Time of Closest Approach and Converging Approach Geometry Conditions - Google Patents

Abstract

The present invention relates to a collision avoidance method based on a closest point of approach (CPA). More particularly, the present invention relates to a CPA-based aircraft collision avoidance technique to which a minimum closest approach time and converging approach geometry conditions are applied. The present invention includes: a state acquisition step of acquiring the respective locations and speed values of an aircraft and an intruder; a closest approach value calculation step of predicting and calculating a closest approach time and the respective CPAs of the intruder and the aircraft based on the locations and the speeds of the intruder and the aircraft and calculating a predicted inter-CPA distance as the distance between the CPAs of the intruder and the aircraft; a collision risk condition determination step of determining the collision risk conditions of the intruder and the aircraft based on the closest approach time, the predicted inter-CPA distance, and a safety distance of the intruder; and a collision avoidance solution calculation step of calculating a collision avoidance solution speed of the aircraft for avoiding a collision of the aircraft with the intruder and a closest approach solution time corresponding to the collision avoidance solution speed.

Description

Closest Point of Approach Based Aircraft Collision Avoidance Method with Minimum Time of Closest Approach and Converging Approach Geometry Conditions}

The present invention relates to an aircraft collision avoidance method based on a recent contact point.

There are various methods of collision avoidance technology for aircraft, and the collision avoidance method based on the Closest Point of Approach (CPA) is calculated by geometrically and mathematically analyzing the state values such as position and speed for moving objects. This is mainly used.

 In the case of the prior art, the collision risk condition of the aircraft is determined based on the current state, and evasion is performed by setting the evasion direction. When the evasion is delayed while maintaining the existing route for another purpose, the evasion time is required. If the upper limit value is not properly set, a problem that the safety distance cannot be sufficiently avoided occurs. Therefore, in general, the upper limit of the time condition is set in consideration of the time required for the maneuvering of the aircraft, but an exceptional case may occur depending on the approach shape, and the avoidance direction may be set in a direction to advance the collision risk time. In this case, there is a risk that safe evasion cannot be guaranteed if the aircraft is not evaded before reaching the upper limit of time conditions.

Republic of Korea Registered Patent Publication No. 10-1307179 "ship collision prediction device and its operation method"

Hyunjin Choi, Youdan Kim, Inseok Hwang, “Reactive Collision Avoidance of Unmanned Aerial Vehicles Using a Single Vision Sensor”, JOURNAL OF GUIDANCE, CONTROL, AND DYNAMICS Vol. 36, No. 4, July-August 2013

The present invention has been devised in order to solve the above problems, and considers not only the closest time of the current state of the aircraft and the intruder, but also the closest time when the aircraft performs collision avoidance with the intruder, and selects the minimum value. Criteria for avoiding collision is proposed.

In addition, when the intruder approaches with the acute angle of the aircraft converging, there is a case where the direct distance from the intruder is closer than the distance to the nearest point or the distance for turning is not sufficiently secured according to the evasion direction. . In contrast, the present invention further provides a collision avoidance condition by further considering the convergent approach geometry.

,

) 와 각각의 속도벡터(

,

)를 획득하는 상태획득단계(S100), 상기 항공기와 상기 침입기 각각의 상기 위치벡터(

,

)와 각각의 상기 속도벡터(

,

)를 기초로 최근접 시간(t_CPA) 및 상기 침입기와 상기 항공기 각각의 최근접점 위치벡터(

,

)를 예측하여 계산하고, 상기 침입기 최근접점 위치벡터(

)와 상기 항공기 최근접점 위치벡터(

) 사이의 거리인 최근접점 사이 예측거리(d_CPA)를 계산하는 최근접 값 계산단계(S200), 상기 최근접 시간(t_CPA)과 상기 최근접점 사이 예측거리(d_CPA) 및 상기 침입기의 안전거리(d_safe)를 기초로 상기 침입기와 상기 항공기의 충돌위험 조건을 판단하는 충돌위험 조건 판단단계(S300) 및 상기 항공기가 상기 침입기와의 충돌을 회피하기 위해 상기 항공기와 상기 침입기 각각의 속도벡터(

,

)와 상기 침입기의 안전거리(d_safe)를 기초로 상기 항공기의 충돌회피 솔루션 속도벡터(

)를 계산하고 상기 충돌회피 솔루션 속도벡터(

)에 상응하는 최근접 솔루션 시간(t_CPA,s)을 계산하는 충돌회피 솔루션 계산단계(S400)를 포함하는 최소 최근접 시간 및 수렴접근기하 조건을 적용한 최근접점 기반 항공기 충돌회피 방법이 개시된다.In order to achieve the above object, the present invention is a closest point of approach (CPA) based collision avoidance method, the position vector of each aircraft and intruder (

,

) And their respective velocity vectors (

,

) Obtaining the state (S100), the position vector of each of the aircraft and the intruder (

,

) And each of the velocity vectors (

,

Based on), the closest time (t _CPA ) and the closest position vector of each of the intruder and the aircraft (

,

), And calculates the location vector of the nearest point of the intruder (

) And the aircraft's closest position vector (

) Estimated distance between the closest point distance between (d _CPA) between the closest point and to calculate the closest value calculation step (S200), the closest time (t _CPA) estimated distance (d _CPA) and of the intrusion group Collision risk condition determination step (S300) of determining the collision risk condition of the intruder and the aircraft based on a _safe distance (d _safe ) and each of the aircraft and the intruder to avoid collision of the aircraft with the intruder Velocity vector (

,

) And the speed vector of the collision avoidance solution of the aircraft based on the _safe distance of the intruder (d _safe )

) And calculate the collision avoidance solution velocity vector (

Disclosed is an approach method for collision avoidance based on a closest approach based on a convergence approach geometry and a minimum nearest time, which includes a collision avoidance solution calculation step (S400) for calculating the nearest solution time (t _{CPA, s} ) corresponding to).

