KR102307584B1 - System for autonomous landing control of unmanned aerial vehicle - Google Patents

Abstract

The present invention provides an autonomous landing control system for an unmanned aerial vehicle capable of precisely landing on a moving landing target (landing platform) and capable of robust altitude control by considering the ground effect. According to an embodiment of the present invention, an autonomous landing control system for an unmanned aerial vehicle comprises: an unmanned aerial vehicle; a photographing unit provided in the unmanned aerial vehicle to photograph a landing target; a landing target state estimation unit for analyzing the image of the landing target obtained from the photographing unit to obtain position or speed information of the landing target with respect to the unmanned aerial vehicle; a position control unit for controlling an altitude or position of the unmanned aerial vehicle with respect to the landing target; and an autonomous precise landing planning unit for receiving the position or speed of the landing target obtained by the landing target state estimation unit, outputting desired position information on the x, y, and z axes, and transmitting the desired position information to the position control unit. The landing target may be moved in a vertical or horizontal direction.

Description

SYSTEM FOR AUTONOMOUS LANDING CONTROL OF UNMANNED AERIAL VEHICLE

The present invention relates to an autonomous landing control system for an unmanned aerial vehicle, and more particularly, to an autonomous landing control system for an unmanned aerial vehicle that can accurately and automatically land by tracking a moving landing platform.

Recently, as a part of the 4th industrial revolution, research on autonomous flight and automation systems of drones is being actively conducted. Accordingly, the use of unmanned aerial vehicles including drones is being considered in various fields. In particular, its use in commercial fields such as logistics and delivery is rapidly expanding, and logistics companies such as Amazon, UPS, DHL in Germany, and Alibaba in China are piloting logistics delivery services using autonomous flight of multicopter drones. have.

As such, autonomous flight is positioned as a core technology element of unmanned aerial vehicles including drones, and among them, automatic landing requires a high level of technology during autonomous flight, so related research is being actively conducted at home and abroad.

In the case of drones or multicopters, there is a limit to long-term mission performance due to the limitation of battery usage time. The limited payload of unmanned aerial vehicles, including quadcopters or multicopters, limits the amount of battery they can carry, requiring frequent landings of unmanned aerial vehicles (UAVs) to replace or recharge batteries after operating for short periods of time. there is a problem.

The landing mission of the UAV is one of the main missions that the UAV must show in applications such as delivery service, terrain exploration, reconnaissance and surveillance. Should be.

On the other hand, as the missions of the unmanned aerial vehicle are diversified, there are cases where the landing platform is not only fixed but also needs to be landed on a moving landing platform. That is, there are cases in which the unmanned aerial vehicle must land on a moving landing target in order to perform landing mission elements. However, the algorithm for landing on a stationary and fixed landing platform cannot satisfy the landing performance requirements when the landing platform is moving.

In addition, the ground effect and external disturbance, known as major factors that degrade the low-altitude flight performance of unmanned aerial vehicles including quadcopters, must be considered in detail in the design of precise landing control for unmanned aerial vehicles. There is a lack of precision landing control technology that has been considered.

The present applicant has proposed the present invention in order to solve the above problems.

Korean Patent Publication No. 10-2014869 (2019.08.21.)

The present invention has been proposed to solve the above problems, and provides an autonomous landing control system for an unmanned aerial vehicle capable of accurately landing on a moving landing target (landing platform) and capable of robust altitude control by considering the ground effect.

An autonomous landing control system of an unmanned aerial vehicle according to an embodiment of the present invention for achieving the above object includes: an unmanned aerial vehicle; a photographing unit provided in the unmanned aerial vehicle to photograph a landing target; a landing target state estimator for analyzing the image of the landing target obtained from the photographing unit to obtain location or speed information of the landing target with respect to the unmanned aerial vehicle; a position controller for controlling an altitude or position of the unmanned aerial vehicle with respect to the landing target; and an autonomous precision landing planning unit that receives the position or speed of the landing target obtained from the landing target state estimation unit, outputs desired position information on the x, y, and z axes, and transmits it to the position control unit; The landing target may be moved in a vertical or horizontal direction.

The landing target state estimator may determine a raw position of the landing target on the fixed fuselage coordinates of the unmanned aerial vehicle by applying geometric optical analysis to the image of the landing target obtained by the photographing unit.

The landing target state estimator may estimate a relative speed of the landing target with respect to the unmanned aerial vehicle by applying a Kalman filter.

The position control unit may control the altitude of the unmanned aerial vehicle in consideration of a ground effect and external disturbance acting on the unmanned aerial vehicle.

The position control unit may include an altitude control unit that performs altitude control based on a disturbance observer in order to perform a high-performance landing operation that is affected by ground effects and external disturbances.

The altitude controller may use a disturbance observer-based sliding mode controller to perform altitude tracking control of the unmanned aerial vehicle in a state where there is a complex disturbance including a ground effect.

The position control unit is composed of an inner loop and an outer loop, the inner loop may use a PID controller and the outer loop may use a multi-mode control rule.

The location control unit may include an x-axis direction multi-mode control unit and a y-axis direction multi-mode control unit that use a multi-mode control rule in an outer loop of the x-axis direction tracking control and the y-axis direction tracking control of the unmanned aerial vehicle.

receiving the x-axis direction control output and the y-axis direction control output respectively output from the x-axis direction multi-mode control unit and the y-axis direction multi-mode control unit, and outputting the roll angle setting value and the pitch angle setting value of the unmanned aerial vehicle It may include a conversion unit.

The difference between the roll angle setting value and the pitch angle setting value and the roll angle and the pitch angle sensed by the unmanned aerial vehicle, the yaw angle setting value of the unmanned aerial vehicle output from the autonomous precision landing planning unit, and sensed by the unmanned aerial vehicle It may include a posture control unit that receives the difference in yaw angle, outputs a roll control input, a pitch control input, and a yaw control input, and transmits it to the unmanned aerial vehicle.

The altitude controller may transmit a thrust control input to the unmanned aerial vehicle.

The autonomous landing control system of the unmanned aerial vehicle according to the present invention can perform precise landing of the unmanned aerial vehicle with respect to a moving landing target.

Since the autonomous landing control system of the unmanned aerial vehicle according to the present invention controls the altitude of the unmanned aerial vehicle in consideration of the ground effect, it minimizes the influence of disturbances acting on the unmanned aerial vehicle during the process of landing the unmanned aerial vehicle on the landing target and ensures precise landing can do.

