KR20230072930A - Drone flight system in which flight altitude is determined based on fusion sensor-based measurement area - Google Patents

Abstract

The present invention relates to a drone flight system where the flight altitude is determined according to the measurement area based on a convergence sensor, not only simplifying the structure of a drone that sprays chemicals while flying by an engine, but also allowing the drone to fly in a horizontal state at a constant flight altitude. The drone flight system according to the present invention comprises: a camera for photographing a mark placed below a drone when the drone is flying; an image analysis unit for analyzing images from the camera; and a flight control unit for adjusting the flight altitude of the drone in response to the analysis results from the image analysis unit. The image analysis unit includes a flight altitude calculation part detecting the mark from the photographed images, calculating the area of the polygon formed from the detected mark, and generating a command to the flight control unit to raise or lower the flight altitude based on the calculated area.

Description

Drone flight system in which the flight altitude is determined according to the measurement area based on the convergence sensor

The present invention relates to a drone flight system, and more particularly, to a drone flight system in which a flight altitude is determined according to a measurement area based on a convergence sensor.

Recently, the need for unmanned aerial vehicles is increasing in an environment where it is difficult for humans to work.

These unmanned aerial vehicles are also very widely used, such as acquiring aerial images in disaster/disaster areas that are difficult to access, inspecting power lines, providing enemy hidden information in battlefield situations, or performing reconnaissance missions and surveillance missions through unmanned aerial vehicles.

Currently, common types of unmanned remote control vertical take-off and landing vehicles include single-rotor helicopters and coaxial reversal helicopters.

Single-rotor type helicopters and coaxial reversing type helicopters have been used for a long time, and have a very large main rotor to generate lift, and are capable of long-term flight and heavy transport. However, single-rotor type helicopters rotate the main rotor To offset the generated anti-torque phenomenon, a variable pitch tail rotor interlocked with the main rotor is provided. At this time, the tail rotor reduces the efficiency by reducing the power of the main rotor by 20% or more.

In addition, the coaxial reversal type helicopter is provided to cancel the torques from each other by rotating the two main rotors in opposite directions on one axis instead of having a tail rotor to prevent the anti-torque phenomenon, but the main rotor The structure is very complicated, and there are disadvantages in that the weight is heavy due to the high weight.

In addition, in the case of a conventional unmanned aerial vehicle, in order to adjust the unmanned aerial vehicle, a separate flight device control terminal is essential, and the user must directly adjust the flight height through operation of the flight device control terminal to perform flight, but keep the unmanned air vehicle level. Maintaining the flight height in one state requires considerable piloting skills, which is a major obstacle to the spread of unmanned aerial vehicles.

Republic of Korea Patent No. 10-1217804 Republic of Korea Patent Publication No. 10-2011-0000767

Therefore, the present invention has been made to solve the problems of the prior art as described above, and not only simplifies the structure of a drone that sprays drugs while flying by an engine, but also keeps the drone level at a constant flight height. It is to provide a drone flight system in which the flight altitude is determined according to the measurement area based on the convergence sensor that can fly.

A drone flight system according to the present invention for achieving the above object includes a camera for photographing a mark disposed below the drone during flight; an image analysis unit for analyzing an image from the camera; And a flight control unit for adjusting the flight height of the drone in response to the analysis result of the image analysis unit,

The image analysis unit detects a mark from the captured image, calculates the area of a polygon formed from the detected mark, and generates a command to increase or decrease the flight height to the flight control unit based on the calculated area. It includes a height calculator.

In the above-described aspect, the image analysis unit includes a storage unit for storing a predetermined number of markers and an area calculator for calculating an area of a polygon formed from the detected markers, and the area calculator includes markers detected in an image captured by the camera. and compare the number of indicia with a predetermined number of indicia stored in the storage unit.

In addition, in the above-described aspect, the area calculation unit compares the number of markers detected in the image captured by the camera with the predetermined number of markers stored in the storage unit, and determines the number of markers detected in the image captured by the camera in advance. If less than the number of the determined mark is configured to generate a command to increase the flight height to the flight control unit flight height calculation unit of the image analysis unit.

In addition, in the above-described aspect, the area calculation unit compares the number of markers detected in the image captured by the camera with the predetermined number of markers stored in the storage unit, and determines the number of markers detected in the image captured by the camera in advance. and calculating an area of a polygon formed by the detected landmarks if equal to the determined number of landmarks.

In addition, in the above-described aspect, the image analysis unit further includes a maximum area detection unit for detecting a maximum area by comparing the calculated area of the polygon, and the area calculation unit stores the number of marks detected in the image captured by the camera in the storage unit When the number of marks detected in the image taken from the camera is equal to the number of predetermined marks compared to the number of predetermined marks, the maximum area detection unit calculates the previously calculated area of the polygon and the currently calculated area of the polygon. Comparing, and if the area of the currently calculated polygon is smaller than the previously calculated area of the polygon, the flight height calculation unit is configured to generate a command to lower the flight height to the flight control unit.

