Apparatus for preventing propeller overshoot
AssigneeAlliedSignal Inc.
InventorsGlen T. High, Larry C. Prevallet, Joseph W. Free
Life of this patent
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Abstract
To prevent propeller overshoot, a propeller governor control generates a signal which modifies a speed command issued to a propeller governor. The signal causes the propeller governor to change blade pitch before the propeller reaches its commanded speed. The propeller governor control also compensates for small calibration errors in the propeller governor.
Claims16
Apparatus for preventing propeller overshoot in a system that generates a speed command for setting a propeller governor to a desired speed and that receives a feedback signal indicating measured propeller speed, said apparatus comprising:
- delta speed means, responsive to said feedback signal, for providing a delta speed signal indicating changes in said measured propeller speed;
- and
- modifying means, responsive to said delta speed signal and said feedback signal, for providing a modified speed command to said propeller governor for modifying said speed command such that said propeller governor changes blade pitch before said feedback signal indicates said desired speed to prevent propeller overshoot, said speed command being modified when said delta speed signal falls outside a first range.
Apparatus for modifying a speed command that sets a governor for a propeller to a desired speed, comprising:
- delta speed means for providing a delta speed signal indicating changes in speed of said propeller;
- anticipating means, responsive to said delta speed means, for providing an anticipation signal that is proportional to said delta speed signal;
- and
- modifying means for modifying said speed command with said anticipation signal such that said governor begins changing said propeller speed before said propeller speed reaches said desired speed, said modified speed command being supplied to said propeller governor.
A method of preventing propeller overshoot in a system including a propeller governor that begins to change propeller blade pitch when propeller speed reaches a desired speed, said method comprising the steps of:
- generating a speed command which sets said propeller governor to said desired speed and
- modifying said speed command such that said propeller governor changes said blade pitch as said propeller speed approaches said desired speed.
Dependencies are inferred from the claim text.