The autonomous landing control system of the unmanned aerial vehicle according to the present invention can ensure a smooth system response when the unmanned aerial vehicle starts moving (flying).

The autonomous landing control system of the unmanned aerial vehicle according to the present invention guarantees a fast target approach speed when the tracking error is small, and due to these characteristics, the unmanned aerial vehicle can perform high-accuracy tasks such as precision landing, obstacle avoidance, and autonomous delivery to tall buildings. to perform smoothly.

1 is a diagram for explaining a schematic configuration of an autonomous landing control system for an unmanned aerial vehicle according to an embodiment of the present invention.
FIG. 2 is a view for explaining the shape and force of an unmanned aerial vehicle according to the system of FIG. 1 .
FIG. 3 is a view for explaining a process of determining a raw position of a landing target in the landing target state estimator of the system according to FIG. 1 .
4 is a coordinate system for explaining the positional relationship between the unmanned aerial vehicle and the landing target in the landing target state estimation unit according to FIG. 3 .
FIG. 5 is a view for explaining a process of applying a Kalman filter to determine a relative speed of a landing target in the landing target state estimator according to FIG. 3 .
6 and 7 are test results showing the performance of the landing target state estimator according to FIG. 3 .
8 and 9 are test results showing the performance of the position control unit of the system according to FIG. 1 .
FIG. 10 is a diagram for explaining multi-loop control of the position control unit of the system according to FIG. 1 .
11 is a graph for explaining the multi-loop control according to FIG. 10 .
12 is a flowchart illustrating an autonomous landing control method of an unmanned aerial vehicle using the system according to FIG. 1 .

Advantages and/or features of the present invention, and methods of achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be embodied in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

In addition, the preferred embodiment of the present invention to be implemented below is already provided in each system functional configuration in order to efficiently describe the technical components constituting the present invention, or system functions normally provided in the technical field to which the present invention belongs The configuration is omitted as much as possible, and the functional configuration to be additionally provided for the present invention will be mainly described. If a person of ordinary skill in the art to which the present invention pertains, it will be possible to easily understand the functions of the conventionally used components among the functions omitted not shown below, and the components omitted as described above. Relationships between elements and components added for purposes of the present invention will also be clearly understood.

In addition, in the following description, the term "transmission", "communication", "transmission", "reception" and other similar meanings of a signal or information means that a signal or information is directly transmitted from one component to another component as well as passing through other components. In particular, to “transmit” or “transmit” a signal or information to a component indicates the final destination of the signal or information and does not imply a direct destination. The same is true for "reception" of signals or information.

1 is a view for explaining the schematic configuration of an autonomous landing control system for an unmanned aerial vehicle according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the shape and the acting force of the unmanned aerial vehicle according to the system of FIG. 1; 3 is a view for explaining the process of determining the raw position of the landing target in the landing target state estimating unit of the system according to FIG. 1 , FIG. 4 is the location of the unmanned aerial vehicle and the landing target in the landing target state estimating unit according to FIG. 3 A coordinate system for explaining the relationship, FIG. 5 is a view for explaining a process of applying the Kalman filter to determine the relative speed of the landing target in the landing target state estimation unit according to FIG. 3, FIGS. 6 and 7 are shown in FIG. The test results showing the performance of the landing target state estimation unit according to FIG. 8 and FIG. 9 are test results showing the performance of the position control unit of the system according to FIG. 1, and FIG. 10 explains the multi-loop control of the position control unit of the system according to FIG. FIG. 11 is a graph for explaining the multi-loop control according to FIG. 10 .

The autonomous landing control system 100 of an unmanned aerial vehicle according to an embodiment of the present invention to be described below is applied to an unmanned aerial vehicle such as a drone, a quadcopter, a multicopter, etc. or a system that includes an unmanned aerial vehicle. Therefore, hereinafter, "unmanned aerial vehicle 110" is a concept including a drone, a quadcopter, a multicopter, and the like.

Referring to FIG. 1 , an autonomous landing control system 100 (hereinafter referred to as “system”) of an unmanned aerial vehicle according to an embodiment of the present invention includes an unmanned aerial vehicle 110 ; a photographing unit 120 provided in the unmanned aerial vehicle 110 to photograph a landing target (LT); a landing target state estimation unit 130 that analyzes the image of the landing target LT obtained by the photographing unit 120 to obtain position or speed information of the landing target LT with respect to the unmanned aerial vehicle 110; a position control unit 150 for controlling the position of the unmanned aerial vehicle 110 with respect to the landing target; and an autonomous precision landing planning unit 140 that inputs the position or speed of the landing target obtained by the landing target state estimation unit, outputs desired position information on the x, y, and z axes, and transmits it to the position control unit 150 ; may be included.

Here, the landing target LT may move in a vertical direction or a horizontal direction. Accordingly, the autonomous landing control system 100 of the unmanned aerial vehicle according to an embodiment of the present invention controls the unmanned aerial vehicle 110 to land on a moving landing target LT rather than a fixed landing target LT.

The system 100 according to an embodiment of the present invention controls the autonomous precision landing of the unmanned aerial vehicle 110. As mentioned above, the unmanned aerial vehicle 110 is a concept including a quadcopter. Hereinafter, a case in which the unmanned aerial vehicle 110 is a quadcopter will be described for better understanding.

2 shows a dynamics model of the unmanned aerial vehicle 110 that is a quadcopter. In FIG. 2, {B} denotes fixed coordinates of the unmanned aerial vehicle, and {E} denotes local earth fixed coordinates.

)을 생성한다.The four rotors of the unmanned aerial vehicle 110 have four thrusts (

) is created.

In [Equation 1], l is the length of the rotor arm, u _i is the control input, and C _fm is the force and moment coefficient.

The overall dynamics model of the unmanned aerial vehicle 110 can be expressed as [Equation 2].

는 관성좌표계 {E}에서의 무인비행체(110)의 자세이고, m은 질량이다. g는 중력가속도이고,

는 x, y, z축에 대한 관성 모멘트이다. In [Equation 2], x, y, and z represent positions,

is the posture of the unmanned aerial vehicle 110 in the inertial coordinate system {E}, and m is the mass. g is the acceleration due to gravity,

is the moment of inertia about the x, y, and z axes.

