Pitot-static system blockage detector
Various implementation described herein are directed to a method for identifying a blockage in a pitot-static system. A pressure signal is received. Pressure fluctuations in the pressure signal are identified. A determination is made as to whether a blockage has occurred in the pitot-static system based on the identified pressure fluctuations.
1. A method for identifying a blockage in a pitot-static system, comprising:
receiving a pressure signal;
identifying pressure fluctuations in the pressure signal;
isolating a frequency from the identified pressure fluctuations, via a notch filter configured to pass signals in a frequency range that includes in-flight longitudinal vibration frequencies that are made up of main rotor frequencies; and
determining whether a blockage has occurred in the pitot-static system based on the identified pressure fluctuations.
2. The method of claim 1 , wherein the pressure signal comprises a total pressure signal received from a total pressure sensor.
3. The method of claim 2 , wherein the total pressure sensor is coupled to a pitot tube of the pitot-static system.
4. The method of claim 3 , wherein a predefined airspeed is attained prior to receiving the pressure signal.
5. The method of claim 1 , wherein the pressure signal comprises a static pressure signal.
6. The method of claim 5 , wherein the static pressure signal is received from a static pressure sensor.
7. The method of claim 6 , wherein the static pressure sensor is coupled to a static port of the pitot-static system.
8. The method of claim 7 , wherein a predefined flight range of a rotor speed is attained prior to receiving the pressure signal.
9. The method of claim 1 , wherein the identified pressure fluctuations comprise a noise component.
10. The method of claim 9 , wherein the noise component comprises the rotor blade passage frequency.
11. The method of claim 9 , wherein the noise component comprises the in-flight longitudinal vibration frequencies.
12. The method of claim 1 , further comprising isolating the identified pressure fluctuations to identify pressure fluctuations characteristic of an open port.
13. The method of claim 1 , wherein the determination of whether the blockage has occurred is processed in a frequency domain.
14. The method of claim 1 , wherein the determination of whether the blockage has occurred is processed in a time domain.
15. The method of claim 1 , wherein the blockage is indicated based on a threshold.
16. An apparatus for identifying a blockage in a pitot-static system, comprising:
a device configured to:
receive a pressure signal;
identify pressure fluctuations in the pressure signal;
isolate a frequency from the identified pressure fluctuations via a notch filter configured to pass signals in a frequency range that includes in-flight longitudinal vibration frequencies that are made up of main rotor frequencies; and
determine whether a blockage has occurred in the pitot-static system based on the identified pressure fluctuations.
17. The apparatus of claim 16 , wherein the device receives the pressure signal from a pressure sensor of the pitot-static system coupled to the device.
18. The apparatus of claim 17 , wherein the pressure sensor coupled to the device comprises a total pressure sensor.
19. The apparatus of claim 18 , wherein the pressure sensor coupled to the device comprises a static pressure sensor.
20. A blockage detector for identifying a blockage in a pitot-static system, comprising:
a pressure sensor; and
a circuit that:
receives a pressure signal from the pressure sensor;
identifies pressure fluctuations in the pressure signal;
isolates a frequency from the identified pressure fluctuations via a notch filter configured to pass signals in a frequency range that includes in-flight longitudinal vibration frequencies that are made up of main rotor frequencies; and
determines whether a blockage has occurred in the pitot-static system based on the identified pressure fluctuations.