In addition, a first auxiliary condition parameter calculation step of calculating a first minimum nearest time (t _{CPA, min1} ) based on the nearest time (t _CPA ) and the nearest solution time (t _{CPA, s} ) (S510) Characterized in that it further comprises.

)와 상기 충돌회피 솔루션 속도벡터(

) 사이 속도벡터들을 샘플링한 속도벡터들을 기초로 제2 최소 최근접 시간(t_CPA,min2)을 계산하는 제2 보조조건 파라미터 계산단계(S511)를 더 포함하는 것을 특징으로 한다.In addition, the aircraft speed vector (

) And the collision avoidance solution velocity vector (

It is characterized in that it further comprises a second auxiliary condition parameter calculation step (S511) for calculating the second minimum nearest time (t _{CPA, min2} ) based on the velocity vectors sampling the velocity vectors between).

In addition, the direction angle (χ) formed by the aircraft and the intruder, the convergence distance (d _conv ) between the aircraft and the intruder, and the required turning distance (d _ρ ) corresponding to the radius (ρ) required for the aircraft to turn It characterized in that it further comprises a third auxiliary condition parameter calculating step (S520) for calculating.

In addition, further comprising a first collision avoidance condition determination step (S610) for determining a collision avoidance condition on the basis of the upper limit time t _U of the avoidance start of the aircraft and the first minimum nearest time (t _{CPA, min1} ). It is characterized by.

In addition, a second collision avoidance condition determination step (S611) for determining a collision avoidance condition based on the upper limit time t _U of the avoidance start of the aircraft and the second minimum closest time t _{CPA, min2} is further included. It is characterized by.

In addition, a third collision avoidance condition determination step of determining a collision avoidance condition based on the direction angle (χ), the convergence distance (d _conv ), the required turning distance (d _ρ ) and the nearest time (t _CPA ) It characterized in that it further comprises (S620).

In addition, a fourth to determine a collision avoidance condition based on the direction angle (χ), the convergence distance (d _conv ), the required turning distance (d _ρ ) and the first minimum closest time (t _{CPA, min1} ) It characterized in that it further comprises a collision avoidance condition determination step (S621).

In addition, the fifth to determine the collision avoidance condition based on the direction angle (χ), the convergence distance (d _conv ), the required turning distance (d _ρ ) and the first minimum closest time (t _{CPA, min2} ) It characterized in that it further comprises a collision avoidance condition determination step (S622).

In addition, the aircraft is characterized in that it further comprises a collision avoidance performing step (S700) to perform a collision avoidance with the intruder.

The present invention according to the configuration as described above, by determining the collision avoidance using the minimum closest time condition, the variable margin at the upper limit of the evasion start time of the aircraft according to the collision avoidance direction of the aircraft and the approach state of the intruder You can get the added effect.

In addition, by applying the convergence approach geometry condition, when the intruder approaches as if the direction of the aircraft converges at an acute angle, the aircraft turns by adding a condition that compares the convergence distance between the aircraft and the intruder and the distance required for turning the aircraft. It is possible to obtain the effect of securing the distance for the.

In addition, by applying the minimum closest time and converging approach geometry conditions together, it is possible to obtain an effect of further securing a distance for turning the aircraft.

1 is a view schematically showing a concept according to a collision avoidance method based on a recent contact.
2 is a view showing the concept of collision avoidance based on the nearest contact based on the minimum close-time condition of the present invention.
3 is a view showing the concept of a collision avoidance based on a recent contact based on the convergence approach geometry condition according to the present invention.
4 is a flowchart schematically showing a method for avoiding collisions based on a closest approach based on the closest approach and convergence approach geometry of the present invention.
5 is a flowchart illustrating a method for avoiding collision of an aircraft based on the closest point to which the minimum closest time condition according to the first embodiment of the present invention is applied.
6 is a flow chart showing a method for avoiding collisions based on a recent approach based on a convergent approach geometry condition according to a second embodiment of the present invention.
7 is a flow chart showing a method for avoiding collisions based on a closest approach based on the closest approach time and the converged approach geometry condition according to an embodiment of the third embodiment of the present invention.
FIG. 8 is a flowchart illustrating a method for avoiding collisions based on a closest approach based on the closest time and converged approach geometry according to another embodiment of the third embodiment of the present invention.
9A is a graph showing an experiment result when using the general closest time condition, and FIG. 9B is using the minimum closest time condition according to the first embodiment of the present invention.
10A is a graph showing another experimental result when using the general closest time condition, and FIG. 10B is using the minimum closest time condition according to the first embodiment of the present invention.
11A is a graph of an experimental result when using a general collision avoidance condition, and FIG. 11B is using a converging approach geometry condition according to a second embodiment of the present invention.

The present invention can be applied to various changes and can have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains.