The system 100 according to an embodiment of the present invention is a landing target (LT) that moves even when the unmanned aerial vehicle 110 modeled as in [Equation 1] and [Equation 2] is affected by ground effects and external disturbances. A new synthetic algorithm can be proposed that can land accurately.

Meanwhile, referring to FIG. 1 , the photographing unit 120 of the system 100 according to an embodiment of the present invention may be mounted on the unmanned aerial vehicle 110 to photograph the landing target LT. Here, the photographing unit 120 may include an infrared (IR) camera for photographing the landing target LT, and the landing target LT may include an infrared beacon. The system 100 according to an embodiment of the present invention implements a vision-based landing target state estimator by using a landing target (LT) including an infrared beacon and a photographing unit 120 such as an infrared camera. can That is, the landing target state estimator 130 to be described later may serve as a vision-based state estimator.

Since the system 100 according to an embodiment of the present invention uses a landing target (LT) including a photographing unit 120 such as an infrared camera and an infrared beacon, the camera is a landing target even at night or in an environment with too strong or insufficient light. can be detected. In addition, since the IR LED is mounted on the landing target (LT), it has the advantage of economical and simple applicability.

On the other hand, the photographing unit 120 including the infrared camera is fixed to the body of the unmanned aerial vehicle (110). Accordingly, the photographing unit 120 moves in the same manner as the unmanned aerial vehicle 110 .

Referring to FIG. 1 , the photographing unit 120 may photograph an object such as a landing target LT and transmit the photographing information to the landing target state estimating unit 130 . Here, the photographing information transmitted to the landing target state estimator 130 may include information of the region of interest.

The landing target state estimator 130 may analyze the image of the landing target obtained by the photographing unit 120 to obtain position or speed information of the landing target LT with respect to the unmanned aerial vehicle 110 .

The system 100 according to an embodiment of the present invention includes the camera-fixed coordinate ({C}), the vehicle-body-fixed coordinate ({B}), and local earth fixed coordinates. A landing target state estimator (LTSE) is provided in order to explicitly express the position of the landing target in (local earth-fixed coordinate, {E}).

In addition, the landing state target estimator 130 may provide stable and reliable information about the relative position and speed between the unmanned aerial vehicle 110 and the landing target LT by using the Kalman filter. This can contribute to increasing the accuracy of precision landing operations.

The landing target state estimator 130 may calculate the position and speed of the landing target LT through the Kalman filter based on the position information recognized by the photographing unit 120 .

및

)을 의미한다.The landing target state estimating unit 130 applies geometric optical analysis to the image of the landing target LT obtained by the photographing unit 120 to obtain a raw position of the landing target LT on the fixed coordinates of the fuselage of the unmanned aerial vehicle 110 . (raw position) can be determined. Here, "raw position" is the input value (

and

) means

A process of determining the raw position of the landing target LT by the landing target state estimator 130 will be described with reference to FIG. 3 .

In FIG. 3, {B} is a fixed coordinate system of the vehicle body, {C} is a fixed camera coordinate system, CAMERA LENS means a lens of the photographing unit 120, and IMAGE FROM CAMERA SENSOR is an image taken by the photographing unit 120 means Here, the camera refers to the photographing unit 120 .

및

)를 결정하는 과정을 보여준다. 착륙 목표(LT)의 로 포지션 정보는 카메라 고정 좌표계{C}의 착륙 목표(LT) 위치에서 얻을 수 있다. 3 is a view showing the low position information of the landing target (LT) in the aircraft body fixed coordinate system {B} through geometric optical analysis in the landing target state estimation unit 130

and

) to show the process of determining The raw position information of the landing target LT may be obtained from the position of the landing target LT in the camera fixed coordinate system {C}.

First, when comparing similar triangles MHB and M ^* CB in FIG. 3, [Equation 3] is established.

[Equation 4] is established by comparing the triangle AHB and A ^{* CB.}

In FIG. 3, x and y indicate a horizontal field of view and a vertical field of view of the photographing unit 120 (camera), respectively.

If [Equation 4] is replaced with [Equation 2], the same result as [Equation 5] can be obtained.

,

,

,

이므로, [수학식 5]를 통해 [수학식 6]을 얻을 수 있다.Referring to [Equation 5] and Figure 3,

,

,

,

Therefore, [Equation 6] can be obtained through [Equation 5].

[Equation 7] can be obtained through a similar process.

The landing target state estimator 130 may obtain the raw position of the landing target LT in the vehicle body fixed coordinate system {B} as in [Equation 6] and [Equation 7]. After determining the raw position of the landing target, the landing target state estimator 130 may estimate the relative speed of the landing target LT with respect to the unmanned aerial vehicle 110 by applying the Kalman filter. That is, the landing target state estimation unit 130 calculates the raw position of the landing target LT in the vehicle-body-fixed coordinate ({B}) with [Equation 6] and [Equation 7] and After determining together, a Kalman filter is applied to estimate the speed of the landing target. To this end, the landing target state estimator 130 may perform a step of establishing a Kalman filter system and a measurement model.

4 is a view showing the position of the landing target LT on the vehicle-body-fixed coordinate ({B}) and the local earth-fixed coordinate ({E}).

는 각각 시점 t 에서의 착륙 목표(LT)의 상태 즉, x축 방향의 위치, x축 방향의 속도, y축 방향의 위치, y축 방향의 속도를 나타낸다. 그런 다음 t+1 시점에서의 착륙 목표의 상태는 [수학식 8]과 같이 계산할 수 있다.

denotes the state of the landing target LT at time t, that is, the position in the x-axis direction, the speed in the x-axis direction, the position in the y-axis direction, and the speed in the y-axis direction, respectively. Then, the state of the landing target at time t+1 can be calculated as in [Equation 8].

는 위치를 측정하는 간격 시간(interval time)을 나타내고,

및

는 각각 상태 전이 노이즈(transition noises)를 나타낸다.In [Equation 8]

represents the interval time (interval time) to measure the position,

and

, respectively, represent transition noises.

Measurement can be modeled as in [Equation 9].

와

는 측정 노이즈(measurement noise)이다.In [Equation 9]

Wow

is the measurement noise.

Since the state variables of the unmanned aerial vehicle, a quadcopter used in the controller, are on the local earth-fixed coordinate ({E}), the vehicle-body-fixed coordinate ({B}) The state of the landing target on the top is converted to the state in {E} by the coordinate transformation formula as in [Equation 10].

In [Equation 10], ψ is as shown in FIG.

5 shows an overall structural diagram constructed through the Kalman filter.

