Vehicle for towing an airplane

• US 8,640,804 B2
• Filed: 06/09/2011
• Issued: 02/04/2014
• Est. Priority Date: 06/09/2010
• Status: Active Grant

• Current Assignee: Israel Aerospace Industries Limited (Government of Israel)
• Original Assignee: Israel Aerospace Industries Limited (Government of Israel)
• Inventors: Levy, Raphael E., Braier, Ran, Perry, Arie
• Primary Examiner(s): Walters, John
• Assistant Examiner(s): TRIGGS, JAMES J
• Application Number:
  US13/702,515
• Publication Number:
  US 20130081890A1
• Time in Patent Office: 971 Days
• Field of Search: 180/167, 180/204, 244/50, 244/51, 244/53.R, 244/58, 244/54, 244/70, 414426-427
• US Class Current: 180/204
• CPC Class Codes: B62D 1/283 for unmanned vehicles
• CPC Class Codes: B64F 1/002 Taxiing aids
• CPC Class Codes: B64F 1/22 for handling aircraft
• CPC Class Codes: B64F 1/227 for direct connection to aircraft, e.g. tow tractors without towing bars
• CPC Class Codes: B64F 1/228 remotely controlled; operating autonomously
• CPC Class Codes: Y02T 50/80 Energy efficient operational measures, e.g. ground operations or mission management

Abstract

A vehicle for towing an airplane by receiving thereupon a nose landing gear of the airplane having an airplane longitudinal axis. The vehicle having a vehicle longitudinal axis and is configured to tow the airplane along a straight or curved path and comprises a controller for directing its operation, including maintaining the vehicle'"'"'s in-phase position in which the vehicle longitudinal axis is parallel to the airplane longitudinal axis.

Claims

1. A vehicle for towing an airplane by receiving thereupon a nose landing gear of the airplane having an airplane longitudinal axis, said nose landing gear of the airplane having at least one front airplane wheel with a first axis of rotation, said airplane having main landing gear wheels with a common second axis of rotation such that, the first and the second axes of rotation intersect in a common airplane pivot point about which the airplane is to turn, said vehicle having a vehicle longitudinal axis and being configured to tow said airplane along a substantially straight or curved path, said vehicle comprising:

a controller for directing operation of the vehicle, including maintaining the vehicle'"'"'s in-phase position in which said vehicle longitudinal axis is substantially parallel to said airplane longitudinal axis;

a plurality of vehicle wheels, each having a vehicle wheel axis of rotation; and

wherein the controller is configured to calculate the location of the pivot point of the airplane according to a steering angle between the first and the second axes of rotation, and to control each vehicle wheel to be turned at its Ackerman angle, which is calculated by the controller according to the steering angle, with respect to the second axis of rotation such that all vehicle wheel axes intersect at the pivot point, whereby said in-phase position is maintained.

2. The vehicle according to claim 1, wherein said airplane is configured for turning about an airplane pivot point which lies on an axis of its main landing gear wheels;

and wherein said vehicle comprises a plurality of wheels each configured for rolling about an axis of rotation, said controller being configured to direct all wheels, during turning of the vehicle, to maintain their axes of rotation so as to intersect at said airplane pivot point.

3. The vehicle according to claim 2, wherein the airplane is configured to receive from an operator thereof a steering command resulting in turning at least one front airplane wheel of the nose landing gear relative to the airplane longitudinal axis, and wherein said controller is configured to receive a first signal indicative of indicative of an angle to which said at least one front airplane wheel is turned relative to said airplane longitudinal axis, for calculating the location of the airplane pivot point, and a second signal indicative of an angle between the vehicle and the airplane longitudinal axes, and said controller is configured to direct operation of the vehicle so as to turn the vehicle about the airplane pivot point, thereby causing said vehicle be in the in-phase position with the airplane.

4. The vehicle according to claim 1, wherein said controller is configured to receive a signal indicative of an out-phase position of the vehicle relative to the airplane, in which there is deviation from the substantially parallel disposition of the vehicle longitudinal axis with respect to the airplane longitudinal axis, and to correct, in response to said signal, the deviation by turning at least part of the vehicle wheels so as to return the vehicle to said in-phase position.

5. The vehicle according to claim 4, wherein the controller is configured to operate all the vehicle wheels such that their wheel axes intersect at an intermediate point that is different from the pivot point, and, only when said deviation disappears, and to turn all the vehicle wheels to their Ackerman angles for maintaining the in-phase position of the vehicle.

6. The vehicle according to claim 5, wherein when the deviation from the substantially parallel disposition of the vehicle longitudinal axis relative to the airplane longitudinal axis is such that the vehicle longitudinal axis is diverted towards the pivot point, the intermediate point being located farther from the airplane longitudinal axis than the pivot point.

7. The vehicle according to claim 5, wherein when the deviation from the substantially parallel disposition of the vehicle longitudinal axis relative to the airplane longitudinal axis is such that the vehicle longitudinal axis is diverted away from the pivot point, the intermediate point is located closer to the airplane longitudinal axis than the pivot point.

8. The vehicle according to claim 5, wherein said vehicle wheels comprise front and rear wheels, and the controller is configured to operate the front wheels to be turned in one direction from their Ackerman angle, and to operate the rear wheels to be turned in another, opposite direction from their Ackerman angle, to yaw the vehicle until brought to the in-phase position with the airplane.

