Optical Sensor Protective Field Selection for Narrow-Aisle Vehicles

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing sensor arrangements for vehicles, particularly in narrow aisles, face challenges in reliably monitoring danger zones without unnecessary stopping or braking due to complex and computationally intensive continuous detection of lane boundaries, which is problematic in environments with rapidly changing conditions.

Innovation Solution

The implementation of a sensor arrangement with multiple activated protective fields and a selection logic that only generates safety signals upon object detection within selected fields, allowing for simultaneous monitoring and eliminating the influence of lane boundaries without continuous adaptation, thus ensuring reliable detection of objects in the danger area without unnecessary braking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If continuous detection of road boundary is performed to optimally dimension the protective field, then the protective field can detect the aisle but not the road boundary, but this method is extremely complex and demands significant computing power

Engineering Contradiction:
Improvereliability of object detectionVSAvoidcomplexity of detection method
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The monitoring area is divided into multiple protective fields (first protective field and second protective field) with different lateral extents. The first protective field has a larger lateral extent to cover the entire aisle including road boundaries, while the second protective field has a smaller lateral extent to exclude road boundaries. This segmentation allows the system to use simple, fixed protective field definitions instead of complex continuous adaptation, resolving the contradiction between detection reliability and system complexity.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If the protective field is adapted to the current direction of travel and surroundings, then unnecessary stopping or braking due to road boundary detection is avoided, but this adaptation reaches its limits in narrow aisles with small oscillations

Engineering Contradiction:
Improvevehicle availabilityVSAvoidreliability of protective field monitoring
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system dynamically selects which protective field to use based on the detected road boundary position. When the road boundary is detected within a predetermined distance, the system switches from using the first protective field to the second protective field. This dynamic selection allows the system to adapt to changing conditions (vehicle oscillations, narrow aisles) without requiring continuous protective field adaptation, thereby maintaining both vehicle availability and monitoring reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The road boundary detection acts as an intermediary that triggers the selection between different protective fields. Instead of directly adapting the protective field to exclude road boundaries (which becomes complex in narrow aisles), the system uses road boundary detection as a mediator to switch between pre-defined protective fields with different lateral extents. This intermediary approach simplifies the system while maintaining reliability in narrow aisle conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the protective field lateral extent is reduced to exclude road boundaries, then false safety signals are avoided, but the protective field may fail to detect objects in the danger zone

Engineering Contradiction:
Improveaccuracy of safety signal generationVSAvoidlateral extent of protective field
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The system activates multiple protective fields with different lateral extents simultaneously or selectively. The first protective field uses a larger lateral extent that may include road boundaries, while the second protective field uses a smaller lateral extent that excludes road boundaries. By having both options available and selecting appropriately based on conditions, the system ensures that the protective field is large enough to detect objects in the danger zone while avoiding false safety signals from road boundaries.

Inventive Principle:
Principle #16Partial or excessive 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

This approach ensures reliable detection of objects in the danger area while preventing unnecessary stopping or braking, enhancing vehicle availability by simplifying the monitoring process and reducing computational demands.

Implementation Method 1

The sensor has a light receiver for converting received light into electrical signals

Methodology Applied
Scientific EffectLight detection and conversion to electrical signals: Photoelectric Effect

Data Source

PatentEP3587894B1Sensor assembly and method for operating a sensor assembly
Publication Date: 2023.08.09 LEUZE ELECTRONIC GMBH & CO KG
  • EP3587894B1 patent drawingFigure 1~2
  • EP3587894B1 patent drawingFigure 3
  • EP3587894B1 patent drawingFigure 4~5

AI summary

The invention relates to a sensor arrangement with an optical sensor (1) for monitoring a danger zone around a vehicle (12) moving along a roadway bounded on both sides by lane boundaries (14). The optical sensor (1) is configured to detect objects in at least one protective field (15a, 15b, 15c) and, depending on this, to generate a binary switching signal, the switching states of which are, on the one hand, a safety signal and, on the other hand, a release signal for the vehicle (12). Several simultaneously activated protective fields (15a, 15b, 15c) are provided. Object detection takes place in each activated protective field (15a, 15b, 15c) by means of the optical sensor (1). A selection logic is provided in an evaluation unit of the optical sensor (1) in which at least one activated protective field (15a, 15b, 15c) is selected.The safety signal is generated only if an object is detected in one or more of the selected protective fields (15a, 15b, 15c).