Method of controlling a propeller with two-position solenoid
A method for controlling an aircraft propeller is provided that comprises obtaining a measurement of a speed of the propeller, comparing the propeller speed to a first threshold, responsive to determining that the propeller speed exceeds the speed threshold, outputting a valve control signal for opening a two-position solenoid valve coupled to the propeller, the two-position solenoid valve configured for controlling fluid flow to and from the propeller to control propeller blade angle, computing a rate of change of the propeller speed, comparing the rate of change of the propeller speed to a second threshold, and responsive to determining that the rate of change of the propeller speed is below the second threshold, outputting the valve control signal for closing the two-position solenoid valve. A system for controlling an aircraft propeller and an aircraft propeller control assembly are also provided.
1. A method for controlling an aircraft propeller, the method comprising:
obtaining a measurement of a speed of the propeller;
comparing the propeller speed to a speed threshold;
in responsive to determining that the propeller speed exceeds the speed threshold, outputting a valve control signal for opening a two-position solenoid valve coupled to the propeller, the two-position solenoid valve configured for controlling fluid flow to and from the propeller to control a blade angle of the propeller;
computing a rate of change of the propeller speed;
comparing the rate of change of the propeller speed to a rate of change threshold, the rate of change threshold computed based on a previous rate of change of the propeller speed recorded upon a last opening of the two-position solenoid valve; and
in responsive to determining that the rate of change of the propeller speed is below the rate of change threshold, outputting the valve control signal for closing the two-position solenoid valve.
2. The method of claim 1 , wherein the rate of change threshold is computed by multiplying the recorded rate of change with a predetermined ratio.
3. The method of claim 1 , wherein the speed threshold is set at a value to prevent overspeed.
4. The method of claim 1 , wherein the valve control signal is output for controlling the two-position solenoid valve comprising a feather solenoid valve.
5. The method of claim 1 , wherein the rate of change of propeller speed is continuously computed.
6. A system for controlling an aircraft propeller, the system comprising:
a processing unit; and
a non-transitory computer-readable storage medium having stored thereon program instructions executable by the processing unit for:
obtaining a measurement of a speed of the propeller;
comparing the propeller speed to a speed threshold;
in response to determining that the propeller speed exceeds the speed threshold, outputting a valve control signal for opening a two-position solenoid valve coupled to the propeller, the two-position solenoid valve configured for controlling fluid flow to and from the propeller to control a blade angle of the propeller;
computing a rate of change of the propeller speed;
comparing the rate of change of the propeller speed to a rate of change threshold, the rate of change threshold computed based on a previous rate of change of the propeller speed recorded upon a last opening of the two-position solenoid valve; and
in response to determining that the rate of change of the propeller speed is below the rate of change threshold, outputting the valve control signal for closing the two-position solenoid valve.
7. The system of claim 6 , wherein the program instructions are further executable by the processing unit for computing the rate of change threshold by multiplying the recorded rate of change with a predetermined ratio.
8. The system of claim 6 , wherein the program instructions are further executable by the processing unit for comparing the propeller speed to the speed threshold set at a value to prevent overspeed.
9. The system of claim 6 , wherein the two-position solenoid valve is a feather solenoid valve.
10. An aircraft propeller control assembly comprising:
an aircraft propeller;
an actuator coupled to the aircraft propeller and comprising a two-position solenoid valve for controlling fluid flow to and from the aircraft propeller to control a blade angle of the propeller; and
a controller coupled to the actuator and configured for:
obtaining a measurement of a speed of the propeller;
comparing the propeller speed to a speed threshold;
in response to determining that the propeller speed exceeds the speed threshold, outputting a valve control signal for opening the two-position solenoid valve;
computing a rate of change of the propeller speed;
comparing the rate of change of the propeller speed to a rate of change threshold, the rate of change threshold computed based on a previous rate of change of the propeller speed recorded upon a last opening of the two-position solenoid valve; and
in response to determining that the rate of change of the propeller speed is below the rate of change threshold, outputting the valve control signal for closing the two-position solenoid valve.
11. The assembly of claim 10 , wherein the controller is configured for computing the rate of change threshold by multiplying the recorded rate of change with a predetermined ratio.
12. The assembly of claim 10 , wherein the controller is configured for comparing the propeller speed to the speed threshold set at a value to prevent overspeed.
13. The assembly of claim 10 , wherein the two-position solenoid valve is a feather solenoid valve.
14. The assembly of claim 10 , wherein the controller is a secondary means of controlling the propeller and is enabled upon failure of a primary means.
15. The assembly of claim 10 , wherein the controller is a primary means of controlling the propeller.
16. The assembly of claim 10 , wherein the aircraft propeller is a single-acting propeller.
17. The assembly of claim 10 , wherein the aircraft propeller is a double-acting propeller.