KR102014869B1 - System and method for autonomous landing of rotor type unmanned areial vehicle - Google Patents

Abstract

Automatic landing system of the rotorcraft unmanned vehicle according to an embodiment of the present invention, the vision sensor unit for detecting a beam generated from the marker display unit provided at the landing point of the rotorcraft drone; A horizontal error calculator configured to calculate a horizontal distance error between the marker display and the vision sensor; A vertical speed calculator configured to receive a horizontal position of the rotor blade drone from the vision sensor unit and calculate a vertical velocity of the rotor blade drone; An altitude estimating unit estimating a desired altitude of the rotorcraft drone by receiving the vertical velocity from the vertical velocity calculating unit; A vertical controller that receives a desired altitude of the rotorcraft unmanned aerial vehicle from the altitude estimating unit and controls the thrust of the rotorcraft unmanned aerial vehicle; A horizontal controller configured to receive a horizontal position and a horizontal speed of the rotorcraft drone from the vision sensor unit or the horizontal error calculator to generate a target attitude of the rotorcraft drone; And a fuzzy controller connected to the horizontal error calculator and the vertical speed calculator to adjust the vertical speed depending on the horizontal distance error.

Description

TECHNICAL AND METHOD FOR AUTONOMOUS LANDING OF ROTOR TYPE UNMANNED AREIAL VEHICLE}

The present invention relates to an automatic landing system and method for a rotorcraft drone, and more particularly, to a fuzzy approach to overcome the limitations and disadvantages of GPS and to reduce the horizontal distance error between the rotorcraft drone and the landing point. A method and method for automatic landing of a vehicle.

Automatic or autonomous landing of rotorcraft drones, such as quadcopters, multicopters or drones against stationary targets, is gaining increasing attention in many fields.

However, low cost GPS is difficult to use for complex tasks or algorithms due to its poor performance or limited accuracy. To overcome these GPS limitations, some studies have suggested using vision cameras that support predetermined ground patterns to land rotorcraft drones.

The operation principle of the vision camera is to analyze and recognize a predetermined pattern on the ground. This type of vision camera has the disadvantage of being difficult to operate in some outdoor conditions because it operates by detecting light. In addition, vision cameras have the disadvantage of being difficult to operate under all lighting conditions.

Therefore, there is a growing demand for a technique for auto or autonomous landing of a rotorcraft drone using a vision sensor operating in all lighting conditions.

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

Korean Patent Publication No. 10-2015-0019771 (2015.02.25.)

The present invention has been proposed to solve the above problems, and provides a system and method for automatic landing of a rotorcraft drone which can operate under all lighting conditions and can reduce horizontal distance error than conventional methods.

According to an aspect of the present invention, there is provided an automatic landing system for a rotorcraft drone, including: a vision sensor unit configured to detect a beam generated at a marker display unit provided at a landing point of a rotorcraft drone; A horizontal error calculator configured to calculate a horizontal distance error between the marker display and the vision sensor; A vertical speed calculator configured to receive a horizontal position of the rotor blade drone from the vision sensor unit and calculate a vertical velocity of the rotor blade drone; An altitude estimating unit estimating a desired altitude of the rotorcraft drone by receiving the vertical velocity from the vertical velocity calculating unit; A vertical controller that receives a desired altitude of the rotorcraft unmanned aerial vehicle from the altitude estimating unit and controls the thrust of the rotorcraft unmanned aerial vehicle; A horizontal controller configured to receive a horizontal position and a horizontal speed of the rotorcraft drone from the vision sensor unit or the horizontal error calculator to generate a target attitude of the rotorcraft drone; And a fuzzy controller connected to the horizontal error calculator and the vertical speed calculator to adjust the vertical speed depending on the horizontal distance error.

The apparatus may further include an altitude sensor unit configured to transmit the vertical position and the vertical speed of the rotorcraft drone to the vertical controller, and to transmit the vertical position of the rotorcraft drone to the vertical speed calculator.

