Traction control method and apparatus for a work vehicle with independent drives

Patent metadata

Field	Value
Publication number	US-2015246612-A1
Application number	US-201514616209-A
Country	US
Kind code	A1
Filing date	Feb 6, 2015
Priority date	Mar 3, 2014
Publication date	Sep 3, 2015
Grant date	—

Abstract

A method and apparatus for controlling traction of a vehicle with independent drives or motors connected to the wheels or other ground engaging apparatuses. Nominal torque allocations can be determined for a set of motors, the motors connected to ground engaging elements and including a front set of motors and a rear set of motors. The nominal torque allocations can be modified based on a lateral differential correction and a fore-aft differential correction to produce modified torque commands and the modified torque commands can be applied to the set of motors.

First claim

What is claimed is:

1 . A work vehicle comprising:
a front-left wheel; a front-left motor mechanically coupled to the front-left wheel to provide torque to the front-left wheel; a front-right wheel; a front-right motor mechanically coupled to the front-right wheel to provide torque to the front-right wheel; a rear-left wheel; a rear-left motor mechanically coupled to the rear-left wheel to provide torque to the rear-left wheel; a rear-right wheel; a rear-right motor mechanically coupled to the rear-right wheel to provide torque to the rear-right wheel; and a fraction controller electrically connected to the front-left motor, the front-right motor, the rear-left motor, and the rear-right motor, the traction controller configured to determine and apply an individual torque command to each of the front-left, front-right, rear-left, and rear-right motors,
the individual torque command for the front-left motor based on at least in part a commanded torque, a front lateral differential correction, and a fore aft differential correction,
the individual torque command for the front-right motor based on at least in part the commanded torque, the front lateral differential correction, and the fore aft differential correction,
the individual torque command for the rear-left motor based on at least in part the commanded torque, a rear lateral differential correction, and the fore aft differential correction, and
the individual torque command for the rear-right motor based on at least in part the commanded torque, the rear lateral differential correction, and the fore aft differential correction.

2 . The work vehicle of claim 1 , wherein the fraction controller is configured to determine a fore-aft differential speed; and
wherein the fore-aft differential correction comprises a fore-aft integral term and a fore-aft proportional term, the fore-aft integral term based on at least in part the fore-aft differential speed and the fore-aft proportional term based on at least in part the fore-aft differential speed.

3 . The work vehicle of claim 2 , wherein the traction controller is configured to determine a front lateral differential speed and to determine a rear lateral differential speed;
wherein the front lateral differential correction comprises a front lateral proportional term based on at least in part the front lateral differential speed; and wherein the rear lateral differential correction comprises a rear lateral proportional term based on at least in part the rear lateral differential speed.

4 . The work vehicle of claim 3 , wherein the individual torque command for the front-left motor equals a front-left motor nominal torque command plus the front lateral differential correction plus the fore-aft differential correction;
wherein the individual torque command for the front-right motor equals a front-right motor nominal torque command minus the front lateral differential correction plus the fore-aft differential correction; wherein the individual torque command for the rear-left motor equals a rear-left motor nominal torque command plus the rear lateral differential correction minus the fore-aft differential correction; and wherein the individual torque command for the rear-right motor equals a rear-right motor nominal torque command minus the rear lateral differential correction minus the fore-aft differential correction.

5 . The work vehicle of claim 4 , wherein the front-left motor nominal torque command equals the front-right motor nominal torque command; and
wherein the rear-left motor nominal torque command equals the rear-right motor nominal torque command.

6 . The work vehicle of claim 4 , wherein the fore-aft integral term can be unwound.

7 . The work vehicle of claim 4 , wherein the fore-aft integral term is a deadband integral term and the fore-aft proportional term is a deadband proportional term.

8 . The work vehicle of claim 7 , wherein the fore-aft deadband integral term can be unwound.

9 . A work vehicle comprising:
a pair of ground engaging front elements, the ground engaging front elements mechanically driven by at least one front motor; a pair of ground engaging rear elements, the ground engaging rear elements mechanically drive by at least one rear motor; a traction controller configured to determine and apply torque commands to the at least one front motor and the at least one rear motor, the fraction controller correcting the torque commands based on at least in part a fore-aft speed error, a front lateral speed error, and a rear lateral speed error.

10 . A method of controlling a work vehicle, the method comprising:
determining nominal torque allocations to a set of motors, the motors connected to ground engaging elements and including a front set of motors and a rear set of motors; modifying the nominal torque allocations based on a lateral differential correction and a fore-aft differential correction to produce modified torque commands; and applying the modified torque commands to the set of motors.

11 . The method of claim 10 , further comprising determining a fore-aft differential speed;
wherein the fore-aft differential correction comprises a fore-aft integral term and a fore-aft proportional term, the fore-aft integral term based on at least in part the fore-aft differential speed and the fore-aft proportional term based on at least in part the fore-aft differential speed.

12 . The method of claim 11 , further comprising determining a front lateral differential speed and determining a rear lateral differential speed;
wherein the front lateral differential correction comprises a front lateral proportional term based on at least in part the front lateral differential speed; and wherein the rear lateral differential correction comprises a rear lateral proportional term based on at least in part the rear lateral differential speed.

13 . The method of claim 12 , wherein each pair of motors includes a right and a left motor, the modified torque allocation for the front-left motor equals a front-left motor nominal torque command plus the front lateral differential correction plus the fore-aft differential correction;
wherein modified torque command for the front-right motor equals a front-right motor nominal torque command minus the front lateral differential correction plus the fore-aft differential correction; wherein the modified torque command for the rear-left motor equals a rear-left motor nominal torque command plus the rear lateral differential correction minus the fore-aft differential correction; and wherein the modified torque command for the rear-right motor equals a rear-right motor nominal torque command minus the rear lateral differential correction minus the fore-aft differential correction.

14 . The method of claim 13 , wherein the front-left motor nominal torque command equals the front-right motor nominal torque command; and
wherein the rear-left motor nominal torque command equals the rear-right motor nominal torque command.

15 . The method of claim 13 , wherein the fore-aft integral term can be unwound.

16 . The method of claim 13 , wherein the fore-aft integran term is a deadband integral term and the fore-aft proportional term is a deadband proportional term.

17 . The method of claim 16 , wherein the fore-aft deadband integral term can be unwound.

Assignees

• Deere & Co

Inventors

• Velde Todd F
• Anderson Eric R

Classifications

• Y02T10/70

  Energy storage systems for electromobility, e.g. batteries · CPC title

• E02F9/207

  of the type electric propulsion units, e.g. electric motors or generators · CPC title

• B60W2720/403

  between front and rear axle · CPC title

• B60Y2200/415

  Wheel loaders · CPC title

• B60L2200/40

  Working vehicles · CPC title