KR102537028B1 - Carrot chasing guidance control method and apparatus, and air vehicle having the apparatus - Google Patents

Abstract

The present invention provides a virtual follow-up target generation step of generating a position after a certain time on a pre-planned reference route of an aircraft as a virtual follow-up target point, and a guide path generation step of generating a guide path from the current position of the aircraft to the virtual follow-up target point. And an acceleration command generation step of generating an acceleration command for following the guidance path generated by the guidance path generation step at the current position of the flight vehicle, According to the present invention, It makes it possible to guide the aircraft to the correct position at the correct time.

Description

Carrot Chasing Guidance Control Method, Carrot Chasing Guidance Control Device, and Flight Vehicle Mounted with the Guidance Control Device

The present invention relates to a Carrot Chasing path-following control method using an Ahead Time-based approach, and more particularly, to follow a virtual point located in front of the Ahead-Time from the current position to eventually guide the aircraft to the correct position at the correct time. It's about technique.

In a guidance method for moving an aircraft along a desired flight path, one of the conventional methods is a path geometry-based Carrot-Chasing technique, and the present invention relates to such a Carrot Chasing guidance control method.

This method is highly dependent on the shape of the path because the virtual point existing on the planned path is located in front of the Ahead-Distance. This means that the complexity of the path can greatly affect the performance of the induction law.

In addition, since the path geometry-based Carrot-Chasing technique does not use a position command and a direction angle command composed of a function of time, it has a limitation in that it cannot guide an aircraft to an accurate position at an accurate time.

Therefore, in order to follow the high maneuvering path of the aircraft, a path following controller that can guide the aircraft to the correct position at the correct time is required.

Matters described in the background art above are intended to aid understanding of the background of the invention, and may include matters other than those of the prior art already known to those skilled in the art.

Korean Patent Publication No. 10-2018-0128618

The present invention has been made to solve the above problems, the present invention is to provide a Carrot Chasing guidance control method of an aircraft, an induction control device, and an aircraft equipped with the device that can guide the aircraft to an accurate position at an accurate time It has its purpose.

The Carrot Chasing induction control method of an aircraft according to one aspect of the present invention includes a virtual follow-up target generation step of generating a position after a certain time on a pre-planned reference path of the aircraft as a virtual follow-up target point, the virtual follow-up target from the current position of the aircraft. A guidance path generation step of generating a guidance path to a point to be followed and an acceleration command generation step of generating an acceleration command for following the guidance path generated by the guidance path creation step at the current location of the vehicle.

And, it may further include an acceleration command following control step of controlling the vehicle to fly guided by the acceleration command.

Here, the generating of the induction path is characterized by generating the induction path in a curved shape.

More specifically, the induction route generating step is characterized in that the induction route is generated by Hermite interpolation using the current position and speed of the aircraft and the position and speed of the virtual tracking target point. do.

In the acceleration command generation step, the acceleration command is generated in a feedback format in the form of PID (Proportional Integral Derivation) using the current position and speed of the aircraft and the position and speed of the virtual tracking target point. .

Next, the Carrot Chasing induction control device of an aircraft according to one aspect of the present invention is a virtual following target unit that generates a position after a certain time on a pre-planned reference path of an aircraft as a virtual tracking target point, from the current position of the aircraft. A guidance path generating unit generating a guidance path to the virtual following target point and an acceleration command generating unit generating an acceleration command for following the guidance path generated by the guidance path generating step at the current location of the aircraft. .

And, it may further include an acceleration command following controller for controlling the vehicle to fly guided by the acceleration command.

Here, the induction path generation unit is characterized in that for generating the induction path in the form of a curve.

More specifically, the guidance path generator generates the guidance path by Hermite interpolation using the current position and speed of the vehicle and the position and speed of the virtual tracking target point. .

Furthermore, the acceleration command generating unit generates the acceleration command in a feedback format in the form of PID (Proportional Integral Derivation) using the current position and speed of the aircraft and the position and speed of the virtual tracking target point.

In addition, the present invention includes an aircraft equipped with the Carrot Chasing induction control device of the aircraft.

