A method and system for providing location feedback

Abstract

The invention provides a method and system for navigating or self-localizing an Unmanned Vehicle (UV) in GNSS-denied environments using position feedback from an external observer sensor with a known location. The system includes at least one UV, at least one observer sensor configured to detect objects and provide location data, a control station to identify the UV among detected objects, and a communication link to relay the location data to the UV.

Description

[0001] A METHOD AND SYSTEM FOR PROVIDING LOCATION FEEDBACK

[0002] Field of the invention

[0003] The present invention relates to the field of navigation systems and technologies, particularly to a method and a system for providing reliable navigation in environments where Global Navigation Satellite System (GNSS) signals are unavailable, degraded, or compromised. The invention enables positioning and navigation across various Unmanned Vehicle (UV) platforms, including unmanned aerial vehicles (UAVs), autonomous ground vehicles, maritime vessels, etc. The invention is relevant to commercial and military applications, addressing the critical need for robust navigation solutions in GNSS-denied environments.

[0004] Background of the invention

[0005] Global Navigation Satellite Systems (GNSS) such as GPS, GLONASS, Galileo, and BeiDou have become indispensable for modern navigation in various platforms, including Unmanned Vehicles (UV) such as Unmanned Aerial Vehicles (UAVs) and autonomous vehicles, maritime vessels, and even pedestrian navigation systems. These systems provide accurate positioning, navigation, and timing information, enabling seamless operation across different terrains and conditions.

[0006] However, GNSS signals are susceptible to various forms of interference, including signal blockage, jamming, and spoofing. Environments such as urban canyons, dense forests, underground facilities, and indoor areas can severely degrade or completely deny GNSS signals. In military operations, adversaries may deliberately jam or spoof GNSS signals to disrupt navigation and timing. This creates significant challenges for autonomous systems and vehicles that rely on GNSS for navigation, necessitating alternative solutions to ensure continuous and reliable operation in GNSS-denied environments. It is an object of the present invention to provide a robust navigation solution for platforms and vehicles operating in GNSS-denied environments to ensure continuous and accurate positioning and navigation capabilities even when GNSS signals are unavailable, degraded, or compromised.

[0007] It is another object of the present invention to ensure versatility and applicability across different platforms, including UAVs, autonomous ground vehicles, maritime vessels, indoor robots, and pedestrian navigation systems.

[0008] It is yet another object of the present invention to mitigate the risks associated with GNSS interference, jamming, and spoofing.

[0009] It is still another object of the invention to support various applications, from commercial to military operations, and improve navigation systems' overall efficiency and accuracy in challenging environments.

[0010] Other objects and advantages of the invention will become apparent as the description proceeds.

[0011] Summary of the Invention

[0012] In one aspect, the present invention relates to a system for navigating in GPS-denied or GPS-spoofed environments, comprising: a) at least one Unmanned Vehicle (UV); b) an observer sensor configured to provide data about the position or location of detected objects in the area where the observer sensor is situated, wherein the position of the observer sensor is known; c) a control station adapted to receive the data from the observer sensor and to identify which object detected is at least one of the UV; and d) a communication link is configured to relay the position or location data to the identified UV.

[0013] In one aspect, the control station can be ground-based or aerial-based.

[0014] In one aspect, the UV is an Unmanned Aerial Vehicle (UAV). In one aspect, the observer sensor is selected from a group consisting of a radar system, an electro-optical camera system, or a thermal imaging camera, including a cooled or uncooled bolometer.

[0015] In one aspect, the UV comprises detection augmentation equipment that is adapted to increase the likelihood of UV detection.

[0016] In one aspect, the detection augmentation equipment is selected from the group consisting of a beacon (visual or radio) or a device suitable to increase radar crosssection.

[0017] In one aspect, the beacon is an active beacon that is synchronized to the ground by means of wireless communication to identify its detection and identification.

[0018] In one aspect, the observer sensor and the control station are embodied in the same sub-system or device.

[0019] In one aspect, the observer sensor is mobile or moving but still has its position known.

[0020] In one aspect, more than one observer sensor is used with the same or different data being fused or used in conjunction by the control station or the UV.

