KR20210115313A - Method for controlling drone and apparatus therefor - Google Patents

Abstract

The present invention relates to a device and method for drone control to control a drone so that the drone can fly normally and autonomously even in a case that the drone does not receive a global position system (GPS) signal. According to an embodiment of the present invention, the method of controlling a drone by selectively transmitting a virtual GPS signal from a communication device to the drone includes: a step of receiving state information on a drone from the drone; a step of determining whether the GPS receiving state of the drone is abnormal based on the drone state information; a step of generating virtual GPS signals to be received by the drone in the next cycle based on the planned flight path of the drone in a case where the GPS receiving state of the drone is abnormal as a result of the determination; and a step of transmitting the generated virtual GPS signals to the drone.

Description

Drone control method and apparatus {Method for controlling drone and apparatus therefor}

The present invention relates to drone control technology, and more particularly, to a drone control method and apparatus for controlling a drone to fly autonomously normally even when a global position system (GPS) signal is not received from the drone.

Currently, the development of drones with various functions is in progress. For example, various drones such as drones for shooting, agricultural drones, delivery drones, and air quality measurement drones are being developed, and some of them are actually used in the field.

Furthermore, a technology for remotely controlling and controlling a drone using a current mobile communication network has emerged. In other words, in the past, drones were controlled through short-range wireless communication such as Bluetooth communication, but in order to remotely control and control a drone located at a greater distance, a technology for controlling the drone via a mobile communication network has emerged.

If the drone is controlled using a mobile communication network in this way, the drone can be controlled over a longer distance, and the drone can be controlled indoors as well. When remotely controlling a remote drone, the control center transmits flight route information of the drone to the drone, and the drone flies autonomously by comparing the currently received GPS information with the flight route information.

However, a drone that performs autonomous flight may encounter a situation in which GPS signals are abnormally received due to weather or the like. For example, a drone may face a situation in which it cannot receive a GPS signal at a specific location during autonomous flight. In this case, the drone will not be able to accurately measure its current position, making it unable to autonomously fly on the planned flight path, and may even fly on the wrong flight path.

The present invention has been proposed to solve these conventional problems, and when a GPS signal is not received from a drone in autonomous flight, a drone control method that provides a virtual GPS signal to the drone to induce the drone to fly normally, and The purpose is to provide a device.

Other objects and advantages of the present invention may be understood by the following description, and will become more clearly understood by the examples of the present invention. Moreover, it will be readily apparent that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to a first aspect of the present invention for achieving the above object, there is provided a method for controlling flight of a drone by selectively transmitting a virtual GPS signal from a communication device to a drone, the method comprising: receiving state information of the drone from the drone; determining whether the GPS reception state of the drone is abnormal based on the state information of the drone; generating a plurality of virtual GPS signals to be received by the drone in a next period based on the planned flight path of the drone when the GPS reception state of the drone is abnormal as a result of the determination; and transmitting the plurality of generated virtual GPS signals to the drone.

The method may include analyzing the state information to predict a position at which the drone will fly in a next period; and calculating a delay time for each of the plurality of virtual GPS signals in order to induce the distance between the predicted position and the corresponding artificial satellite to be measured by the drone. In this case, the transmitting includes transmitting the corresponding virtual GPS signal to the drone after the corresponding delay time has elapsed.

In the calculating of the delay time, the first distance between the predicted position and the satellite and the second distance between the base station in which the communication device is mounted and the predicted position are checked, and the first distance, the second distance and The delay time may be calculated using the speed of the virtual GPS signal.

The generating of the plurality of virtual GPS signals may include identifying a plurality of GPS signals used by the drone to calculate coordinates in the state information, and a plurality of virtual GPS signals having the same satellite identification information as any one of the plurality of GPS signals. can create

The method includes the steps of counting a duration during which the GPS reception state of the drone is abnormally maintained: and if the counted duration exceeds a threshold time, transmitting a command instructing an emergency landing to the drone, the drone It may further include the step of emergency landing.

The communication device may be an edge cloud.

The method may be implemented in the form of a computer program recorded on a computer-readable recording medium.

According to a second aspect of the present invention for achieving the above object, a communication device for selectively transmitting a virtual GPS signal to a drone receives status information of the drone from a drone, and based on the status information of the drone, the drone a drone control unit that determines whether the GPS reception state of the system is abnormal; and when the GPS reception state of the drone is abnormal as a result of the determination, a plurality of virtual GPS signals to be received by the drone in the next cycle are generated based on the planned flight path of the drone, and the generated plurality of virtual GPS signals are used in the and a virtual GPS signal generator to be transmitted to the drone.

According to a third aspect of the present invention for achieving the above object, a drone flying by selectively using a virtual GPS includes: a storage unit for storing a planned flight path; a GPS receiver for receiving one or more GPS signals; a wireless communication unit for wireless communication with a base station built in a mobile communication network; and measuring the current position of the drone based on the plurality of GPS signals received from the GPS receiver, comparing the measured position with the flight path, and at least one provided in the drone so that the drone can fly along the planned flight path. A control unit for controlling the propeller is included.

The control unit determines whether the GPS reception state of the GPS receiver is normal, and if the determination result is normal, the control unit measures the current location of the drone using a plurality of GPS signals acquired through the GPS receiver, and the determination result If the GPS reception state is abnormal, the current position of the drone is measured using virtual GPS signals received through the wireless communication unit.