)이다. 칼만 필터는 [수학식 8]을 이용하여 시스템 모델을 수립하고 [수학식 9]를 이용하여 측정 모델을 수립한다.The input data of the Kalman filter is the low position (

)am. The Kalman filter establishes a system model using [Equation 8] and establishes a measurement model using [Equation 9].

In this way, the landing target state estimator 130 may estimate the state of the landing target at a specific point in time by applying the Kalman filter to the raw position and speed of the landing target LT.

6 and 7 are results of testing the performance of the landing target state estimator 130, that is, the vision-based state estimator of the system 100 according to an embodiment of the present invention.

In order to test the performance of the landing target state estimation unit 130, a quadcopter equipped with an infrared (IR) camera, an IR beacon (moving landing target), a sturdy hanger (to hang the unmanned aerial vehicle), and four springs (unmanned aerial vehicle) To hang the aircraft on a hanger), a test bed was created.

In order to check the performance of the landing target state estimator 130 , the present applicant tested the case where the IR beacon corresponding to the landing target is stopped at a specific position and the case where the IR beacon moves at a specific speed.

Referring to FIG. 6 showing the test results when the IR beacon is stopped at a specific position, the altitude and heading angle of the unmanned aerial vehicle during the test are stimulated to vibrate. Despite the vibration, the landing target state estimation unit 130 is stable and It can be seen that the estimation performance is very accurate. For the position of each IR beacon (landing target), the peak-to-peak estimated position and the magnitude of the velocity error are in the range of 5.0 [cm] and 5.0 [cm/s], respectively.

Referring to FIG. 7 showing the test results when the IR beacon moves at a specific speed, the IR beacon sequentially moves along the axis at a specific speed, and the landing target state estimator 130 (LTSE) is based on the position and speed of the IR beacon. It is considered to provide an accurate estimate of

During the initial phase t = 0~35 [s] (see Figs. 7(a) and (b)) the IR beacon is 0.3 [m/s] (approx. ), moving backward and forward. It can be seen from FIG. 7 that the position error estimated in this first step reaches 0.1 [m] in the case of the y-axis and 0.05 [m] in the case of the x-axis (peak to peak). The estimated velocity error does not exceed 0.1 [m/s], and during the latter 35 to 80 [s], the IR beacon is positioned at (0.2, 0) and (-0.2, 0) at a velocity of 0.1 m/s (approx.) move between (reverse and forward). It can be seen that the peak-to-peak error is maintained in the range of 0.05 [m] and 0.05 [m/s] for the estimated position and velocity, respectively.

From the test results of FIGS. 6 and 7 , it is found that the landing target state estimator 130 of the system 100 according to an embodiment of the present invention provides reliable estimates for the position and speed of the landing target LT. Able to know.

(착륙 목표의 x축 방향에서의 위치 정보),

(착륙 목표의 y축 방향에서의 위치 정보),

(착륙 목표의 x축 방향에서의 속도 정보),

(착륙 목표의 y축 방향에서의 속도 정보)를 자율정밀착륙 계획부(140)에 전달한다.Meanwhile, referring to FIG. 1 , the landing target state estimating unit 130 provides state information of the landing target LT, that is,

(location information in the x-axis direction of the landing target),

(position information in the y-axis direction of the landing target),

(velocity information in the x-axis direction of the landing target),

(speed information in the y-axis direction of the landing target) is transmitted to the autonomous precision landing planning unit 140 .

) 또는 속도(

)를 전달 받고, 무인비행체(110)에서 측정한 x,y,z축에서의 위치정보(x,y,z)와 x,y,z축에서의 원하는 위치정보(x_d,y_d,z_d)의 차이를 위치 제어부(150)에 전달할 수 있다. 또한, 자율정밀착륙 계획부(140)는 무인비행체(110)의 요 각도(yaw angle) 설정값(

)을 자세 제어부(170, Attitude controller)에 전달할 수 있다.The autonomous precise landing planning unit 140 determines the position ( ) of the landing target LT obtained from the landing target state estimation unit 130 .

) or speed (

), position information (x, y, z) in the x, y, z axes measured by the unmanned aerial vehicle 110 and desired position information in the x, y, z axes (x _d ,y _d ,z) _d ) may be transmitted to the location control unit 150 . In addition, the autonomous precision landing planning unit 140 sets the yaw angle of the unmanned aerial vehicle 110 (

) may be transmitted to the posture controller 170 (attitude controller).

In the system 100 according to an embodiment of the present invention, the unmanned aerial vehicle 110 flies by considering the effect of the ground effect and external disturbance that inevitably occurs in the process of the unmanned aerial vehicle 110 landing on the landing target LT. It can be controlled to keep the altitude robustly. To this end, the system 100 according to an embodiment of the present invention is provided with a location control unit 150, the location control unit 150 taking into account the ground effect and external disturbance acting on the unmanned aerial vehicle 110, the unmanned aerial vehicle ( 110) can be controlled stably or robustly.

The position control unit 150 may include a robust altitude control unit 151 that performs strong altitude control based on a disturbance observer in order to perform a high-performance landing operation that is affected by ground effects and external disturbances.

In general, when an unmanned aerial vehicle equipped with a rotor, such as a quadcopter, approaches the ground or landing site to land, the downdraft generated by the rotor hits the ground or landing site and affects the unmanned aerial vehicle. This is called the ground effect. External disturbance refers to wind, etc. acting on the unmanned aerial vehicle.

The robust altitude control unit 151 may define vertical translation dynamics in consideration of the ground effect and external disturbance generated during the landing of the unmanned aerial vehicle 110 as in [Equation 11] and [Equation 12].

는 양의 계수(positive coefficient), R은 프로펠러 반지름, Z_r은 수직 거리(지면과 프로펠러 표면 사이), d는 외부 외란(느린 시간 변화에 따른 경계), u₁은 z축 방향에서의 추력(thrust force)을 나타낸다.In [Equation 11] and [Equation 12],

is the positive coefficient, R is the propeller radius, Z _r is the vertical distance (between the ground and the propeller surface), d is the external disturbance (boundary with slow time change), u ₁ is the thrust in the z-axis direction ( thrust force).

)는 정확하게 측정하기 어렵기 때문에, 본 발명의 일 실시예에 따른 시스템(100)의 강인한 고도 제어부(151)는 양의 계수의 공칭 값(nominal value)인

를 사용한다.