Hereinafter, the technical spirit of the present invention will be described in more detail with reference to the accompanying drawings.

The accompanying drawings are only examples shown in order to explain the technical spirit of the present invention in more detail, so the technical spirit of the present invention is not limited to the form of the accompanying drawings.

)은 일정하다고 가정하고, 상기 침입기의 현재 속력과 방향(속도벡터,

)을 기준으로 항공기와 상기 침입기 각각의 위치벡터(

,

)와 각각의 속도벡터(

,

)를 획득하는 상태획득단계(S100)를 수행한다. 이후 상기 항공기와 상기 침입기 각각의 상기 위치벡터(

,

)를 외삽(extrapolation)하여 서로 가장 가까워졌을 때의 상기 항공기와 상기 침입기 각각의 최근접점 위치벡터(

,

)와 최근접시간(t_CPA) 등의 정보를 계산하는 최근접 값 계산단계(S200)를 수행한다.In the case of a collision avoidance method based on a closest point of approach (CPA), the access geometry is considered as shown in FIG. 1. The speed and direction of the intruder (velocity vector,

) Is constant, and the current speed and direction of the intruder (velocity vector,

Position vector of each of the aircraft and the intruder based on)

,

) And their respective velocity vectors (

,

) Is performed (S100). Then, the position vector of each of the aircraft and the intruder (

,

) Is extrapolated to the nearest vector of each position of the aircraft and the intruder when they are closest to each other (

,

) And the nearest value calculation step (S200) for calculating information such as the nearest time (t _CPA ).

)와 상기 침입기 위치벡터(

)의 상대위치벡터(

)는 아래 수학식 1If the closest value calculation step (S200) is mathematically arranged as an example, the aircraft position vector (

) And the position vector of the intruder (

) Relative position vector (

) Is the following equation 1

[Equation 1]

)와 상기 침입기 속도벡터(

)의 상대속도벡터(

)는 아래 수학식 2Defined as, and the aircraft velocity vector (

) And the velocity vector of the intruder (

) 'S relative velocity vector (

) Is Equation 2 below

[Equation 2]

,

)는 아래 수학식 3Is defined as The closest time (t _CPA ) and the closest position vector of each of the intruder and the aircraft (

,

) Is Equation 3 below

[Equation 3]

If you obtain through, Equation 4

[Equation 4]

The closest time (t _CPA ) can be obtained.

)와 상기 침입기 최근접점 위치벡터(

)는 수학식 5In addition, the position vector of the aircraft's closest point is predicted by predicting the position moved by the closest time (t _CPA ) from the current position.

) And the position vector of the nearest point of the intruder (

) Is Equation 5

[Equation 5]

Can be obtained through

)와 상기 침입기 최근접점 위치벡터(

) 사이의 예측거리(d_CPA)는 아래 수학식 6At this time, the aircraft's closest position vector (

) And the position vector of the nearest point of the intruder (

), The predicted distance (d _CPA ) is

[Equation 6]

)가 상기 침입기 주변으로 상기 안전거리(d_safe) 만큼의 원을 향하는 방향을 나타낸다.Can be obtained as Here, the d _safe is a predetermined safety distance of the intruder. The situation for equation (6) is the relative velocity vector of FIG. 1 (

) Indicates a direction toward the circle of the _safe distance (d _safe ) around the intruder.

,

) 사이의 상기 예측거리(d_CPA)가 상기 침입기 안전거리(d_safe) 보다 작은 경우 충돌위험이 있다고 판단하는 충돌위험 조건 판단단계(S300)를 수행한다. 상기 충돌위험 조건 판단단계(S300)에서, 예를 들어서, 도 1과 같이 상기 침입기 주변으로 상기 안전거리(d_safe) 만큼의 원이 있다고 가정할 때, 상기 항공기와 상기 침입기 사이의 상기 상대속도벡터(

)가 상기 원 안을 향하고 있으면 충돌위험이 존재한다고 해석할 수도 있다.At this time, the position vector of the closest point of each of the aircraft and the intruder (

,

), If the predicted distance d _CPA is smaller than the intruder safety distance d _safe , a collision risk condition determination step S300 is performed. In the collision risk condition determination step (S300), for example, assuming that there is a circle of the safe distance (d _safe ) around the intruder as shown in Figure 1, the opponent between the aircraft and the intruder Velocity vector (

) Can be interpreted as the presence of a collision hazard if it is directed inside the circle.

When the collision risk condition determination step (S300) is mathematically summarized as an example, when considering Equation 4 as a reference, the basic condition for determining that there is a collision risk in general is the closest time (t _CPA ). If> 0 and the predicted distance (d _CPA ) <the safe distance (d _safe ) are satisfied at the same time, it can be determined as a collision risk condition.

)의 크기(속력) 또는 상기 항공기 속도벡터(

)의 방향(헤딩각)을 조정하여 도 2의 상기 항공기 속도벡터(

)의 방향이 상기 침입기 주변의 원 밖으로 향하도록 상기 항공기의 충돌회피 솔루션 속도벡터(

)와 상기 충돌회피 솔루션 속도벡터(

)에 상응하는 최근접 솔루션 시간(t_CPA,s)을 계산하게 된다.Then, a collision avoidance solution calculation step (S400) is performed. In the collision avoidance solution calculation step (S400), when the collision risk is determined, the aircraft speed vector (

) Size (speed) or the aircraft speed vector (

) Direction (heading angle) to adjust the aircraft speed vector (

) The direction of the collision avoidance solution velocity vector of the aircraft so that the direction is out of the circle around the intruder (

) And the collision avoidance solution velocity vector (

) Corresponds to the nearest solution time (t _{CPA, s} ).