[0021] In another aspect, the present invention relates to a method for navigating in GPS- denied or GPS-spoofed environments based on the system of claim 1, comprising: a) providing an observer sensor capable of generating data about the position or location of detected objects in the area where the observer sensor is situated, thereby telling information about the location of detected objects in said area; b) providing a control station capable of receiving the generated data from the observer sensor and accordingly discerning which object detected is an Unmanned Vehicle (UV); and c) communicating, via a communication link, information about the location of the detected UV, thereby enabling the detected UV to gain a sense of self-position to improve its navigation path. In one aspect, the UV is gaining a sense of self-position by feeding the information to a Kalman Filter or to any UV onboard microprocessor suitable for providing selfposition.

[0022] In one aspect, at the beginning of the movement of the UV, the system automatically detects said UV based on a known initial position of said UV.

[0023] In one aspect, when the initial position of the UV is unknown, said UV will conduct a "detection maneuver" where the control station detects an "indicative" maneuver that is untypical for other objects of its kind.

[0024] In one aspect, the UV sends information regarding estimated movements to the control station to facilitate the identification of said UV among all objects detected by the observer sensor.

[0025] In one aspect, the UV uses optical flow to track the ground to improve the accuracy of the "detection maneuver".

[0026] In one aspect, the method further comprises compensating for control errors and wind drift by utilizing an available camera or electro-optic sensor of the UV to improve the accuracy of the detection maneuver of said UV.

[0027] In one aspect, the method further improves the accuracy of the UV detection maneuver by using an onboard radar sensor, thereby compensating for control errors and wind drift.

[0028] In one aspect, the detection maneuver is being sent to the UV by the ground-control station based on currently detected objects.

[0029] In one aspect, after the potential detection of the UV, the ground-control station instructs the UV to change its path uniquely to distinguish its movement with respect to all current potential detected targets, thereby facilitating the identification of the UV.

[0030] In one aspect, the system serves as a "sanity check" of alternative GNSS or any location-based system, wherein if the sanity shows the solution is OK, the other GNSS solution can be used, and if or when the GNSS system is disrupted or spoofed, the UV will navigate based on said system.

[0031] In one aspect, the observer sensor is configured to provide information with or without accurate timestamps of its detection.

[0032] In one aspect, the observer sensor is configured to provide datum relative to position information in any geographic absolute coordinates, or datum relative to its own position, or to provide only some of said datum.

[0033] Brief Description of the Drawings

[0034] The above and other characteristics and advantages of the invention will be better understood through the following illustrative and non-limitative detailed description of preferred embodiments thereof, with reference to the appended drawings, wherein:

[0035] Fig. 1 schematically illustrates a system for providing location feedback, according to an embodiment of the invention;

[0036] Fig. 2 is a flowchart of a method for providing location feedback, according to an embodiment of the invention; and

[0037] Fig. 3 schematically illustrates a system for providing location feedback incorporating radar, according to an embodiment of the invention.

[0038] A detailed description of the invention

[0039] The present invention relates to a method and system for navigating and / or achieving self-localization in GNSS-denied environments for an Unmanned Vehicle (UV) by providing location feedback based on an additional sensor (refers herein to observer sensor) located externally to the UV with its location known.

[0040] Fig. 1 schematically illustrates a system 100 for location feedback, according to an embodiment of the invention. System 100 comprises at least one observer sensor 11 adapted to detect objects and to provide data about the position or location of the detected objects in the area where the at least one observer sensor 11 is situated, a control station 12 configured to identify whether the detected object is a UV 13 based on the data received from the at least one observer sensor 11 and to communicate the provided data about the position or location to the UV 13. Control station 12 can be ground-based or aerial-based.

[0041] According to an embodiment of the invention, the generated output data of observer sensor 11 can be communicated to control station 12 and UV 13, utilizing formats suitable for live data streaming. The communication can be performed via any suitable data network 14.

[0042] According to an embodiment of the invention, observer sensor 11 may utilize various sensing technologies to determine and monitor the location and movement of UV accurately. For example, observer sensor 11 can incorporate Frequency Modulated Continuous Wave (FMCW) radar, optical systems such as cameras and LIDAR (e.g., electro-optical camera system, cooled or uncooled bolometer (i.e., thermal camera), acoustic sensors, and radio frequency (RF) detectors. By leveraging these technologies, observer sensor 11 can provide real-time data on the UVs' range, azimuth, elevation, velocity, and unique identification, ensuring tracking and effective management of UV activities within a designated area (e.g., designated airspace).

