Blade control device and blade control method

Patent metadata

Field	Value
Publication number	US-12031291-B2
Application number	US-201917044438-A
Country	US
Kind code	B2
Filing date	Jan 28, 2019
Priority date	May 31, 2018
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

A blade control method includes: acquiring a design surface indicating a target shape of an excavation object to be excavated by a blade supported by a vehicle body of a work vehicle, the design surface including a first surface present in front of the work vehicle and a second surface having a slope different from a slope of the first surface; acquiring an observed pitch angle indicating an inclination angle of the vehicle body in a longitudinal direction; and calculating a planned pitching angle indicating a deviation between the observed pitch angle and a design surface pitch angle indicating an inclination angle of the second surface in a state in which the vehicle body is positioned on the first surface and the blade is positioned above the second surface.

First claim

The invention claimed is:

1. A blade control device comprising:
a processor configured to perform the following:
acquiring a design surface indicating a target shape of an excavation object to be excavated by a blade supported by a vehicle body of a work vehicle, the design surface including a first surface present in front of the work vehicle and a second surface having a slope different from a slope of the first surface;
acquiring an observed pitch angle indicating an inclination angle of the vehicle body in a longitudinal direction;
in a state in which at least a part of the vehicle body is positioned on the first surface and the blade is positioned above the second surface, calculating a planned pitching angle indicating a deviation between the observed pitch angle and a design surface pitch angle indicating an inclination angle of the second surface;
correcting the observed pitch angle based on the planned pitching angle and calculating a corrected pitch angle of the vehicle body;
acquiring a target height of the blade, the target height being calculated based on the design surface;
correcting the target height based on the corrected pitch angle, and generating a corrected target height,
based on the corrected pitch angle, calculating a target cylinder speed of a hydraulic cylinder that adjusts a height of the blade,
calculating a corrected target height variation based on the corrected target height,
calculating a target cylinder speed correction value based on the planned pitching angle and the corrected target height variation, and
determining a correction gain for the corrected target height variation based on a correction table and the planned pitching angle,

wherein the correction table includes correlation data indicating a relationship between the planned pitching angle and the correction gain to be given to the corrected target height variation.

2. The blade control device according to claim 1 , further comprising the following steps performed by the processor:
searching for an inflection position indicating a boundary between the first surface and the second surface on the design surface; and
calculating the planned pitching angle based on the inflection position.

3. The blade control device according to claim 1 , further comprising the following steps performed by the processor:
acquiring a position of the vehicle body;
acquiring an operation amount of the hydraulic cylinder;
calculating the height of the blade based on the position of the vehicle body, the inclination angle of the vehicle body, and the operation amount of the hydraulic cylinder; and
calculating the target cylinder speed such that a deviation between a height of a cutting edge of the blade and the corrected target height becomes small.

4. The blade control device according to claim 3 , further comprising the following steps performed by the processor:
calculating the target cylinder speed based on the corrected target height;
adding the target cylinder speed and the target cylinder speed correction value to each other and calculates a corrected cylinder speed; and
outputting a control command to control the height of the blade based on the corrected cylinder speed.

5. The blade control device according to claim 1 ,
wherein an angle formed by the first surface and the second surface is larger than 180[°] on the design surface.

6. A blade control method comprising:
acquiring a design surface indicating a target shape of an excavation object to be excavated by a blade supported by a vehicle body of a work vehicle, the design surface including a first surface present in front of the work vehicle and a second surface having a slope different from a slope of the first surface;
acquiring an observed pitch angle indicating an inclination angle of the vehicle body in a longitudinal direction;
calculating a planned pitching angle indicating a deviation between the observed pitch angle and a design surface pitch angle indicating an inclination angle of the second surface in a state in which the vehicle body is positioned on the first surface and the blade is positioned above the second surface;
correcting the observed pitch angle based on the planned pitching angle and calculating a corrected pitch angle of the vehicle body;
acquiring a target height of the blade, the target height being calculated based on the design surface;
correcting the target height based on the corrected pitch angle, and generating a corrected target height;
calculating a target cylinder speed of a hydraulic cylinder that adjusts a height of the blade, based on the corrected pitch angle;
calculating a corrected target height variation based on the corrected target height;
calculating a target cylinder speed correction value based on the planned pitching angle and the corrected target height variation; and
determining a correction gain for the corrected target height variation based on a correction table and the planned pitching angle;
wherein the correction table includes correlation data indicating a relationship between the planned pitching angle and the correction gain to be given to the corrected target height variation.

Assignees

• Komatsu Mfg Co Ltd

Inventors

• Ishihara Takao
• Noborio Daichi
• Nakayama Yutaka

Classifications

• G01C9/00

  Measuring inclination, e.g. by clinometers, by levels · CPC title

• E02F9/265

  with follow-up actions (e.g. control signals sent to actuate the work tool) · CPC title

• E02F9/2267

  Valves or distributors (position of valves arrangements on upper-structures E02F9/0875) · CPC title

• E02F3/7618

  with the scraper blade adjustable relative to the pivoting arms about a horizontal axis · CPC title

• G01C21/165

  combined with non-inertial navigation instruments · CPC title