)로 충돌회피명령을 생성하면 상기 항공기의 충돌회피를 수행할 수 있다. 하지만 운용개념 상 상기 항공기가 상기 침입기와 충돌위험이 임박하기 전까지는 기존 경로로 비행하고자 할 수 있기 때문에 다음 단계를 수행한다.In the collision avoidance solution calculation step (S400), the collision avoidance solution velocity vector (

) To generate a collision avoidance command to perform collision avoidance of the aircraft. However, because of the operational concept, the aircraft performs the next step because it may wish to fly in an existing route until the intruder and collision risk are imminent.

,

,

,

)을 획득하고, 이를 바탕으로 상기 최근접 값 계산단계(S200)에서 상기 최근접점 위치벡터(

,

) 및 상기 최근접 시간(t_CPA)을 계산한다. 그리고 상기 충돌위험 조건 판단단계(S300)에서 최근접 조건을 바탕으로 충돌위험을 판단한다. 그리고 상기 충돌회피 솔루션 계산단계(S400)에서 충돌회피를 위한 상기 항공기의 속력 및 방향의 해인 상기 충돌회피 솔루션 속도벡터(

)를 도출한다.In summary, as shown in FIG. 4, first, the state values of the aircraft and the intruder in the state acquisition step (S100) in the computing computer that is processed at regular intervals (

,

,

,

), And based on this, the closest position vector (S200)

,

) And the nearest time (t _CPA ) are calculated. Then, in the collision risk condition determination step (S300), the collision risk is determined based on the nearest condition. And in the collision avoidance solution calculation step (S400), the speed vector of the collision avoidance solution which is the solution of the speed and direction of the aircraft for collision avoidance (

).

And, in the case of setting the upper limit time t _U of the avoidance operation of the aircraft according to the concept of aircraft operation, the first minimum closest time t _{CPA, min1} is calculated in the first auxiliary condition parameter calculation step S510, and the second auxiliary In the condition parameter calculation step (S511), the second minimum closest time (t _{CPA, min2} ) is calculated, and in the third auxiliary condition parameter calculation step (S520), the direction angle (χ), convergence between the aircraft and the intruder The distance d _conv is calculated, and the turning distance d _ρ corresponding to the radius ρ required for the aircraft to turn is calculated.

)를 상기 연산컴퓨터에 출력하게 된다. 이런 방식으로 일정한 주기로 프로세스가 실행되면서 상기 항공기가 제어된다.In addition, in the collision avoidance condition determination step S600, the collision avoidance condition is additionally determined and evasion is performed. And the collision avoidance solution velocity vector (the solution of the speed and direction of the aircraft derived from the collision avoidance solution calculation step (S400) in the collision avoidance step (S700))

) To the computer. In this way, the aircraft is controlled while the process is executed at regular intervals.

After the collision avoidance solution calculation step (S400), the first, second and third auxiliary condition parameter calculation steps (S510, S511, S520), and the collision avoidance condition determination step (S600) are implemented in [Example 1], [Execution] Examples 2] and [Example 3] will be described in detail as follows.

[Example 1] Collision avoidance condition determination using minimum closest time condition

)를 움직여서, 예를 들어, 상기 침입기 주변 원에 접하는 방향으로 상기 항공기와 상기 침입기의 상대속도벡터(

-

)를 만드는 경우를 생각하면, 상기 항공기 속도벡터(

)를 오른쪽으로 회전시켜 상기 항공기의 충돌회피 솔루션 속도벡터(

)를 생성하는 경우의 상기 솔루션 속도벡터(

)와 상기 침입기 속도벡터(

)의 상대속도벡터(

-

)크기가 현재 상기 항공기 속도벡터(

)와 상기 침입기 속도벡터(

)의 상대속도벡터(

-

) 크기보다 큰 상황이 발생한다.2, the aircraft speed vector (

), For example, the relative velocity vector of the aircraft and the intruder in a direction in contact with a circle around the intruder (

-

Considering the case of making), the aircraft velocity vector (

) To the right to speed the collision avoidance solution of the aircraft.

The solution velocity vector (

) And the velocity vector of the intruder (

) 'S relative velocity vector (

-

) The size of the aircraft speed vector above

) And the velocity vector of the intruder (

) 'S relative velocity vector (

-

) A situation that is larger than the size occurs.

)와 상기 최근접 솔루션 시간(t_CPA,s)에 대해, 상기 최근접 솔루션 시간(t_CPA,s) < 상기 최근접 시간(t_CPA) 인 상황이 발생한다. 이 경우 상기 항공기의 회피방향이 상기 침입기와의 충돌상황을 앞당겨서 회피를 위한 시간을 줄이는 상황을 발생시킨다. 만약에 상기 항공기의 회피기동 상한 시간(t_U)에 대한 마진이 적은 경우 상기 침입기 안전거리(d_safe)를 침범하는 상황이 발생할 수 있다.Meanwhile, the set speed vector of the collision avoidance solution (

) And the nearest solution time (t _{CPA, s} ), a situation in which the nearest solution time (t _{CPA, s} ) <the nearest time (t _CPA ) occurs. In this case, a situation in which the evasion direction of the aircraft shortens the time for evasion by accelerating the collision situation with the intruder. If the margin for the upper limit avoidance time t _U of the aircraft is small, a situation may occur in which the intruder safety distance (d _safe ) is violated.

