KR101979860B1 - Local-Area Differential GNSS for UAV navigation - Google Patents

Abstract

The present invention relates to a system for improving the accuracy and safety of navigation of an unmanned aircraft, and more specifically, to a system which monitors errors and failures of a GNSS navigation signal in a ground module, broadcasts error correction information and integrity information to an unmanned aircraft within a radius of about 20 km so that the unmanned aircraft applies the information, thereby improving the navigation accuracy of the unnamed aircraft and enabling a flight by using safe navigation information. According to the present invention, the ground module calculates GNSS navigation error information by receiving the GNSS navigation signal, generates correction information, and monitors a fault through a simplified fault monitoring algorithm. An airborne module receives a message broadcast from the ground module, and by applying thereof, the system and method for calculating accurate and safe navigation information are provided.

Description

{Local-Area Differential GNSS for UAV Navigation}

The present invention relates to a system for improving the accuracy and safety of an unmanned aerial vehicle navigation system, and more particularly, to a system for monitoring errors and failures of a GNSS navigation signal in a ground module and transmitting error correction information and integrity information to an unmanned air vehicle The present invention relates to a system for enabling an unmanned airplane to improve the accuracy of navigation of an unmanned airplane by applying the information, and to enable flight using safe navigation information.

FIG. 1 is a view showing an installation constraint of a hardware of a local reinforcement navigation system for a conventional manned aircraft.

Navigation sensors, which are most commonly used in unmanned aerial vehicles, are global navigation satellite systems (GNSS) sensors, which have the advantage of being able to estimate absolute positions globally. However, since the GNSS sensor performs position estimation based on the signals of the satellites far from the earth, there is a limitation in supporting precise navigation. In particular, in the case of UAVs operating in the private sector, the concept of integrity, which defines the boundaries in which UAVs can actually exist, must be considered as a means of monitoring sensor failures with a high probability in order to prevent civilian damage.

As a related prior art, there is GBAS, a local reinforcement navigation system for manned aircraft. GBAS is a system that provides high accuracy and safety to navigation using GNSS signals. It monitors the errors and failures of GNSS signals at ground stations installed at airports, and provides correction information and integrity information to manned aircraft approaching the airport. By broadcasting, it helps precise approach of manned aircraft. However, as shown in FIG. 1, the GBAS is very difficult to install, is expensive, and has a very complicated failure detection algorithm. Therefore, there is a limit to support commercial unmanned aerial vehicles.

The local reinforcement navigation system for unmanned aircraft proposed by the present invention is a system that can solve the above problems and also calculates the boundary line where the actual unmanned air vehicle can exist by using the navigation error model, . In the present invention, a local reinforcement navigation system for UAVs is developed for safe and accurate navigation support of UAVs.

In this paper, we have developed a local reinforcement navigation system for unmanned aerial vehicles that can be applied to unmanned aerial vehicles by reducing installation complexity / hardware complexity and algorithm complexity. It improves navigation accuracy by providing navigation correction information to unmanned aircraft, and improves navigation integrity by monitoring various failures that may occur.

KR 10-0980762 B1

The present invention has been developed in order to solve such a problem, and develops a local reinforcement navigation system for an unmanned airplane navigation composed of a ground module and a mounting module. The ground module receives the GNSS navigation signal, calculates the GNSS navigation error information, generates correction information, and monitors the failure through a simplified failure monitoring algorithm. The present invention provides a system and method for receiving accurate and safe navigation information of a UAV by receiving and broadcasting a message broadcasted from a ground module.

In order to achieve the above object, there is provided a method for generating navigation information for unmanned airplane navigation, the method comprising the steps of: (a) Receiving data from a satellite; (b) monitoring a fault based on the received signal to remove a faulty signal or receiver; (c) receiving data including correction information and integrity information broadcast by a ground station system; (d) generating current location information of the UAV by applying correction information and integrity information to the received GNSS data; And (e) calculating an optimal protection level from the level of protection calculated for each failure mode received from the terrestrial system, wherein the failure of step (b) includes at least one of a satellite failure, a signal delay, The signal delay and the signal failure due to the ionospheric layer including at least one of a failure of the aircraft carrier receiver and the like are not calculated in all phase geometries so that the algorithm can be simplified and the operation of the unmanned aerial vehicle can be performed, The protection level of the step (e) is a vertical protection level (VPL), the VPL optimally divides the probability of integrity loss for each failure mode, Fault-free mode, reference receiver fault mode, ephemeris fault mode, excessive acceleration (EA) fault mode, and code carrier di and the VPL value in each of the vergence (CCD) fault modes.