The fuzzy controller may use the horizontal distance error as an input variable and use the vertical speed as an output variable.

The fuzzy control unit may define a fuzzy set for each of the input variable and the output variable, wherein the membership function of the input variable may be defined as a triangle and a trapezoid membership function, and the membership function of the output variable may be defined as a triangle membership function. have.

The fuzzy controller may obtain or adjust the output variable by using a Mamdani fuzzy model and by a weighted average method.

The vision sensor unit may use an IR-lock sensor.

On the other hand, according to another field of the present invention, the automatic landing method of the rotorcraft unmanned vehicle using the automatic landing system of the rotorcraft unmanned vehicle, Comprising: calculating a horizontal distance error between the rotorcraft drone and the landing point; Calculating a vertical speed of the rotorcraft drone; Estimating a desired altitude of the rotorcraft drone; Generating thrust control and a target posture of the rotorcraft drone with respect to a desired altitude and position of the rotorcraft drone; Changing the attitude and altitude of the rotorcraft drone; And adjusting a vertical speed of the rotorcraft drone using a fuzzy approach.

Adjusting the vertical speed of the rotorcraft drone using the fuzzy approach, the horizontal distance error is defined as an input variable and the vertical speed is defined as an output variable, wherein the membership function of the input variable is a triangle and trapezoidal membership. It can be defined as a function and the membership function of the output variable can be defined as a triangle membership function.

Adjusting the vertical velocity of the rotorcraft drone using the fuzzy approach may normalize the values of the input variable and the output variable between 0 and 1 using a scale factor.

In the adjusting of the vertical speed of the rotorcraft drone using the fuzzy approach, the vertical speed may be obtained using the following equation.

는 수직 속도,

는 각 소속 함수의 기하학적 중심,

는 각 소속 함수의 소속 정도이다.here,

The vertical speed,

Is the geometric center of each membership function,

Is the membership of each membership function.

Since the automatic landing system and method of the rotorcraft unmanned aerial vehicle according to the present invention uses a vision sensor such as an IR-lock sensor, it is possible to automatically land the rotorcraft unmanned vehicle under all light conditions including bright sunlight and complete darkness.

The automatic landing system and method for a rotorcraft drone according to the present invention can reduce the horizontal distance error of the rotorcraft drone at low altitude close to the landing point because the vertical speed can be smoothly adjusted according to the horizontal distance error using a fuzzy approach.

The automatic landing system and method for a rotorcraft drone according to the present invention can reduce the horizontal distance error of the rotorcraft drone to the landing point even when the landing point or landing target moves or there is a disturbance due to wind.

The automatic landing system and method for a rotorcraft unmanned aerial vehicle according to the present invention controls the vertical velocity of the rotorcraft unmanned aerial vehicle by applying fuzzy logic according to the horizontal distance error or position error during the landing of the rotorcraft unmanned aerial vehicle. It is robust to disturbance caused by the disturbance and the accuracy can be improved by applying nonlinear fuzzy logic.

1 is a view showing a rotorcraft drone applied to the automatic landing system and method according to an embodiment of the present invention.
2 is a block diagram illustrating an automatic landing system of a rotorcraft drone according to an embodiment of the present invention.
3 is a flowchart illustrating a method for automatic landing of a rotorcraft drone according to an embodiment of the present invention.
4 is a view showing the membership function of the input variable used in the automatic landing system and method for a rotorcraft drone according to an embodiment of the present invention.
5 is a view showing a function of belonging to the output variable used in the automatic landing system and method for a rotorcraft drone according to an embodiment of the present invention.
6A and 6B are graphs showing results of experiments of landing precision of the automatic landing system and method for a rotorcraft drone according to an embodiment of the present invention.
7A and 7B are graphs showing the results of experiments on landing precision of the automatic landing method of the rotorcraft drone according to the prior art.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention; However, the present invention is not limited or limited by the embodiments. Like reference numerals in the drawings denote like elements.