According to the drone flight system of the present invention, the drug is sprayed while flying by an engine, the drone can stably take off and land in a horizontal state by a plurality of main propellers, simplify the structure of the drone, and fly It has the advantage of being able to fly with minimal energy loss.

1 is a configuration diagram of a drone according to the present invention.
2 is a configuration diagram showing a power transmission unit of a main rotor configured in a drone according to the present invention.
3 is a configuration diagram showing the internal configuration of the fuselage of the drone according to the present invention.
4 is a configuration diagram showing a cooling structure of a drone according to the present invention.
5 is a diagram showing a control circuit of a drone flight system according to the present invention.
6 is a diagram showing the configuration of an image analysis unit of a drone flight system according to the present invention.
7 is an explanatory diagram for explaining that a mark is recognized as a polygon in the drone flight system according to the present invention.
8 is a diagram showing an example of flight height control processing in the drone flight system according to the present invention.
9 is a diagram showing the flow of flight height control processing using a camera view angle in a drone flight system according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The terms used in the present invention are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of the user or operator, so the definitions of these terms are meanings consistent with the technical details of the present invention. and should be interpreted as a concept.

In addition, the embodiments of the present invention do not limit the scope of the present invention, but are only exemplary of the components presented in the claims of the present invention, are included in the technical spirit throughout the specification of the present invention, and cover the scope of the claims. It is an embodiment including components that can be replaced as equivalents in components.

In addition, optional terms in the following embodiments are used to distinguish one element from other elements, and elements are not limited by the terms.

Therefore, in describing the present invention, detailed descriptions of related known technologies that may unnecessarily obscure the gist of the present invention will be omitted.

1 to 4 are diagrams illustrating a drone according to the present invention.

As shown in FIG. 1, the drone 100 according to the present invention has a central body portion 110, a frame 310 protruding outward from the body portion 110, and a frame 310 rotatably. It includes a rotor that is installed to allow the drone 100 to fly.

The body part 110 is formed in the shape of a hexahedral box, and each case 111 is coupled to its upper and lower surfaces and side surfaces, and these cases 111 are in charge of each surface of the body part 110. It may be detachably provided for each unit case.

Thus, the inside of the fuselage 110 is formed as an empty space, and inside the fuselage 110, an engine 120, a battery 140, a gearbox 130, a fuel tank 150, and a chemical tank (which will be described later) 160) may be mounted and provided.

In particular, the engine 120 is an internal combustion engine that drives the main rotor 200 to be described later, and the battery 140 is a power supply that provides power to the auxiliary rotor 300 to be described later.

In addition, the battery 140 may be provided with a self-power generation function capable of converting and storing kinetic energy generated when the engine 120 is driven into electrical energy, or may be provided with a separate self-generator.

On the other hand, since the engine 120 and the battery 140 are heavier than other parts provided in the fuselage 110, they may affect the center of gravity of the drone 100, so the engine 120 It is preferable to arrange the battery 140 in a line on the center line within the fuselage 110 orthogonal to the flight direction of the drone 100.

This is in consideration of the fact that the fuselage 110 flies in a tilted state in the flight direction due to the nature of the drone 100, and when the engine 120 and the battery 140 are disposed in the flight direction of the drone 100, the tilted Since the weight of the engine 120 or the battery 140 is added to the fuselage 110 and tilted at a more severe angle, normal flight is difficult. Therefore, it is preferable to have the center line within the fuselage 110 orthogonal to the flight direction of the drone 100, which is a position that can have the least influence on the flight of the drone 100.

Meanwhile, the remaining parts provided in the fuselage 110 are provided symmetrically with respect to the center line where the engine 120 and the battery 140 are disposed.

That is, a fuel tank 150 for storing fuel necessary for flight is provided in the fuselage 110, and a plurality of fuel tanks 150 are prepared and provided symmetrically on both sides of the fuselage 110. Here, in the present embodiment, two fuel tanks 150 are provided on both sides of the fuselage 110 as an example, and the same amount of fuel is supplied to the engine 120 at the same time in the fuel tanks 150 on both sides. ) is preferably designed to be supplied.

Therefore, since the fuel in both fuel tanks 150 is uniformly consumed, weight imbalance of the drone 100 caused by both fuel tanks 150 can be prevented in advance.

With the same principle as the fuel tank 150, the chemical tank 160 mounted for the purpose of pest control is also provided symmetrically with respect to the center line of the fuselage 110 where the engine 120 and the battery 140 are disposed.