According to the present invention, when a GPS signal is not received from a drone in autonomous flight, a virtual GPS signal is transmitted to the drone through a mobile communication network, thereby allowing the drone to autonomously fly normally even in an environment where a GPS signal is not received. It has the advantage of improving the reliability and stability of the

In addition, the present invention induces the drone to make an emergency landing when the time during which the GPS signal is not received from the drone exceeds a threshold time, thereby preventing the drone flying on the wrong path due to the actual GPS non-reception situation lasting for a long time. there is an advantage to

In addition, the present invention predicts the GPS signal to be provided in the next cycle based on the planned flight path, the speed and direction of the current drone, and provides the predicted GPS signal to the drone as a virtual GPS signal, so that the drone can autonomously fly It has the effect of proceeding accurately.

The following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical spirit of the present invention together with specific details for carrying out the invention, so the present invention is described in the drawings It should not be construed as being limited only to the matters.
1 is a diagram illustrating a drone control system according to an embodiment of the present invention.
2 is a flowchart illustrating a method of controlling a drone through an edge cloud in a drone control system according to an embodiment of the present invention.
3 is a diagram illustrating the configuration of an edge cloud according to an embodiment of the present invention.
4 is a diagram illustrating distances of artificial satellites and base stations from positions predicted to have moved by a drone, according to an embodiment of the present invention.
5 is a flowchart illustrating a method of generating a virtual GPS signal in an edge cloud and transmitting it to a drone according to an embodiment of the present invention.
6 is a diagram illustrating a configuration of a drone according to an embodiment of the present invention.
7 is a flowchart illustrating a method of performing autonomous flight using a GPS signal in a drone according to an embodiment of the present invention.

The above-described objects, features, and advantages will become more apparent through the following detailed description in relation to the accompanying drawings, whereby those of ordinary skill in the art to which the present invention pertains can easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a drone control system according to an embodiment of the present invention.

As shown in FIG. 1 , the drone control system according to an embodiment of the present invention includes a drone 100 , a plurality of base stations 300-N, and a drone control server 200 .

The drone control server 200 communicates with each of the drone 100 and the base station 300-N via the network 400 . The network 400 includes a wired communication network as well as a mobile communication network such as a 5th generation mobile communication network and a 4th generation mobile communication network.

The base station 300-N is a NodeB, an e-NodeB, a next generation NodeB (gNB), etc., and provides a mobile communication service to the drone 100 through a wireless interface. The base station 300-N has a main function of radio resource management (RRM) such as radio bearer control, radio admission control, dynamic radio resource allocation, load balancing, and inter-cell interference control (ICIC).

In particular, the base station 300-N may be equipped with an edge cloud for supporting drone control. The edge cloud is a device that controls the drone 100 at the forefront and provides a virtual GPS signal to the drone 100 when the GPS reception state is unstable, and the base station 300-N under the control of the drone control server 200 ) is optionally mounted on The virtual GPS signal is not a signal transmitted from an actual satellite, but a GPS signal generated from an edge cloud. The edge cloud may be equipped with a control function capable of automatically controlling the drone 100 . The edge cloud monitors whether the GPS reception state of the drone 100 is normal, and if the GPS reception state is abnormal, generates a plurality of virtual GPS signals to be received by the drone 100 in the next cycle, and virtual GPS The signal is transmitted to the drone 100 using a wireless signal (ie, a downlink wireless signal) used in the mobile communication network. The edge cloud mounted on the base station 300-N includes the planned flight path of the drone 100 received from the drone control server 200, the flight speed periodically received from the drone 100, and the movement direction of the drone 100. , based on the location information, it is possible to predict the location of the drone 100 in the next period, and generate a plurality of virtual GPS signals to be received by the drone 100 at the predicted location.

The base station 300-N may include one or more memories and a processor, and the edge cloud may be mounted in the memory in a form executed by the processor. The base station 300-N may employ a gNB, which is a 5G base station, in order to provide an ultra-delay response speed.

The drone 100 is an unmanned aerial vehicle equipped with a take-off means such as a propeller, and is equipped with a wireless communication unit and a GPS receiver capable of communicating with the base station 300-N. Also, the drone 100 may autonomously fly to a destination according to a movement path. The drone 100 may perform wireless communication with the base station 300-N using a wireless communication unit. In addition, the drone 100 periodically collects state information including movement direction, movement speed, current coordinates, a plurality of GPS signals used to calculate the current coordinates, reception time for each GPS signal, battery state, etc. The state information is transmitted to the edge cloud mounted in the base station 300-N. The drone 100 may check the moving direction by using a tilt sensor, a gyro sensor, or the like, or may check the moving direction by comparing previous coordinates with current coordinates. An azimuth may be used as the movement direction.

On the other hand, the GPS signal transmitted from the artificial satellite includes identification information of the satellite, position information of the satellite, and the transmission time of the GPS signal. In other words, the artificial satellite periodically transmits a GPS signal to the earth at regular intervals, and the GPS signal includes identification information of the satellite, position information of the satellite, and transmission time of the GPS signal.

The drone 100 may calculate a time difference between a transmission time and a reception time of the GPS signal based on the time the GPS signal is received and the transmission time included in the GPS signal, and the GPS signal speed (eg, , the speed of light) to calculate the distance between the satellite and itself. In addition, the drone 100 confirms the position of the satellite in the GPS signal, and confirms that it is located by the calculated distance from the position of the satellite. The drone 100 analyzes three or more GPS signals, performs triangulation based on the position and distance of each satellite, and measures the position.

