Work Vehicle Obstacle Sensing for False Collision Avoidance

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Solution Overview

Problem

Existing automatic travel systems for work vehicles face issues with inaccurate obstacle detection due to radar devices, leading to unnecessary collision avoidance operations when tall grass or dust is present, causing erroneous detection of obstacles.

Innovation Solution

An automatic travel system that combines an imaging unit for capturing images and an active sensor for measuring distances, allowing the automatic travel control unit to execute collision avoidance based on accurate separation distance information from the obstacle, thereby reducing false alarms and unnecessary operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a radar device is used as the obstacle detection sensor, then the device complexity is reduced and ease of manufacture is improved, but the measurement precision deteriorates leading to erroneous detection of obstacles

Engineering Contradiction:
Improveease of manufactureVSAvoidmeasurement precision
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent combines multiple types of sensors (radar device, imaging device, and active sensor such as LiDAR) into an integrated obstacle detection system. The radar provides initial obstacle candidates, the imaging device verifies object identity, and the active sensor measures precise separation distances. This merging of different sensing modalities resolves the contradiction by maintaining manufacturing simplicity while achieving high measurement precision through sensor fusion.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If the peripheral monitoring device warns the driver about obstacles in the warning area, then the reliability of obstacle detection is improved, but unnecessary collision avoidance operations occur when tall grass or dust is present

Engineering Contradiction:
ImprovereliabilityVSAvoidproductivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent introduces an intermediary verification process using an imaging device and active sensor between the radar's obstacle detection and the collision avoidance action. The imaging device acts as an intermediary to verify whether the detected object is a genuine obstacle, and the active sensor provides intermediary distance measurement data. This intermediary verification step filters out false alarms from tall grass or dust while maintaining reliable detection of actual obstacles, thus preventing unnecessary collision avoidance operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the work vehicle performs collision avoidance operations based on radar detection, then the safety is improved, but unnecessary operations are performed reducing productivity

Engineering Contradiction:
ImprovereliabilityVSAvoidproductivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements preliminary verification actions before executing collision avoidance operations. The imaging device performs preliminary identification of detected objects, and the active sensor performs preliminary distance measurement verification. Only after these preliminary actions confirm the presence of a genuine obstacle does the system execute collision avoidance operations. This preliminary action approach maintains safety by ensuring real obstacles are detected while preventing unnecessary operations that would reduce productivity.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system accurately detects obstacles and avoids collisions without performing unnecessary collision avoidance operations, enhancing the reliability and efficiency of automatic travel for work vehicles.

Implementation Method 1

an active sensor that measures a set range in the same predetermined direction as the imaging unit from the work vehicle

Methodology Applied
Scientific EffectTime of Flight: Time of Flight

Implementation Method 2

a radar device with low object discrimination accuracy is adopted as the obstacle detection sensor

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 3

an imaging unit that image-captures a set range in a predetermined direction from the work vehicle

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3997973B1Automatic travel system for work vehicle
Publication Date: 2024.09.04 YANMAR POWER TECH CO LTD
  • EP3997973B1 patent drawingFigure 1
  • EP3997973B1 patent drawingFigure 2
  • EP3997973B1 patent drawingFigure 3

AI summary

An automatic travel system for a work vehicle (1) has an automatic travel control unit (23F) that causes a work vehicle, which is provided with an obstacle detection unit (80) that detects obstacles, to travel automatically. The obstacle detection unit (80) includes imaging units (81-84) and active sensors (86-88). When the obstacle detection unit (80) detects an obstacle based on information from the imaging units (81-84), and the separation distance from the obstacle is acquired based on information from the active sensors (86-88), the automatic travel control unit (23F) executes a first collision avoidance control for avoiding a collision between the work vehicle and the obstacle, on the basis of the separation distance from the obstacle acquired based on the information from the active sensors (86-88).