는

에 따른

의 공칭 값이다.

는

(즉, 실제 값과 공칭 값의 차이)이다. 그러고 나면 [수학식 11]은 [수학식 13]과 같이 된다.positive coefficient (

) is difficult to accurately measure, so the robust altitude control unit 151 of the system 100 according to an embodiment of the present invention is the nominal value of the positive coefficient.

use

Is

In accordance

is the nominal value of

Is

(i.e. the difference between the actual value and the nominal value). Then, [Equation 11] becomes [Equation 13].

The robust altitude control unit 151 of the system 100 according to an embodiment of the present invention considers complex disturbances for a robust altitude control algorithm necessary for precisely landing the landing target LT in which the unmanned aerial vehicle 110 moves. Here, the compound disturbance means a sum of a ground effect and an external disturbance. The complex disturbance (D) may be expressed as [Equation 14].

는 지면 효과를 의미한다.In [Equation 14], d is an external disturbance,

is the ground effect.

[Equation 11] can be expressed again as [Equation 15].

The robust altitude control unit 151 of the system 100 according to an embodiment of the present invention is based on a disturbance observer to solve the problem of robust altitude tracking control of the unmanned aerial vehicle 110 in the presence of complex disturbance. (disturbance-observer-based) sliding mode controller is available.

The control goal of the robust altitude control unit 151 of the system 100 according to an embodiment of the present invention is that an unmanned aerial vehicle such as a quadcopter is stationary or mobile despite the presence of both system parameter uncertainty and external disturbance. It is to derive a robust thrust control input (u ₁ ) that controls the landing robustly at (landing point altitude (z _{d ) can vary over time).}

The altitude tracking error can be defined as follows [Equation 16].

The differentiation of E _z is as [Equation 17].

A sliding surface may be introduced as in [Equation 18].

In [Equation 18], k ₁ is the selected controller gain value. The derivative of s is as in [Equation 19].

The derivative of s from [Equation 17] and [Equation 19] can be expressed as [Equation 20].

For the controller to deal with the complex disturbance equation, the disturbance observer can be modified as [Equation 21].

는 D의 추정치,

는 양의 방향 관측기 이득 값(positive observer gain),

는 관측기의 보조 상태(auxiliary state of observer)를 의미한다.In [Equation 21]

is the estimate of D,

is the positive observer gain,

denotes an auxiliary state of observer.

For a given time-varying altitude command z _d , [Equation 2], which means the quadcopter system equation with vertical dynamics under complex disturbance as described in [Equation 15], is ultimately becomes stable with

(1) The controller u ₁ is designed as in [Equation 22].

는 [수학식 21]에서 계산된다.

is calculated in [Equation 21].

(2) The controller and observer gain values satisfy the following [Equation 23].

라고 하면, 다음 [수학식 24]를 얻을 수 있다.proof:

, the following [Equation 24] can be obtained.

A Lyapunov function candidate is selected as in [Equation 25].

Then, the following [Equation 26] can be obtained together with [Equation 23].

이다.In [Equation 26]

am.

[Equation 26] is from the comparison principle, the sliding surface and the disturbance estimate error are ultimately bounded, so it is clear that the system is ultimately stable.

The present applicant has applied the robust altitude control unit 151 adopted in the system 100 according to an embodiment of the present invention, that is, the robust altitude control unit 151 that performs robust altitude control in consideration of the ground effect and external disturbance. A verification test was conducted, and the results are shown in FIGS. 8 and 9 .

8 is a result of comparing the stability and performance of the robust altitude controller (Proposed RAC), the general primary sliding mode controller (SMC), and the general PID controller (PID) according to an embodiment of the present invention. 8(a) is a result of comparing altitude performance, FIG. 8(b) is an altitude tracking performance, and FIG. 8(c) is a result of comparing vertical performance.

A multi-step simulation was performed to validate the robust altitude controller (RAC) according to an embodiment of the present invention in various flight scenarios. The multiple stages are (i) Stage 1: Initialization, (ii) Stage 2: Take-off, (iii) Stage 3: Hovering, (iv) Stage 4: Landing. is done

* Simulation Description

은 초기 값 0에서 13.5[N]로 증가한다.0<t<5[s] (Phase 1): Unmanned aerial vehicle (quadcopter) is initialized. In other words, it is ready for takeoff and the control lock is in place. Altitude, vertical velocity, and acceleration are all zero (see Fig. 8(a)~(c)), and the control signal

increases from the initial value 0 to 13.5[N].

5<t<25[s] (Steps 2-3): The unmanned aerial vehicle (quadcopter) takes off and ascends to the required altitude of 10[m]. The altitude response is ideal for almost all three controllers during the second stage flight segment (5<t<10[s], see Fig. 8(a)). For 10<t<25[s], the robust altitude controller (RAC) according to an embodiment of the present invention exhibits significantly superior performance compared to other controllers.

후 거의 0에 가까운 작은 범위에 도달하는 동안 추적 오차는

의 범위로 수렴한다(도 8(b)에서 Inset 1 참조). 다른 제어기의 속도 성능은 더 큰 진폭과 약간 느리게 수렴하는 속력을 보인다(도 8(c) 참조).another controller

After reaching a small range close to zero, the tracking error is

It converges to the range of (refer to Inset 1 in FIG. 8(b)). The speed performance of the other controllers showed larger amplitudes and slightly slower convergence speeds (see Fig. 8(c)).

25<t<50[s] (Phase 4): The unmanned aerial vehicle (quadcopter) is currently ordered to land at an altitude of 10 [m]. It is a well-known fact that when an UAV descends into a low-altitude range, its vertical flight performance is destructively affected by ground effects. If the control algorithms are not properly designed (i.e. not robust enough), ground effects can degrade and even destroy an unmanned aerial vehicle's altitude performance. Looking at Inset 2 of FIG. 8(b), it can be seen that the controller responds smoothly and the unmanned aerial vehicle rapidly reaches the ground at t=34[s].

From the result of FIG. 8, the remaining controllers that showed a similar response in the take-off phase could only lower the unmanned aerial vehicle to an altitude of about 0.4 m, and the ability to complete the landing process because the unmanned aerial vehicle slides at that altitude due to the ground effect. You can see that it doesn't show. In addition, it was possible to verify the strong altitude control stability and effectiveness of the robust altitude control unit according to the present invention because the estimated value of the complex disturbance changes within an appropriate range and is particularly reliable when the unmanned aerial vehicle is in stationary flight.