1 is a view showing a rotorcraft drone applied to the automatic landing system and method according to an embodiment of the present invention, Figure 2 is a block diagram for explaining an automatic landing system of a rotorcraft drone according to an embodiment of the present invention, Figure 3 is a flow chart for explaining the automatic landing method of the rotorcraft drone according to an embodiment of the present invention, Figure 4 is an input variable used in the automatic landing system and method of a rotorcraft drone according to an embodiment of the present invention Figure 5 shows the membership function, Figure 5 is a view showing the membership function of the output variable used in the automatic landing system and method of the rotorcraft drone according to an embodiment of the present invention, Figures 6a and 6b is an embodiment of the present invention 7A and 7B are graphs showing results of experiments of landing precision of the automatic landing system and method for a rotorcraft drone according to FIG. 7A and 7B. According to a graph showing the results of experiments the landing accuracy of the automatic landing method for unmanned rotary wing aircraft.

Hereinafter, the rotorcraft drone 10 has a concept including a drone, a quadcopter, and a multicopter.

1 and 2, the automatic landing system 100 of the rotorcraft drone 10 according to an embodiment of the present invention lands using the vision sensor unit 110 mounted on the rotorcraft drone 10. By allowing the marker display unit 20 provided at the point to be recognized, the rotorcraft unmanned aerial vehicle 10 can be accurately and automatically landed on the marker display unit 20.

The automatic landing system 100 of the rotorcraft unmanned aerial vehicle 10 according to an embodiment of the present invention may include a vision sensor unit 110 that detects and recognizes a marker display unit 20 provided at a landing point.

Here, the vision sensor unit 110 includes a vision camera, and may detect and identify the marker display unit 20 under all lighting conditions (light conditions) including bright sunlight or complete darkness.

Vision sensor unit 110 of the automatic landing system 100 according to an embodiment of the present invention preferably uses an IR-lock sensor. The IR-lock sensor used in the vision sensor unit 110 is an extended version of the Pixy camera, and may detect and recognize various colors. The IR-lock sensor can be configured to act as an infrared detector.

On the other hand, the IR-lock sensor is used with a transmitter (beam) for generating a beam, the transmitter is provided at the landing point. Here, the marker display unit 20 becomes a transmitter. When the vision sensor unit 110 is an IR-lock sensor, MarkOne Beacon may be used as the marker display unit 20.

When the rotorcraft drone 10 approaches the landing point, the vision sensor unit 110 detects a beam (for example, an infrared beam) from the marker display unit 20 provided at the landing point, and thus, the rotorcraft drone 10 May automatically land on the marker display unit 20.

Automatic landing system 100 according to an embodiment of the present invention may be mounted on the rotorcraft unmanned vehicle 10 or may be provided in a control center (not shown) for controlling the flight of the rotorcraft drone 10. Hereinafter, for convenience of explanation, it is assumed that the auto landing system 100 is mounted on the rotorcraft drone 10.

Referring to FIG. 2, the automatic landing system 100 of the rotorcraft unmanned aerial vehicle 10 according to an embodiment of the present invention includes a beam generated by the marker display unit 20 provided at the landing point of the rotorcraft unmanned aerial vehicle 10. The rotary unmanned aerial vehicle 10 in the vision sensor unit 110 to detect, the horizontal error calculator 130 to calculate the horizontal distance error between the marker display unit 20 and the vision sensor unit 110, the vision sensor unit 110 Vertical speed calculator 140 for calculating the vertical velocity (vertical velocity) of the rotorcraft unmanned aerial vehicle 10 receives the horizontal position of the rotor blade drone 10 receives the vertical speed from the vertical speed calculator 140 Vertical controller for controlling the thrust of the rotorcraft drone 10 by receiving the desired altitude of the rotorcraft drone 10 from the altitude estimator 160, the altitude estimator 160 to estimate the desired altitude of the ( Vertical controller, 170), vision sensor unit 110 or A horizontal controller for receiving the horizontal position and horizontal velocity of the rotorcraft drone 10 from the horizontal error calculator 130 to generate a target posture of the rotorcraft drone 10 (Horizontal Controller, 150). And a fuzzy controller 180 connected to the horizontal error calculator 130 and the vertical speed calculator 140 to adjust the vertical speed depending on the horizontal distance error.