On the other hand, the drone 100 receives virtual GPS signals from the edge cloud mounted in the base station 300-N using a wireless communication unit when a threshold number (eg, two) or less is received in the currently received GPS signal. And, based on these virtual GPS signals, the current position is measured and autonomous flight is performed. The drone 100 may attempt an emergency landing when the number of GPS signals is continuously received below a threshold number for a preset time period (eg, 10 seconds).

The drone control server 200 is a device that mounts the edge cloud for controlling the drone 100 on the base station 300-N, and creates a planned flight path of the drone 100 and transmits it from the drone 100 Receive and store information. Specifically, the drone control server 200 divides the installation location of each base station 300-N and the range information (ie, GPS coordinate range information) for the cell coverage formed by each base station 300-N by each base station. Save, and save the coordinate information for the no-fly zone. The no-fly zone may include an area where a high-rise building is located, a military area, a security area, a hazardous material storage area, and the like.

The drone control server 200 receives destination information of the drone 100 from the drone operator, and generates a planned flight path from the current location of the drone 100 to the destination. At this time, the drone control server 200 checks the no-fly zone being stored, has the shortest distance from the location of the drone 100 to the destination, and creates a planned flight path that does not pass through the no-fly zone. can The drone control server 200 compares the generated flight path with the coverage for each base station being stored, and confirms one or more base stations 300-N that form coverage on the planned flight path of the drone 100, and the one checked in this way The edge cloud installation data is transmitted to the above base station 300-N. The edge cloud installation data is a kind of program for drone control, a function for monitoring the status of the drone 100, a function to predict the location of the drone 100 in the next cycle, and a virtual GPS signal to the drone 100 functions for transmission, and the like.

The base station receiving the edge cloud installation data, when the drone 100 is located in its coverage, not only performs wireless communication with the drone 100 but also receives the state information of the drone through the edge cloud, and the drone ( 100) may selectively transmit a virtual GPS signal according to the GPS reception state.

2 is a flowchart illustrating a method of controlling a drone through an edge cloud in a drone control system according to an embodiment of the present invention.

Referring to FIG. 2 , the drone control server 200 receives destination information of the drone 100 and identification information of the drone 100 to be controlled from the drone operator ( S201 ). Then, the drone control server 200 requests and receives the current location information from the drone 100 having the identification information. And with reference to the no-fly zone being stored, the drone control server 200 creates a planned flight path that has the shortest distance from the current location of the drone 100 to the destination but does not pass through the no-fly zone (S203). ). The flight path includes a number of GPS coordinates that must be traversed over time.

Next, the drone control server 200 compares the generated flight path with the coverage for each base station in storage, and confirms one or more base stations 300-N that form coverage in the planned flight path of the drone 100, One or more of the confirmed base stations 300-N are selected as base stations where the edge cloud is installed (S205). In the description with reference to FIG. 2 , it is assumed that the base station #1 300-1 is selected as the base station where the edge cloud is installed, and the reference code of the base station #1 300-1 is 300-1. Next, the drone control server 200 transmits edge cloud installation data to the base station #1 (300-1) so that the edge cloud for drone control is mounted on the base station #1 (300-1) (S207, S209) ). The edge cloud installation data is a kind of program for drone control, a function for monitoring the status of the drone 100, a function to predict the location of the drone 100 in the next cycle, and a virtual GPS signal to the drone 100 functions for transmission, and the like. In addition, the drone control server 200 transmits the generated planned flight path to the drone 100 (S211). In addition, the drone control server 200 transmits the generated planned flight path to the edge cloud of the base station #1 (300-1), so that the planned flight path is stored in the edge cloud.

Then, the drone 100 performs autonomous flight with reference to a plurality of GPS coordinates included in the planned flight path. That is, the drone 100 measures the current position (ie, coordinates) based on a plurality of GPS signals received from the artificial satellite, compares the current coordinates with the coordinates included in the flight path, and compares the current position (ie, coordinates). After checking whether the coordinate) corresponds to a point in the entire flight path, autonomous flight is carried out in the direction corresponding to the next coordinate.

When autonomous flight is in progress, the drone 100 collects and collects data such as current movement speed data, current coordinate data, a plurality of GPS signals used to calculate coordinates, reception time for each GPS signal, battery status, and movement direction. The state information including the data is transmitted to the edge cloud mounted in the base station #1 (300-1) (S213, S215). The drone 100 determines whether the number of currently received GPS signals exceeds a threshold number (eg, two) and, if it exceeds, may record the indication information 'GPS normal' in the status information, and vice versa. If the number of GPS signals is less than or equal to the threshold number, display information of 'GPS abnormal' may be recorded.

Next, the edge cloud mounted on the base station #1 (300-1) analyzes the state information to determine whether the GPS reception state of the drone 100 is normal or abnormal, and if the determination result is normal, a virtual GPS signal is generated. Without it, the state information is transmitted to the drone control server 200 (S217). The edge cloud may check the GPS reception state of the drone 100 by checking 'GPS normal' or 'GPS abnormal' in the status information.