In addition, on the center line of the fuselage 110 where the engine 120 and the battery 140 are disposed, an intercooler 171 for cooling and supplying compressed air supplied to the engine 120 and cooling the cooling water of the engine 120 are provided. A radiator 170 is provided to supply the heat to the engine 120 again.

The intercooler 171 and the radiator 170 protrude from the fuselage 110 and are positioned below the main rotor 200 to be described later. Accordingly, there is an advantage in that the intercooler 171 and the radiator 170 can be naturally cooled by high-speed wind generated by the rotation of the main rotor 200 .

In addition, the fuselage 110 may be provided with a radar 180 and a navigation 181 for identifying objects and measuring distances during flight, and a control unit 190 and power electronics 192 for controlling them. It may be provided, and these parts are relatively light compared to the above-described engine 120, battery 140, fuel tank 150, drug tank 160, etc. do.

On the other hand, a gearbox 130 connected to and interlocked with an output shaft from which power of the engine 120 is output is provided at the top of the engine 120, and a plurality of gearboxes 130 are rotated by the output of the engine 120. Of the drive pulley 131 is provided. At this time, the gearbox 130 is preferably provided with a reducer for reducing the output of the engine 120 and transmitting it to both drive pulleys 131, and both drive pulleys 131 are opposed to each other by the gearbox 130. It is provided to rotate in the opposite direction to rotate the main rotors 200 on both sides, which will be described later, in opposite directions.

In addition, the frame 310 connected to the body part 110 is provided with a rotor that enables the drone 100 to fly, and the rotor is provided on both sides of the body part 110, respectively, It includes a pair of main rotors 200 for vertical take-off and landing, and an auxiliary rotor 300 for providing propulsion so that the take-off drone 100 can fly.

The main rotor 200 includes a rotor shaft 210 rotatably fixed to the frame 310 and a driven pulley 211 fixed to the lower end of the rotor shaft 210 and rotated together with the rotor shaft 210. do.

At this time, the main rotor 200 is disposed at a higher position than the fuselage 110 by the rotor shaft 210, and the rotation radius of the main rotor 200 extends beyond the intercooler 171 and the radiator 170 to the fuselage. It may be provided to include an area on one side of the unit 110.

The driven pulley 211 of the main rotor 200 is connected to the drive pulley 131 of the gearbox 130 provided in the fuselage 110 as a belt 220 and interlocked, so that both main rotors 200 They rotate in opposite directions at the same rotational speed.

Therefore, the force of action and reaction generated by the pair of main rotors 200 is offset to take off, and the large lift required for takeoff is reduced by the power of the engine 120 through the gearbox 130 to the main rotor ( 200), thereby minimizing energy loss.

On the other hand, the reason why the main rotor 200 is provided as a pair and rotates in the opposite direction is that when the main rotor 200 is one, the fuselage 110 acts and reacts with the rotational direction of the main rotor 200 Force to rotate in the opposite direction is generated, but when the pair of main rotors 200 are rotated in opposite directions, the torque is offset by the action and reaction of the pair of main rotors 200, so the fuselage 110 does not rotate. and can remain stationary.

In addition, as the pair of main rotors 200 rotate, a large force of lift is generated to offset gravity, so that the drone 100 can stably maintain the take-off state by the pair of main rotors 200.

In addition, lift corresponding to gravity is applied to the lower part of the main rotor 200 by a pair of main rotors 200 rotated during this process, and high-speed wind due to this lift is blown through the intercooler 171 and the radiator 170. The intercooler 171 and the radiator 170 are naturally cooled by blowing directly into the air.

And, as described above, the belt 220 connecting the drive pulley 131 of the gearbox 130 and the driven pulley 211 of the main rotor 200 has a tensioner 230 capable of adjusting the tension of the belt 220 Is provided, the tensioner 230 is provided to be movable in the body portion 110 to adjust the tension of the belt 220.

On the other hand, the auxiliary rotor 300 is provided at the end of the frame 310 in a state inclined in one direction, each auxiliary rotor 300 is driven by a motor provided in the lower part, these motors are attached to the fuselage 110 The rotational speed is controlled by the provided electronic speed controller 191 (ESC: Electronic Speed Controls).

In particular, the auxiliary rotor 300 is a member that generates propulsion necessary for the flight of the drone 100, and the auxiliary rotor 300 positioned in a diagonal direction is inclined in the same direction, and the auxiliary rotor ( 300) are provided so as to incline in opposite directions to each other.

Accordingly, the drone 100 may fly forward or backward, change direction, and turn in place by adjusting the rotational speed of the auxiliary rotor 300 .

