US 11,873,081 B2
Supplemental engine power control
Charles Eric Covington, Colleyville, TX (US); Chia-Wei Su, Lewisville, TX (US); Darren Gregory Lang, Dallas, TX (US); Thomas Parsons, Fort Worth, TX (US); and Cody Earl Fegely, Irving, TX (US)
Assigned to Textron Innovations Inc., Providence, RI (US)
Filed by Bell Textron Inc., Fort Worth, TX (US)
Filed on Jun. 9, 2021, as Appl. No. 17/342,963.
Prior Publication US 2022/0396353 A1, Dec. 15, 2022
Int. Cl. B64C 27/12 (2006.01); B64D 31/12 (2006.01)
CPC B64C 27/12 (2013.01) [B64D 31/12 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A rotorcraft, comprising:
a drive system including a main rotor coupled to a main rotor gearbox to rotate the main rotor at a rotor speed;
a main engine coupled to the drive system to provide a first power;
a supplemental engine coupled, when a first clutch is engaged, to the drive system to provide a second power additive to the first power; and
a control system, comprising a processor, operable to control the main engine and the supplemental engine to provide a total power demand, wherein the main engine is controlled based on variations in the rotor speed and with a power compensation command to produce the first power, and the supplemental engine is controlled to produce the second power in response to a supplemental power demand;
wherein the control system imposes:
an upper supplemental power limit to maintain the first power at a first power level for the main engine to govern the rotor speed; and
a lower supplemental power limit to maintain the first clutch engaged;
wherein the upper supplemental power limit takes priority over the lower supplemental power limit during operation when the main engine is controlling the rotor speed.