Here, the "vertical velocity" refers to the falling speed of the rotorcraft drone 10.

On the other hand, the automatic landing system 100 of the rotorcraft drone 10 according to an embodiment of the present invention, the vertical position (Vertical position) and the vertical velocity (Vertical velocity) of the rotorcraft drone 10 to the vertical controller 170 ) May further include an altitude sensor unit 120 for transmitting the vertical position of the rotorcraft drone 10 to the vertical speed calculator 140.

Lidar sensor may be used as the altitude sensor unit 120. Lidar sensors can determine the distance using the speed of light. The lidar sensor may also be used to measure the altitude of the rotorcraft drone 10 in the range of 40 meters. The lidar sensor is easy to be mounted on the rotorcraft unmanned aerial vehicle 10 because of its low power consumption and light weight.

When a landing command is given to the rotorcraft unmanned aerial vehicle 10, the automatic landing system 100 of the rotorcraft unmanned aerial vehicle 10 according to an embodiment of the present invention first enters a sensor checking mode. In the sensor test mode, it is checked whether the vision sensor unit 110 or the altitude sensor unit 120 is recognized. When the vision sensor unit 110 or the altitude sensor unit 120 is recognized, the sensor units 110 and 120 operate.

As described above, the vision sensor unit 110 scans an IR beam emitted from the marker display unit 20. When the vision sensor 110 scans and recognizes the IR beam, the vertical speed calculator 140 calculates a vertical speed, that is, a falling speed, of the rotorcraft drone 10, as shown in Equation 1 below.

는 회전익 무인비행체(10)에 탑재된 비전 센서부(110)와 착륙 지점에 마련된 마커 표시부(20) 사이의 수평 거리 오차(Horizontal error)이고,

는 회전익 무인비행체(10)의 수직 속도이다.In Equation 1

Is a horizontal error (Horizontal error) between the vision sensor unit 110 mounted on the rotorcraft drone 10 and the marker display unit 20 provided at the landing point,

Is the vertical speed of the rotorcraft drone 10.

The mode for calculating the vertical velocity as shown in [Equation 1] is called a velocity calculation mode.

)를 추정한다. [수학식 2]와 같이 표현된다.When the vertical speed of the rotorcraft drone 10 is obtained, the altitude sensor 120 and the altitude estimator 160 determine the desired altitude of the rotorcraft drone 10 in the altitude estimation mode.

Estimate). It is expressed as shown in [Equation 2].

는 샘플링 타임,

는 이전의 고도이다.In [Equation 2]

Is the sampling time,

Is the previous altitude.

Once the altitude is estimated, the automatic landing system 100 will run the vertical controller 170 and the horizontal controller 150. Here, the vertical controller 170 and the horizontal controller 150 are PID controllers. As such, the mode in which the vertical controller 170 and the horizontal controller 150 are executed is called a landing mode.

The horizontal controller 150 may be connected to the vision sensor 110 or the horizontal error calculator 130 to receive position information or horizontal distance error of the rotorcraft 10. The vertical controller 170 may be connected to the altitude sensor unit 120 or the altitude estimator 160 to receive a desired altitude of the rotorcraft drone 10.

The rotorcraft drone 10 with automatic landing should generate a target attitude and thrust control for the desired position and desired altitude, which is controlled by the vertical controller 170 and the horizontal controller 150. Can be processed. After the target attitude and thrust control is performed by the vertical controller 170 and the horizontal controller 150, the rotorcraft drone 10 changes the attitude and the altitude.

