Helicopter rotor icing detection system and method

Patent metadata

Field	Value
Publication number	US-9957053-B2
Application number	US-201414465448-A
Country	US
Kind code	B2
Filing date	Aug 21, 2014
Priority date	Aug 21, 2014
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

A system includes a signal monitor to monitor a time rate of change of a revolutions per minute (RPM) trim signal that is received from an RPM command path to control a velocity of a helicopter rotor. An icing detector detects for the presence of ice accumulation on the helicopter rotor by comparing the time rate of change of the RPM trim signal to a predetermined threshold for the time rate of change.

First claim

What is claimed is:

1. A system comprising:
a signal monitor to monitor a time rate of change of a revolutions per minute (RPM) trim signal that is received from an RPM command path to control a velocity of a helicopter rotor; and
an icing detector to detect for the presence of ice accumulation on the helicopter rotor by comparing the time rate of change of the RPM trim signal to a predetermined threshold for the time rate of change.

2. The system of claim 1 , further comprising a collective pitch command path having a collective pitch output that is summed with an RPM output from the RPM command path to generate a fuel control command to control engine speed of a helicopter engine.

3. The system of claim 2 , the collective pitch command path further comprising a first gain component having a first gain to scale a collective pitch command applied to the collective pitch command path.

4. The system of claim 1 , the RPM command path further comprising an error node to generate an error signal based on an RPM command fed to the RPM command path and a feedback signal representing engine speed of a helicopter engine, the RPM command and the feedback signal subtracted at the error node to generate the error signal.

5. The system of claim 4 , further comprising a second gain component having a second gain to scale the RPM command into an output signal.

6. The system of claim 5 , further comprising an integrator to integrate the output signal into an integrated output signal to supply the RPM trim signal.

7. The system of claim 6 , wherein the output signal or the integrated output signal are employed to determine the time rate of change for the RPM trim signal.

8. The system of claim 6 , further comprising a filter that includes a band pass or washout function to determine the time rate of change for the RPM trim signal.

9. The system of claim 6 , further comprising a differencing component to perform differencing of successive discrete samples of the integrated output signal to determine the time rate of change for the RPM trim signal.

10. The system of claim 1 , further comprising an unmanned aerial vehicle (UAV) controller to control flight operations of a UAV, wherein the UAV controller initiates corrective actions to mitigate ice accumulation for the UAV upon notification of icing by the icing detector.

11. A method comprising:
monitoring, by a controller, a revolutions per minute (RPM) trim signal that is received from an RPM command path to control a velocity of a helicopter rotor;
determining a time rate of change for the RPM trim signal;
comparing the time rate of change of the RPM trim signal to a predetermined threshold setting for the time rate of change; and
detecting ice accumulation on the helicopter rotor if the time rate of change for the RPM trim signal exceeds a predetermined threshold for the time rate of change.

12. The method of claim 11 , further comprising initiating corrective action to mitigate ice accumulation for a helicopter upon detecting the ice accumulation on the helicopter rotor.

Assignees

• Almond Jonathan D
• Northrop Grumman Systems Corp

Inventors

• Almond Jonathan D

Classifications

• B64U2201/10

  autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS] · CPC title

• G05D1/0816

  to ensure stability · CPC title

• B64C2201/024

  Operations & Transport · mapped topic

• B64C39/024

  of the remote controlled vehicle type, i.e. RPV · CPC title

• B64C2201/141

  Operations & Transport · mapped topic