On the other hand, when the GPS reception state of the autonomous drone 100 is abnormal, the moving direction (eg, azimuth), current flight speed, coordinates recently calculated using normal GPS signals, and a plurality of coordinates used for calculating the coordinates Data such as the GPS signal of the GPS signal, the reception time of each GPS signal used for calculating the coordinates, the battery status, etc. are immediately collected, and the status information including the collected data and 'GPS abnormal' indication information is transmitted to the base station #1 (300- It is transmitted directly to the edge cloud mounted in 1) (S219, S221). The drone 100 may determine that the GPS reception state is abnormal when the number of currently received GPS signals is less than or equal to a threshold number.

Then, the edge cloud mounted on the base station #1 (300-1) receives the flight speed of the drone 100 included in the state information, the coordinates (ie, location) of the drone 100, and the drone control server 200 Based on the flight path of one drone, the position of the drone 100 expected to move in the next period is predicted. And the edge cloud generates a plurality of virtual GPS signals to be received by the drone 100 at the location (S231).

In addition, the edge cloud calculates a delay time for each virtual GPS signal, transmits the virtual GPS signal to the drone 100 after the delay time (S233), and receives the state information of the drone 100 is transmitted to the drone control server 200 (S235). When the edge cloud mounted on the base station #1 (300-1) transmits a virtual GPS signal based on the actual satellite transmission period, the drone 100 sets the distance to the satellite much shorter (that is, to the base station). distance), and an error in the coordinates measured by the drone 100 occurs. Accordingly, in order for the distance between the predicted coordinates and the actual satellite to be accurately calculated by the drone 100, the edge cloud calculates a delay time for each virtual GPS signal, and after a corresponding delay time elapses, the virtual GPS send a signal A method for calculating the delay time will be described in detail with reference to FIGS. 3 to 5 .

The drone 100 measures the current position using the virtual GPS signals received from the base station #1 300-1, compares the measured position with the stored planned flight path, and continues autonomous flight. . That is, the drone 100 can continue autonomous flight by positioning the current location using the virtual GPS signals received from the edge cloud of the base station #1 (300-1) even if GPS signals are not received from the artificial satellite. have.

On the other hand, the edge cloud mounted on the base station #1 (300-1) counts the time when the GPS reception state of the drone 100 is abnormally confirmed, and when this counting time exceeds a threshold time (eg, 10 seconds), By transmitting a command instructing an emergency landing to the drone 100 , the drone 100 may be forced to make an emergency landing.

3 is a diagram illustrating the configuration of an edge cloud according to an embodiment of the present invention.

As shown in FIG. 3 , the edge cloud 500 according to an embodiment of the present invention is a device that provides a virtual GPS signal to the drone 100 , and includes a storage unit 510 , a drone control unit 520 and The virtual GPS signal generator 530 is included, and these components may be implemented as hardware or software, or may be implemented through a combination of hardware and software. The storage unit 510 , the drone control unit 520 , and the virtual GPS signal generation unit 530 may be mounted in the base station 300-N when the edge cloud installation data is installed in the base station 300-N. . In addition, the storage unit 510 , the drone control unit 520 , and the virtual GPS signal generation unit 530 may be mounted on the base station 300 -N in the form of a virtual machine.

The storage unit 510 is a storage means such as a memory or a disk device, and periodically stores state information from the drone 100 . Also, the storage unit 510 stores the planned flight path of the drone 100 .

The drone control unit 520 communicates with each of the drone control server 200 and the drone 100 , and performs a function of monitoring the state of the drone 100 based on the state information received from the drone 100 . Specifically, the drone control unit 520 receives the planned flight path of the drone 100 from the drone control server 200 and stores it in the storage unit 510 . In addition, the drone control unit 520 stores the state information of the drone 100 received from the drone 100 in the storage unit 510 , and transmits the state information to the drone control server 200 . In addition, the drone control unit 520 checks whether the 'GPS normal' or 'GPS abnormal' indication information is recorded in the state information of the drone 100, thereby whether the GPS reception state of the drone 100 is normal or abnormal. to determine When it is determined that the GPS reception state of the drone 100 is abnormal, the drone control unit 520 requests the virtual GPS signal generation unit 530 to generate a virtual GPS signal, and counts the duration of the GPS signal non-reception. When the counted GPS non-reception duration exceeds a threshold time (eg, 10 seconds), the drone control unit 520 commands the drone 100 to make an emergency landing, so that the drone 100 does not autonomously fly any more. , control to make an emergency landing.

When it is determined that the GPS reception state of the drone 100 is abnormal, the virtual GPS signal generator 530 generates a plurality of virtual GPS signals, calculates a delay time of each virtual GPS signal, and calculates a corresponding delay time. After this elapses, the corresponding virtual GPS signal is transmitted to the drone 100 . Specifically, the virtual GPS signal generator 530 checks the flight speed, the moving direction, and the location (ie, coordinates) of the drone 100 included in the recently received state information of the drone 100 . After checking the planned flight path of the drone 100 stored in the storage unit 510, the drone in the next cycle based on the flight speed, flight direction, location (ie, coordinates) of the drone 100 and the planned flight path ( 100) predicts the position (ie, coordinates) to which it should be moved. In addition, the virtual GPS signal generator 530 checks the GPS signals recently used by the drone 100 to calculate the coordinates from the state information, and location information for each satellite in each GPS signal (ie, the location information of the artificial satellites used to calculate the coordinates). location information). The virtual GPS signal generator 530 measures the distance between the position corresponding to the predicted coordinates (ie, the drone position of the next cycle) and each confirmed satellite, and also between the predicted coordinates and the base station 300-N. Measure the distance. The location of the base station 300-N is stored in advance by the virtual GPS signal generator 530 .