The automatic landing system 100 of the rotorcraft drone 10 according to an embodiment of the present invention will be described again with reference to FIG. 2.

The vision sensor unit 110 moves horizontally or descends while scanning the beam emitted from the marker display unit 20. While the rotorcraft drone 10 moves, the vision sensor unit 110 continues to move the marker display unit 20. Update the current position information while scanning the beam.

The horizontal error calculator 130 calculates a horizontal distance error between the rotorcraft unmanned vehicle 10 and the marker display unit 20, depending on the influence of disturbance such as wind or the vertical speed of the rotorcraft drone 10. The current horizontal position in 10 may be different from the calculated horizontal position, and the difference may be referred to as a horizontal distance error.

On the other hand, the vision sensor unit 110 may transmit the horizontal position of the rotorcraft drone 10 obtained by recognizing the marker display unit 20 to the vertical speed calculator 140. In addition, the horizontal position and the horizontal speed may be transmitted to the horizontal controller 150.

The altitude sensor unit 120 may transmit the vertical position of the rotorcraft drone 10 to the vertical speed calculator 140, and the vertical speed calculator 140 may determine the vertical position and the horizontal position of the rotorcraft drone 10. The vertical speed can be calculated.

The vertical speed of the rotorcraft drone 10 calculated by the vertical speed calculator 140 may be transmitted to the altitude estimator 160. The altitude estimator 160 estimates a desired altitude of the rotorcraft drone 10 and transmits the value to the vertical controller 170. In addition, the altitude sensor unit 120 may transmit the vertical speed and the vertical position of the rotorcraft drone 10 to the vertical controller 170.

The vertical controller 170 may control the thrust of the rotorcraft drone 10 by using a desired altitude, a vertical speed, and a vertical position.

The horizontal controller 150 may receive a horizontal position and a horizontal speed received from the vision sensor unit 110 and a desired position of the rotorcraft drone 10 to generate a target posture of the rotorcraft drone 10.

On the other hand, the automatic landing system 100 of the rotorcraft drone 10 according to an embodiment of the present invention may include a purge controller 180.

The automatic landing system 100 of the rotorcraft unmanned aerial vehicle 10 according to an embodiment of the present invention is a linear to adjust the vertical speed depending on the horizontal distance error between the rotorcraft unmanned aerial vehicle 10 and the marker display unit 20. Although a function may be used, the fuzzy control unit 180 is further provided to secure good characteristics when the altitude of the rotorcraft 10 is less than 2 meters. By providing the purge control unit 180, precise automatic landing of the rotorcraft unmanned aerial vehicle 10 is possible.

The fuzzy controller 180 may use a fuzzy logic approach, but may use a Mamdani Fuzzy Model.

)를 입력 변수(Input variable)로 이용하고, 수직 속도(

)를 출력 변수(Output variable)로 이용할 수 있다.The fuzzy controller 180 has a horizontal distance error (

) As an input variable, and the vertical velocity (

) Can be used as an output variable.

)와 수직 속도(

) 사이의 관계를 다음과 같은 5가지의 퍼지 집합으로 표현할 수 있다.The fuzzy controller 180 may define a fuzzy set for the input variable and the output variable, and define five fuzzy subsets for both the input variable and the output variable. The fuzzy controller 180 has a horizontal distance error (

) And vertical speed (

) Can be expressed by the following five fuzzy sets.

)가 VSM이면, 수직 속도(

)는 VB이다.Horizontal distance error (

) Is VSM, the vertical speed (

) Is VB.

)가 SM이면, 수직 속도(

)는 B이다.Horizontal distance error (

) Is SM, the vertical speed (

) Is B.

)가 M이면, 수직 속도(

)는 M이다.Horizontal distance error (

) Is M, the vertical velocity (

) Is M.

)가 B이면, 수직 속도(

)는 SM이다.Horizontal distance error (

) Is B, the vertical speed (

) Is SM.