Meanwhile, the motor of the auxiliary rotor 300 is driven by receiving power from the battery 140, and the battery 140 generates self-generation when the engine 120 is driven, so that electric energy is continuously supplied and charged.

And, although not shown in the drawings, the frame 310 may be provided with a plurality of nozzles for injecting the medicament stored in the medicament tank 160 into the air.

The drone of the present invention as described above flies by driving the engine.

That is, when the engine 120 is driven, the power of the engine 120 is transmitted to the gearbox 130 through the output shaft, which is again decelerated in the gearbox 130 and moves both drive pulleys 131 in opposite directions to each other. will rotate

Then, the main rotors 200 connected to both drive pulleys 131 as belts 220 are rotated in opposite directions to generate lift to take off the drone 100, and the pair of main rotors 200 rotate in opposite directions to each other. Since the torque of the main rotor 200 is offset as it rotates in the opposite direction, the fuselage 110 can stably maintain a stationary state.

In addition, when the main rotor 200 is rotated and lift is generated, high-speed wind blows to the bottom of the main rotor 200 to naturally cool the intercooler 171 and the radiator 170 .

Meanwhile, when the engine 120 is running, kinetic energy of the engine 120 is converted into electrical energy and stored in the battery 140, and power from the battery 140 is supplied to the motor of the auxiliary rotor 300 to operate the motor. will make it work

At this time, the rotational speed of each motor is controlled by each electronic speed controller 191, so that forward flight or backward flight, direction change, flight such as rotation in place is possible.

Next, the automatic flight of the drone, that is, the configuration related to flight height adjustment will be described. 5 is a block diagram showing a control circuit 400 of a drone according to the present invention. The control circuit 400 may be included in the body part 110 of the drone or installed in a frame supporting the body part 110, but the present invention is not limited thereto and may be installed in any area of the drone.

In the drone according to the present invention, the body part 110 is an external support device (or sensor group) for supporting the automatic flight height of the drone, and as shown in FIG. 5, the camera 410, the GPS sensor 422, the acceleration / It includes a gyro sensor 424, a radar sensor 180, and a navigation 181. Such a sensor group is input to the flight control unit 440 through an appropriate support interface, and the flight control unit 440 can perform autonomous flight or automatic take-off and landing based on the value of the input sensor group.

The camera 410 is mounted on the drone and captures an object to be a landmark located below the drone, for example, a landmark on the ground. Here, an example of using a camera equipped with a lens (zoom lens) for adjusting the angle of view as the camera 410 is shown. The camera 410 transmits captured image data to the image analyzer 430 .

The GPS sensor 422 measures distance based on the time taken for a signal to arrive from the satellite to the receiver. In other words, GPS in drones is a global positioning system using artificial satellites. It is a system that obtains the three-dimensional coordinates and world time of an observation point by receiving radio waves from a satellite with an accurate location and observing the time required to reach the observation point. Therefore, autonomous flight from take-off to landing is supported by using the GPS sensor 422 to make the drone fly along the route point or return to the original position.

The accelerometer and gyro sensor 424 functions as an inertial sensor of the drone. The accelerometer measures the drone's acceleration, and the gyro sensor measures the drone's rotational force. Both the accelerometer and the gyro sensor use 3-axis sensors, and the 3-axis here means that when the sensor moves in 3 dimensions, it can measure the acceleration in the x-axis, y-axis, and z-axis directions. The relative position and movement of drones can be measured.

The gyro sensor is the most basic sensor that helps keep the drone level, and provides tilt information of the drone by measuring angular acceleration in three axis directions. The control module integrates and analyzes the two measured values to calculate the current attitude (angle) of the drone and performs attitude correction necessary for the desired flight.

In addition, the drone 1 according to the present invention may further include a LiDAR (Light Detection And Ranging) or radar sensor 180 . The lidar sensor 180 detects and measures the distance to the object, direction, speed, temperature, material distribution and concentration characteristics, etc. can do. The LiDAR sensor 180 is generally used for more precise physical property observation and distance measurement in the air by utilizing the advantages of a laser capable of generating a pulse signal having a high energy density and a short period. LiDAR sensors can be used to measure distances from several meters to several kilometers. By using very short invisible near-infrared laser pulses to expand the range of LiDAR systems, it is safe for the eye and enables much higher laser power than conventional continuous wave lasers.

In the present invention, the lidar sensor 180 is installed to detect obstacles or objects ahead during flight of the drone, and the detection value from the lidar sensor 180 is input to the flight controller through the controller 190.

The flight state of the drone is defined as a rotational motion state and a translational motion state, and the rotational motion state is

- Yaw (or rudder, rotating the fuselage while keeping the drone level): z-axis rotation;

- Pitch (Pitch or Elevator, forward or backward by moving the nose of the drone up and down): x-axis rotation

- Roll (Roll or Aileron, the drone moves left and right as the body is tilted left and right): Includes y-axis rotation.