To this end, a collision avoidance condition is proposed based on the minimum value, considering not only the closest time in the current state, but also the closest time when performing collision avoidance.

)와 상기 충돌회피 솔루션 속도벡터(

)로 구할 수 있는 최근접시간을 각각 구하여 둘 중 하나를 비교하여 최소값을 구할 수 있다.The method of calculating the first minimum nearest time (t _{CPA, min1} ) in the first auxiliary condition parameter calculation step (S510) of FIG. 5 is the current aircraft speed vector (

) And the collision avoidance solution velocity vector (

) To find the closest time, respectively, and compare one of the two to obtain the minimum value.

)와 상기 충돌회피 솔루션 속도벡터(

) 사이 속도벡터들을 샘플링하여, 상기 샘플링한 속도벡터들에 상응하는 최근접시간들 중에서 최소값을 구할 수 있다.In addition, the method for calculating the second minimum nearest time (t _{CPA, min2} ) in the second auxiliary condition parameter calculation step (S511) of FIG. 5 is the current aircraft speed vector (

) And the collision avoidance solution velocity vector (

), The minimum value among the closest times corresponding to the sampled velocity vectors can be obtained.

As shown in FIG. 5, a first collision avoidance condition determination step (S610) is performed after the first auxiliary condition parameter calculation step (S510), or a second collision avoidance condition is calculated after the second auxiliary condition parameter calculation step (S511). The determination step S611 is performed. The collision avoidance condition of the first or second collision avoidance condition determination steps (S610, S611) is the closest time (t _CPA ). > 0 and the predicted distance (d _CPA ) <satisfies the _safe distance (d _safe ) at the same time, and the first minimum closest time (t _{CPA, min1} ) <upper limit avoidance start time (t _U ) (or the second minimum closest time) (t _{CPA, min2} ) <upper limit of avoidance start time (t _U )) is also a condition that satisfies at the same time.

Therefore, it is possible to obtain an effect of adding a variable margin to the upper limit time t _{U of} the avoidance start according to the collision avoidance direction and the approach state through the collision avoidance condition using the minimum nearest time condition.

[Example 2] Determination of collision avoidance conditions using convergent approach geometry conditions

)와 상기 침입기 최근접점 위치벡터(

) 사이의 상기 예측거리(d_CPA)거리보다 상기 항공기와 상기 침입기와의 직접적인 거리가 더 가깝거나 회피방향에 따라 선회를 하기 위한 거리가 충분히 확보되지 않는 경우가 존재한다. 이에 대해 도 3과 같은 기하를 추가로 고려하여 충돌회피 조건을 추가할 수 있다.When the intruder approaches as if converging while making an acute angle with the traveling direction of the aircraft, the position vector of the aircraft's closest contact point (

) And the position vector of the nearest point of the intruder (

) There is a case where a direct distance between the aircraft and the intruder is closer than the predicted distance (d _CPA ) distance between, or the distance for turning according to the avoiding direction is not sufficiently secured. In this regard, a collision avoidance condition may be added by additionally considering the geometry shown in FIG. 3.

)를 알고 있고 상기 침입기 위치벡터(

)와 상기 침입기 진행방향(

의 방향)을 알고 있으므로 상기 침입기의 진행방향에 대한 직선의 방정식을 세울 수 있고, 상기 직선의 방정식의 직선과 상기 항공기 위치벡터(

) 사이의 최소거리를 구할 수 있다. 여기에 회피를 위한 상기 침입기 안전거리(d_safe)를 빼면 아래 수학식 7과 같이 상기 수렴거리(d_conv)를 구할 수 있다. 따라서 도 6의 제3 보조조건 파라미터 계산단계(S520)를 수식적으로 예를들어 정리하면 In FIG. 3, the current aircraft position vector (

) And the intruder position vector (

) And the direction of the intruder (

Since the direction of the intruder is known, it is possible to set up the equation of the straight line with respect to the traveling direction of the intruder, the straight line of the equation of the straight line and the aircraft position vector (

) To find the minimum distance. Subtracting the intruder safety distance (d _safe ) for avoidance, the convergence distance (d _conv ) can be obtained as shown in Equation 7 below. Therefore, the third auxiliary condition parameter calculation step (S520) of FIG.

[Equation 7]

Where 1 is the aircraft, 2 is the intruder, χ ₂ is the direction angle of the intruder, x, y is the x, y axis position.

And the distance (d _ρ ) required for the aircraft to turn can be obtained by obtaining α in FIG. 3 at an angle generated according to the intruder and the direction of the aircraft as shown in FIG. 3, and then obtaining the following equations (8) and (9).

[Equation 8]

Required turning distance (d _ρ ) = ρ + ρsinα + (margin)

Alternatively, it may be set as Equation 9 in consideration of the maximum sinα.

[Equation 9]

Required turning distance (d _ρ ) = 2ρ + (margin)

Then, a third collision avoidance condition determination step S620 is performed as shown in FIG. 6. When the convergence distance d _conv becomes smaller than the required turn distance d _ρ , conditions may be set as follows so that the aircraft avoids the intruder.