[0043] According to an embodiment of the invention, observer sensor 11 can be static or mobile, providing flexibility and adaptability in various operational environments, as long as its position is known. In a static arrangement, observer sensor 11 is typically installed at a fixed location, continuously monitoring UVs 13 within its range. Conversely, in a mobile arrangement, observer sensor 11 can be mounted on vehicles, ships, aircrafts, or even portable units, allowing for dynamic deployment in diverse and changing scenarios. Whether static or mobile, observer sensor 11 ensures comprehensive and real-time tracking of multiple UVs 13, enhancing situational awareness and airspace management by delivering precise data on the location, movement, and unique IDs of detected UVs, as long as the position of observer sensor 11 is known.

[0044] According to an embodiment of the invention, each UV 13 is equipped with a unique identification (ID), which serves as a distinctive identifier for tracking and management purposes. In this embodiment, observer sensor 11 can detect not only the position and location of each UV 13 but also capture data indicating its unique ID. This can be achieved by installing / mounting detection augmentation equipment on each UV 13 that is capable of increasing its likelihood of detection, such as a beacon (visual or radio), or a device adapted to increase radar cross-section. For example, UV 13 can be equipped with an active beacon that is synchronized to the ground by means of wireless communication to identify its detection and identification, or it can be achieved through integrated transponders or communication modules within the UVs 13 that broadcast their ID signals. When observer sensor 11 and / or control station 12 receive these signals, it can correlate the unique ID with the UVs 13 detected range, azimuth, elevation, and velocity data. According to an embodiment of the invention, system 100 is designed to work with a plurality of UVs 13 simultaneously, ensuring that each UV 13 can be individually identified and monitored in real-time. This capability enhances management by providing precise and comprehensive information about the identity and location / movements of multiple UVs, and enabling each UV 13 to improve its path in GNSS-denied environments.

[0045] According to an embodiment of the invention, at the beginning of the movement of UV 13, system 100 automatically detects it by data received from observer sensor 11, based on the known initial location of UV 13 (e.g., the initial location of UV 13 from which it launches to a mission, or as GPS is becoming unavailable, etc.). In case the initial position of UV 13 is unknown. UV 13 conducts a "detection maneuver" where control station 12 detects an "indicative" maneuver that is untypical for other objects of its kind. In some embodiments, UV 13 uses optical flow to track the ground to improve the accuracy of the "detection maneuver". UV 13 may use an available camera or electro-optic sensor (e.g., pre-installed on UV 13 and directed for other missions) to improve the accuracy of its detection maneuver. For example, pointing the available camera down and using optical flow image processing to cancel lateral movement (left and right) to achieve an accurate flight path (specific path, azimuth, etc.) compensates for control errors and wind drift. According to an embodiment of the invention, UV 13 sends information regarding estimated movements to control station 12. For example, for a UAV, the maneuver will done based on general flight direction, but unaware of current winds so that a drift could happen, but general information such as flight directions and timing of change in flight directions will be broadcasted to control station 12, such as to facilitate the identification of UV 13 among all objects detected by observer sensor 11.

[0046] According to an embodiment of the invention, UV 13 uses an onboard radar sensor (e.g., a Doppler radar) to improve the accuracy of the detection maneuver. For example, UV 13 will point its onboard radar to its side and down and use information about the velocity of the object to adjust its flight path to achieve an accurate flight path (specific path, azimuth, etc.), compensating for control errors and wind drift.

[0047] According to an embodiment of the invention, the detection maneuver can be sent by control station 12, based on currently detected objects. For example, if current detected objects are in a clockwise maneuver, control station 12 may instruct UV 13 to perform a counter-clockwise maneuver. After the potential detection of UV 13, control station 12 may instruct UV 13 to change its path uniquely. For example, suppose more than one object is performing a possible "back-and-forth" movement. In that case, control station 12 will instruct UV 13 to perform a "left and climb" because this is the most unique movement to all potential targets.

