Excavator Operation Support Using External Position Measurement

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Solution Overview

Problem

Existing operation support systems for work machines like hydraulic excavators require lengthy calibration processes for onboard sensors, leading to reduced productivity during retrofitting, as they cannot be used for work during calibration of IMU attachment angles and bucket claw tip position confirmation.

Innovation Solution

A work machine equipped with an onboard monitor and controller that receives coordinate data from external measurement devices to compute and display operation support information, allowing operation support without prior calibration of onboard sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If onboard sensors are calibrated using traditional methods (total station or camera), then measurement precision is improved, but loss of time increases significantly

Engineering Contradiction:
Improveattachment angle calibration precisionVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the mechanical measurement systems (total station and camera) with a laser tracker that uses optical measurement principles. The laser tracker measures the position of reflective markers on the bucket claw tip and IMU more efficiently, obtaining multiple coordinate points simultaneously rather than sequentially, thus reducing calibration time while maintaining precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements preliminary action by pre-installing reflective markers on the bucket claw tip and IMU before the calibration process begins. This preparation allows the laser tracker to immediately capture position data without requiring complex setup or alignment procedures, significantly reducing the overall calibration time.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If onboard sensors are calibrated before use, then reliability is improved, but loss of time increases due to work stoppage

Engineering Contradiction:
Improveoperation support reliabilityVSAvoidwork downtime
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The laser tracker system replaces traditional calibration methods by enabling continuous operation during calibration. The optical measurement system can acquire data while the excavator remains in position, eliminating the need to stop work for calibration and thereby maintaining both reliability and productivity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent enables continuity of useful action by allowing the excavator to remain operational during the calibration process. The laser tracker continuously tracks the position of markers on moving components, ensuring that calibration data is collected without interrupting the work flow, thus maintaining both reliability and productivity.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP4685294A1Work machinery and operation assistance system for work machinery
Publication Date: 2026.01.28 HITACHI CONSTRUCTION MACHINERY CO LTD
  • EP4685294A1 patent drawingFigure 1
  • EP4685294A1 patent drawingFigure 2
  • EP4685294A1 patent drawingFigure 3

AI summary

Provided is a work machine including: a machine body that has an operation room; a front work device that is attached to the machine body; a monitor that is provided in the operation room; and a controller that causes the monitor to display operation support information including information on a position of a predetermined portion of the front work device, in which the controller receives, from an external measurement device installed around the machine body, information on coordinates of two or more specific points for each movable member configuring the front work device measured by the external measurement device, computes a first position as the position of the predetermined portion on the basis of the coordinates of the specific points received from the external measurement device, and causes the monitor to display first operation support information including information on the first position, as the operation support information. Accordingly, it is possible to support an operator's operation of a work machine even if the work machine is not provided with an onboard sensor with the attachment angle calibrated.