)가 VB이면, 수직 속도(

)는 VSM이다.Horizontal distance error (

) Is VB, the vertical velocity (

) Is VSM.

Here, VB (Very Big, Very Large), B (Big, Large), M (Medium, Medium), SM (Small, Small), VSM (Very Small, Very Small).

On the other hand, the fuzzy set should be defined to cover all possible situations.

The fuzzy controller 180 defines a membership function for the input variable and the output variable, respectively, and the membership function of the input variable is defined as a triangle and a trapezoid membership function, and the membership function of the output variable is defined as a triangle membership function. can do.

)의 소속 함수가 도시되어 있고, 도 5에는 출력 변수 즉, 수직 속도(

)의 소속 함수가 도시되어 있다.4 shows an input variable, that is, a horizontal distance error (

) Is a function of membership, and in Fig. 5 the output variable,

) Is a function of membership.

The input and output variables can be normalized to values between 0 and 1 using appropriate scale factors. The process of normalizing may include appropriate scale mapping to the input variable and the output variable. Here, the selection of scale factor and output factor can affect the overall performance of the controller.

4 and 5, the horizontal axis represents the normalized value of the input variable and the output variable, respectively, and the vertical axis represents the degree of membership.

)를 얻거나 조정할 수 있다. 즉, 출력 변수 즉, 회전익 무인비행체(10)의 수직 속도(

)는 [수학식 3]과 같이 가중 평균법을 사용하여 얻을 수 있다.As mentioned above, the fuzzy controller 180 uses a Mamdani fuzzy model for the automatic landing algorithm, and can easily execute the automatic landing algorithm on the hardware mounted on the rotorcraft drone 10. By the weighted average method, the output variable, or vertical velocity (

Can be adjusted or adjusted. That is, the output variable, that is, the vertical velocity of the rotorcraft drone 10 (

) Can be obtained using the weighted average method as shown in [Equation 3].

는 각 소속 함수의 기하학적 중심(centroid of membership function),

는 각 소속 함수의 소속 정도(Degree of memebership function)이다.In [Equation 3]

Is the geometric center of each membership function,

Is the degree of memebership function of each membership function.

Here, as the membership function increases, the computational amount may increase because the fuzzy rule increases.

Hereinafter, with reference to the drawings will be described in the automatic landing method which is another field of the invention.

Referring to FIG. 3, in the automatic landing method of the rotorcraft unmanned vehicle using the automatic landing system 100 of the rotorcraft unmanned vehicle 10, calculating a horizontal distance error between the rotorcraft drone 10 and the landing point 20. 1100, calculating the vertical speed of the rotorcraft drone 10 (1200), estimating a desired altitude of the rotorcraft drone 10 (1300), at the desired altitude and position of the rotorcraft drone 10 Thrust control of the rotorcraft drone 10 and generating a target attitude (1400), changing the attitude and altitude of the rotorcraft drone 10 (1500), and the rotorcraft drone 10 using a fuzzy approach. Adjusting the vertical speed of the (1600) may include.

The step 1100 of calculating the horizontal distance error between the rotorcraft drone 10 and the landing point 20 may be performed by the horizontal error calculator 130. In the process of scanning the beam of the marker display unit 20 by the vision sensor unit 110, a horizontal distance error between the rotorcraft drone 10 and the marker display unit 20 may be calculated.

The step 1200 of calculating the vertical speed of the rotorcraft unmanned aerial vehicle 10 may be performed by the vertical speed calculator 140. The vertical speed calculator 140 may calculate the vertical speed to the lower speed of the rotorcraft unmanned aerial vehicle 10 in the speed calculation mode. Here, the vertical speed may be adjusted according to the horizontal distance error.

The step 1300 of estimating a desired altitude of the rotorcraft drone 10 may be performed by the altitude estimator 160. The altitude estimator 160 may estimate the altitude of the rotorcraft drone 10 in the altitude estimating mode.