The collision avoidance condition of the third collision avoidance condition determination step (S620) is the closest time (t _CPA ) <the upper limit avoidance start time (t _U ) if the difference between the aircraft and the intruder direction angle is within ± 90 degrees. And the convergence distance (d _conv ) <the turning required distance (d _ρ ) is determined to satisfy one or more, and if the difference between the aircraft and the intruder direction angle is not within ± 90 degrees, the closest time (t _CPA ) <It is determined whether the upper limit time t _{U of} the avoidance start is satisfied.

[Example 3] Collision avoidance condition determination using minimum closest time and convergent approach geometry

Example 3 consists of a combination of Example 1 and Example 2.

7, the first minimum nearest time (t _{CPA, min1} ) or the second minimum nearest time (at the first auxiliary condition parameter calculating step S510 or the second auxiliary condition parameter calculating step S511) t _{CPA, min2} ), and in the third auxiliary condition parameter calculation step (S520), the direction angle (χ) between the aircraft and the intruder, and the convergence distance (d _conv ) between the aircraft and the intruder , Calculate the required turning distance (d _ρ ) corresponding to the radius (ρ) required for the aircraft to turn.

Meanwhile, as illustrated in FIG. 8, after the third auxiliary condition parameter calculating step (S520), the first auxiliary condition parameter calculating step (S510) or the second auxiliary condition parameter calculating step (S511) may be performed.

Then, the fourth or fifth collision avoidance condition determination steps S621 and S622 are performed as shown in FIGS. 7 to 8. In the third collision avoidance condition determination step (S620), the collision avoidance condition is determined using the closest time (t _CPA ), but in the fourth or fifth collision avoidance condition determination steps (S621, S622), the first Alternatively, the second minimum nearest time (t _{CPA, min1,} t _{CPA, min2} ) may be used to determine the collision avoidance condition as follows.

The collision avoidance condition of the fourth or fifth collision avoidance condition determination steps (S621, S622) is the first or second minimum nearest time (t) if the difference between the aircraft and the intruder direction angle is within ± 90 degrees. _{CPA, min1,} t _{CPA, min2} ) <The evasion start upper limit time (t _U ) and the convergence distance (d _conv ) <The turning required distance (d _ρ ) is determined to satisfy one or more, and the aircraft and the intrusion If the difference in the forward direction angle is not within ± 90 degrees, it is determined whether the first or the second minimum nearest time (t _{CPA, min1,} t _{CPA, min2} ) <the avoided start upper limit time (t _U ) is satisfied.

Looking at the experimental results according to various embodiments of the present invention, FIG. 9 shows the experimental results according to [Example 1], when the technique of the present invention was not used (FIG. 9A) and used (FIG. 9B). The simulation is performed, and the difference between applying the modified closest time condition is shown in FIG. 9. I init of FIG. 9 is an intruder in the current state, and the intruder moves from I init to I end. U init is an aircraft in the current state, and the aircraft performs collision avoidance from U init to U end.

In the experiment of FIG. 9, the safety distance (d _safe ) of the intruder was set to 170 m, and when the left (FIG. 9A) avoidance result was seen, the aircraft was slightly _rounded with a circle consisting of the safety distance (d _safe ) of the intruder. You can see the invasion. On the other hand, the right side (FIG. 9B) did not invade the circle composed of the intruder safety distance (d _safe ).

The simulation results show that the actual closest distance between the aircraft and the intruder was 157.2662m on the left (FIG. 9A) and 176.8695m on the right (FIG. 9B), which applied the modified closest time condition of the present invention. It can be seen that the actual closest distance between the resultant aircraft and the intruder is about 1.12 times farther than the actual closest distance between the resultant aircraft and the intruder using the general closest time condition.

The simulation result of FIG. 10 is an experimental result according to [Example 1], and I init of FIG. 10 is an intruder in the current state, and the intruder moves in the direction of I end from I init. U init is an aircraft in the current state, and the aircraft performs collision avoidance from U init to U end.

)의 크기가 현재 상기 항공기 속도벡터(

)의 크기보다 더 크기 때문에 최소 최근접시간 조건을 사용했을 때의 결과가 더 좋음을 쉽게 확인할 수 있다.The experiment of FIG. 10 is a case where the aircraft and the intruder approach each other in a converging form, in which case a collision avoidance solution velocity vector for collision avoidance (

) Is currently the aircraft velocity vector (

Since it is larger than), it is easy to confirm that the result is better when the minimum closest time condition is used.

The simulation results show that the actual closest distance between the aircraft and the intruder is 105.5603m on the left (FIG. 10A) and 176.5112m on the right (FIG. 10B), which is the result of applying the modified closest time condition of the present invention. It can be seen that the actual closest distance between the aircraft and the intruder is about 1.67 times greater than the actual closest distance between the aircraft and the intruder as a result of using the general closest time condition.

11 shows the results of the experiment according to [Example 2], wherein I init in FIG. 11 is an intruder in the current state, and the intruder moves from I init to I end. U init is an aircraft in the current state, and the aircraft performs collision avoidance from U init to U end.