The virtual GPS signal generator 530 generates virtual GPS signals based on the GPS signals included in the state information. The virtual GPS signal includes identification information of a satellite recently used by the drone 100 and location information of the satellite. For example, when the GPS signals normally used before the GPS reception state of the drone 100 becomes abnormal are the first GPS signal, the second GPS signal, and the third GPS signal, the first GPS signal, the second GPS signal, and the third GPS signal are based on each to generate a virtual GPS signal. The virtual GPS signal includes the same satellite identification information as the basic GPS signal, but includes the transmission time for the next period in the transmission time.

When the drone 100 is located at the predicted coordinates, the virtual GPS signal generator 530 calculates a delay time for each virtual GPS signal so that the drone 100 can calculate the distance between the corresponding artificial satellites, and , a virtual GPS signal is transmitted to the drone 100 after a corresponding delay time has elapsed. That is, the virtual GPS signal generator 530 does not transmit the virtual GPS signal according to the transmission time, but transmits the virtual GPS signal after a delay time elapses. When the virtual GPS signal generator 530 mounted on the base station 300-N transmits a virtual GPS signal based on the actual satellite transmission period, the drone 100 measures the distance to the satellite much shorter. Therefore, the position (ie, coordinates) measured by the drone 100 has a significant error. Accordingly, in order to induce the drone 100 to measure the distance between the corresponding artificial satellites at the predicted coordinate positions, the delay time for each virtual GPS signal is calculated, and the virtual GPS signal is delayed by the corresponding delay time. to send

4 is a diagram illustrating distances of artificial satellites and base stations from positions predicted to have moved by a drone, according to an embodiment of the present invention.

Referring to FIG. 4 , when it is predicted that the drone 100 has moved from the position of point 41 to point 42 in the next cycle and it is confirmed that the GPS signal being received by the drone 100 is abnormal, the virtual GPS signal generator 530 ) generates a virtual GPS signal on behalf of the first artificial satellite 43 . The virtual GPS signal includes identification information of the first artificial satellite 43 and a transmission time at which the GPS signal is transmitted in the next period from the first artificial satellite.

The distance between the position 42 where the drone 100 should be located in the next period and the first artificial satellite 43 may be expressed as in Equation 1.

(Equation 1)

d1 = (Rt - St + Dt) × C

where d1 is the distance between the position 42 of the drone 100 and the first artificial satellite 43 expected in the next period, Rt is the time at which the virtual GPS signal is received from the drone 100, and St is the base station 300- It is the time at which the virtual GPS signal was transmitted in 1). Dt is the delay time of the virtual GPS signal. In addition, Rt - St denotes a radio wave transmission/reception difference, and C is the speed of the virtual GPS signal transmitted from the base station 300-1. The speed C of the virtual GPS signal is recognized in advance by the virtual GPS signal generator 530 .

The transmission/reception difference (Rt - St) can be canceled in Equation 1 through Equation 2 below.

Equation 2 below is an equation for calculating the distance d2 between the base station 300-1 and the position 42 of the drone 100 predicted to move in the next period.

(Equation 2)

d2 = (Rt - St) × C

Here, d2 is the distance between the position 42 of the drone 100 expected to be located in the next period and the base station 300-1. (Rt - St) can be expressed as d2/C, and by substituting d2/c into Equation 1, Equation 3 below can be derived.

(Equation 3)

Dt = (d1 - d2)/C

In Equation 3, d1 and d2 can be confirmed through calculation, and since C is already known, the virtual GPS signal generator 530 can calculate the delay time Dt. That is, according to Equation 3, the virtual GPS signal generator 530 calculates the distance d1 between the position 42 of the drone 100 expected in the next period and the first artificial satellite 43 and the drone expected in the next period. When measuring the distance between the position 42 of (100) and the base station 300-1, the delay time Dt can be calculated.

After counting the calculated delay time, the virtual GPS signal generating unit 530 is configured to generate a virtual number including identification information of the first artificial satellite 43 and the transmission time of the first artificial satellite when the delay time Dt has elapsed. A 1GPS signal is transmitted to the drone 100 . The virtual GPS signal generator 530 calculates a delay time for each of the other virtual GPS signals (eg, the virtual second GPS signal and the virtual third GPS signal) in addition to the virtual GPS signal, and then the corresponding delay After the time is counted, a corresponding virtual GPS signal is transmitted to the drone 100 .

5 is a flowchart illustrating a method of generating a virtual GPS signal in an edge cloud and transmitting it to a drone according to an embodiment of the present invention.

Referring to FIG. 5 , the drone control unit 520 receives status information from the drone 100 in autonomous flight, stores it in the storage unit 510 , and transmits the status information to the drone control server 200 ( S401 ). ).

Next, the drone control unit 520 determines whether the GPS reception state of the drone 100 is normal or abnormal based on the 'GPS abnormal' or 'GPS normal' indication information included in the status information (S403). When it is determined that the GPS reception state of the drone 100 is abnormal as a result of the determination, the drone control unit 520 counts the GPS signal non-reception duration (S405), and generates a virtual GPS signal with the virtual GPS signal generation unit 530 request.

Then, the virtual GPS signal generation unit 530 checks the flight speed of the drone 100 and the location (ie, coordinates) of the drone 100 included in the state information received in step S401 , and stores the information in the storage unit 510 . After checking the planned flight path of the stored drone 100, the position to which the drone 100 of the next cycle should move based on the flight speed, flight direction, location (ie, coordinates) of the drone 100 and the planned flight path ( That is, coordinates) are predicted (S407).