[0048] According to an embodiment of the invention, system 100 serves as a "sanity check" of alternative GNSS or any location-based system (i.e., applying a simple verification to ensure that the results of GNSS solution made by these GNSS system are not incorrect or unreasonable). If the sanity shows the solution is OK, the other GNSS solution can be used, and if (or when) the GNSS system is disrupted or spoofed, UV 13 will navigate based on system 100.

[0049] Fig. 2 is a flowchart of a method for providing location feedback, according to an embodiment of the invention. The method may involve the following procedures:

[0050] Generating data about the position or location of detected objects in a designated area monitored by observer sensor 11 (101). The generated data indicative of the position information, can be generated by observer senor 11 in any geographic absolute coordinates, or relative to its own position (such as azimuth, elevation range, or relative position), or when observer sensor 11 is only providing some of this datum (for example only range, or only directional information);

[0051] Processing the generated data, by control station 12, for determining whether an object detected by observer sensor 11 is UV 13 (102). It should be mentioned that observer sensor 11 may send the information (i.e., the generated data) to control station 12 with or without accurate timestamps of its detection; and

[0052] Upon identifying UV 13, communicating the position data information to UV 13 enables a robust navigation solution for platforms and vehicles operating in GNSS-denied environments to ensure continuous and accurate positioning and navigation capabilities even when GNSS signals are unavailable, degraded, or compromised.

[0053] According to an embodiment of the invention, UV 13 uses the position data information to improve its path and feeds it to an onboard processing unit to gain a sense of self-position, e.g., by utilizing Kalman Filter or other algorithm(s) suitable for guidance, navigation, and control of UV 13.

[0054] According to an embodiment of the invention, more than one observer sensor 11 is used with the same or different data being fused or used in conjunction by control station 12 or UV 13.

[0055] Fig. 3 schematically illustrates a system 200 for location feedback that incorporates radar, according to an embodiment of the invention. System 200 comprises an observer sensor 110 adapted to detect objects and to provide data about the position or location of the detected objects in the area where it is situated, control station 12 and UV 13.

[0056] According to this embodiment, observer sensor 110 is a scanning radar setup that includes a Frequency Modulated Continuous Wave (FMCW) radar system. By continuously transmitting modulated signals and analyzing the received echoes, the FMCW radar system can effectively track the position of objects in its vicinity, providing accurate real-time data on their location and movement. For example, the radar system may feature both transmitting and receiving antennas, enclosed in a radome 111 to minimize signal disturbance. The antennas 112 are mounted on a rotatable support structure, allowing for horizontal rotation. An azimuth encoder (not shown) may provide high-precision encoding and communication of the azimuth angle. The radar system may transmit radar signals 113 within a specific frequency range and power level, with an antenna configuration that ensures extended target exposure time for better data processing. Typical targets may include unmanned vehicles (UVs) such as unmanned aerial vehicles (UAVs) and other flying objects, autonomous vehicles, maritime vessels, etc.

[0057] For example, such a radar system may include front-end electronic circuitry (not shown) for managing signal transmission and reception, shielded to prevent electronic noise. This circuitry can be connected to a back-end circuitry (not shown) and a computer system (not shown), forming the processing circuitry. In a typical radar system, such a processing circuitry handles signal processing to generate radar plots and tracks and classify detected objects.

[0058] For example, the radar system may operate by scanning for objects within a 360° range, generating radar images divided into multiple image lines, each covering a specific azimuth range. Each image line is divided into range cells, and the radar transmits multiple sweep signals per image line. The radar's beam width is configured to cover each image line during rotation, allowing for effective signal transmission and reception.

[0059] According to an embodiment of the invention, observer sensor 110 detects the position of objects such as UVs by determining their range, azimuth angle, and radial velocity. For example, the detection process may involve clutter filtering, scan data storage, Fourier transform application, and range-Doppler velocity data sets generation. These data sets are used to create radar plots, which are analyzed and grouped based on matching conditions. The system generates range-azimuth plots for a full radar image, analyzing and grouping neighboring range cells with matching data. The radar plots and tracks are combined, classified, and used to track and classify detected UVs based on their velocity profiles and other parameters, ensuring accurate position detection.

[0060] The classified radar tracks are analyzed in real-time at control station 12, facilitating decision-making regarding identifying the detected object that is likely to be UV 13 and broadcasting the position information to the detected UV 13.