When the converging approach geometry condition is used, it can be seen that the aircraft can avoid the invader, which converges at a very narrow angle, as shown in the simulation result of FIG. 11. The simulation results show that the actual closest distance between the aircraft and the intruder is 75.8203m on the left (FIG. 11A) and 170.6068m on the right (FIG. 11B), which is the result of applying the converging approach condition of the present invention. It can be seen that the actual closest distance between the aircraft and the intruder is about 2.25 times farther than the actual closest distance between the aircraft and the intruder as a result of using a general collision avoidance condition.

The present invention is not limited to the above-described embodiment, the scope of application is, of course, various modifications are possible without departing from the gist of the invention as claimed in the claims.

S100: State acquisition step S200: Nearest value calculation step
S300: collision risk condition determination step S400: collision avoidance solution calculation step
S500: Auxiliary condition parameter calculation step
S510: First auxiliary condition parameter calculation step
S511: Second auxiliary condition parameter calculation step
S520: Third auxiliary condition parameter calculation step
S600: collision avoidance condition determination step
S610: First collision avoidance condition determination step
S611: Second collision avoidance condition determination step
S620: third collision avoidance condition determination step
S621: Fourth collision avoidance condition determination step
S622: fifth collision avoidance condition determination step S700: collision avoidance execution step

Claims (6)

delete Position vector of aircraft and intruder (

,

) And their respective velocity vectors (

,

) Obtaining a state (S100);
Position vector of each of the aircraft and the intruder (

,

) And their respective velocity vectors (

,

Based on), the closest time (t _CPA ) and the closest position vector of each of the aircraft and the intruder (

,

), And calculates the location vector of the nearest point of the intruder (

) And the aircraft's closest position vector (

), A closest value calculation step of calculating a predicted distance (d _CPA ) between closest contacts, which is a distance between (S200);
A collision risk condition determination step of determining a collision risk condition between the intruder and the aircraft based on the predicted distance (d _CPA ) between the closest time (t _CPA ) and the closest point (d _safe ) (S300); And
The velocity vector of each of the aircraft and the intruder in order for the aircraft to avoid collision with the intruder (

,

) And the speed vector of the collision avoidance solution of the aircraft based on the _safe distance of the intruder (d _safe )

) And calculate the collision avoidance solution velocity vector (

Collision avoidance solution calculation step of calculating the nearest solution time (t _{CPA, s} ) corresponding to) (S400);
It includes,
The collision avoidance solution calculation step (S400); Since the,
A first auxiliary condition parameter calculation step of calculating a first minimum nearest time (t _{CPA, min1} ) based on the nearest time (t _CPA ) and the nearest solution time (t _{CPA, s} ) (S510);
A first collision avoidance condition determination step (S610) for determining a collision avoidance condition based on the upper limit time t _U of the avoidance start of the aircraft and the first minimum closest time t _{CPA, min1} ; And
A collision avoidance performing step in which the aircraft performs collision avoidance with the intruder (S700);
Aircraft collision avoidance method based on the closest time based on the closest time and convergence approach geometry.
Position vector of aircraft and intruder (

,

) And their respective velocity vectors (

,

) Obtaining a state (S100);
Position vector of each of the aircraft and the intruder (

,

) And their respective velocity vectors (

,

Based on), the closest time (t _CPA ) and the closest position vector of each of the aircraft and the intruder (

,

), And calculates the location vector of the nearest point of the intruder (

) And the aircraft's closest position vector (

), A closest value calculation step of calculating a predicted distance (d _CPA ) between closest contacts, which is a distance between (S200);
A collision risk condition determination step of determining a collision risk condition between the intruder and the aircraft based on the predicted distance (d _CPA ) between the closest time (t _CPA ) and the closest point (d _safe ) (S300); And
The velocity vector of each of the aircraft and the intruder in order for the aircraft to avoid collision with the intruder (

,

) And the speed vector of the collision avoidance solution of the aircraft based on the _safe distance of the intruder (d _safe )

) And calculate the collision avoidance solution velocity vector (

Collision avoidance solution calculation step of calculating the nearest solution time (t _{CPA, s} ) corresponding to) (S400);
It includes,
The collision avoidance solution calculation step (S400); Since the,
The aircraft speed vector (

) And the collision avoidance solution velocity vector (

A second auxiliary condition parameter calculating step (S511) of calculating the second minimum nearest time (t _{CPA, min2} ) based on the velocity vectors sampled between the velocity vectors;
A second collision avoidance condition determination step (S611) for determining a collision avoidance condition based on the upper limit time t _U of avoidance of the aircraft and the second minimum nearest time t _{CPA, min2} ; And
A collision avoidance performing step in which the aircraft performs collision avoidance with the intruder (S700);
Aircraft collision avoidance method based on the closest time based on the closest time and convergence approach geometry.
Position vector of aircraft and intruder (

,

) And their respective velocity vectors (

,

) Obtaining a state (S100);
Position vector of each of the aircraft and the intruder (

,

) And their respective velocity vectors (

,

Based on), the closest time (t _CPA ) and the closest position vector of each of the aircraft and the intruder (

,

), And calculates the location vector of the nearest point of the intruder (

) And the aircraft's closest position vector (

), A closest value calculation step of calculating a predicted distance (d _CPA ) between closest contacts, which is a distance between (S200);
A collision risk condition determination step of determining a collision risk condition between the intruder and the aircraft based on the predicted distance (d _CPA ) between the closest time (t _CPA ) and the closest point (d _safe ) (S300); And
The velocity vector of each of the aircraft and the intruder in order for the aircraft to avoid collision with the intruder (

