Excavator Avoidance Control for Inertia-Driven Obstacle Contact

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Solution Overview

Problem

Existing work machines face risks of contacting obstacles due to inertia when abnormalities occur in devices for identifying vehicle position, direction, or soil removal position, leading to inadequate operation signal restriction.

Innovation Solution

A work machine system with a control device that includes an abnormality detection section, an avoiding movement necessity determination section, and an avoidance control instruction section to prioritize avoiding movements over operation instructions in case of abnormalities, using sensors and stored information to calculate and execute avoidance control instructions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the operation signal is restricted during abnormality to prevent contact, then safety is improved, but the vehicle body may still contact obstacles due to inertia

Engineering Contradiction:
ImprovesafetyVSAvoidcontact with obstacle
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The control device executes preliminary avoidance control actions when abnormality is detected, calculating and implementing avoidance trajectories before the vehicle body completes its movement. This proactive approach addresses the inertia problem by pre-positioning the vehicle to avoid obstacles rather than merely restricting operation signals after the fact.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control device continuously monitors the vehicle body's movement state and adjusts avoidance control instructions in real-time based on feedback from sensors. This closed-loop control ensures that even with inertia, the vehicle body can be guided to avoid obstacles by dynamically adjusting control signals during the avoidance maneuver.

Inventive Principle:
Principle #23Feedback

2Reliability

If the vehicle body speed is lowered to avoid contact, then safety is improved, but inertia still causes contacting with obstacles

Engineering Contradiction:
ImprovesafetyVSAvoidinertia-induced contact
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The control device dynamically adjusts avoidance control instructions based on the vehicle body's current speed, movement state, and detected abnormality. Rather than simple speed reduction, the system calculates optimal avoidance trajectories that account for inertia, adjusting control parameters in real-time to guide the vehicle body safely away from obstacles despite its momentum.

Inventive Principle:
Principle #15Dynamics

3Reliability

If abnormality detection and avoidance control systems are added, then safety is improved, but device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control device integrates multiple functions including abnormality detection, avoidance necessity determination, and avoidance control instruction calculation within a single unified system. This multi-functional approach improves safety while minimizing the increase in device complexity by consolidating control functions rather than adding separate independent systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4321692B1Work machine and work machine system
Publication Date: 2026.02.25 HITACHI CONSTRUCTION MACHINERY CO LTD
  • EP4321692B1 patent drawingFigure 1
  • EP4321692B1 patent drawingFigure 2
  • EP4321692B1 patent drawingFigure 3

AI summary

Provided are a work machine and a work machine system that reduce risk that a vehicle body comes into contact with an obstacle nearby in a case wherein abnormality arises in the work machine. The work machine comprises: a traveling body; a rotary body rotatably mounted onto the traveling body; a work machinery of an articulated type mounted to the rotary body and including a boom, an arm and a work tool; and a control device. The control device comprises a control instruction calculation section, a machine control section, an abnormality detection section, an avoiding movement necessity determination section and an avoidance control instruction section. The machine control section controls the traveling body, the rotary body and the work machinery putting priority on the avoidance control instruction over the operation control instruction.