9. The vehicle according to claim 5, wherein when the deviation from the substantially parallel disposition of the vehicle longitudinal axis relative to the airplane longitudinal axis is such that the vehicle longitudinal axis is diverted away from the pivot point, the controller is configured to correct the deviation by turning the front wheels towards the airplane longitudinal axis, and by turning the rear wheels away from the airplane longitudinal axis.

10. The vehicle according to claim 9, wherein the turning of the front wheels towards the airplane longitudinal axis is provided such that the angle between the axis of each front wheel and the second axis of rotation is a sum of the Ackerman angle of each wheel and a correction angle;

and wherein the turning of the rear wheels away from the airplane longitudinal axis is provided such that the angle between the axis of each rear wheel and the second axis of rotation is a subtraction of a correction angle which is multiplied by a wheel base ration λ

from the Ackerman angle of each wheel, when λ

is associated with the location of the nose landing gear on the vehicle and the distance of the vehicle wheels therefrom.

11. The vehicle according to claim 5, wherein when the deviation from the substantially parallel disposition of the vehicle longitudinal axis relative to that of the airplane is such that the vehicle longitudinal axis is diverted towards the pivot point, the controller is configured to correct the deviation by turning the front wheels away from the airplane longitudinal axis, and by turning the rear wheels towards the airplane longitudinal axis.

12. The vehicle according to claim 11, wherein the turning of the front wheels away from the airplane longitudinal axis is provided such that the angle between the axis of each front wheel and the second axis of rotation is a subtraction of a correction angle from the Ackerman angle of each wheel;

and wherein the turning of the rear wheels towards the airplane longitudinal axis is provided such that the angle between the axis of each rear wheel and the second axis of rotation is a sum of the Ackerman angle of each wheel and a correction angle which is multiplied by a wheel base ration λ

that is associated with the location of the nose landing gear on the vehicle.

20. A system including an airplane having a longitudinal axis and a vehicle according to claim 1 for towing the airplane.

13. A method for directing operation of a vehicle configured to tow an airplane by receiving thereupon a nose landing gear of the airplane having an airplane longitudinal axis, said nose landing gear of the airplane having at least one front airplane wheel with a first axis of rotation, said airplane having main landing gear wheels with a common second axis of rotation such that, the first and the second axes of rotation intersect in a common airplane pivot point about which the airplane is to turn, said vehicle having a vehicle longitudinal axis and being configured to tow said airplane along a substantially straight or curved path and comprising a controller, said vehicle comprises a plurality of vehicle wheels, each having a vehicle wheel axis of rotation, said method comprising:

directing the operation of the vehicle;

maintaining the vehicle'"'"'s in-phase position in which said vehicle longitudinal axis is substantially parallel to said airplane longitudinal axis; and

calculating, via said controller, the location of the pivot point of the airplane according to a steering angle between the first and the second axes of rotation, and controlling, each vehicle wheel to be turned at its Ackerman angle, which is calculated by the controller according to the steering angle, with respect to the second axis of rotation such that all vehicle wheel axes intersect at the pivot point, thereby maintaining said in-phase position of the vehicle.

14. The method according to claim 13, wherein said vehicle comprises a controller and a plurality of wheels each configured for rolling about an axis of rotation, said method further comprising:

turning the airplane about an airplane pivot point which lies on an axis of its main landing gear wheels;

turning the vehicle; and

directing, via said controller, all the wheels of the vehicle, during turning of the vehicle, to maintain their axes of rotation so as to intersect at said airplane pivot point.

15. The method according to claim 13, further comprising receiving, by said controller, a first signal indicative of an angle between at least one front airplane wheel of the nose landing gear and the airplane longitudinal axis, indicative of a steering command of the airplane for calculating the location of the airplane pivot point, and a second signal indicative of an angle between the vehicle and airplane longitudinal axes and directing, via said controller, the operation of the vehicle so as to turn about the airplane pivot point, thereby causing said vehicle be in the in-phase position with the airplane.

16. The method according to claim 15, further comprising receiving, by said controller, signal indicative of an out-phase position of the vehicle relative to the airplane, in which there is deviation from the substantially parallel disposition of the vehicle longitudinal axis with respect to the airplane longitudinal axis, and correcting, by said controller, in response to said signal, the deviation by turning at least part of the vehicle wheels so as to return the vehicle to said in-phase position.

17. The method according to claim 16, further comprising operating all the vehicle wheels to be turned such that their wheel axes intersect at an intermediate point which is different from the pivot point, and, only when said deviation disappears, turning all the vehicle wheels to their Ackerman angles for maintaining the in-phase position of the vehicle.

18. The method according to claim 17, wherein when the deviation from the substantially parallel disposition of the vehicle longitudinal axis relative to the airplane longitudinal axis is such that the vehicle longitudinal axis is diverted towards the pivot point, the intermediate point being located farther from the airplane longitudinal axis than the pivot point.

19. The method according to claim 17, wherein when the deviation from the substantially parallel disposition of the vehicle longitudinal axis relative to the airplane longitudinal axis is such that the vehicle longitudinal axis is diverted away from the pivot point, the intermediate point is located closer to the airplane longitudinal axis than the pivot point.