US 11,724,923 B1
Active tether control for a tethered multirotor
Diane Schafer Callow, Albuquerque, NM (US); Steven James Spencer, Albuquerque, NM (US); and Scott E. Rose, Albuquerque, NM (US)
Assigned to National Technology & Engineering Solutions of Sandia, LLC, Albuquerque, NM (US)
Filed by National Technology & Engineering Solutions of Sandia, LLC, Albuquerque, NM (US)
Filed on May 15, 2020, as Appl. No. 16/875,010.
Int. Cl. B66D 1/50 (2006.01); B65H 59/38 (2006.01); B65H 75/42 (2006.01); B65H 75/44 (2006.01); B66D 1/38 (2006.01); B66D 1/20 (2006.01); B64F 3/00 (2006.01); B65H 59/40 (2006.01)
CPC B66D 1/505 (2013.01) [B64F 3/00 (2013.01); B65H 59/384 (2013.01); B65H 75/42 (2013.01); B65H 75/4484 (2013.01); B66D 1/20 (2013.01); B66D 1/38 (2013.01); B65H 59/40 (2013.01); B65H 2701/365 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A control system for tensioning an active tether for a multirotor unmanned aerial system, the control system comprising:
a tensioning pulley and a tensioning spring;
the tensioning spring arranged to generate a variable tension force on the active tether;
a transducer connected adjacent to the tensioning spring to sense a linear displacement position of the tensioning pulley and to transmit a position signal to a controller, the position signal proportional to the linear displacement position;
a servomotor in communication with the controller for receiving a control signal from the controller in response to the position signal; and
the servomotor configured to drive a cable reel, the cable reel being rotatably mounted in a frame for spooling the tether in response to rotation of the servomotor;
wherein the cable reel is rotated by the servomotor to maintain a predetermined tension on the tensioning spring.