Front Work Implement Control for Dead Angle Collision Prevention

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Solution Overview

Problem

Conventional construction machines cannot effectively prevent contact between a front work implement and a moving body that appears from a dead angle, as they do not account for the possibility of a moving body existing in the dead angle of a detected object.

Innovation Solution

A construction machine equipped with a posture sensor, external environment recognition device, and controller that calculates a dead angle range and assumed movement range to perform preventive control, ensuring the front work implement does not collide with a moving body by determining the movable range of the work implement and the movement range of the moving body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional obstacle detection is used, then detected objects can be identified, but moving bodies in dead angles cannot be detected

Engineering Contradiction:
Improveobject detection accuracyVSAvoiddead angle coverage
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The system performs preliminary action by calculating the dead angle range in advance based on detected object positions, and proactively determines assumed movement ranges within these dead angles before any collision can occur. This predictive approach allows the system to prepare preventive control measures ahead of time, addressing the detection blind spot issue by preemptively analyzing potential moving body trajectories in undetected zones.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The controller acts as an intermediary by introducing the concept of 'assumed movement range' as a mediating parameter between the detected object positions and the front work implement motion control. This intermediary calculation layer processes the spatial relationships and temporal constraints to generate safe movement boundaries, effectively bridging the information gap created by dead angles in the detection system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the front work implement moves freely, then work efficiency is high, but contact with moving bodies cannot be prevented

Engineering Contradiction:
Improvework efficiencyVSAvoidcollision prevention
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system applies dynamics by making the movable range of the front work implement adjustable and time-dependent rather than fixed. The controller dynamically calculates the movable range based on current posture information, assumed movement ranges of potential moving bodies, and temporal constraints. This dynamic adjustment allows the work implement to move freely when safe while automatically constraining it when potential collisions are detected, resolving the contradiction between productivity and safety.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements feedback by continuously monitoring posture information of the front work implement, recalculating assumed movement ranges based on detected object positions, and adjusting the movable range in real-time. This closed-loop control ensures that productivity is maintained when conditions permit while automatically preventing collisions when moving bodies are detected or when dead angle analysis indicates potential risks.

Inventive Principle:
Principle #23Feedback

3Reliability

If preventive control is implemented, then collision prevention is improved, but control complexity increases

Engineering Contradiction:
Improvecollision preventionVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The controller segments the complex control problem into distinct functional modules: detecting object positions, calculating dead angle ranges, determining assumed movement ranges, calculating movable ranges based on posture information, and executing preventive control. This segmentation of the control logic into manageable computational steps reduces overall system complexity while maintaining high reliability through systematic processing of each control aspect.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3904609B1Construction machine
Publication Date: 2024.01.17 HITACHI CONSTRUCTION MACHINERY CO LTD
  • EP3904609B1 patent drawingFigure 1
  • EP3904609B1 patent drawingFigure 2
  • EP3904609B1 patent drawingFigure 3

AI summary

A construction machine includes a posture sensor that is provided on a front member of a front work implement and detects posture information of the front member, an external environment recognition device that detects an object around a main body, and a controller calculates a dead angle range that is a range that becomes a dead angle from a recognition range of the external environment recognition device, the dead angle arising from an object recognized by the external environment recognition device, calculates an assumed movement range that is a range within which a moving body assumed to exist in the dead angle is movable in a period of time determined in advance, calculates a movable range that is a range within which the front work implement is movable in a period of time determined in advance on the basis of the posture information detected by the posture sensor, and performs preventive control for preventing contact between the moving body and the front work implement on the basis of the assumed movement range of the moving body and the movable range of the front work implement. Consequently, the construction machine can deal also with a moving body in a dead angle of an object sufficiently and can prevent contact between the front work implement and a moving body with a higher degree of certainty.