In addition, the translational motion state of the drone means longitude, latitude, altitude, and speed.

A 3-axis gyro sensor, a 3-axis acceleration sensor, and a 3-axis geomagnetic sensor can be used to measure the rotational motion of the drone, and a GPS receiver and an air pressure sensor can be used to measure the translational motion of the drone.

In addition, the drone may further include a magnetometer sensor that performs a compass function and an inertial measurement unit (IMU). A magnetometer is a sensor that functions as a compass and serves to measure a magnetic field. The force is measured, and the flight controller (FC) cannot know the direction of the drone with only the acceleration sensor and the gyro sensor, but the direction information of the drone can be obtained by measuring the magnetic north using the magnetometer sensor. The movement of the drone can be grasped by combining the orientation information of the magnetometer and the movement information of the accelerometer.

In addition, the Inertial Measurement Unit (IMU) is interlocked with GPS to maintain the moving direction, moving path, and speed of the aircraft, and the information obtained in the form of a combination of a 3-axis magnetometer and GPS receiver is used for the flight of the drone. It may also be transmitted to the controller 440.

As described above, the camera 410 captures an object to be a landmark located below the drone, for example, a landmark on the ground. Here, an example of using a camera equipped with a lens (zoom lens) for adjusting the angle of view as the camera 410 is shown. The camera 410 transmits captured image data to the image analyzer 430 .

The image analysis unit 430 calculates the flight height using image data from the camera.

The flight control unit 440 is configured to control flight conditions including the flight height of the drone, and the driving unit 460 is configured of a propeller and a motor that rotates the propeller. The flight controller 440 appropriately controls the number of revolutions of the propeller of the drive unit 460 through the ESC to control the moving direction or flight height of the drone. The camera controller 450 controls the angle of view (zooming) of the camera 410 .

More specifically, as shown in FIG. 6, the image analysis unit 430 includes a mark detection unit 432, an area calculation unit 434, a maximum area detection unit 435, a flight height calculation unit 436, and a camera view angle adjustment unit ( 437).

When receiving an image taken from a camera, the landmark detection unit 432 recognizes a ground landmark from the received image. A specific shape or geometric shape can be used as a ground mark.

The storage unit M stores the number of preset marks as the number of reference marks. For example, the storage unit M stores the number of reference marks.

The mark detection unit 432 compares the number of marks recognized through the mark detection unit with the number of reference marks stored in the storage unit 16, outputs the comparison result to the flight height calculation unit 436, and takes pictures by the camera. The obtained image and the comparison result are output to the area calculation unit 434 .

When the number of marks recognized by the mark detection unit 432 matches the number of marks pre-registered in the storage unit 16, the area calculation unit 434 uses the image captured by the camera to determine the number of marks. The position is detected, the area (area) of the polygon formed by the number of marks corresponding to the number of reference marks is calculated, and the calculated area of the polygon is output to the maximum area detection unit 435.

The maximum area detection unit 435 receives the area of the polygon calculated by the area calculation unit 434, stores it, compares the area of the previous polygon with the area of the newest polygon, and detects the maximum area value. and outputs the comparison result to the flight height calculator 436.

The flight height calculation unit 436 calculates the flight height of the drone equipped with the camera so that the area of the polygon is maximized based on the comparison result of the mark detection unit 432 and the comparison result of the maximum area detection unit 435, and the flight control unit Sends a control signal to 440.

Specifically, the flight height calculation unit 436 controls the flight height of the drone to increase the flight height of the drone when the number of marks recognized by the mark detection unit 432 is less than the reference number of marks. A control command is created and the created control command is transmitted to the flight control unit 440 .

In addition, the flight height calculation unit 15 gives a control command to lower the flight height of the drone when the number of the plurality of marks coincides with the number of reference marks and the area of the polygon is smaller than the previously calculated area of the polygon. is created, and the created control command is transmitted to the flight control unit 440.

In addition, the flight height calculation unit 436 controls the flight height to maintain the flight height of the drone when the number of the plurality of marks coincides with the number of registration marks and the area of the polygon is greater than or equal to the previously calculated area of the polygon. A control command is created, and the created control command is transmitted to the flight control unit 440.

The camera view angle adjusting unit 437 controls the view angle or zooming of the camera mounted on the drone. Specifically, the mark detection unit 432 recognizes a plurality of ground marks from an image captured by the camera 410 while maintaining the flight height of the drone at the current flight height. The area calculating unit 434 calculates the area of a polygon formed by the plurality of marks recognized while maintaining the flight height of the drone at the current flight height as the area when the flight height is maintained. The camera view angle adjusting unit 437 creates a control command for controlling the angle of view of the camera 410 so that the area is maximized when the altitude is maintained, and controls the angle of view of the camera through the created control command.

