Work Machine Control Method for Operability and Safety

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Solution Overview

Problem

Existing work machines may incorrectly determine that the operation device is not being operated by the operator's hand, leading to unintended restriction of the actuator's motion, which reduces operability, especially when operators wear gloves or partially grip the operation lever.

Innovation Solution

A work machine control method that shifts the machine's state from an inoperable to an operable state based on an unlock operation, and then shifts back to an inoperable state when a specific condition, including a standby time after the unlock operation, is met without the operator engaging the specific operation unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a camera-based detector is used to determine whether the operation device is operated by the operator's hand, then the work machine can suppress erroneous actuation, but it may incorrectly determine when the operator wears gloves or partially grips the lever, reducing operability

Engineering Contradiction:
Improvesuppression of erroneous actuationVSAvoidoperability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces the optical detection system (camera-based image recognition) with a mechanical detection system (detector that directly senses operation lever movement). This substitution eliminates the issues with image-based recognition that fail when operators wear gloves or use partial grips, as the mechanical detector directly senses the physical movement of the operation lever regardless of hand condition.

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

Solution Approach 2:

The patent introduces a mechanical detector as an intermediary between the operation lever and the control system. This detector acts as a mediator that translates physical lever movement into control signals, providing a reliable detection mechanism that works independently of the operator's hand condition (gloves, grip style) while maintaining suppression of erroneous actuation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the work machine returns to inoperable state after a standby time without operation, then it can prevent unintended actuation, but it reduces productivity by requiring repeated unlock operations

Engineering Contradiction:
Improveprevention of unintended actuationVSAvoidoperational continuity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements a standby time mechanism that performs preliminary assessment of operator intent before locking the system. By monitoring whether the operation lever is moved within a predetermined time period after unlocking, the system determines if the operator intends to use the machine, allowing continuous operation without repeated unlocking for legitimate uses while still preventing unintended actuation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses feedback from the operation lever detector to dynamically control the state transition between operable and inoperable states. The detector's continuous monitoring of lever position provides feedback that prevents the system from locking when the operator is preparing to operate, thereby maintaining productivity while ensuring safety through conditional locking based on actual operational intent.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4517009A1Work machine control method, work machine control program, work machine control system, and work machine
Publication Date: 2025.03.05 YANMAR HLDG CO LTD
  • EP4517009A1 patent drawingFigure 1
  • EP4517009A1 patent drawingFigure 2
  • EP4517009A1 patent drawingFigure 3

AI summary

[Problem] A work machine control method, a work machine control program, a work machine control system, and a work machine, each of which easily improves operability, are provided. [Solution] A control method for a work machine 3 has: shifting a state of the work machine 3 from an inoperable state to an operable state on the basis of an unlock operation by an unlock operation unit 20. The control method for the work machine 3 further has: shifting the state of the work machine 3 from the operable state to the inoperable state when a specific condition including a condition that a specific operation unit related to an operation of the work machine 3 remains unoperated for a standby time after the unlock operation is satisfied.