Automatic adjustment of center of mass of a vehicle

Patent metadata

Field	Value
Publication number	US-10669015-B2
Application number	US-201715616762-A
Country	US
Kind code	B2
Filing date	Jun 7, 2017
Priority date	Jun 7, 2017
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

A method, vehicle, and system for calculating the location of a center of mass of the vehicle and transferring fuel to move the location of the center of mass are provided. The location of the center of mass of the vehicle is determined by measuring or calculating forces acting on the vehicle that counteract the gravitational forces on the vehicle. The location of the center of mass is calculated by determining on a moment arm of the gravitational force that counteracts the moment arms of the other forces acting on the vehicle. Fuel can be transferred among differently-located fuel tanks in the vehicle to move the location of the center of mass to a position in which at least some of the other forces acting on the vehicle are reduced, which may increase the speed and/or efficiency of the vehicle.

First claim

What is claimed is:

1. A method for calculating a center of mass of an aircraft during flight, the method comprising:
receiving a plurality of sensor signals indicating positions of a plurality of control surfaces on a plurality of aerodynamic bodies of the aircraft;
calculating, based on the indicated positions, a plurality of aerodynamic forces of the plurality of aerodynamic bodies;
determining locations, relative to the aircraft, of centers of pressure of the plurality of aerodynamic forces;
receiving a current total mass of the aircraft; and
calculating a location of the center of mass of the aircraft, based on the plurality of aerodynamic forces, the determined locations of the centers of pressure, and the received current total mass.

2. The method of claim 1 , wherein receiving a current total mass of the aircraft comprises calculating the current total mass of the aircraft.

3. The method of claim 1 , further comprising transferring fuel from a first fuel tank of the aircraft to at least a second fuel tank of the aircraft to move the location of the center of mass from the calculated location toward a location of an aft center of mass limit.

4. The method of claim 3 , further comprising:
determining masses of fuel in respective fuel tanks of the aircraft;
calculating a remainder mass based on the received current total mass of the aircraft and the determined fuel masses in the fuel tanks of the aircraft, wherein the remainder mass comprises the mass of the aircraft when empty, any passengers onboard, and any cargo onboard;
calculating a location of a center of mass for the remainder mass, based on current total mass, the calculated location of the center of mass of the aircraft, the fuel masses of the fuel tanks, and respective locations of centers of mass of fuel in the fuel tanks; and
calculating an amount of fuel to transfer from the first fuel tank to the second fuel tank based on the location of the aft center of mass limit, the calculated remainder mass, and the calculated location of the center of mass for the remainder mass,
wherein transferring fuel from the first fuel tank to the second fuel tank comprises transferring the calculated amount of fuel from the first fuel tank to the second fuel tank.

5. The method of claim 4 , wherein respective locations of centers of mass of fuel in the fuel tanks depend on fuel masses in the respective fuel tanks, and further comprising:
calculating the respective locations of the centers of mass of the fuel tanks based on determined fuel masses in the respective fuel tanks.

6. The method of claim 4 , wherein respective locations of centers of mass of fuel in the fuel tanks depend on at least one of a pitch attitude and roll attitude of the aircraft, and further comprising:
calculating the respective locations of the centers of mass of the fuel tanks based on at least one of a determined pitch attitude and roll attitude of the aircraft.

7. The method of claim 1 , wherein determining locations relative to the aircraft of centers of the plurality of aerodynamic forces comprises:
calculating centers of pressure for the respective aerodynamic bodies, based on at least one of airspeed, angle of attack, and the indicated positions of the control surfaces.

8. An aircraft, comprising:
a fuselage that includes a center fuel tank;
a left wing extending from the fuselage, the left wing comprising a left fuel tank and a left aileron;
a right wing extending from the fuselage, the right wing comprising a right fuel tank and a right aileron;
a left elevator;
a right elevator; and
a controller operable to:
receive a plurality of sensor signals indicating positions of the left aileron, the right aileron, a control surface of the left elevator, and a control surface of the right elevator;
calculate aerodynamic forces of the left wing, the right wing, the left elevator, and the right elevator based on the indicated positions;
determine locations, relative to the aircraft, of centers of pressure of the calculated aerodynamic forces;
receive a current total mass of the aircraft; and
calculate a location of a center of mass of the aircraft, based on the calculated aerodynamic forces, the determined locations of the centers of pressure, and the received current total mass of the aircraft.

9. The aircraft of claim 8 , wherein the controller is operable to calculate the current total mass of the aircraft.

10. The aircraft of claim 8 , further comprising a fuel transfer system in communication with the controller, wherein the fuel transfer system is operable to selectively transfer fuel from a first one or more of the left fuel tank, right fuel tank, and center fuel tank to a second one or more of the left fuel tank, right fuel tank, and center fuel tank, and wherein the controller directs the fuel transfer system to transfer fuel from a first one or more of the left fuel tank, right fuel tank, and center fuel tank to a second one or more of the left fuel tank, right fuel tank, and center fuel tank to move the location of the center of mass from the calculated location toward a location of an aft center of mass limit.

11. The aircraft of claim 10 wherein the controller directs the fuel transfer system to transfer fuel from the left fuel tank and from the right fuel tank to the center fuel tank to move the location of the center of mass toward a location of an aft center of mass limit.

12. The aircraft of claim 10 , wherein the controller is further operable to:
determine respective masses of fuel in the left fuel tank, right fuel tank, and center fuel tank;
calculate a remainder mass based on the received current total mass of the aircraft and the determined fuel masses in the fuel tanks of the aircraft, wherein the remainder mass comprises the mass of the aircraft when empty, any passengers onboard, and any cargo onboard;
calculate a location of a center of mass for the remainder mass, based on current total mass, the calculated location of the center of mass of the aircraft, the fuel masses of the fuel tanks, and respective locations of centers of mass of fuel in the fuel tanks; and
calculate an amount of fuel to transfer from the first fuel tank to the second fuel tank based on the location of the aft center of mass limit, the calculated remainder mass, and the calculated location of the center of mass for the remainder mass,
wherein the controller directs the fuel transfer system to transfer the calculated amount of fuel from a first one or more of the left fuel tank, right fuel tank, and center fuel tank to a second one or more of the left fuel tank, right fuel tank, and center fuel tank.

13. The aircraft of claim 12 , wherein respective locations of centers of mass of fuel in at least one of the left fuel tank, right fuel tank, and center fuel tank depend on fuel masses in the respective fuel tanks, and wherein the controller is further operable to:
calculate the respective locations of the centers of mass of the left fuel tank, right fuel tank, and center fuel tank based on determined fuel masses in the respective fuel tanks.

14. The aircraft of claim 12 , wherein respective locations of centers of mass of fuel in at least one of the left fuel tank, right fuel tank, and center fuel tank depend on at least one of a pitch attitude and roll attitude of the aircraft, and wherein the controller is further operable to:
calculate the respective locations of the centers of mass of the left fuel tank, right fuel tank, and center fuel tank based on at least one of a determined pitch attitude and roll attitude of the aircraft.

15. The aircraft of claim 8

Assignees

• Boeing Co

Inventors

• Kneuper Nils
• Cabos Ralf Rene Shu-Zhong

Classifications

• G01M1/127

  during the flight · CPC title

• B64C17/10 Primary

  Transferring fuel to adjust trim · CPC title

• B64C9/00

  Adjustable control surfaces or members, e.g. rudders (trimming stabilising surfaces B64C5/10) · CPC title

• B64D37/02

  Tanks (tanks constructed integrally with aircraft wings B64C3/34) · CPC title

• B64C3/00 Primary

  Wings (ornithopter wings B64C33/02) · CPC title