In addition, the camera view angle adjuster 437 creates a control command to widen the view angle of the camera when the number of the plurality of marks recognized while maintaining the current flight height of the drone is less than the number of reference marks. Here, when the angle of view of the camera cannot be widened any further, the camera view angle adjustment unit 437 generates a control command to maintain the current angle of view of the camera, and the flight height calculator 436 generates a control command to increase the flight height of the flying drone. is created and transmitted to the flight control unit 440.

In addition, the camera view angle adjusting unit 437 determines that the number of the plurality of marks recognized while maintaining the flight height of the drone at the current flight height coincides with the number of registration marks, and the area of the polygon when the altitude is maintained is previously calculated. If the area is smaller than the area at the time of maintaining the altitude, a control command for controlling the camera to narrow the angle of view of the camera is created and transmitted to the camera controller 450 . Here, when the angle of view of the camera cannot be narrowed any further, the camera view angle adjusting unit 437 creates a control command for maintaining the current angle of view of the camera, and the flight height calculator 436 calculates the flight height of the drone. Creates a control command to descend and transmits it to the flight control unit 440.

In addition, the configuration of the camera view angle adjusting unit 437 is not particularly limited to the above example, and various changes are possible. For example, the camera view angle adjusting unit 437 is omitted and the flight height calculation unit 436 uses the camera view angle The function of the adjustment unit 437 may be further performed.

In the configuration described above, the camera always captures an image below the drone's flying position, and therefore, the area of the area captured by the drone's camera changes according to the flight height of the drone and the angle of view of the camera mounted on the camera. That is, when the drone zooms out the angle of view from the telephoto side to the wide angle side, the angle of view widens and the area to be photographed also widens. In addition, the camera of the drone zooms from the wide-angle side to the telephoto side, and the angle of view narrows, and the area to be photographed also narrows.

In this embodiment, the angle of view of the camera is maintained at the maximum wide angle, that is, a state in which the largest number of objects can be photographed with the widest angle of view in the initial state. Below the drone, landmarks are developed, and a camera captures images of these landmarks, thereby generating a polygon having the position of the landmark on the ground as a vertex.

7 is an image diagram illustrating an example of a state when a drone captures two or more ground landmarks A1 to A7 according to an embodiment of the present invention. In the embodiment shown in FIG. 7 , a drone is flying in the sky, and seven ground markers are arranged below the flying position. Each of the marks A1 to A7 may be a fixed mark or a movable mark, and the mark may include, for example, a light emitting part and light the light emitting part in a predetermined color. At this time, the drone captures an image below the flying position using a camera, and the image analysis unit 430 recognizes the light emitting parts of the plurality of signs from the captured image, and the drone uses a camera to capture seven ground signs. The flight height of the drone is controlled so that all light emitters can be photographed.

As shown in FIG. 7, the recognized mark is connected to a line segment to form one polygon. As shown in FIG. 7 , the image analyzer 430 recognizes 7 ground marks as recognized marks A1 to A7 and calculates the area of a polygon composed of 7 line segments.

Here, in the embodiment, if the flight height of the drone is low, the number of marks captured by the camera does not reach the preset number of reference marks, so a polygon having the number of recognized marks as vertices is not formed.

Accordingly, the flight height calculation unit 436 increases the flight height of the drone until the number of marks stored in the storage unit M is recognized. In this way, a polygon in which the number of markers is the number of vertices can be obtained. In the process of the drone raising the flight height, the camera starts to photograph a mark, and when the mark is captured from the image of the camera, the mark detection unit 432 starts counting the number of recognized marks, and then recognizes It ascends and flies until the number of marked marks reaches the preset number.

If the number of marks coincides with the number of registered marks while the drone continues to ascend, since a polygon having each mark as a vertex can be recognized, the area calculation unit 434 calculates the area of the polygon.

Since the area of the polygon is related to the flight height of the drone, the area of the polygon decreases as the flight height of the drone increases. On the other hand, as the flying height of the drone decreases, the area of the polygon increases conversely. Since the marks appear from outside the angle of view of the camera, polygons having the marks of the preset number of registration marks as vertices cannot be detected.