Step 1400 of generating thrust control and target posture of the rotorcraft drone 10 with respect to a desired altitude and position of the rotorcraft drone 10 may be performed by the horizontal controller 150 and the vertical controller 170.

If the altitude of the rotorcraft drone 10 is estimated in step 1300, the horizontal controller 150 and the vertical controller 170 are executed in step 1400. The target attitude and the desired altitude for the desired position and desired altitude of the rotorcraft drone 10 are determined. Vertical controller 170 and horizontal controller 150 may be executed to generate thrust control.

In operation 1500 of changing the attitude and altitude of the rotorcraft drone 10, the attitude and the altitude may be changed according to the target attitude and the thrust control of the rotorcraft drone 10.

The step 1600 of adjusting the vertical speed of the rotorcraft drone using a fuzzy approach may be performed by the fuzzy controller 180.

In operation 1600, the horizontal distance error may be defined as an input variable, and the vertical velocity may be defined as an output variable, but the membership function of the input variable may be defined as a triangle and a trapezoid membership function, and the membership function of the output variable may be defined as a triangle membership function. .

Further, step 1600 of adjusting the vertical speed of the rotorcraft drone 10 using the fuzzy approach may normalize the values of the input and output variables between 0 and 1 using a scale factor.

In addition, in the step 1600 of adjusting the vertical speed of the rotorcraft drone 10 using the fuzzy approach, the vertical speed may be obtained by using Equation 3 above.

Operation 1600 may be performed by the fuzzy controller 180. Since the same process as the description of the fuzzy controller 180 may be performed by operation 1600, repeated description thereof will be omitted.

On the other hand, the inventors of the present invention carried out the landing test of the rotorcraft drone in the outdoors to compare the automatic landing system 100 and method of the rotorcraft unmanned vehicle according to an embodiment of the present invention, and the automatic landing method according to the prior art. .

The rotorcraft drone 10 is connected to the RC transmitter to change the user's flight mode. The marker indicator 20 was installed on the ground to transmit the IR beam. Landing experiments were conducted in an environment with a wind speed of 3 m / s.

The experimental process is as follows. First, the rotorcraft drone takes off by the user in stabilization mode (posture control). The flight mode then switches to loiter mode so that the rotorcraft drone floats at the desired position, such as 9 meters. When the rotorcraft drone stabilizes in Reuters mode, the user changes the flight mode to return-to-launch mode. In this mode, the rotorcraft drone moves to its home position and waits 5 seconds before landing.

)를 나타내고, 점선은 수평 거리 오차(

)를 나타낸다.The results of precise landing experiments in the automatic landing system 100 and method according to an embodiment of the present invention using the fuzzy controller 180 and the fuzzy approach, and the landing method according to the related art are shown in FIGS. 6A, 6B and 7A, respectively. And in FIG. 7B. 6A and 6B, 7A and 7B, the solid line indicates the vertical velocity (

), And the dotted line indicates the horizontal distance error (

).

This experiment was repeated eight times for the present invention and the prior art.

After measuring eight times at the landing point, that is, the marker display unit 20, the horizontal distance error between the vision sensor unit 110 and the marker display unit 20 is shown in Table 1 below.

Count Prior art The present invention One 15.2 cm 6.5 cm 2 14.4 cm 4.6 cm 3 12.4 cm 3.9 cm 4 16.3 cm 6.6 cm 5 9.38 cm 5.5 cm 6 10.1 cm 5.7 cm 7 10 cm 2.2 cm 8 6.3 cm 5.7 cm Average 11.76 cm 5.09 cm

In the automatic landing system 100 and method of the rotorcraft drone 10 according to the embodiment of the present invention as described above, the landing target moves because the vertical speed by the fuzzy logic can be adjusted smoothly according to the horizontal distance error. Or even in the event of wind disturbance, it is possible to implement precise automatic landing.