According to the Carrot Chasing guidance control method and apparatus of the present invention, a guidance control method for guiding an aircraft to an accurate position at an accurate time is proposed, and in the present invention, as described in FIG. 4, a reference path represented as a function of time It can be seen that it follows exactly.

1 shows a Carrot Chasing induction control device for an aircraft of the present invention.
Figure 2 shows the concept of the Carrot Chasing induction control method of the aircraft of the present invention.
Figure 3 shows sequentially the aircraft following the planned path according to the present invention.
4 illustrates an example of accurately following a reference path expressed as a function of time.

In order to fully understand the present invention and the advantages in operation of the present invention and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

In describing the preferred embodiments of the present invention, known techniques or repetitive descriptions that may unnecessarily obscure the subject matter of the present invention will be reduced or omitted.

1 shows a Carrot Chasing induction control device for an aircraft of the present invention, Figure 2 shows the concept of the Carrot Chasing induction control method for an aircraft of the present invention, and FIG. It is shown sequentially to follow.

Hereinafter, with reference to FIGS. 1 to 3, a Carrot Chasing induction control method and guidance control apparatus of an aircraft according to an embodiment of the present invention will be described.

The present invention is a device and method for guiding an aircraft (aircraft) to an accurate position at the correct time by newly defining the existing Ahead-Distance-based Carrot Chasing guidance control method among techniques for inducing and controlling the path of an aircraft.

As shown in FIG. 1, the Carrot Chasing guidance control device for an aircraft of the present invention includes a virtual following target generation unit 10 for generating a virtual following target on a reference path to be followed, and a guidance path from the current position of the aircraft to the virtual following target. An acceleration command generating unit 30 that generates an acceleration command from the guidance path generation unit 20, the guidance path and the current state of the aircraft, and an acceleration command following controller 40 that controls the following flight of the aircraft by the generated acceleration command. ).

The virtual following target generation unit 10 creates a virtual following target that the aircraft wants to follow. That is, when an aircraft is said to be in flight, it must be at a current route point along a planned route expressed as a function of time. To this end, the virtual follow target generating unit 10 creates a route point at a point in time after a certain time of flight as much as the Ahead Time from the planned reference route point at the current point in time as a virtual follow target.

The guidance path generation unit 20 creates a guidance path connecting the current position of the aircraft and the virtual following target. In order for the aircraft to follow the virtual follow target, the aircraft must not simply fly in a straight line towards the point, but must fly along a guidance path connecting the current position and the virtual follow target. To this end, the induction path generation unit 20 generates an induction path using a Hermite interpolation technique.

When the guidance path is created, the acceleration command generation unit 30 generates an acceleration command for the aircraft to follow the guidance path. The acceleration command combines the position and velocity required from the initial position of the guidance path, and proportional (P: Proportional), integral (I: (Proportional) Integral), and derivative (D: (Proportional) Derivative) to reduce the error of the current state. It is generated in the form of feedback in the form of PID (Proportional Integral Derivation), which is a method of controlling by

The acceleration command following controller 40 guides and controls the flight vehicle to follow and fly the virtual following target by the acceleration command generated in this process.

Hereinafter, a Carrot Chasing induction control method of an aircraft according to an embodiment of the present invention will be described in more detail.

는 현 시점에서의 항공기의 위치를,

는 현 시점에서의 항공기의 속도를 의미한다.

은 현 시점에 항공기가 위치해야 하는 계획된 기준 경로 상의 지점을 의미한다.

는 Ahead Time을 의미한다.A conceptual diagram of the proposed technique is shown in FIG. 2 means the present time

is the position of the aircraft at the current time,

is the speed of the aircraft at the present time.

means the point on the planned reference path where the aircraft should be located at the present time.

means Ahead Time.

는 현 시점으로부터 Ahead Time 만큼 지난 시간을 의미하며 수학식 1로 표현된다.

Means the time that has passed as much as the Ahead Time from the current point in time and is expressed by Equation 1.

로 표현된다.