[0061] Although embodiments of the invention have been described by way of illustration, it will be understood that the invention may be carried out with many variations, modifications, and adaptations, without exceeding the scope of the claims.

Claims

Claims1. A system for navigating in GPS-denied or GPS-spoofed environments, comprising: a) at least one Unmanned Vehicle (UV); b) an observer sensor configured to provide data about the position or location of detected objects in the area where the observer sensor is situated, wherein the position of the observer sensor is known; c) a control station adapted to receive the data from the observer sensor and to identify which object detected is at least one of the UV; and d) a communication link is configured to relay the position or location data to the identified UV.

2. A system according to claim 1, wherein the control station can be ground- based or aerial-based.

3. A system according to claim 1, wherein the UV is an Unmanned Aerial Vehicle (UAV).

4. A system according to claim 1, wherein the observer sensor is selected from a group consisting of a radar system, an electro-optical camera system, or a thermal imaging camera including a cooled or uncooled bolometer.

5. A system according to claim 1, wherein the UV comprising detection augmentation equipment that is capable of increasing the likelihood of the UV detection.

6. A system according to claim 5, wherein the detection augmentation equipment is selected from the group consisting of a beacon (visual or radio), or a device suitable to increase radar cross-section.

7. A system according to claim 6, wherein the beacon is an active beacon that is synchronized to the ground by means of wireless communication to identify its detection and identification.

8. A system according to claim 1, wherein the observer sensor and the control station are embodied in the same sub-system or device.

9. A system according to claim 1, wherein the observer sensor is mobile or moving but still has its position known.

10. A system according to claim 1, wherein more than one observer sensor is used with the same or different data being fused or used in conjunction either by the control station or by the UV.

11. A method for navigating in GPS-denied or GPS-spoofed environments based on the system of claim 1, comprising: a) providing an observer sensor capable of generating data about the position or location of detected objects in the area where the observer sensor is situated, thereby telling information about the location of detected objects in said area; b) providing a control station capable of receiving the generated data from the observer sensor and accordingly discerning which object detected is an Unmanned Vehicle (UV); and c) communicating, via a communication link, information about the location to the detected UV, thereby enabling the detected UV to gain a sense of self-position to improve its navigation path.

12. A method according to claim 11, wherein the UV is gaining a sense of selfposition by feeding the information to a Kalman Filter, or to any UV onboard microprocessor suitable for providing self-position.

13. A method according to claim 11, wherein at the beginning of the movement of the UV, the system automatically detects said UV based on a known initial position of said UV.

14. A method according to claim 13, wherein when the initial position of the UV is unknown, said UV will conduct a "detection maneuver" where the controlstation detects an "indicative" maneuver that is untypical for other objects of its kind.

15. A method according to claim 14, wherein the UV sends information regarding estimated movements to the control station to facilitate the identification of said UV among all objects detected by the observer sensor.

16. A method according to claim 14, wherein the UV uses optical flow to track the ground to improve the accuracy of the "detection maneuver".

17. A method according to claim 14, further comprising compensating control errors and wind drift by utilizing an available camera or electro-optic sensor of the UV to improve the accuracy of the detection maneuver of said UV.

18. A method according to claim 14, further comprising improving the accuracy of the detection maneuver of the UV by using an onboard radar sensor, thereby compensating for control errors and wind drift.

19. A method according to claim 14, wherein the detection maneuver is being sent to the UV by the ground-control station, based on currently detected objects.

20. A method according to claim 11, wherein after potential detection of the UV, the ground-control station instructs the UV to change its path in a unique way to distinguish its movement with respect to all current potential detected targets, thereby facilitating the identification of the UV.

21. A method according to claim 11, wherein the system serves as a "sanity check" of alternative GNSS or any location-based system, wherein if the sanity shows the solution is OK, the other GNSS solution can be used, and if or when the GNSS system is disrupted or spoofed, the UV will navigate based on said system.

22. A method according to claim 11, wherein the observer sensor is configured to provide information with or without accurate timestamps of its detection.

23. A method according to claim 11, wherein the observer sensor is configured to provide datum relative to position information in any geographic absolute coordinates, or relative to its own position, or to provide only some of said datum.

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