Steering a differential steering machine while commanded to be in neutral

Patent metadata

Field	Value
Publication number	US-11148714-B2
Application number	US-201916266456-A
Country	US
Kind code	B2
Filing date	Feb 4, 2019
Priority date	Feb 4, 2019
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

A method for steering a machine while commanded to be in neutral, including: sensing that a transmission is in a neutral setting; applying one or more service brakes into a braking mode; ramping off a steering pump on a hydraulic steering system; sensing a steering command; releasing the one or more service brakes from the braking mode in response to sensing the steering command; and ramping on the steering pump on the hydraulic steering system.

First claim

What is claimed is:

1. A method for steering a machine while commanded to be in neutral, comprising:
sensing that a transmission has been commanded to be in a neutral setting;
applying one or more service brakes into a braking mode;
ramping off a steering pump on a hydraulic steering system;
sensing a steering command;
releasing the one or more service brakes from the braking mode in response to sensing the steering command; and
ramping on the steering pump on the hydraulic steering system.

2. The method of claim 1 , where the machine is in motion and the braking mode slows the machine.

3. The method of claim 1 , where the step of ramping off the steering pump on the hydraulic steering system is performed after a transmission output is determined to be below a threshold value.

4. The method of claim 1 , where the step of ramping off the steering pump on the hydraulic steering system renders the hydraulic steering system unable to steer the machine, and the step of ramping on the steering pump on the hydraulic steering system allows the hydraulic steering system to steer the machine.

5. The method of claim 1 , where the method further comprises a step of determining that a transmission output speed is zero and prohibiting the transmission output shaft from rotating using one or more transmission clutches.

6. The method of claim 5 , where there is a waiting period of about 0.1 seconds to about 0.5 seconds between the step of determining that a transmission output speed is zero and prohibiting the transmission output shaft from rotating.

7. The method of claim 1 , where the steering command requires an input from a steering interface exceeds a threshold value, and the threshold value is variable based upon a grade angle of the ground on which machine is positioned.

8. The method of claim 1 , where the machine includes at least two ground engaging traction devices selected from belts, tracks, and wheels.

9. The method of claim 1 , where the step of applying one or more service brakes into a braking mode further comprises determining the absence of a steering command.

Assignees

• Caterpillar Inc

Inventors

• Anderson Randall T
• Miller Benjamin D
• Sheley Luke R
• Berry Michael Anthony

Classifications

• B62D5/04

  electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear · CPC title

• B60W30/18109

  Braking · CPC title

• B62D11/08 Primary

  using brakes or clutches as main steering-effecting means · CPC title

• B62D11/183

  Control systems therefor · CPC title

• B62D11/02 Primary

  by differentially driving ground-engaging elements on opposite vehicle sides · CPC title