,

) And the speed vector of the collision avoidance solution of the aircraft based on the _safe distance of the intruder (d _safe )

) And calculate the collision avoidance solution velocity vector (

Collision avoidance solution calculation step of calculating the nearest solution time (t _{CPA, s} ) corresponding to) (S400);
It includes,
The collision avoidance solution calculation step (S400); Since the,
Calculate the direction angle (χ) formed by the aircraft and the intruder, the convergence distance (d _conv ) between the aircraft and the intruder, and the required turning distance (d _ρ ) corresponding to the radius (ρ) required for the aircraft to turn A third auxiliary condition parameter calculation step (S520);
A third collision avoidance condition determination step (S620) for determining a collision avoidance condition based on the direction angle (χ), the convergence distance (d _conv ), the required turning distance (d _ρ ), and the nearest time (t _CPA ) ); And
A collision avoidance performing step in which the aircraft performs collision avoidance with the intruder (S700);
Aircraft collision avoidance method based on the closest time based on the closest time and convergence approach geometry.
Position vector of aircraft and intruder (

,

) And their respective velocity vectors (

,

) Obtaining a state (S100);
Position vector of each of the aircraft and the intruder (

,

) And their respective velocity vectors (

,

Based on), the closest time (t _CPA ) and the closest position vector of each of the aircraft and the intruder (

,

), And calculates the location vector of the nearest point of the intruder (

) And the aircraft's closest position vector (

), A closest value calculation step of calculating a predicted distance (d _CPA ) between closest contacts, which is a distance between (S200);
A collision risk condition determination step of determining a collision risk condition between the intruder and the aircraft based on the closest time (t _CPA ) and the predicted distance (d _CPA ) between the closest point and the safe distance (d _safe ) of the intruder (S300); And
The velocity vector of each of the aircraft and the intruder in order for the aircraft to avoid collision with the intruder (

,

) And the speed vector of the collision avoidance solution of the aircraft based on the _safe distance of the intruder (d _safe )

) And calculate the collision avoidance solution velocity vector (

Collision avoidance solution calculation step of calculating the nearest solution time (t _{CPA, s} ) corresponding to) (S400);
It includes,
The collision avoidance solution calculation step (S400); Since the,
A first auxiliary condition parameter calculation step of calculating a first minimum nearest time (t _{CPA, min1} ) based on the nearest time (t _CPA ) and the nearest solution time (t _{CPA, s} ) (S510);
Calculate the direction angle (χ) formed by the aircraft and the intruder, the convergence distance (d _conv ) between the aircraft and the intruder, and the required turning distance (d _ρ ) corresponding to the radius (ρ) required for the aircraft to turn. A third auxiliary condition parameter calculation step (S520);
A fourth collision avoidance determining a collision avoidance condition based on the direction angle (χ), the convergence distance (d _conv ), the required turn distance (d _ρ ), and the first minimum nearest time (t _{CPA, min1} ) Condition determination step (S621); And
A collision avoidance performing step in which the aircraft performs collision avoidance with the intruder (S700);
Aircraft collision avoidance method based on the closest time based on the closest time and convergence approach geometry.
Position vector of aircraft and intruder (

,

) And their respective velocity vectors (

,

) Obtaining a state (S100);
Position vector of each of the aircraft and the intruder (

,

) And their respective velocity vectors (

,

Based on), the closest time (t _CPA ) and the closest position vector of each of the aircraft and the intruder (

,

), And calculates the location vector of the nearest point of the intruder (

) And the aircraft's closest position vector (

), A closest value calculation step of calculating a predicted distance (d _CPA ) between closest contacts, which is a distance between (S200);
A collision risk condition determination step of determining a collision risk condition between the intruder and the aircraft based on the predicted distance (d _CPA ) between the closest time (t _CPA ) and the closest point (d _safe ) (S300); And
The velocity vector of each of the aircraft and the intruder in order for the aircraft to avoid collision with the intruder (

,

) And the speed vector of the collision avoidance solution of the aircraft based on the _safe distance of the intruder (d _safe )

) And calculate the collision avoidance solution velocity vector (

Collision avoidance solution calculation step of calculating the nearest solution time (t _{CPA, s} ) corresponding to) (S400);
It includes,
The collision avoidance solution calculation step (S400); Since the,
The aircraft speed vector (

) And the collision avoidance solution velocity vector (

A second auxiliary condition parameter calculating step (S511) of calculating the second minimum nearest time (t _{CPA, min2} ) based on the velocity vectors sampled between the velocity vectors;
Calculate the direction angle (χ) formed by the aircraft and the intruder, the convergence distance (d _conv ) between the aircraft and the intruder, and the required turning distance (d _ρ ) corresponding to the radius (ρ) required for the aircraft to turn A third auxiliary condition parameter calculation step (S520);
Fifth collision avoidance for determining a collision avoidance condition based on the direction angle (χ), the convergence distance (d _conv ), the required turning distance (d _ρ ), and the second minimum nearest time (t _{CPA, min2} ) Condition determination step (S622); And
A collision avoidance performing step in which the aircraft performs collision avoidance with the intruder (S700);
Aircraft collision avoidance method based on the closest time based on the closest time and convergence approach geometry.

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