On the other hand, in order to verify the validity and effectiveness of the robust altitude control unit 151 of the system 100 according to an embodiment of the present invention capable of strong altitude control by considering the ground effect, flight test of the unmanned aerial vehicle in real conditions as well as simulation was also performed.

Flight tests consisted of (i) initialization and manual take-off, (ii) step-setpoint-altitude tracking and landing using a robust altitude control (RAC) according to the present invention, and (iii) control lock. It is carried out in the steps of releasing and finishing (refer to Fig. 9(a)).

* Description of the flight test process

(i) Initialization and manual take-off: This step covers the period from t=0 to t=23 seconds. Initially, the stabilized controller activates the unmanned aerial vehicle on a flat surface. It then takes off manually and reaches an altitude of about 1.0 m before the system switches to stage two.

(ii) step-setpoint-altitude tracking and landing using the robust altitude control (RAC) according to the present invention: this step starts when the robust altitude control (RAC) is activated (t =23 seconds). From the initial interval t=23[s] to t=52[s] in this phase, the unmanned aerial vehicle (quadcopter) is commanded to track an altitude setpoint of 2.8 m (this value is the test site height of 4 m). chosen because it is limited).

It can be seen in FIG. 9(a) that the unmanned aerial vehicle only settles down to the desired altitude after 6 [s]. The altitude is maintained while the tracking error does not exceed 0.03 [m] (see Fig. 9(b)). The thrust control input u ₁ is seen to be stable and free from chattering.

Then, from t=52 to t=60 seconds, the drone is commanded to land at the current location. Despite external disturbances and ground effects, the UAV descends smoothly to reach the ground. The performance of tracking error, vertical velocity, complex disturbance estimation and control input also indicates the stability and reliability of the robust altitude controller (RAC).

(iii) Release and finish the control lock: After the unmanned aerial vehicle reaches the ground and stabilizes, manually dismantle the control lock and the flight test is completed.

* Flight test results

As can be seen from FIGS. 8 and 9 , flight test verification and numerical simulation results show that the robust altitude control unit (RAC) of the system 100 according to an embodiment of the present invention is much better than the conventional PID and primary SMC. It can be seen that the performance The robust altitude control unit 151 of the system 100 according to an embodiment of the present invention can improve the altitude control performance when the unmanned aerial vehicle (quadcopter) ascends or descends by considering the complex disturbance including the ground effect. In addition, the altitude control algorithm applied to the robust altitude control unit 151 of the system 100 according to an embodiment of the present invention is simple to design and implement, and can be applied to a wide range of altitude control applications for unmanned aerial vehicles.

Meanwhile, referring to FIG. 1 , the position control unit 150 of the system 100 according to an embodiment of the present invention includes not only the robust altitude control unit 151 , but also the x-axis direction tracking control and y-axis control of the unmanned aerial vehicle 110 . The outer loop of the direction tracking control may include an x-axis direction multi-mode control unit 153 and a y-axis direction multi-mode control unit 155 using a multi-mode control rule.

The difference between the position (altitude value, z) in the z-axis direction output from the unmanned aerial vehicle 110 and the desired position in the z-axis direction (altitude setting value; design value of altitude, z _d ) is input to the robust altitude control unit 151 . The difference between the position (x) in the x-axis direction output from the unmanned aerial vehicle 110 and the desired position (x _d ) in the x-axis direction is input to the x-axis direction multi-mode control unit 153, and the y-axis direction multi-mode is input. A difference between the position y in the y-axis direction output from the unmanned aerial vehicle 110 and the desired position y _{d in the} y-axis direction may be input to the controller 155 .

As described above, the position control unit 150 including the x-axis direction multi-mode control unit 153 and the y-axis direction multi-mode control unit 155 is a new trajectory tracking control (TTC) composed of an outer loop and an inner loop. ) algorithm can be provided. That is, since the position control unit 150 includes the x-axis direction multi-mode control unit 153 and the y-axis direction multi-mode control unit 155, the outer loop operates in multiple modes (ie, non-linear and linear modes) while the inner loop is a PID controller. ) can be derived from the control law.

_{x d} and y _d output from the autonomous precision landing planning unit 140 are to indicate a desired position, and v _x and v _y are to indicate the horizontal speed of the unmanned aerial vehicle. A position tracking error occurring along each horizontal axis may be expressed as [Equation 27].

The position tracking error e _xy is defined as [Equation 28].

The differential values of e _x and e _y are as in [Equation 29].

Hereinafter, the x-axis direction tracking control will be described. For reference, the approach for tracking control in the y-axis direction is the same.

A multi-mode control rule may be applied to the outer loop of the multi-mode control unit 153 in the x-axis direction as shown in [Equation 30].

가 곡선(S)에 접선이 되고,

, k, e₀는 양의 상수,

는 속도 기준으로 도 10의 내부 루프(inner loop)로 공급될 제어 작용(control action)이다.In [Equation 30], a _max is a positive constant representing the maximum acceleration required for the unmanned aerial vehicle, d _l is a positive constant in a straight line (Δ),

becomes a tangent to the curve (S),

, k, e ₀ are positive constants,

is a control action to be supplied to the inner loop of FIG. 10 on a speed basis.

10 is a diagram showing a multi-loop TTC system of an unmanned aerial vehicle that is a quadcopter, and the multi-mode controllers 153 and 155 of the system 100 according to the present invention may be implemented in the outer loop while the PID controller is used in the inner loop. .

에 해당하는 [수학식 30]에서 e_x의 함수로

를 나타낸다.11 is a graph of a curve (blue), a line (green) and their relationship. 11 in Fig.

As a function of _{e x} in [Equation 30] corresponding to

indicates

에 대해, 도 11에서 곡선(

)와 직선(

)사이 관계식의 어떤 변화 없이

축에 따라

의 양이 이동한다.

For , the curve in FIG. 11 (

) and a straight line (

) without any change in the relation between

along the axis

amount of moving

에서 직선(

)이 곡선(

)과 접선이 되려면 다음 [수학식 31]이 충족되어야 한다.

straight line (

) this curve (

) and the tangent, the following [Equation 31] must be satisfied.

If [Equation 31] is manipulated and written again, [Equation 32] becomes [Equation 32].

If the parameter is designed as [Equation 30] that satisfies [Equation 32], the system of the unmanned aerial vehicle ([Equation 2]) is asymptotically stable, and the tracking error can be forced to zero.