Next, the virtual GPS signal generator 530 checks the GPS signals from the state information, and checks the location information of the artificial satellites (ie, the location information of the artificial satellites used to calculate the coordinates) in each GPS signal. The virtual GPS signal generator 530 measures the distance between the position corresponding to the predicted coordinates (that is, the drone position of the next cycle) and each confirmed satellite, and the predicted coordinates and the base station equipped with the edge cloud ( 300-N) and measure the distance between them. Next, the virtual GPS signal generator 530 generates virtual GPS signals that induce the distance between the corresponding artificial satellites to be measured at the location corresponding to the predicted coordinates. The virtual GPS signal includes the same satellite identification information as the basic GPS signal, but includes a transmission time corresponding to the next period in the transmission time.

The virtual GPS signal generator 530 calculates a delay time for each virtual GPS signal in order to induce the drone 100 to measure the distance between the corresponding artificial satellites at the location corresponding to the predicted coordinates (S408), At this time, the virtual GPS signal generator 530 substitutes the predicted coordinates and the distance d2 between the base station 300-N and the predicted coordinates and the distance d1 between the artificial satellites into Equation 3, and each virtual GPS The delay time (Dt) of the signal can be calculated.

Next, the virtual GPS signal generator 530 counts the calculated delay times Dt, and when a specific delay time Dt elapses, the virtual GPS signal having this delay time is transmitted to the drone 100 by , transmits a plurality of virtual GPS signals to the drone 100 instead of the satellite (S409).

Next, the drone control unit 520 receives another state information from the drone 100 at different periods, stores it in the storage unit 510 , and transmits the state information to the drone control server 200 ( S411 ) . Next, the drone control unit 520 determines whether the GPS reception state of the drone 100 is normal or abnormal based on the 'GPS normal' or 'GPS abnormal' indication information included in the other status information received in step S411. is determined (S413). When the GPS state of the drone is changed from abnormal to normal as a result of the determination in step S413, the drone control unit 520 initializes the GPS signal non-reception duration counted so far to '0' (S415).

On the other hand, when it is determined that the GPS state of the drone is still abnormal as a result of the determination in step S413, the drone control unit 520 determines whether the GPS signal non-reception duration counted so far exceeds a threshold time (eg, 10 seconds). It is determined (S417). As a result of the determination, the drone control unit 520 requests the virtual GPS signal generation unit 530 to generate another virtual GPS signal if the duration of the GPS signal non-reception is less than or equal to a threshold time (eg, 10 seconds).

Then, the virtual GPS signal generator 530 re-progresses after step S407, analyzes the state information received in step S411, predicts the coordinates at which the drone 100 should be located in the next cycle, and should be received at these coordinates. After generating a plurality of virtual GPS signals, and calculating a delay time for each virtual GPS signal, when the delay time elapses, the virtual GPS signal is transmitted to the drone 100 .

On the other hand, as a result of the determination, the drone control unit 520 transmits a command instructing an emergency landing to the drone 100 when the duration of GPS signal non-reception exceeds the threshold time to force the drone 100 to make an emergency landing. (S419).

6 is a diagram illustrating a configuration of a drone according to an embodiment of the present invention.

As shown in FIG. 6 , the drone 100 according to an embodiment of the present invention includes a wireless communication unit 110 , a driving unit 120 , a GPS receiver 130 , a storage unit 140 , a sensing unit 150 and It includes a control unit 160, and these components can communicate with each other through a bus line.

The wireless communication unit 110 is a communication module capable of performing wireless communication with the base station 300-N, and transmits and receives various data to and from the base station 300-N. The wireless communication unit 110 periodically transmits the state information of the drone 100 to the edge cloud mounted in the base station 300-N.

The driving unit 120 performs a function of driving a plurality of propellers provided in the drone 100 . The driving unit 120 drives the propeller of the drone 100 based on the motion control signal received from the control unit 160 . The driving unit 120 may control the propeller rotation speed differently for each propeller.

The GPS receiver 130 performs a function of receiving a satellite signal detected in the vicinity.

The storage unit 140 is a storage means such as a memory, and stores various data necessary for the operation of the drone 100 . In addition, the storage unit 140 stores the planned flight path. In the flight path, a plurality of coordinates to be passed by the drone 100 are recorded according to time sequence.

The sensing unit 150 includes a gyro sensor, an acceleration sensor, and a current/voltage sensor, and the sensing unit 150 measures the yaw, pitch, and roll of the drone 100 through the gyro sensor and the acceleration sensor. Also, the sensing unit 150 may measure the X-axis acceleration, the Y-axis acceleration, and the Z-axis acceleration of the drone 100 by using the gyro sensor and the acceleration sensor, respectively. In addition, the sensing unit 150 may measure the state (ie, current or voltage) of the battery using the current and voltage sensors.

