US 9,162,752 C1 (12,849th)
Flight control laws for automatic hover hold
Kevin Thomas Christensen, Plano, TX (US); Shyhpyng Jack Shue, Grapevine, TX (US); and Troy Sheldon Caudill, Burleson, TX (US)
Filed by Kevin Thomas Christensen, Plano, TX (US); Shyhpyng Jack Shue, Grapevine, TX (US); and Troy Sheldon Caudill, Burleson, TX (US)
Assigned to Textron Innovations Inc.
Reexamination Request No. 90/019,236, Aug. 11, 2023.
Reexamination Certificate for Patent 9,162,752, issued Oct. 20, 2015, Appl. No. 13/703,640, Dec. 12, 2012.
PCT Filed Jul. 15, 2011, PCT No. PCT/US2011/044160
§ 371(c)(1), (2), (4) Date Dec. 12, 2012,
PCT Pub. No. WO2013/012408, PCT Pub. Date Jan. 24, 2013.
Ex Parte Reexamination Certificate issued on Feb. 13, 2025.
Int. Cl. G01C 23/00 (2006.01); B64C 11/00 (2006.01); B64C 19/00 (2006.01); G05D 1/10 (2006.01)
CPC B64C 19/00 (2013.01)
OG exemplary drawing
AS A RESULT OF REEXAMINATION, IT HAS BEEN DETERMINED THAT:
The patentability of claim 13 is confirmed.
Claims 1-7, 10 and 12 were previously cancelled.
New claims 21-30 are added and determined to be patentable.
Claims 8, 9, 11 and 14-20 were not reexamined.
13. A flight control system for a rotary aircraft, the rotary aircraft having a longitudinal controller, a lateral controller, a directional controller, and a vertical controller, the control system comprising:
a longitudinal loop design having:
a forward speed hold loop;
a pitch attitude loop; and
a pitch rate loop;
wherein the forward speed hold loop automatically engages when the longitudinal controller is returned to a detent position and the aircraft groundspeed is outside a first groundspeed threshold; and
wherein longitudinal maneuverability of the rotary aircraft is controlled by either the pitch attitude loop or the pitch rate loop when the longitudinal controller is out of the detent position;
a lateral loop design having:
a lateral speed hold loop; and
a roll rate loop;
wherein the lateral speed hold loop automatically engages when the lateral controller is returned to a detent position and the aircraft groundspeed is outside the first groundspeed threshold; and
wherein lateral maneuverability of the rotary aircraft is controlled by either the lateral speed hold loop or the roll rate loop when the lateral controller is out of the detent position;
a directional loop design having:
a yaw rate command loop; and
a heading hold loop;
wherein the heading hold loop will be re-engaged automatically during flight in the first groundspeed threshold when the directional controller is in detent; and
a vertical control loop design having:
a vertical speed hold loop; and
an altitude hold loop;
wherein the altitude hold loop automatically engages when the vertical controller is returned to a detent position and the aircraft groundspeed is inside the first groundspeed threshold; and
wherein vertical maneuverability of the rotary aircraft is controlled by the vertical speed hold loop if the vertical controller is out of the detent position.
[ 21. The flight control system of claim 13, wherein the forward speed hold loop is configured to hold a zero forward speed.]
[ 22. The flight control system of claim 13, wherein the forward speed hold loop is configured to hold a non-zero forward speed.]
[ 23. The flight control system of claim 13, wherein the longitudinal loop design is configured to command a target speed and close at least the forward speed hold loop to achieve the target speed.]
[ 24. The flight control system of claim 13, wherein the longitudinal loop design is configured to command a target speed.]
[ 25. The flight control system of claim 24, wherein the target speed is zero.]
[ 26. The flight control system of claim 24, wherein the target speed is non-zero.]
[ 27. The flight control system of claim 13, wherein an amount of displacement of one or more of the longitudinal controller, the lateral controller, the directional controller, or the vertical controller corresponds to a commanded translational rate, and a proportion of the amount of displacement to the corresponding commanded translational rate is adjustable.]
[ 28. The flight control system of claim 13, further comprising an emergency hover hold mode.]
[ 29. The flight control system of claim 13, wherein the longitudinal controller, the lateral controller, the directional controller, and the vertical controller are on-board the rotary aircraft.]
[ 30. A flight control system for a rotary aircraft, the rotary aircraft having a longitudinal controller, a lateral controller, a directional controller, and a vertical controller, the control system comprising:
a longitudinal loop design having:
a forward speed hold loop;
a pitch attitude loop; and
a pitch rate loop;
wherein the forward speed hold loop automatically engages when the longitudinal controller is returned to a detent position and the aircraft groundspeed is outside a first groundspeed threshold; and
wherein longitudinal maneuverability of the rotary aircraft is controlled by either the pitch attitude loop or the pitch rate loop when the longitudinal controller is out of the detent position;
a lateral loop design having:
a lateral speed hold loop; and
a roll rate loop;
wherein the lateral speed hold loop automatically engages when the lateral controller is returned to a detent position and the aircraft groundspeed is outside the first groundspeed threshold; and
wherein lateral maneuverability of the rotary aircraft is controlled by the roll rate loop when the lateral controller is out of the detent position;
a directional loop design having:
a yaw rate command loop; and
a heading hold loop;
wherein the heading hold loop will be re-engaged automatically during flight in the first groundspeed threshold when the directional controller is in detent; and
a vertical control loop design having:
a vertical speed hold loop; and
an altitude hold loop;
wherein the altitude hold loop automatically engages when the vertical controller is returned to a detent position and the aircraft groundspeed is inside the first groundspeed threshold; and
wherein vertical maneuverability of the rotary aircraft is controlled by the vertical speed hold loop if the vertical controller is out of the detent position.]