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According to another aspect of the present invention, there is provided an apparatus for mounting an unmanned air vehicle on which a local reinforcement navigation for unmanned aircraft navigation support is implemented, comprising: a GNSS data receiver for receiving GNSS data from a satellite; A failure monitoring unit for monitoring a failure based on the received signal and removing a faulty signal or a receiver; A ground station system data receiver for receiving data such as integrity information broadcasted by the ground station system; A position information generator for generating position information by applying correction information and integrity information to the GNSS data received by the GNSS data receiver; A protection level calculating and optimizing unit for calculating an optimum protection level from the calculated protection level for each failure mode; A database for storing various data related to the calculation of the location information and the protection level; And a controller for controlling each of the components of the unmanned aerial vehicle mounting apparatus to perform a series of processes related to generation of navigation information of the unmanned aerial vehicle mounting apparatus, wherein the malfunction includes satellite failure, signal delay, signal failure, The failure of the signal due to the ionosphere is not calculated in all phase geometries so as to realize the simplification of the algorithm and enable the operation of an accurate UAV, The protection level is a vertical protection level (VPL), and the VPL is divided into a fault-tolerance level and a fault-tolerance level so that the integrity loss probability is divided optimally for each failure mode and the size of the final VPL is reduced. free mode, reference receiver fault mode, ephemeris fault mode, excessive acceleration (EA) fault mode, and code carrier diverg ence (CCD) fault modes, respectively.

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The receiver used by the GNSS data receiver may be the same receiver as the receiver used by the ground station system.

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According to the present invention, the ground module receives the GNSS navigation signal, calculates GNSS navigation error information to generate correction information, and monitors the failure through a simplified failure monitoring algorithm. The present invention provides a system and method for receiving accurate and safe navigation information of a UAV by receiving a broadcast message from a terrestrial module and applying the message.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing an installation constraint of a hardware of a local reinforcement navigation system for a conventional manned aircraft. FIG.
2 is a conceptual diagram of a local reinforcement navigation system for supporting navigation of an unmanned aerial vehicle according to the present invention.
FIG. 3 is a schematic diagram of a ground reinforcement module and an unmanned airplane loading module of a local reinforcement navigation system for supporting an unmanned airplane navigation according to the present invention.
FIG. 4 is a block diagram of a ground module and a UAV module of a local reinforcement navigation system for supporting an unmanned aircraft navigation according to the present invention. FIG.
5 is a sequence diagram illustrating an unmanned aerial vehicle navigation support according to the present invention.
FIG. 6 is a diagram illustrating a flight path of a UAV by applying a local reinforcement navigation system for supporting UAV navigation according to the present invention; FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be interpreted in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined. Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

The local reinforcement navigation system for supporting the navigation of the unmanned aerial vehicle according to the present invention comprises a ground module and a mounting module. The ground module receives the GNSS signal, generates the correction information and the integrity information after monitoring the navigation fault, and transmits it to the mounting module through the modem. The mounting module receiving the correction information and the integrity information applies the information to the GNSS signal received from the mounting module to calculate the position of the GNSS based UAV. The calculated GNSS-based location information is transmitted to the UAV controller and used for unmanned aircraft flight. The navigation system for the unmanned aerial vehicle proposed in the present invention can guarantee much higher accuracy and navigation safety than the system using only the conventional GNSS.

2 is a conceptual diagram of a local reinforcement navigation system for supporting the navigation of an unmanned aerial vehicle according to the present invention.

The present invention relates to a system for improving the accuracy and safety of an unmanned aerial vehicle navigation system, in which an error and failure of a GNSS navigation signal is monitored in a ground module, and error correction information and integrity information are broadcasted to a UAV The present invention relates to a system for improving the accuracy of navigation of an unmanned airplane by applying the information to an aircraft and enabling flight to be performed using safe navigation information.

FIG. 3 is a schematic diagram of a ground module and an unmanned airplane loading module of a local reinforcement navigation system for supporting an unmanned airplane navigation according to the present invention. FIG. 4 is a diagram illustrating a ground module and a ground module of a local reinforcement navigation system FIG. 5 is a sequence diagram illustrating the operation of the unmanned aerial vehicle navigation system according to the present invention. Referring to FIG.