The controller 160 is a control means such as a microprocessor, and controls the state of the drone 100 , and controls the driving unit 120 to perform autonomous flight of the drone 100 . The control unit 160 compares the planned flight path stored in the storage unit 140 with the current position of the drone 100 measured based on GPS signals, and operates the driving unit 120 so that the drone 100 flies on the flight path. Control. In addition, the control unit 160 collects the data of the drone 100 at regular intervals, and then transmits state information including the collected data to the drone control server 200 through the wireless communication unit. At this time, the control unit 160, through the GPS receiver 130, calculates the current location information (ie, coordinates) of the drone 100, a plurality of GPS signals used for location measurement and the reception time for each GPS signal Check, and include the location information, speed, moving speed of the drone 100, the plurality of checked GPS signals and the reception time for each GPS signal in the state information. The control unit 160 may check the speed and movement direction of the drone 100 measured by the sensing unit 150, or check the speed and movement direction of the drone 100 by comparing the previous coordinates with the currently measured coordinates. may be In addition, the control unit 160 checks the voltage/current and the remaining amount of the battery using the sensing unit 150 and includes it in the state information. In particular, the controller 160 checks the number of GPS signals received through the GPS receiver 130, and when the number of GPS signals is less than or equal to a threshold number, the status information includes 'GPS abnormal' indication information, and the number of GPS signals When the number exceeds the threshold number, 'GPS normal' indication information may be included in the status information. In addition, when the number of GPS signals is less than or equal to the threshold number, the controller 160 measures the current location of the drone 100 using the virtual GPS signal received from the wireless communication unit 110, and measures the drone based on the virtual GPS signals. By comparing the current position of the drone 100 measured based on the location of 100 and the planned flight path stored in the storage unit 140 and the GPS signals, the driving unit 120 so that the drone 100 flies on the flight path. Control.

7 is a flowchart illustrating a method of performing autonomous flight using a GPS signal in a drone according to an embodiment of the present invention.

Referring to FIG. 7 , when flight is started, the control unit 160 compares the planned flight path stored in the storage unit 140 with the current location of the drone 100 measured based on GPS signals, By controlling the driving unit 120 to fly in the flight path, autonomous flight is performed (S601).

When autonomous flight of the drone 100 is performed in this way, the control unit 160 uses the sensing unit 150 and the GPS receiver 130 to control the moving speed, the moving direction, the current coordinate data, and the current coordinates of the drone 100 . Data such as a plurality of GPS signals used for calculation, reception time of each GPS signal, and battery status are collected at regular intervals, and status information including the collected data is transmitted to the edge cloud of the base station 300-N do (S603).

The controller 160 may monitor the number of GPS signals received from the GPS receiver 130 in real time to determine whether the GPS reception state is normal or abnormal ( S605 ). At this time, the controller 160 determines that the GPS reception state is normal when the number of GPS signals received from the GPS receiver 130 exceeds the threshold number, and when the number of GPS signals received from the GPS receiver 130 is less than or equal to the threshold number, the It can be determined that the reception state is abnormal.

When it is determined that the GPS reception state is abnormal, the controller 160 uses the sensing unit 150 and the GPS receiver 130 to calculate the moving speed, the moving direction, the recently measured coordinate data, and the coordinate calculation of the drone 100 . Data such as a plurality of used GPS signals, reception time for each GPS signal, battery status, etc. are immediately collected, and status information including the collected data is directly transmitted to the edge cloud of the base station 300-N (S607).

When the GPS reception state is determined to be abnormal, the controller 160 monitors whether a plurality of virtual GPS signals are received from the wireless communication unit 110 without using the GPS signal received from the GPS receiver 130 . When a plurality of virtual GPS signals are received from the wireless communication unit 110 (S609), the control unit 160 measures the current position of the drone 100 using the virtual GPS signals, and the drone ( 100) and the planned flight path stored in the storage unit 140 and the current position of the drone 100 measured based on GPS signals, and control the driving unit 120 so that the drone 100 flies on the flight path do (S611).

Based on the virtual GPS signals, even in the process in which the drone 100 is autonomously flying, the controller 160 receives the number of GPS signals exceeding the threshold number from the GPS receiver 130 and determines whether the GPS reception state is normally restored. is determined (S613). If the GPS reception state is still abnormal, the controller 160 performs autonomous flight based on the virtual GPS signals received from the wireless communication unit 110 .

On the other hand, when the GPS reception state is normally restored, the controller 160 measures the current position of the drone 100 using a plurality of GPS signals received through the GPS receiver 130 and then Based on the location and the planned flight path stored in the storage unit 140 , autonomous flight of the drone 100 is performed.

On the other hand, when the duration for which the GPS reception state is maintained in an abnormal state exceeds a preset time (eg, 10 seconds), the controller 160 controls the driving unit 120 by itself to make an emergency landing of the drone 100 . can proceed. As another embodiment, when the duration for which the GPS reception state is maintained in an abnormal state exceeds a preset time (eg, 10 seconds), the wireless communication unit 110 emergency from the edge cloud mounted in the base station 300-N. Upon receiving the landing command, the controller 160 may control the driving unit 120 according to the emergency landing command to make an emergency landing of the drone 100 .

Meanwhile, although it has been described that the edge cloud is mounted on the base station 300-N in the above-described embodiment, the edge cloud may be physically or logically implemented in various communication nodes existing in the network.

While this specification contains many features, such features should not be construed as limiting the scope of the invention or the claims. Also, features described in individual embodiments herein may be implemented in combination in a single embodiment. Conversely, various features described herein in a single embodiment may be implemented in various embodiments individually, or may be implemented in appropriate combination.