는 가상 추종 대상의 속도를 의미한다.The virtual following target that the aircraft wants to follow is the point on the reference route at the time it has flown as much as the Ahead Time from the planned reference route point at the current time,

is expressed as

denotes the speed of the virtual following target.

일 때

에 위치한 항공기는 위치

를 잇는 유도 경로를 따라 비행한다. 이 과정을 연속적으로 수행하여 계획 경로 위의 점인 가상 추종 대상

,

등을 향해 계속 비행함으로써, 점차 추종 오차

이 줄어들게 되고, 항공기가 계획 경로 위에 안착될 수 있다.Figure 3 shows the sequence in which an aircraft follows a planned route utilizing the present invention. hour

when

aircraft located in the position

flies along a guidance path that connects By performing this process continuously, the virtual follow-up target, which is a point on the planned path,

,

By continuing to fly toward the back, the following error gradually

is reduced and the aircraft can land on the planned path.

The Hermite Interpolation method is used to create a guidance path connecting the current position of the aircraft and the virtual tracking target. The Hermite Interpolation technique is a technique that can obtain a polynomial that smoothly connects two points by using the position of two points and its derivative value, and through this, it is possible to create a curved derivation path that is not a straight line to a virtual follow-up point.

In order to create a guidance path using the Hermite Interpolation technique, state variables at the current point of the aircraft and the virtual tracking target point are required. These state variables affect the order of the induced path polynomial, and the order varies depending on the combination of state variables available at each point.

An example of the process of generating a derivation path for the x-coordinate component of 3-dimensional coordinates.

만 활용 가능하고, 가상 추종 대상의 위치, 속도 그리고 가속도 상태변수

,

가 사용 가능한 경우에는 3차 다항식의 형태로 유도 경로를 생성할 수 있다. 수학식 3은 시간을 무차원화 변수로 표현한 3차 다항식 형태의 유도 경로를 나타냈다. 시간을 무차원화 하는 방법은 수학식 2와 같다. 이와 같이 Hermite Interpolation 기법에 의해 유도 경로는 수학식 4와 같이 계산되며, 속도와 가속도는 각각 수학식 5와 수학식 6과 같다.aircraft position state variable

It can be used only, and the position, velocity and acceleration state variables of the virtual tracking target

,

When is available, an induction path can be created in the form of a third-order polynomial. Equation 3 shows the derivation path in the form of a third-order polynomial expression in which time is expressed as a non-dimensionalized variable. A method of dimensionless time is as shown in Equation 2. As such, the induced path is calculated as in Equation 4 by the Hermite Interpolation technique, and the velocity and acceleration are as in Equation 5 and Equation 6, respectively.

The same process is performed for each of the other coordinate components. Table 1 shows the guidance path creation rules according to the state variables of the usable aircraft and the state variables of the usable virtual tracking target.

turn Available aircraft state variables State variables of usable virtual followers One

2

3

4

5

6

7

8

,

), 그리고 현재 상태의 오차(

)를 줄이는 PID 형태의 피드백 루프로 구성된다. 모든 상태변수에 대하여 표현하면 수학식 8과 같으며,

,

그리고

는 순서대로 비례 제어 게인(Proportional Control Gain), 미분 제어 게인(Derivative Control Gain), 그리고 적분 제어 게인(Integral Control Gain)이다. 그리고 요구되는 지점에서 가속도가 존재한다면 이를 Feed forward 형태로 가속도 입력에 추가하였으며,

는 가속도의 Feed forward 게인 값이다.Next, the acceleration command generation is the position and velocity required at the initial position of the guidance path as shown in Equation 7 (

,

), and the error of the current state (

) is composed of a PID-type feedback loop that reduces When expressed for all state variables, it is the same as Equation 8,

,

and

is a proportional control gain, a derivative control gain, and an integral control gain in order. And if there is acceleration at the required point, it is added to the acceleration input in the form of Feed Forward.

is the feed forward gain value of the acceleration.

을 대입함으로써 계산 가능하며, 수학식 9와 같이 시간 차원에 대하여 나타냈다. 수학식 9를 통해 요구 위치는 항공기의 현재 위치와 같음을 확인할 수 있다. To follow the guidance path, the required position, velocity, and acceleration at the first point of the guidance path are given by Equations 4, 5, and 6

It can be calculated by substituting , and is shown in the time dimension as shown in Equation 9. Through Equation 9, it can be confirmed that the requested position is the same as the current position of the aircraft.

