US 12,140,608 B2
Systems and methods for starting a sensorless motor
Bart Dean Hibbs, Simi Valley, CA (US)
Assigned to AEROVIRONMENT, INC., Arlington, VA (US)
Appl. No. 17/783,486
Filed by AEROVIRONMENT, INC., Arlington, VA (US)
PCT Filed Dec. 7, 2020, PCT No. PCT/US2020/063611
§ 371(c)(1), (2) Date Jun. 8, 2022,
PCT Pub. No. WO2021/118928, PCT Pub. Date Jun. 17, 2021.
Claims priority of provisional application 62/945,813, filed on Dec. 9, 2019.
Prior Publication US 2023/0017339 A1, Jan. 19, 2023
Int. Cl. G01P 3/48 (2006.01); B64C 39/02 (2023.01); B64U 10/25 (2023.01); B64U 30/10 (2023.01); B64U 30/20 (2023.01); B64U 50/13 (2023.01); B64U 50/19 (2023.01); G01P 13/04 (2006.01); H02P 6/182 (2016.01); H02P 6/20 (2016.01)
CPC G01P 3/48 (2013.01) [B64C 39/024 (2013.01); B64U 10/25 (2023.01); B64U 30/10 (2023.01); B64U 50/13 (2023.01); B64U 50/19 (2023.01); G01P 13/045 (2013.01); H02P 6/182 (2013.01); H02P 6/20 (2013.01); B64U 30/20 (2023.01)] 17 Claims
OG exemplary drawing
 
1. A system comprising:
an unmanned aerial vehicle (UAV);
at least one sensorless motor of the UAV, the at least one sensorless motor comprising a set of windings and a rotor;
at least one propeller connected to the at least one sensorless motor;
a microcontroller in communication with the at least one sensorless motor,
wherein the microcontroller is configured to:
determine a rotation rate of the at least one propeller;
determine a rotation direction of the at least one propeller;
provide an output to stop the at least one propeller if at least one of: the determined rotation rate is not a desired rotation rate and the determined rotation direction is not a desired rotation direction; and
provide an output to start the at least one propeller if the at least one propeller is stopped at the desired rotation rate and the desired rotation direction;
wherein the determined rotation rate is based on a measured frequency of a back electromotive force (EMF) generated by the at least one sensorless motor; and
wherein stopping the at least one propeller further comprises energizing the at least one sensorless motor with current at a same frequency as the measured frequency of the back-EMF.