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

Patent metadata

Field	Value
Publication number	US-9956874-B2
Application number	US-201514616209-A
Country	US
Kind code	B2
Filing date	Feb 6, 2015
Priority date	Mar 3, 2014
Publication date	May 1, 2018
Grant date	May 1, 2018

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 traction 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 a front lateral differential correction, a rear lateral differential correction, and a fore-aft differential correction 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, the front lateral differential correction, and the 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,
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,
wherein the controller is configured to apply an individual torque command for the front-left motor equal to a front-left motor nominal torque command plus the front lateral differential correction plus the fore-aft differential correction;
wherein the controller is configured to apply an individual torque command for the front-right motor equal to a front-right motor nominal torque command minus the front lateral differential correction plus the fore-aft differential correction;
wherein the controller is configured to apply an individual torque command for the rear-left motor equal to a rear-left motor nominal torque command plus the rear lateral differential correction minus the fore-aft differential correction; and
wherein the controller is configured to apply an individual torque command for the rear-right motor equal to a rear-right motor nominal torque command minus the rear lateral differential correction minus the fore-aft differential correction.

2. The work vehicle of claim 1 , 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.

3. 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;
applying the modified torque commands to the set of motors;
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; and
determining a front lateral differential speed and determining a rear lateral differential speed, wherein a front lateral differential correction comprises a front lateral proportional term based on at least in part the front lateral differential speed, and wherein a rear lateral differential correction comprises a rear lateral proportional term based on at least in part the rear lateral differential speed.

4. The method of claim 3 , wherein each set 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.

5. The method 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 method 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.

Assignees

• Deere & Co

Inventors

• Velde Todd F
• Anderson Eric R

Classifications

• B60L2260/28

  Four wheel or all wheel drive · CPC title

• B60L2240/423

  Torque · CPC title

• B60W2300/17

  Construction vehicles, e.g. graders, excavators · CPC title

• B60L3/106

  for maintaining or recovering the adhesion of the drive wheels · CPC title

• E02F9/2253

  Controlling the travelling speed of vehicles, e.g. adjusting travelling speed according to implement loads, control of hydrostatic transmission · CPC title