Referring to FIGS. 4 and 5, the system includes a ground station system 100 and an unmanned aerial vehicle mounting apparatus 200.

The ground station system 100 includes a GNSS data receiving unit 110 for receiving Global Navigation Satellite Systems (GNSS) data from the satellites (S101), and for each fault (satellite fault, (S102). The failure monitoring unit 120 calculates various kinds of integrity information as described above by using the received GNSS data, (S103), and transmits a message including the calculated integrity information to each unmanned airplane (step S 103) S104) a message broadcasting unit 140, and a database 150 for storing data including correction information and integrity information. The generated error correction information and integrity information are transmitted to the UAV 200 through a modem.

The GNSS data receiving unit 210 receives the GNSS data from the satellites (S101). The GNSS data receiving unit 210 receives the GNSS data from the GNSS data receiving unit 210, Receiver failure, etc.) and removing a faulty signal or a receiver (S102). The fault monitoring unit 220 receives data including correction information and integrity information broadcast by the ground station system 100 (S104) A position information generating unit 240 for generating current position information of the UAV by applying correction information and integrity information to the GNSS data received by the ground station system data receiving unit 230 and the GNSS data receiving unit 210, The protection level calculating and optimizing unit 250 calculates an optimal protection level from the protection level calculated for each failure mode using the integrity information received from the protection level calculating unit 100, And a database 260 for storing various data related to the calculation of the protection level. The position information and the protection level thus generated are utilized for controlling the unmanned airplane (S107). Although not shown, the ground station system 100 and the UAV 200 are controlled by the respective modules of the ground station system 100 or the UAV 200 to generate navigation information of the UAV And a control unit for performing a series of processes associated with the control unit.

The local reinforcement navigation system architecture for unmanned aerial vehicles is basically sharing the GBAS (Ground Based Augmentation System) architecture, which is a regional reinforcement navigation system developed for manned aircraft. However, the system proposed in the present invention reduces the complexity of algorithms and alleviates hardware installation constraints in order to provide a commercial system for navigation support of an unmanned aerial vehicle.

In the case of GBAS, the antennas of ground equipment are usually installed at intervals of several hundred meters to mitigate multipath errors. Considering the characteristics of the commercial system, which is difficult to secure a wide space, the local reinforcement navigation system for unmanned aerial vehicles is proposed to install the antennas at a distance of several tens of meters. Considering the installation of the low-cost antenna instead of the expensive MLA (Multipath-Limiting Antenna) have. Multipath error increases due to hardware change. This part can be solved from algorithmic performance improvement.

Simplifying the algorithm streamlined the two algorithms known to be the most complex in the existing GBAS.

The first algorithm is known as a SDM (Signal Deformation Monitor), and its shape is similar between the same receiver models. Thus, by setting the constraint that the ground station system 100 and the UAV 200 use the same receiver , It is possible to remove the monitor for satellite signal deformation canceled by the correction information. That is, by using the same receiver in the ground station system 100 and the UAV 200, it is not necessary to monitor the satellite signal deformation.

As the second monitor, it is a geometry screening monitor. This corresponds to the failure monitoring unit 220 of the UAV 200 as described above. The monitor, that is, the failure monitoring unit 220 monitors the error of the satellite signal generated by the ionosphere, that is, the signal delay / signal failure due to the ionosphere, thereby protecting the unmanned airplane (user). Unlike the GBAS in which such a monitor is installed in a conventional ground station system, in the UAV system of the present invention, it is installed (220) in the UAV 200 so that calculation is performed in all the satellite geometries as in the case of the ground station system However, the worst user error is calculated considering only the satellite geometry currently used by the UAV. This makes it possible to operate the unmanned aerial vehicle accurately and safely while realizing the simplification of the algorithm.

A high level of VPL (vertical protection level) performance can be achieved by using an optimal protection level calculation algorithm even for low performance GNSS antennas / receivers, low performance hardware and limited installation constraints compared to manned aircraft. The optimum protection level calculation algorithm can reduce the final VPL size by calculating all five VPLs by calculating all the VPLs previously calculated considering the complexity of the algorithm in the existing GBAS. The five VPLs are VPL values obtained in fault-free mode, reference receiver fault mode, ephemeris fault mode, excessive acceleration (EA) fault mode, and code carrier divergence (CCD) fault mode.