At this time, the flight height calculation unit 436 changes the flight height of the drone, and based on the comparison result of the maximum area detector 435, the flight height of the drone is determined so that the area of the polygon photographed by the camera is maximized. . When the mark moves, for example, in the case of a mobile vehicle, the area of the polygon changes, and the maximum area detection unit 435 sequentially compares the area of the polygon that changes, and the flight height calculation unit 436 adjusts the area of the polygon to the mark. The flight height of the drone is controlled so that the area of the polygon formed by

8 and 9 are flowcharts showing an example of processing of the flight height calculator. First, raise the drone with the angle of view of the camera set to the maximum wide angle. As shown in Fig. 8, the flight controller starts flight height processing (step S101). Next, in step S102, the mark detection unit 432 acquires an image captured by the camera 410 and recognizes the mark.

Next, in step S103, the mark detection unit 432 compares the number of recognized marks with the number of reference marks previously stored in the storage unit M. If the number of recognized marks is less than the preset number of marks (that is, when the number of marks is insufficient), the control moves to step S107, and the mark detection unit 432 determines that the number of recognized marks is greater than the number of registration marks. The flight height calculator 436 is notified of the small number. Then, the flight height calculation unit 436 instructs the flight control unit to increase the flight height of the drone. The flight control unit 440 increases the flight height of the drone according to the instruction.

Meanwhile, when the number of recognized marks is equal to the number of marks preset in the storage unit, the process proceeds to step S104 of calculating the area of a polygon formed by the marks. In step S104, the area calculation unit 434 detects the position of the mark using the image captured by the camera 410, and calculates the area of the polygon having the detected mark as a vertex.

Next, in step S105, the maximum area detection unit 435 stores the area of the previously calculated polygon and compares the area of the previous polygon with the area of the current polygon calculated in step S104. If the area of the current polygon is smaller than the area of the previous polygon, the process proceeds to step S106, and the maximum area detection unit 435 notifies the flight height calculation unit 436 that the area of the current polygon is smaller than the area of the previous polygon. , The flight height calculation unit 436 instructs the flight control unit 440 to lower the flight height of the drone. The flight controller 440 controls the flight height of the drone according to instructions.

On the other hand, when the area of the current polygon is larger than the area of the previous polygon, the maximum area detection unit 435 notifies the flight height calculation unit 436 that the area of the current polygon is greater than or equal to the area of the previous polygon, and the flight height calculation unit ( 436) moves to step S111 shown in FIG. 9 while maintaining the current altitude.

Next, in FIG. 9, the flight controller starts an adjustment process based on the angle of view (step S111). In step S112, the mark detector 432 acquires an image captured by the camera 410 and recognizes the mark.

Next, in step S113, the mark detector 432 compares the number of recognized marks with the number of reference marks previously stored in the storage unit M. If the number of recognized marks is less than the preset number of marks, the process goes to step S119, and the mark detection unit 432 notifies the flight height calculation unit 436 that the number of recognized marks is less than the number of registration marks. do. Thereafter, the flight height calculation unit 436 determines whether the camera 410 can reduce the angle of view.

For example, the flight height calculation unit 436 inquires the camera view angle adjusting unit 437 as to whether a wide angle is possible, and determines whether a wide angle is possible according to a response from the camera view angle adjusting unit 437 . In addition, the determination of whether or not the wide angle is possible is not particularly limited to the above example, and various changes are possible. For example, the flight height calculator 436 calculates the current angle of view and the maximum wide angle value of the camera 410 mounted By comparing, it may be determined whether a wide angle is possible, or the camera view angle adjusting unit 437 may determine.

If it is determined that the wide angle is possible, the flight height calculation unit 436 instructs the camera view angle adjusting unit 437 to change the angle of view to the wide angle. Next, in step S120, the camera view angle adjusting unit 437 instructs the camera controller 450 to change the camera view angle to a wide angle, and the camera controller 450 zooms out the lens of the camera. After that, the processing proceeds to step S112 to continue processing thereafter.

Meanwhile, in step S119, when it is determined that the angle of view cannot be changed to the wide angle through an inquiry in the flight height calculation unit 436, the flight height of the drone is increased by switching to step S107 shown in FIG. 8.

When the number of marks recognized in step S113 is equal to the preset number of marks, the process proceeds to step S114 for calculating the area of the polygon formed by the marks. In step S114, the area calculation unit 434 detects the position of the marker using the camera image captured by the camera 410, and obtains the area of a polygon having the detected marker as a vertex as an altitude holding area.

Next, in step S115, the maximum area detection unit 435 memorizes the area of the previously calculated polygon, and the area of the previous polygon (previously calculated area for maintaining elevation) and the area for the current polygon (area for maintaining elevation) calculated in step S114. Compare If the area of the current polygon is smaller than the area of the previous polygon, the process goes to step S116, and the maximum area detection unit 435 informs the flight height calculation unit 436 that the area of the current polygon is smaller than the area of the previous polygon. Upon notification, the flight height calculation unit 436 determines whether or not the camera 410 can change the angle of view to the telephoto.

