초록 ▼

A digital fuel control (53) for a helicopter engine (20) controls fuel flow (52) to the engine in response to a turbine reference speed (62) determined in a normal mode (FIG. 5) to be a rated speed, in a fade-in mode (FIG. 6) to be incremented (117, 120) to an estimated optimum minimum speed (114, 1

A digital fuel control (53) for a helicopter engine (20) controls fuel flow (52) to the engine in response to a turbine reference speed (62) determined in a normal mode (FIG. 5) to be a rated speed, in a fade-in mode (FIG. 6) to be incremented (117, 120) to an estimated optimum minimum speed (114, 115, 125), in an optimizer mode (FIG. 7) to be incremented (138) in a direction (137) leading to least fuel consumption (135), and in a fade-out mode (FIG. 8) to be incremented (151, 153) back to rated speed (154). The invention provides an engine reference speed which results in minimum fuel consumption during cruise flight.

대표청구항 ▼

A control for a helicopter engine having a free turbine for normally driving the helicopter rotors at a rated speed, comprising: means for providing an actual speed signal indicative of the rotary speed of the free turbine; a fuel valve means for metering fuel to said engine at a rate determined by

A control for a helicopter engine having a free turbine for normally driving the helicopter rotors at a rated speed, comprising: means for providing an actual speed signal indicative of the rotary speed of the free turbine; a fuel valve means for metering fuel to said engine at a rate determined by a fuel command signal applied thereto; and a fuel controlling signal processing means connected for response to said actual speed signal, for providing a reference speed signal indicative of desired rotary speed of the free turbine, for providing, in response to said actual speed signal and said reference speed signal, a speed error signal indicative of the difference in turbine speed indicated by said actual speed signal and said reference speed signal, for providing said fuel command signal to said fuel valve means indicative of a desired fuel flow rate as a function of said speed error signal; wherein the improvement comprises: said signal processing means comprising means for registering a plurality of flight parameter signals, including an altitude signal indicative of current altitude of the helicopter, a temperature signal indicative of the current temperature of the environment outside of the helicopter, an airspeed signal indicative of the current airspeed of the helicopter, and a weight signal indicative of the current total weight of the helicopter, for providing, in response to all of said flight parameter signals, an optimum speed signal indicative of an estimated optimum free turbine speed for minimum engine fuel requirement for helicopter flight conditions indicated by said flight parameter signals, and for providing a manifestation of whether said speed reference signal indicates a speed which is respectively higher or lower than said estimated optimum free turbine speed.