A Lyapunov function candidate is selected as shown in Equation 33 below.

임이 분명하다. 따라서 아래의 [수학식 34]를 얻을 수 있다.this is

it is clear that Therefore, the following [Equation 34] can be obtained.

By substituting [Equation 29] into [Equation 34] and selecting the control law as [Equation 30], the following [Equation 35] can be obtained.

을 가진다.This means that the tracking error e _x converges to 0 when t → ∞.

have

)을 따라가는 제어 행동을 발생시킨다. 이 경우 곡선(

)의 기울기는 직선(

)의 기울기보다 작기 때문에 가속도가 제한되며, 결과적으로 오버슈트와 무인비행체 절크(vehicle jerks)가 더 적게 발생한다. 반면에, -d_l≤e_x≤d_l 일 때, 제어 동작은 더 높은 경사를 가진 직선(

)선을 따른다. 이렇게 하면 추적 오류가 신속하고 강력한 방식으로 0으로 수렴하게 된다.If e _x <-d _l or e _x >d _l , the controller

) to generate a control action that follows In this case, the curve (

) is the slope of the straight line (

), the acceleration is limited, resulting in fewer overshoots and less vehicle jerks. On the other hand, when -d _l ≤e _x ≤d _l , the control action is a straight line with a higher slope (

) along the line. This ensures that the tracking error converges to zero in a fast and robust manner.

)은 곡선(

)에 접하는 부분이 되며, 가속도와 속도 모두에 대해 제어기가 제어 모드(비선형 모드와 선형 모드 사이)를 전환할 때 부드러운 전환이 발생하게 된다.When -d _l ≤e _x ≤d _l , the proposed controller becomes a Proportional-PID (P-PID) control scheme, which shows that the parameters can be obtained through the existing PID tuning process. Furthermore, e _x = -d _l or e _x = d _l in a straight line (

) is the curve (

), a smooth transition occurs when the controller switches control modes (between non-linear and linear modes) for both acceleration and velocity.

The position control unit 150 according to an embodiment of the present invention described above may include a PID controller for controlling the posture of the unmanned aerial vehicle, and may define maximum acceleration and deceleration of the unmanned aerial vehicle.

The applicant has confirmed that the position control unit 150 of the system 100 according to an embodiment of the present invention shows much better performance than the existing PID controller through flight test verification and numerical simulation results. The location control unit 150 having the above characteristics can solve some of the disadvantages of the existing PID method while using the advantages of the existing PID approach. The conventional PID control has a disadvantage that the fixed gain of the PID controller limits system performance in a wider operating range. In addition, when the required operating range is large, conventional PID controllers are prone to instability because they cannot properly handle the nonlinearities of the system, and because they are based on linear models, their performance will be degraded in nonlinear systems such as quadcopters. It has the disadvantage that it requires complex or significant computational resources.

Compared with the existing PID control, the new TTC algorithm proposed by the position control unit 150 of the system 100 according to an embodiment of the present invention guarantees a smooth system response when the unmanned aerial vehicle starts moving and , guarantees fast target approaching speed when tracking errors are small It has the advantage of being useful for performing

Meanwhile, referring to FIG. 1 , the x-axis direction multi-mode control unit 153 and the y-axis direction multi-mode control unit 155 of the system 100 according to an embodiment of the present invention each receive an x-axis direction control output (T _{x ).} ; output of control of x-axis) and y-axis direction control output (T _y ; output of control of y-axis) can be output.

; design value of roll angle) 및 피치 각도 설정값(

; design value of pitch angle)을 출력할 수 있다.The x-axis direction control output T _x and the y-axis direction control output T _y may be input to the converter 160 . The conversion unit 160 converts the control signal (T; T _x , T _y ) into attitude setpoints to set the roll angle setting value (

; design value of roll angle) and pitch angle setting value (

; design value of pitch angle) can be output.

) 및 피치 각도 설정값(

)과 무인비행체(110)에서 센싱된 롤 각도(

; roll angle from sensor) 및 피치 각도(

; pitch angle from sensor)의 차이, 자율 정밀 착륙 계획부(140)에서 출력된 무인비행체(110)의 요 각도 설정값(

; design value of yaw angle)과 무인비행체(110)에서 센싱된 요 각도(

; yaw angle from sensor)의 차이는 자세 제어부(170)에 입력될 수 있다.The roll angle setting value (

) and pitch angle settings (

) and the roll angle sensed by the unmanned aerial vehicle 110 (

; roll angle from sensor) and pitch angle (

; pitch angle from sensor), the yaw angle setting value of the unmanned aerial vehicle 110 output from the autonomous precision landing planning unit 140 (

; design value of yaw angle) and the yaw angle sensed by the unmanned aerial vehicle 110 (

; yaw angle from sensor) may be input to the posture controller 170 .

The attitude control unit 170 may control the attitude of the unmanned aerial vehicle by using the PID control. The posture control unit 170 uses a roll angle, a pitch angle, and a yaw angle to provide a roll control input (u ₂ ; roll control input), a pitch control input (u ₃ ; pitch control input), and a yaw control input (u ₄ ; yaw control). input) can be output.

On the other hand, the robust altitude control unit 151 may output a thrust control input (u ₁ ; thrust control input) expressed by [Equation 22].

As described above, the system 100 according to an embodiment of the present invention includes a thrust control input (u ₁ ), a roll control input (u ₂ ), a pitch control input (u ₃ ) and a yaw control input (u ₄ ). By inputting into the unmanned aerial vehicle 110, it is possible to control the unmanned aerial vehicle 110 to track and accurately land the landing target (LT) moving vertically or horizontally, and it is robust because both ground effects and external disturbances are considered in the process. It can exhibit high-altitude control performance.

12 is a flowchart illustrating an autonomous landing control method of the unmanned aerial vehicle 110 using the system 100 according to an embodiment of the present invention.

Referring to FIG. 12 , the step of horizontally flying the unmanned aerial vehicle 110 toward the landing area is performed ( 1110 ). Here, the landing area means an area in which the landing target LT is located. A step 1120 of confirming whether the landing target LT exists in the landing area is performed, and the unmanned aerial vehicle 110 determines whether the landing target LT is visible using the photographing unit 120 .

When the landing target is seen, a step 1130 of horizontally flying the unmanned aerial vehicle 110 toward the landing target LT is performed. If the landing target is not visible, a step 1210 of determining whether the maximum search is attempted to search for the landing target LT is performed.