Although acts have been described in the drawings in a specific order, it should not be understood that the acts are performed in the specific order as shown, or that all of the described acts are performed in a continuous order, or to obtain a desired result. . Multitasking and parallel processing can be advantageous in certain circumstances. In addition, it should be understood that the division of various system components in the above-described embodiments does not require such division in all embodiments. The program components and systems described above may generally be implemented as a package in a single software product or multiple software products.

The method of the present invention as described above may be implemented as a program and stored in a computer-readable form in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.). Since this process can be easily performed by a person skilled in the art to which the present invention pertains, it will not be described in detail any more.

The present invention described above, for those of ordinary skill in the art to which the present invention pertains, various substitutions, modifications and changes are possible without departing from the technical spirit of the present invention. It is not limited by the drawing.

100: drone 110: wireless communication unit
120: driving unit 130: GPS receiver
140: storage unit 150: sensing unit
160: control unit 200: drone control server
300: base station 400: network
500: edge cloud 510: storage
520: drone control unit 530: virtual GPS signal generation unit

Claims (15)

A method of controlling the flight of a drone by selectively transmitting a virtual GPS signal from a communication device to the drone,
Receiving status information of the drone from the drone;
determining whether the GPS reception state of the drone is abnormal based on the state information of the drone;
generating a plurality of virtual GPS signals to be received by the drone in a next period based on the planned flight path of the drone when the GPS reception state of the drone is abnormal as a result of the determination; and
and transmitting the plurality of generated virtual GPS signals to the drone. According to claim 1,
predicting a position at which the drone will fly in a next period by analyzing the state information; and
In order to induce the distance between the predicted position and the corresponding satellite to be measured by the drone, calculating a delay time for each of the plurality of virtual GPS signals,
In the transmitting, the corresponding virtual GPS signal is transmitted to the drone after the corresponding delay time has elapsed. 3. The method of claim 2,
Calculating the delay time comprises:
A first distance between the predicted position and an artificial satellite and a second distance between a base station equipped with the communication device and the predicted position are checked, and the first distance, the second distance, and the speed of the virtual GPS signal are used to determine Drone control method, characterized in that calculating the delay time. According to claim 1,
The generating of the plurality of virtual GPS signals comprises:
A drone control method, characterized in that by checking a plurality of GPS signals used by the drone to calculate coordinates from the status information, and generating a plurality of virtual GPS signals having the same satellite identification information as any one of the plurality of GPS signals. According to claim 1,
Counting the duration that the GPS reception state of the drone is abnormally maintained: And
When the counted duration exceeds a threshold time, transmitting a command instructing an emergency landing to the drone, further comprising the step of emergency landing the drone. According to claim 1,
The drone control method further comprising the step of receiving and storing the planned flight path of the drone in advance from the drone control server. 7. The method according to any one of claims 1 to 6,
The communication device is a drone control method, characterized in that the edge cloud. A computer program for executing the method according to any one of claims 1 to 6 and recorded in a computer-readable recording medium. In a communication device for selectively transmitting a virtual GPS signal to a drone,
a drone control unit that receives status information of the drone from the drone and determines whether a GPS reception state of the drone is abnormal based on the status information of the drone; and
As a result of the determination, if the GPS reception state of the drone is abnormal, a plurality of virtual GPS signals to be received by the drone in the next cycle are generated based on the planned flight path of the drone, and the generated plurality of virtual GPS signals are applied to the drone. A communication device comprising a virtual GPS signal generator for transmitting to the . 10. The method of claim 9,
The virtual GPS signal generation unit,
The delay time for each of the plurality of virtual GPS signals is calculated to predict the position at which the drone will fly in the next cycle by analyzing the state information, and to induce the distance between the predicted position and the corresponding satellite to be measured by the drone. After the calculation, after the corresponding delay time has elapsed, the communication device characterized in that it transmits the corresponding virtual GPS signal to the drone. 11. The method of claim 10,
The virtual GPS signal generation unit,
A first distance between the predicted position and an artificial satellite and a second distance between a base station equipped with the communication device and the predicted position are checked, and the first distance, the second distance, and the speed of the virtual GPS signal are used to determine and calculating the delay time. 10. The method of claim 9,
The virtual GPS signal generation unit,
A communication device, characterized in that by checking a plurality of GPS signals used by the drone to calculate coordinates from the status information, and generating a plurality of virtual GPS signals having the same satellite identification information as any one of the plurality of GPS signals. 10. The method of claim 9,
The drone control unit,
Counting the duration during which the GPS reception state of the drone is abnormally maintained, and when the counted duration exceeds a threshold time, sending a command instructing an emergency landing to the drone to make an emergency landing of the drone communication device. In a drone flying by selectively using a virtual GPS,
a storage unit for storing the planned flight path;
a GPS receiver for receiving one or more GPS signals;
a wireless communication unit for wireless communication with a base station built in a mobile communication network; and
One or more propellers provided in the drone to measure the current position of the drone based on the plurality of GPS signals received from the GPS receiver, compare the measured position with the flight path, and allow the drone to fly along the planned flight path A control unit for controlling the
The control unit is
It is determined whether the GPS reception state of the GPS receiver is normal, and if the determination result is normal, the current position of the drone is measured using a plurality of GPS signals obtained through the GPS receiver, and the GPS reception state is determined as a result of the determination If it is abnormal, the drone's current location is measured using virtual GPS signals received through the wireless communication unit. 15. The method of claim 14,
The control unit is
When the abnormal time of the GPS reception state exceeds a threshold time, the drone is controlled to make an emergency landing.

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