In order for the aircraft to satisfy the required speed and acceleration, the acceleration input of Equation 8 is required. By substituting the result of Equation 9 into Equation 7 and rearranging, an acceleration command such as Equation 10 can be generated, and acceleration commands can be generated for the remaining axes in the same way.

Table 2 shows the acceleration command generation law according to the state variables of the available aircraft and the state variables of the virtual tracking target that can be used.

turn Available aircraft state variables State variables of usable virtual followers

Defined as

One

2

3

4

5

6

7

8

4 shows the flight path (solid line) of the aircraft to which the Ahead-Time Approach Carrot Chasing Trajectory Tracking controller (acceleration command following controller 40) proposed in the present invention is applied, the flight path to be followed (dotted line), and every 4 seconds Each aircraft's position is shown.

Although the present invention as described above has been described with reference to the illustrated drawings, it is not limited to the described embodiments, and it is common knowledge in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. It is self-evident to those who have Therefore, such modified examples or variations should be included in the claims of the present invention, and the scope of the present invention should be interpreted based on the appended claims.

10: Virtual follower target generation unit
20: induction path generation unit
30: acceleration command generation unit
40: acceleration command following controller

Claims (11)

a virtual follow-up target creation step of generating a position after a predetermined time on a pre-planned reference path of the flying vehicle as a virtual follow-up target point;
a guidance path creation step of generating a guidance path from the current location of the vehicle to the virtual tracking target point; and
Including an acceleration command generation step of generating an acceleration command for following the guidance path generated by the guidance path generation step at the current position of the vehicle,
Carrot Chasing Guidance Control Method of Aircraft. The method of claim 1,
Further comprising an acceleration command following control step of controlling the aircraft to fly guided by the acceleration command.
Carrot Chasing Guidance Control Method of Aircraft. The method of claim 2,
Characterized in that the induction path generating step generates the induction path in the form of a curve,
Carrot Chasing Guidance Control Method of Aircraft. The method of claim 3,
The induction path generating step is characterized in that the induction path is generated by Hermite interpolation using the current position and speed of the vehicle and the position and speed of the virtual follow-up target point,
Carrot Chasing Guidance Control Method of Aircraft. The method of claim 4,
In the acceleration command generating step, the acceleration command is generated in a feedback format in the form of PID (Proportional Integral Derivation) using the current position and speed of the aircraft and the position and speed of the virtual following target point. Characterized in that,
Carrot Chasing Guidance Control Method of Aircraft. a virtual follow-up target unit that creates a position after a certain time on a pre-planned reference path of the flying vehicle as a virtual follow-up target point;
a guiding path generating unit generating a guiding path from the current position of the vehicle to the virtual following target point; and
Including an acceleration command generation unit for generating an acceleration command for following the guidance path generated by the guidance path generating step at the current position of the vehicle,
Vehicle's Carrot Chasing Guidance Control System. The method of claim 6,
Further comprising an acceleration command following controller for controlling the vehicle to fly guided by the acceleration command.
Vehicle's Carrot Chasing Guidance Control System. The method of claim 7,
Characterized in that the induction path generation unit generates the induction path in the form of a curve,
Vehicle's Carrot Chasing Guidance Control System. The method of claim 8,
Characterized in that the guidance path generation unit generates the guidance path by Hermite interpolation using the current position and speed of the aircraft and the position and speed of the virtual follow-up target point,
Vehicle's Carrot Chasing Guidance Control System. The method of claim 9,
Characterized in that the acceleration command generation unit generates the acceleration command in a feedback format in the form of PID (Proportional Integral Derivation) using the current position and speed of the aircraft and the position and speed of the virtual follow-up target point,
Vehicle's Carrot Chasing Guidance Control System. Claims 6 to 10 of any one of the carrot tracking (Carrot Chasing) induction control device of the flight vehicle mounted.

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