Helicopter engine control having lateral cyclic pitch anticipation
First Claim
1. A helicopter comprising:
- a main rotor;
an engine;
rotor drive means including an overrunning clutch for connecting said main rotor to said engine whenever the speed of said main rotor does not exceed the speed of said engine;
pilot operated cyclic pitch control means for changing the cyclic pitch of said main rotor;
engine control means for providing a fuel command signal indicative of fuel flow required for desired engine operation, and for metering fuel flow to said engine in response to said fuel command signal;
helicopter roll acceleration indicating means for providing a roll acceleration signal indicative of helicopter roll acceleration;
lateral cyclic pitch control indicating means for providing a lateral cyclic pitch signal indicative of the amount of lateral cyclic pitch being commanded by said pilot operated cyclic pitch control means; and
said engine control means comprising means for providing said fuel command signal with a lateral cyclic pitch component in response to said lateral cyclic pitch signal for increasing or decreasing fuel flow to said engine, the magnitude of said fuel command signal lateral cyclic pitch component being determined as a function of said roll acceleration signal.
2 Assignments
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Accused Products
Abstract
A helicopter engine fuel control anticipates changes in main rotor torque in response to lateral cyclic pitch commands, to thereby minimize engine and main rotor speed droop and overspeed during left and right roll maneuvers. A fuel compensation signal (100,101) is summed with a helicopter fuel control (52) fuel command signal (67) in response both to a lateral cyclic pitch command signal (LCP) (107) from a pilot operated cyclic pitch control exceeding a left or right threshold magnitude (201,210) and a total lateral cyclic pitch command signal (TCP) (108) from a lateral cyclic pitch control system exceeding a left or right threshold magnitude (202,207,215,220). The magnitude of the fuel compensation signal is dependant upon the direction of TCP and LCP, e.g., left or right, and helicopter roll acceleration (115). Alternatively, the magnitude and duration of the fuel compensation signal is dependant upon the rate of change in commanded lateral cyclic pitch (107,400,407). A limiter (120) limits the magnitude of the fuel compensation signal. The fuel compensation signal is overridden (127,125,103) when it is increasing fuel flow ( 303) during rotor overspeed (128,301), and when it is decreasing fuel flow (311) if rotor acceleration (130,133) is negative (310) during rotor droop (128,301).
33 Citations
15 Claims
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1. A helicopter comprising:
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a main rotor; an engine; rotor drive means including an overrunning clutch for connecting said main rotor to said engine whenever the speed of said main rotor does not exceed the speed of said engine; pilot operated cyclic pitch control means for changing the cyclic pitch of said main rotor; engine control means for providing a fuel command signal indicative of fuel flow required for desired engine operation, and for metering fuel flow to said engine in response to said fuel command signal; helicopter roll acceleration indicating means for providing a roll acceleration signal indicative of helicopter roll acceleration; lateral cyclic pitch control indicating means for providing a lateral cyclic pitch signal indicative of the amount of lateral cyclic pitch being commanded by said pilot operated cyclic pitch control means; and said engine control means comprising means for providing said fuel command signal with a lateral cyclic pitch component in response to said lateral cyclic pitch signal for increasing or decreasing fuel flow to said engine, the magnitude of said fuel command signal lateral cyclic pitch component being determined as a function of said roll acceleration signal. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A helicopter comprising:
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a main rotor; an engine; rotor drive means including an overrunning clutch for connecting said main rotor to said engine whenever the speed of said main rotor does not exceed the speed of said engine; pilot operated cyclic pitch control means for changing the cyclic pitch of said main rotor; engine control means for providing a fuel command signal indicative of fuel flow required for desired engine operation, and for metering fuel flow to said engine in response to said fuel command signal; means for providing a lateral cyclic pitch signal indicative of the amount of lateral cyclic pitch being commanded by said pilot operated cyclic pitch control means; means responsive to said lateral cyclic pitch signal for providing a lateral cyclic pitch rate signal indicative of the rate of change of said lateral cyclic pitch signal; means for providing a fuel compensation signal the magnitude and duration of which are dependent upon said lateral cyclic pitch rate signal; and said engine control means comprising means for combining said fuel compensation signal with said fuel command signal. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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Specification