For example, the flight height calculation unit 436 queries the camera view angle adjuster 437 whether the angle of view can be changed to telephoto, and determines whether the angle of view can be changed to telephoto according to a response from the camera view angle adjuster 437. In addition, the determination of whether or not telephoto is possible is not particularly limited to the above example, and various changes are possible. For example, the flight height calculation unit 436 compares the current angle of view and the maximum telephoto value of the camera 410 to telephoto. You can judge whether it can be changed.

If it is determined that the angle of view can be changed to telephoto, the flight height calculation unit 436 instructs the camera view angle adjusting unit 437 to change to telephoto. Next, in step S117, the camera view angle adjuster 437 instructs the camera controller 450 to change the camera view angle to telephoto, and the camera controller 450 zooms in the lens of the camera. After that, the process moves to step S112 and the subsequent process continues.

Meanwhile, in step S116, when the flight height calculation unit 436 determines that the angle of view of the camera cannot be changed to telephoto, the process is switched to step S106 shown in FIG. 8, and the flight control unit 440 switches to a process of changing the flight height of the drone. do.

In addition, when the area of the current polygon is greater than or equal to the area of the previous polygon, the maximum area detection unit 435 notifies the flight height calculation unit 436 that the area of the current polygon is greater than or equal to the area of the previous polygon, and the flight height calculation unit 436 , in a state where the flight height of the drone is maintained, the camera view angle adjustment unit 437 is instructed to maintain the current view angle of the camera, and the process moves to step S111 and the subsequent processing is repeated (step S118).

Through the above process, the flight control unit 440 recognizes the ground mark captured using the camera, forms a polygon having the recognized mark as a vertex, and flies the drone at an altitude capable of capturing an image maximizing the area of the polygon. can make it As a result, the flying height of the drone can be maintained at a constant optimal altitude using the mounted camera.

Although the present invention has been described in detail through specific examples, this is for explaining the present invention in detail, the present invention is not limited thereto, and within the technical spirit of the present invention, by those skilled in the art It is clear that modifications and improvements are possible.

All simple modifications or changes of the present invention fall within the scope of the present invention, and the specific protection scope of the present invention will be clarified by the appended claims.

100: drone 110: fuselage
111: case 120: engine
130: gear box 131: driving pulley
140: battery 150: fuel tank
160: chemical tank 170: radiator
171: intercooler 180: radar
181: navigation 190: control unit
191: electronic speed controller (ESC) 192: power electronics
200: main rotor 210: rotor shaft
211: driven pulley 220: belt
230: tensioner 300: auxiliary rotor
310: frame

Claims (5)

In the drone flight system in which the flight altitude is determined according to the convergence sensor-based measurement area,
A camera for photographing a mark disposed below the drone during flight of the drone;
an image analysis unit for analyzing an image from the camera; and
A flight control unit for adjusting the flight height of the drone in response to the analysis result of the image analysis unit;
The image analysis unit detects a mark from the captured image, calculates the area of a polygon formed from the detected mark, and generates a command to increase or decrease the flight height to the flight control unit based on the calculated area. Characterized in that it comprises a height calculation unit
drone flight system.
According to claim 1,
The image analysis unit includes a storage unit for storing a predetermined number of marks and an area calculation unit for calculating an area of a polygon formed from the detected marks,
Characterized in that the area calculation unit is configured to compare the number of marks detected in the image captured by the camera with a predetermined number of marks stored in the storage unit
drone flight system.
According to claim 2,
The area calculation unit compares the number of marks detected in the image captured by the camera with a predetermined number of marks stored in the storage unit,
When the number of signs detected in the image taken from the camera is less than the number of predetermined signs, the flight height calculation unit of the image analysis unit generates a command to increase the flight height to the flight control unit. Characterized in that
drone flight system.
According to claim 2,
The area calculator compares the number of markers detected in the image captured by the camera with the predetermined number of markers stored in the storage unit, so that the number of markers detected in the image captured by the camera is equal to the predetermined number of markers. characterized in that configured to calculate the area of the polygon formed by the detected landmarks in the case of the same
drone flight system.
According to claim 4,
The image analysis unit further includes a maximum area detector for detecting a maximum area by comparing the calculated area of the polygon,
The area calculator compares the number of markers detected in the image captured by the camera with the predetermined number of markers stored in the storage unit, so that the number of markers detected in the image captured by the camera is equal to the predetermined number of markers. In the case of the same
The maximum area detection unit compares the previously calculated area of the polygon with the currently calculated area of the polygon, and if the currently calculated area of the polygon is smaller than the previously calculated area of the polygon, the flight height calculation unit lowers the flight height to the flight control unit. Is configured to generate a command
drone flight system.

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