Excavator Bucket Discharge Control for Balanced Dump Truck Loading

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Solution Overview

Problem

Existing work machines, such as hydraulic excavators, unevenly distribute excavated sediment during loading operations, leading to potential weight imbalance and limited load capacity on dump trucks, which can affect travel operations.

Innovation Solution

A work machine equipped with a controller that sets discharge start and completion positions based on vessel position information, using posture sensors to guide the work device's movement, ensuring the bucket reaches a predetermined discharge angle along a planned trajectory for even distribution of excavated material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the bucket rotates about its geometrical center as a rotation axis, then the discharge operation is executed to a specific position on the vessel, but the excavated sediment is unevenly dumped, limiting the amount loaded and affecting weight balance

Engineering Contradiction:
Improvedischarge position accuracyVSAvoidmaterial distribution uniformity
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent applies dynamics by transitioning from a fixed rotation axis (geometrical center) to a moving discharge position. The control point is dynamically adjusted along the arc trajectory to different locations on the vessel, allowing the system to adapt its discharge pattern throughout the operation to achieve uniform material distribution while maintaining precise position control

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control point serves as an intermediary between the bucket's fixed rotation axis and the vessel's surface. By moving this control point along the arc trajectory and discharging at different positions relative to it, the system mediates between the mechanical constraint of fixed rotation and the operational requirement for uniform distribution

Inventive Principle:
Principle #24Intermediary (Mediator)

2Extent of automation

If automatic earth removal control is used, then the dumping operation is automated, but the excavated sediment is discharged to a specific position causing uneven distribution

Engineering Contradiction:
Improvedumping operation automationVSAvoidmaterial distribution uniformity
Core Design Contradiction:
Extent of automationVSManufacturing precision

Solution Approach 1:

The automated control system is enhanced with dynamic position adjustment. Instead of fixed-point discharge, the control point moves along an arc trajectory, and the discharge position is dynamically changed throughout the dumping operation. This allows automation to achieve uniform material distribution across the vessel by systematically varying the discharge location

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If the bucket discharges sediment to a specific position, then the discharge operation is precise, but the weight balance of the dump truck changes, influencing travel operation

Engineering Contradiction:
Improvedischarge position precisionVSAvoidweight balance stability
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

The discharge operation is segmented into multiple discharge points along the vessel rather than concentrating material at a single location. By dividing the discharge locations along the arc trajectory, the system distributes the load across different positions on the vessel, preventing weight concentration that would affect the dump truck's balance and stability

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4600427A1Work machine
Publication Date: 2025.08.13 HITACHI CONSTRUCTION MACHINERY CO LTD
  • EP4600427A1 patent drawingFigure 1
  • EP4600427A1 patent drawingFigure 2
  • EP4600427A1 patent drawingFigure 3

AI summary

Provided is a controller of a work machine which sets side by side, a discharge start position that is a position for starting a discharge operation executed above the vessel for the excavated object and a discharge completion position that is a position for completing the discharge operation, in a direction having a component of a front-rear direction of the vessel, on the basis of position information on a vessel acquired by a vessel position acquisition device at a position at which an excavation operation is completed, moves a control point of the work device from the discharge start position to the discharge completion position by controlling, on the basis of the posture of a work device and the posture of a swing structure sensed by a posture sensor, at least one of the work device and the swing structure, and controls the operation of the work device such that a ground angle of a bucket reaches a discharge completion angle set in advance during the movement of the control point of the work device from the discharge start position to the discharge completion position.