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EP-4104161-B1 - ADHOC GEO-FIDUCIAL MATS FOR LANDING UAVS

EP4104161B1EP 4104161 B1EP4104161 B1EP 4104161B1EP-4104161-B1

Inventors

  • JOURDAN, DAMIEN
  • SEKINE, ANTHONY
  • VELEZ, Scott
  • Prager, André

Dates

Publication Date
20260506
Application Date
20210301

Claims (14)

  1. A system comprising: an unmanned aerial vehicle, UAV (105), which comprises an optical navigation system; and an apparatus (100) for use in visual navigation of the UAV (105), the apparatus comprising: a geo-fiducial mat (110) including: a landing pad region (211) that provides a location for aligning with a landing pad of the UAV; and a survey point; and a plurality of geo-fiducials disposed in or about the landing pad region and each specified for a unique directional and offset position relative to the survey point, wherein the geo-fiducials each includes a two-dimensional, 2D, pattern that visually conveys an alphanumerical code, wherein the 2D pattern has a shape from which the optical navigation system of the UAV can visually triangulate a position of the UAV, wherein the UAV is configured to compute the positions of each of the geo-fiducials based on location information for the survey point and the unique directional and offset position relative to the survey point specified for each geo-fiducial, and then to visually triangulate its position.
  2. The system of claim 1, wherein the geo-fiducials comprise at least three geo-fiducials that each convey a different alphanumerical code and are disposed at three different corners or along three different sides of the landing pad region.
  3. The system of claim 1, wherein the geo-fiducials comprise: first geo-fiducials having a first size that are configured to be disposed on or attached to the landing pad.
  4. The system of claim 3, wherein the geo-fiducials further comprise: second geo-fiducials having a second size, larger than the first size, the second geo-fiducials positioned further from a center of the landing pad region than the first geo-fiducials.
  5. The system of claim 4, wherein the geo-fiducials further comprise: third geo-fiducials having a third size, larger than the first and second sizes, the third geo-fiducials positioned further from the center of the landing pad region than the first and second geo-fiducials.
  6. The system of claim 4, wherein the landing pad region comprises a rectangular shaped region, wherein the first geo-fiducials are disposed proximate to corners of the landing pad region, and wherein the second geo-fiducials are substantially centered along sides of the landing pad region, and/or wherein the second geo-fiducials are integrated into the geo-fiducial mat while the first geo-fiducials are configured to be physically distinct and separate from the geo-fiducial mat for adhering to or otherwise disposing on the landing pad of the UAV.
  7. The system of claim 1, wherein the geo-fiducial mat further includes: a directional marker (215) disposed on the geo-fiducial mat for aligning the geo-fiducial mat with a predetermined direction such that positions of the geo-fiducials are determinable based upon location information of the survey point and the unique directional and offset position specified for each of the geo-fiducials.
  8. The system of claim 1, wherein the geo-fiducial mat further includes: alignment markings (210) disposed on the geo-fiducial mat for indicating the landing pad region and aiding alignment of the landing pad to the landing pad region.
  9. The system of claim 1, wherein the geo-fiducial mat comprises a flexible substrate material that is amenable to rolling or folding, or wherein the geo-fiducial mat comprises puzzle sections that are separable.
  10. The system of claim 1, wherein the alphanumerical code conveyed by each of the geo-fiducials shares a common first portion (225) that is associated with a pad identification of the landing pad and a different second portion (230) that individually distinguishes each of the geo-fiducials of the geo-fiducial mat from each other, and optionally wherein the pad identification includes: a first segment having a value indicating that the geo-fiducials are not individually surveyed, but rather locations of the geo-fiducials are computable based at least in part upon location information of the survey point; and a second segment that matches the common first portion of the alphanumerical code of each of the geo-fiducials.
  11. The system of claim 1, further comprising the landing pad for the UAV, wherein the landing pad for the UAV is a charging pad for charging the UAV.
  12. The system of claim 11, wherein the alphanumerical code conveyed by each of the geo-fiducials shares a common first portion that is associated with a pad identification of the landing pad and a different second portion that individually distinguishes each of the geo-fiducials of the geo-fiducial mat from each other.
  13. The system of claim 12, wherein the UAV includes a controller coupled to memory storing instructions that when executed by the controller cause the UAV to perform operations comprising: identifying a first segment of the pad identification as indicating that the charging pad has multiple geo-fiducials associated with the charging pad that are not individually surveyed; computing locations for the geo-fiducials based at least in part upon location information of the survey point received by the UAV and the unique directional and offset position specified for each of the geo-fiducials; and populating a geo-fiducial map stored within the UAV with the locations for the geo-fiducials.
  14. The system of claim 11, wherein the UAV further comprises a global positioning system, GPS, sensor and a controller coupled to memory storing instructions that when executed by the controller cause the UAV to perform operations comprising: flying the UAV to a takeoff way point above the geo-fiducial mat; visually triangulating the position of the UAV with the optical navigation system based upon one or more of the geo-fiducials; and validating correct operation of the GPS sensor at the takeoff waypoint based upon the position that is visually triangulated.

