Estimation of gross weight and center-of-gravity

Patent metadata

Field	Value
Publication number	US-10267669-B2
Application number	US-201414225659-A
Country	US
Kind code	B2
Filing date	Mar 26, 2014
Priority date	Mar 26, 2014
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

Embodiments are directed to obtaining data from at least one sensor, the data pertaining to rotor loads and motion, processing, by a device comprising a processor, the data to obtain an estimate of at least one of gross weight (GW) and center of gravity (CG) for a rotorcraft, and outputting the estimate.

First claim

What is claimed is:

1. A method comprising:
obtaining data from at least one sensor disposed in a rotor blade of a rotorcraft at a plurality of rotor azimuth positions for a revolution of the rotor blade, the data pertaining to rotor loads and motion on the rotor blade;
processing, by a device comprising a processor, the data to obtain an estimate of at least one of gross weight (GW) and center of gravity (CG) for the rotorcraft, wherein processing the data comprises:
concatenating rotor loads and motion waveforms from the plurality of rotor azimuth positions over one rotor revolution to obtain a vector,
multiplying the vector by a low rank matrix to reduce a rank of the vector; and
relating the reduced vector to a vector representing a state of the rotorcraft to obtain the estimate;

determining a linear relation between the state of the rotorcraft and a perturbation in the rotor blade; and
controlling an aircraft state variable based on the determined linear relation between the state of the rotorcraft and rotor blade perturbations in order to control a rotor blade perturbation.

2. The method of claim 1 , wherein the processing is performed to obtain an estimate of both GW and CG for the rotorcraft.

3. The method of claim 1 , wherein the data is based on multiple rotor revolutions.

4. The method of claim 1 , wherein the estimate is based on an application of a matrix completion technique to reconstruct missing data.

5. The method of claim 1 , wherein a principal component analysis technique is applied to analyze and estimate rotor loads and motion in obtaining the estimate.

6. The method of claim 1 , wherein a principal component pursuit technique is applied to analyze and estimate rotor loads and motion in obtaining the estimate.

7. The method of claim 1 , wherein a nuclear-norm regularized multivariate linear regression technique is applied to analyze and estimate rotor loads and motion in obtaining the estimate.

8. An apparatus comprising:
at least one processor; and
memory having instructions stored thereon that, when executed by the at least one processor, cause the apparatus to:
obtain data from at least one sensor disposed in a rotor blade of a rotorcraft at a plurality of rotor azimuth positions for a revolution of the rotor blade, the data pertaining to rotor loads and motion on the rotor blade;
process the data to obtain an estimate of at least one of gross weight (GW) and center of gravity (CG) for the rotorcraft wherein processing the data comprises:
concatenate rotor loads and motion waveforms from the plurality of rotor azimuth positions over one rotor revolution to obtain a vector,
multiply the vector by a low rank matrix to reduce a rank of the vector; and
relate the reduced vector to a vector representing a state of the rotorcraft to obtain the estimate;
determine a linear relation between the state rotorcraft and a perturbation in the rotor blade; and
control an aircraft state variable based on the determined linear relation between the state of the rotorcraft and rotor blade perturbations in order to control a rotor blade perturbation.

9. The apparatus of claim 8 , wherein the instructions, when executed by the at least one processor, cause the apparatus to:
process the data to obtain an estimate of both GW and CG for the rotorcraft.

10. The apparatus of claim 8 , wherein the data is based on multiple rotor revolutions.

11. The apparatus of claim 8 , wherein the estimate is based on an application of a numerical technique to analyze and estimate rotor loads and motion.

12. A rotorcraft comprising:
a plurality of sensors disposed in a rotor blade of the rotorcraft configured to obtain data pertaining to rotor loads and motion on the rotor blade;
an analysis unit configured to:
receive the data from the plurality of sensors, wherein the data is obtained at a plurality of rotor azimuth positions for a revolution of the rotor blade;
process the data to obtain an estimate of gross weight (GW) and center of gravity (CG) for the rotorcraft, wherein processing the data comprises:
concatenating rotor loads and motion waveforms from the plurality of rotor azimuth positions over one rotor revolution to obtain a vector,
multiplying the vector by a low rank matrix to reduce a rank of the vector; and
relating the reduced vector to a vector representing a state of the rotorcraft to obtain the estimate;

determining a linear relation between the state of the rotorcraft and a perturbation in the rotor blade; and
control an aircraft state variable based on the determined linear relation between the state of the rotorcraft and rotor blade perturbations in order to control a rotor blade perturbation.

13. The rotorcraft of claim 12 , wherein the analysis unit is configured to receive the data wirelessly.

14. The rotorcraft of claim 12 , wherein the analysis unit is configured to detect and isolate faults based on a processing of the data.

15. The rotorcraft of claim 14 , wherein the faults comprise faults associated with the sensors.

16. The rotorcraft of claim 14 , wherein the faults comprise faults associated with a rotor system structure.

17. The rotorcraft of claim 12 , wherein the analysis unit is configured to process the data based on coefficients for perturbation modes to reconstruct the rotor loads and motion.

Assignees

• Sikorsky Aircraft Corp

Inventors

• Isom Joshua D
• Fang Austin
• Wong Jonathan K

Classifications

• G01G19/07 Primary

  for weighing aircraft · CPC title

• G01M1/127

  during the flight · CPC title

• G01M1/28

  with special adaptations for determining imbalance of the body in situ, e.g. of vehicle wheels · CPC title

• G05D1/0858

  specially adapted for vertical take-off of aircraft · CPC title

• G01G19/086

  wherein the vehicle mass is dynamically estimated · CPC title