After the unmanned aerial vehicle 110 flies horizontally toward the landing target LT ( 1130 ), a step 1140 of determining whether the unmanned aerial vehicle 110 horizontally approaches the landing target LT is performed ( 1140 ).

If the landing target LT is horizontally approached, step 1150 of the unmanned aerial vehicle 110 descending above the landing target LT is performed, and if it is not horizontally close to the landing target LT, step 1130 is again is carried out

After descending 1150 above the landing target LT, a step 1190 of determining whether the unmanned aerial vehicle 110 has landed on the landing target LT is performed, or a step of determining whether the landing target LT is lost ( 1160) is performed.

When the unmanned aerial vehicle 110 loses the landing target LT, a step 1170 of determining whether the unmanned aerial vehicle 110 vertically approaches the landing target LT is performed, and the landing target LT is not lost. In this case, step 1140 is performed again.

Here, step 1160 may be performed after step 1130, and step 1160 may be performed after step 1150.

As a result of step 1170, when the unmanned aerial vehicle 110 vertically approaches the landing target LT, the final approaching step 1180 is performed, and when the unmanned aerial vehicle 110 does not vertically approach the landing target LT, step 1210 is performed. is done again

After step 1180, a step 1190 of determining whether the unmanned aerial vehicle 110 has landed on the landing target LT is performed. As a result of step 1190 , when the unmanned aerial vehicle 110 lands on the landing target LT, the landing is completed ( 1300 ) and the landing procedure is terminated.

On the other hand, as a result of step 1210, when the maximum search is performed, the step 1240 of landing the unmanned aerial vehicle 110 at the current location is performed, and when the maximum search is not performed, the unmanned aerial vehicle 110 rises to the search altitude. Step 1220 is performed.

After the unmanned aerial vehicle 110 rises to the search altitude ( 1220 ), a step 1230 of determining whether the unmanned aerial vehicle 110 confirms the landing target LT is performed.

As a result of step 1230, if the landing target LT is visible, step 1130 is performed, and if not, step 1240 is performed.

As described above, the autonomous landing control system 100 of an unmanned aerial vehicle according to an embodiment of the present invention provides a robust altitude control algorithm and a landing target tracking control algorithm even when the landing target LT moves vertically or horizontally. can be used to control the unmanned aerial vehicle 110 to precisely and autonomously land on the landing target LT.

As described above, in an embodiment of the present invention, specific matters such as specific components, etc., and limited embodiments and drawings have been described, but these are only provided to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. It is not limited, and various modifications and variations are possible from these descriptions by those of ordinary skill in the art to which the present invention pertains. Accordingly, the spirit of the present invention should not be limited to the described embodiments, and not only the following claims, but also all equivalents or equivalent modifications to these claims will fall within the scope of the spirit of the present invention.

100: autonomous landing control system of unmanned aerial vehicle
110: unmanned aerial vehicle 120: photographing unit
130: landing target state estimation unit 140: autonomous precision landing planning unit
150: position control 151: strong altitude control
160: conversion unit 170: posture control unit

Claims (11)

unmanned aerial vehicles;
a photographing unit provided in the unmanned aerial vehicle to photograph a landing target;
a landing target state estimator for analyzing the image of the landing target obtained from the photographing unit to obtain location or speed information of the landing target with respect to the unmanned aerial vehicle;
a position controller for controlling an altitude or position of the unmanned aerial vehicle with respect to the landing target; and
An autonomous precise landing planning unit that receives the position or speed of the landing target obtained from the landing target state estimation unit, outputs desired position information on the x, y, and z axes, and transmits it to the position control unit;
The landing target moves in a vertical or horizontal direction,
The landing target state estimating unit applies geometric optical analysis to the image of the landing target obtained by the photographing unit to determine the raw position of the landing target on the fixed coordinates of the fuselage of the unmanned aerial vehicle. system.
delete According to claim 1,
The autonomous landing control system of the unmanned aerial vehicle, characterized in that the landing target state estimating unit estimates the relative speed of the landing target with respect to the unmanned aerial vehicle by applying a Kalman filter.
4. The method of claim 3,
The position control unit is an autonomous landing control system of the unmanned aerial vehicle, characterized in that to control the altitude of the unmanned aerial vehicle in consideration of the ground effect and external disturbance acting on the unmanned aerial vehicle.
5. The method of claim 4,
The position control unit autonomous landing control system of the unmanned aerial vehicle, characterized in that it comprises an altitude control unit that performs altitude control based on the disturbance observer in order to perform a high-performance landing operation that is affected by the ground effect and external disturbance.
6. The method of claim 5,
The autonomous landing control system of the unmanned aerial vehicle, characterized in that the altitude controller uses a disturbance observer-based sliding mode controller to perform altitude tracking control of the unmanned aerial vehicle in a state where there is a complex disturbance including a ground effect.
7. The method of claim 6,
The position control unit is composed of an inner loop and an outer loop, the inner loop uses a PID controller and the outer loop uses a multi-mode control rule.
8. The method of claim 7,
The position control unit comprises an x-axis direction multi-mode control unit and a y-axis direction multi-mode control unit using a multi-mode control rule in an outer loop of the x-axis direction tracking control and y-axis direction tracking control of the unmanned aerial vehicle. Autonomous landing control system for unmanned aerial vehicles.
9. The method of claim 8,
receiving the x-axis direction control output and the y-axis direction control output respectively output from the x-axis direction multi-mode control unit and the y-axis direction multi-mode control unit, and outputting the roll angle setting value and the pitch angle setting value of the unmanned aerial vehicle Autonomous landing control system of an unmanned aerial vehicle, characterized in that it comprises a conversion unit.
10. The method of claim 9,
The difference between the roll angle setting value and the pitch angle setting value and the roll angle and the pitch angle sensed by the unmanned aerial vehicle, the yaw angle setting value of the unmanned aerial vehicle output from the autonomous precision landing planning unit, and the unmanned aerial vehicle sensed An autonomous landing control system for an unmanned aerial vehicle, comprising: an attitude control unit that receives a difference in yaw angle, outputs a roll control input, a pitch control input, and a yaw control input, and transmits the output to the unmanned aerial vehicle.
11. The method of claim 10,
The autonomous landing control system of the unmanned aerial vehicle, characterized in that the altitude control unit transmits a thrust control input to the unmanned aerial vehicle.

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