Description

TECHNICAL FIELD This disclosure relates generally to unmanned aerial vehicles (UAVs), and in particular but not exclusively, relates to visual navigation and landing pads for UAVs. BACKGROUND INFORMATION A UAV is a vehicle capable of air travel without a physically-present human operator. UAVs may be provisioned to perform various different missions, including payload delivery, exploration/reconnaissance, imaging, public safety, surveillance, or otherwise. The mission definition will often dictate a type of specialized equipment and/or configuration of the unmanned vehicle. Safe and efficient UAV navigation relies upon the UAV having an accurate and precise navigation solution (for example, a latitude, longitude, and altitude). For example, a UAV may rely on a global positioning system (GPS) to generate a navigation solution in wide open environments; however, GPS navigation may lack the precision necessary to navigate a UAV in confined or crowded environments (such as an indoor UAV base having numerous UAVs). In addition, weather and other contingencies may degrade GPS signal strength, which may compromise the ability of a UAV to generate an accurate navigation solution by GPS. Some environments may experience degraded GPS performance, for example due to multipath, and others may be completely GPS-denied, i.e., may lack GPS signal altogether. These are merely exemplary scenarios, as other challenges characterize UAV navigation. Ultimately, the ability to generate a reliable, accurate, and precise navigation solution is important to efficient and safe UAV navigation. US 2017 /0225800 A1 discloses visual landing aids including a series of contrasting circles and polygons for unmanned aerial vehicles that are capable of being accurately detected over a wide range of angles and distances by an unmanned aerial vehicle equipped with a camera and shape detection capabilities. The visual landing aids may be implemented using contrasting colors for the pattern which reflect visible and/or UV or infrared light, or by light emitting elements. In some examples, the landing aids includes a secondary smaller version of the landing aid shape pattern that is embedded within the larger pattern, to enable greater detection range while facilitating close-in precision guidance. In still further examples, light emitting elements may be pulsed at a rate that is synchronized with the camera shutter on the unmanned aerial vehicle to further enhance accurate detection. CN108275281A discloses an automatic wireless charging device for drones comprising multi-scale two-dimensional code landing marks that can help the drone to land accurately on the charging device at different heights. US 2017 /0096075 A1 discloses reconfigurable system capable of autonomously exchanging material from unmanned vehicles of various types and sizes. The system comprises an environmental enclosure, a landing area, a universal mechanical system to load and unload material from the unmanned vehicle, and a central processor that manages the aforementioned tasks. The landing area may comprise a one or more visible or non-visible markers/emitters capable of generating composite images to assist in landing the unmanned vehicle upon the reconfigurable, autonomous system. US 2020/0017237 A1 discloses delivery landing pads for unmanned aerial vehicles (UAVs). An example landing pad includes a landing surface, a landing reticle (e.g., a centering reticle, a target landing reticle, etc.), a visual identifier, which is implemented as a quick response (QR) code, a lateral support and a vertical support. According to an example, the landing reticle is used by a UAV to align the UAV to the landing pad during landing while the visual identifiers are used by the UAV to verify the corresponding landing pad ( e.g., verify that the landing pad corresponds to a specific user or consumer). A center position of the landing surface may be determined based on relative positions of multiple ones of the visual identifiers. US 2018/0053139 A1 discloses an aerial drone parcel delivery/transfer management server (ADPTMS) configured for facilitating flexible management of aerial drone parcel deliveries to or transfers between aerial drone landing pads (ADLPs). Each ADLP has a corresponding ADLP address that includes a unique ADLP identifier (e.g., a manufacturing serial number); current or most-recently known AD LP geolocation data ( e.g., 2D or 3D geospatial coordinates); and possibly current or most-recently known ADLP elevation data. The ADPTMS can communicate with order management/fulfillment servers associated with online stores, which can communicate with aerial drone parcel delivery/transfer services for dispatching aerial drones to particular ADLP addresses as part of fulfilling online orders. An ADLP can present a machine readable code such as a quick response (QR) code thereon (e.g., on a landing mat) that can be captured by an aerial drone and processed to verify the ADLP's