If the magnitude of the probability of the integrity loss used in the calculation is fixed to some extent by preliminarily calculating the size of some of the VPLs, the remaining VPLs are increased in size. However, as in the present invention, 200), it is possible to divide the probability of integrity loss according to the situation (satellite geometry, error, etc.) optimally for each failure mode, thereby reducing the size of the final VPL.

FIG. 6 is a diagram showing a flight path of a UAV by applying a local reinforcement navigation system for UAV support according to the present invention.

The unmanned aircraft received correction information and integrity information broadcast from the ground module at the time of actual flight, and calculated the position and transmitted it to the controller. As a result of the flight, I confirmed that the position accuracy is calculated within 1m at all times during the flight of about 6 minutes.

The local reinforcement navigation system for the unmanned aircraft navigation support proposed by the present invention supports the accurate and safe navigation of the unmanned airplane and can be used to support missions requiring high performance navigation such as precision approach of unmanned airplane, automatic takeoff and landing, .

100: ground station system
200: Unmanned aerial vehicle mounted device

Claims (11)

A method for generating navigation information for unmanned airplane navigation, wherein the unmanned aerial vehicle equipped with local reinforcement navigation for unmanned aircraft navigation is communicated with a ground station system,
(a) receiving GNSS data from a satellite;
(b) monitoring a fault based on the received signal to remove a faulty signal or receiver;
(c) receiving data including correction information and integrity information broadcast by a ground station system;
(d) generating current location information of the UAV by applying correction information and integrity information to the received GNSS data; And
(e) calculating an optimized protection level from the calculated protection level for each failure mode received from the ground station system
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The failure of step (b)
Satellite failure, signal delay, signal failure, unmanned aircraft carrier receiver failure,
The signal delay, signal failure due to the ionosphere,
It is necessary to calculate only the satellite geometry used by the unmanned aerial vehicle mounting apparatus, instead of calculating all of the topological geometries so that the operation of the unmanned aerial vehicle can be performed while realizing the simplification of the algorithm ,
The level of protection of step (e)
Vertical protection level (VPL)
The VPL divides the integrity loss probability optimally for each failure mode so that the size of the final VPL is reduced ,
which is obtained from the VPL value in each of the fault-free mode, the reference receiver fault mode, the ephemeris fault mode, the excessive acceleration (EA) fault mode, and the code carrier divergence (CCD)
A method of generating navigation information of an unmanned aerial vehicle mounted device.
delete delete delete Unmanned aerial vehicle equipped with local reinforcement navigation for unmanned aircraft navigation support,
A GNSS data receiver for receiving GNSS data from satellites;
A failure monitoring unit for monitoring a failure based on the received signal and removing a faulty signal or a receiver;
A ground station system data receiver for receiving data such as integrity information broadcasted by the ground station system;
A position information generator for generating position information by applying correction information and integrity information to the GNSS data received by the GNSS data receiver;
A protection level calculating and optimizing unit for calculating an optimum protection level from the calculated protection level for each failure mode;
A database for storing various data related to the calculation of the location information and the protection level; And
A controller for controlling each of the components of the unmanned aerial vehicle mounting apparatus to perform a series of processes related to generation of navigation information of the unmanned aerial vehicle mounting apparatus
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The failure may be,
Satellite failure, signal delay, signal failure, unmanned aircraft carrier receiver failure,
The signal delay, signal failure due to the ionosphere,
It is necessary to calculate only the satellite geometry used by the unmanned aerial vehicle mounting apparatus, instead of calculating all of the topological geometries so that the operation of the unmanned aerial vehicle can be performed while realizing the simplification of the algorithm ,
The protection level may be,
Vertical protection level (VPL)
The VPL divides the integrity loss probability optimally for each failure mode so that the size of the final VPL is reduced ,
which is obtained from the VPL value in each of the fault-free mode, the reference receiver fault mode, the ephemeris fault mode, the excessive acceleration (EA) fault mode, and the code carrier divergence (CCD)
Unmanned aerial vehicle mounted device.
delete delete delete The method of claim 5,
Wherein the receiver used in the GNSS data receiver comprises:
The same receiver as the receiver used by the ground station system
Wherein the unmanned airplane is mounted on the unmanned airplane.

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