As described above, in one embodiment of the present invention has been described by the specific embodiments, such as specific components and limited embodiments and drawings, but this is provided to help a more general understanding of the present invention, the present invention in the above embodiment The present invention is not limited thereto, and various modifications and variations can be made by those skilled in the art to which the present invention pertains. Therefore, the spirit of the present invention should not be limited to the described embodiments, and all the things that are equivalent to or equivalent to the claims as well as the following claims will belong to the scope of the present invention.

10: rotorcraft drone
20: marker display unit
100: automatic landing system
110: vision sensor unit
120: altitude sensor unit
130: horizontal error calculation unit
140: vertical speed calculator
150: horizontal controller
160: altitude estimator
170: vertical controller
180: fuzzy control unit

Claims (10)

A vision sensor unit for detecting a beam generated from a marker display unit provided at a landing point of the rotorcraft drone;
A horizontal error calculator configured to calculate a horizontal distance error between the marker display and the vision sensor;
A vertical speed calculator configured to receive a horizontal position of the rotor blade drone from the vision sensor unit and calculate a vertical velocity of the rotor blade drone;
An altitude estimating unit estimating a desired altitude of the rotorcraft drone by receiving the vertical velocity from the vertical velocity calculating unit;
A vertical controller that receives a desired altitude of the rotorcraft unmanned aerial vehicle from the altitude estimating unit and controls the thrust of the rotorcraft unmanned aerial vehicle;
A horizontal controller configured to receive a horizontal position and a horizontal speed of the rotorcraft drone from the vision sensor unit or the horizontal error calculator to generate a target attitude of the rotorcraft drone;
An altitude sensor unit configured to transmit a vertical position and a vertical speed of the rotorcraft drone to the vertical controller and a vertical position of the rotorcraft drone to the vertical speed calculator; And
A fuzzy controller connected to the horizontal error calculator and the vertical speed calculator to adjust the vertical speed depending on the horizontal distance error;
Including;
The purge control unit,
Using the horizontal distance error as an input variable and the vertical speed as an output variable.
delete delete The method of claim 1,
The purge control unit,
A fuzzy set is defined for each of the input variable and the output variable, wherein the membership function of the input variable is defined as a triangle and a trapezoidal membership function, and the membership function of the output variable is defined as a triangle membership function. Landing system.
The method of claim 4, wherein
And the fuzzy control unit uses a Madam fuzzy model and obtains or adjusts the output variable by a weighted average method.
The method according to any one of claims 1, 4 or 5,
The vision sensor unit using an IR-lock sensor, automatic landing system of a rotorcraft drone.
In the automatic landing method of a rotorcraft drone using the system according to any one of claims 1, 4 or 5,
Calculating a horizontal distance error between the rotorcraft drone and the landing point;
Calculating a vertical speed of the rotorcraft drone;
Estimating a desired altitude of the rotorcraft drone;
Generating thrust control and a target posture of the rotorcraft drone with respect to a desired altitude and position of the rotorcraft drone;
Changing the attitude and altitude of the rotorcraft drone; And
Adjusting the vertical speed of the rotorcraft drone using a fuzzy approach;
Including, automatic landing method of the rotorcraft drone.
The method of claim 7, wherein
Adjusting the vertical speed of the rotorcraft drone using the fuzzy approach,
The horizontal distance error is defined as an input variable and the vertical velocity is defined as an output variable, wherein the membership function of the input variable is defined as a triangle and a trapezoidal membership function, and the membership function of the output variable is defined as a triangle membership function. Method of automatic landing of unmanned aerial vehicle.
The method of claim 8,
Adjusting the vertical speed of the rotorcraft drone using the fuzzy approach,
Using a scale factor to normalize the values of the input variable and the output variable between 0 and 1.
The method of claim 9,
Adjusting the vertical speed of the rotorcraft drone using the fuzzy approach,
Automatic landing method for a rotorcraft drone, which obtains a vertical speed by using the following equation.

here,

The vertical speed,

Is the geometric center of each membership function,

Is the membership of each membership function.

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