Method for maximizing powered aircraft drive wheel traction

Patent metadata

Field	Value
Publication number	US-9725161-B2
Application number	US-201414341746-A
Country	US
Kind code	B2
Filing date	Jul 25, 2014
Priority date	Dec 10, 2013
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

A method for maximizing traction in an aircraft drive wheel powered by non-engine drive means controllable to move the aircraft on the ground without reliance on the aircraft's brakes and dependence on friction defined by a mu-slip curve. The non-engine drive means is operated to control wheel speed and maintain the powered drive wheel in a maximized optimal traction condition when driving torques are applied to the drive wheel. Traction can be automatically maximized and maintained within an optimal range defined by a relationship between slippage and braking for maximum efficiency of aircraft ground travel under a wide variety of surface, weather, temperature, tire, and other conditions.

First claim

The invention claimed is:

1. An improved method for controlling and optimizing traction during ground travel under a plurality of ground travel conditions in aircraft driven autonomously without reliance on aircraft engines and brakes, comprising:
a. mounting non-engine drive means controllable to power and direct torque through an aircraft drive wheel and move the aircraft during ground travel within one or more landing gear drive wheels and tires on the landing gear drive wheels in contact with an aircraft ground travel surface;
b. as the aircraft is driven on the ground travel surface under one or more of the plurality of ground travel conditions by controlling the non-engine drive means to power and direct torque through the landing gear drive wheels, directly or indirectly obtaining speed and torque information comprising a ground speed of the aircraft, a speed or torque of the non-engine drive means-powered landing gear drive wheels, and a speed of one or more components that rotate with a speed proportional to aircraft speed;
c. processing the obtained speed and torque information and controlling the non-engine drive means in response to processed speed and torque information indicating slipping or skidding of one or more of the non-engine drive means-powered landing gear drive wheels to adjust drive torque directed to the slipping or skidding drive wheels as required, and maintaining speed of the one or more non-engine drive means-powered landing gear drive wheels in an optimal traction condition for the one or more of the plurality of ground travel conditions; and
d. maintaining said optimal traction condition during aircraft ground travel within an optimal traction range corresponding to at least an area near a peak on a mu-slip curve representing maximum traction efficiency for movement of a non-engine drive means-powered landing gear drive wheel on the ground travel surface.

2. The method of claim 1 , further comprising mounting non-engine drive means comprising electric drive motors within each aircraft nose landing gear drive wheel, powering and controlling the electric drive motors to direct drive torque to the nose landing gear drive wheels, and driving the aircraft on the ground travel surface at a speed that maintains the optimal traction conditions between tires mounted on the nose landing gear drive wheels and the ground travel surface under the plurality of ground travel conditions.

3. The method of claim 1 , further comprising mounting the non-engine drive means within each of both wheels in an aircraft nose landing gear and individually maintaining traction of each of said driven nose landing gear wheels within an optimal traction range in response to the processed speed and torque information.

4. The method of claim 1 , further comprising controlling traction automatically in response to the processed speed and torque information indicating slipping or skidding and existing runway or aircraft ground surface travel conditions as the aircraft is driven by the non-engine drive means and maintaining the speed of the one or more non-engines drive means-powered landing gear drive wheels within an optimal traction range for said ground surface travel conditions.

5. The method of claim 1 , further comprising controlling speed of said one or more non-engine drive means-powered landing gear drive wheels and preventing an overspeed condition when drive torque is directed to said one or more slipping or skidding landing gear drive wheels.

6. The method of claim 1 , further comprising measuring speed of said non-engine drive means-powered landing gear drive wheels to determine slip, and automatically adjusting the drive torque directed to said non-engine drive means-powered landing gear drive wheels to maintain traction of the tires on contact with the aircraft ground travel surface within an optimal traction range for a prevailing one of the plurality of ground travel conditions.

7. The method of claim 1 , further comprising automatically reducing drive torque to the slipping or skidding drive wheels when said tires mounted on the one or more non-engine drive means-powered landing gear drive wheels experiences slip in excess of a predetermined desired amount.

8. The method of claim 1 , further comprising, when the non-engine drive means comprises an electric motor and reduced power draw on the electric motor is detected, automatically reducing drive torque directed to said one or more slipping or skidding landing gear drive wheels.

9. The method of claim 1 , further comprising automatically increasing driving torque to said one or more non-engine drive means-powered landing gear drive wheels when increased traction between the tires mounted on one or more of said non-engine drive means-powered landing gear drive wheels and the aircraft ground travel surface is detected.

10. The method of claim 3 , further comprising determining or measuring aircraft ground travel speed, measuring speed or torque for each of the non-engine drive means-powered nose landing gear drive wheels, comparing and analyzing aircraft speed and speed or torque of each said nose landing gear drive wheels, and automatically adjusting the speed or torque of each of the nose landing gear drive wheels to maintain the optimal traction condition for the determined or measured aircraft ground travel speed.

Assignees

• Cox Isaiah W
• Borealis Tech Ltd

Inventors

• Cox Isaiah W

Classifications

• B64C25/405 Primary

  Powered wheels, e.g. for taxing · CPC title

• Y02T50/823

  Cross-Sectional Technologies · mapped topic

• Y02T50/80

  Energy efficient operational measures, e.g. ground operations or mission management · CPC title