US 11,866,198 B2
Long-duration, fully autonomous operation of rotorcraft unmanned aerial systems including energy replenishment
Roland Brockers, Pasadena, CA (US); Stephan Michael Weiss, Lenzburg (CH); Danylo Malyuta, Seattle, WA (US); Christian Brommer, Werne (DE); and Daniel Robert Hentzen, Zurich (CH)
Assigned to CALIFORNIA INSTITUTE OF TECHNOLOGY, Pasadena, CA (US)
Filed by California Institute of Technology, Pasadena, CA (US)
Filed on Oct. 29, 2019, as Appl. No. 16/667,655.
Claims priority of provisional application 62/752,199, filed on Oct. 29, 2018.
Prior Publication US 2020/0130864 A1, Apr. 30, 2020
Int. Cl. B64F 1/36 (2017.01); B60L 53/12 (2019.01); B60L 53/14 (2019.01); B64C 39/02 (2023.01); G05D 1/00 (2006.01); B64F 5/60 (2017.01); B64D 47/08 (2006.01); B64U 10/13 (2023.01); B64U 30/20 (2023.01); B64U 101/00 (2023.01); B64U 101/30 (2023.01)
CPC B64F 1/362 (2013.01) [B60L 53/12 (2019.02); B60L 53/14 (2019.02); B64C 39/024 (2013.01); B64D 47/08 (2013.01); B64F 5/60 (2017.01); G05D 1/0088 (2013.01); B60L 2200/10 (2013.01); B64U 10/13 (2023.01); B64U 30/20 (2023.01); B64U 2101/00 (2023.01); B64U 2101/30 (2023.01); B64U 2201/10 (2023.01)] 30 Claims
OG exemplary drawing
 
1. A method for autonomously operating an unmanned aerial system (UAS), comprising:
(a) the UAS autonomously taking off from a take-off landing-charging station;
(b) the UAS autonomously executing a mission based on a mission plan, wherein:
(1) the executing comprises the UAS autonomously observing data during flight;
(2) the executing comprises the UAS autonomously updating the mission plan based on the observed data; and
(3) the mission comprises a set of waypoints connected by individual trajectory segments, wherein the individual trajectory segments are autonomously generated onboard the UAS;
(c) the UAS autonomously traveling to a hover position above a target landing-charging station;
(d) the UAS autonomously precision landing on the target landing-charging station, wherein the precision landing comprises:
(1) the UAS utilizing a camera to detect a landing bundle comprised of multiple tag fiducials, wherein a placement of the multiple tag fiducials around a charging area of the target landing-charging station will not obscure the charging area;
(2) the UAS performing a landing bundle calibration by:
(A) calibrating the camera and the multiple tag fiducials based on:
a camera frame of the camera;
a master tag of the multiple tag fiducials;
additional tags of the multiple tag fiducials; and
a position and altitude of each additional tag relative to the master tag:
(B) orienting the camera downfacing with the landing bundle visible to form a rigid body transform triad, wherein the rigid body transform triad is comprised of the camera frame, the master tag, and one or more of the additional tags;
(C) collecting a sequence of multiple calibration transforms based on the rigid body transform triad;
(D) combining the multiple calibration transforms to generate a geometric position and an attitude of each of the multiple tag fiducials relative to a landing pad frame;
(3) based on the landing bundle calibration, the UAS utilizing a bundle pose measurement algorithm to produce a bundle pose measurement of the target landing charging-station in a world frame;
(4) utilizing the bundle pose measurement to generate a yaw measurement wherein the bundle pose measurement and yaw measurement are used for landing navigation;
(5) the UAS autonomously realigning itself, using a landing pose estimate, with the target landing-charging station, wherein the realignment is necessary due to drift;
(6) the UAS autonomously determining and issuing a new trajectory to the target landing-charging station; and
(7) the UAS autonomously following the new trajectory to land on the target landing-charging station;
(e) the UAS autonomously re-charging via the target landing-charging station, wherein once re-charged, the UAS is ready to execute a next sortie; and
(f) when landed, the UAS autonomously transmitting mission data,
wherein the UAS autonomously performs the above steps onboard the UAS without any human intervention.