Patent ID: 11866198
Assignee: CALIFORNIA INSTITUTE OF TECHNOLOGY
Field: Transport (Mechanical engineering)
Classification: CPC B  G  Y | IPC B  G

Claim 14:
15. An unmanned aerial system (UAS) comprising:
(a) a take-off landing-charging station and a target landing-charging station; and
(b) a UAS vehicle comprising:
(i) one or more rotors for operating the UAS vehicle aerially;
(ii) a processor;
(iii) software executed by the processor for conducting onboard autonomy on the UAS vehicle, wherein the software causes the UAS vehicle to:
(A) autonomously take off from the take-off landing-charging station;
(B) autonomously execute a mission based on a mission plan, wherein:
(1) the executing comprises the UAS vehicle autonomously observing data during flight;
(2) the executing comprises the UAS vehicle 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) autonomously travel to a hover position above a target landing-charging station;
(D) autonomously precision land on the target landing-charging station, wherein the precision landing comprises:
(1) 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) 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, 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) autonomously re-charge via the target landing-charging station, wherein once re-charged, the UAS vehicle is ready to execute a next sortie; and
(F) autonomously transmit mission data, and
wherein the software is executed by the processor onboard the UAS vehicle without any human intervention.