Optical Sensor Signal Comparison for Windscreen Contamination

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Solution Overview

Problem

Optical sensors in industrial environments suffer from contamination that impairs detection capability, making cleaning processes time-consuming and costly, as the degree of contamination is not a reliable indicator of the need for cleaning.

Innovation Solution

An optical sensor generates a detection impairment signal by comparing the actual detection signal with an expected detection signal, allowing a needs-based assessment of contamination impact, using multi-level or analog signals to account for different types and degrees of contamination, and incorporating signal processing to compensate for contamination effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cleaning processes are performed based on degree of contamination, then the front window is maintained clean, but time and cost are wasted on unnecessary cleaning operations

Engineering Contradiction:
Improvedetection capabilityVSAvoidcleaning time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the mechanical cleaning process with an optical evaluation system that continuously monitors detection quality. Instead of mechanically cleaning based on contamination degree, the system uses optical signal analysis to determine when cleaning is actually necessary, substituting physical maintenance with intelligent monitoring.

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

Solution Approach 2:

The system implements feedback by continuously comparing actual detection signals with expected signals and using this information to determine cleaning necessity. The evaluation unit provides real-time feedback on detection quality, enabling dynamic adjustment of maintenance schedules based on actual performance rather than fixed contamination thresholds.

Inventive Principle:
Principle #23Feedback

2Reliability

If cleaning processes are performed based on degree of contamination, then the front window is maintained clean, but cost increases due to unnecessary cleaning operations

Engineering Contradiction:
Improvedetection capabilityVSAvoidcleaning cost
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent replaces cost-intensive mechanical cleaning operations with a low-cost optical monitoring system. By substituting expensive routine maintenance with inexpensive signal analysis, the system reduces overall operational costs while maintaining detection reliability.

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

Solution Approach 2:

The system performs self-diagnosis by automatically evaluating its own detection quality and determining when external cleaning intervention is needed. This self-service capability eliminates the need for costly routine maintenance schedules, as the system monitors and manages its own performance.

Inventive Principle:
Principle #25Self-service

3Device complexity

If the detection signal is used directly without comparison, then the system operates simply, but the reliability of cleaning decision is insufficient

Engineering Contradiction:
Improvesystem complexityVSAvoidcleaning decision reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system performs preliminary action by storing expected detection signals in advance under clean conditions. This pre-established reference data enables reliable cleaning decisions without requiring complex real-time analysis, as the comparison is made against pre-computed baseline values.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The evaluation unit acts as an intermediary that simplifies the complex task of contamination assessment by comparing signals and generating straightforward cleaning recommendations. This intermediary layer translates complex optical signal variations into simple, actionable decisions.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enables reliable and efficient cleaning planning by distinguishing between necessary and unnecessary cleaning processes, reducing unnecessary cleaning and extending the time between cleaning operations.

Implementation Method 1

a light transmitter for emitting transmitted light beams 23 through the front screen 20 in the direction of an object 13 to be detected, a light receiver 25 for receiving received light beams 27 passing through the front screen 20

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP4614195A1Optical sensor
Publication Date: 2025.09.10 SICK AG
  • EP4614195A1 patent drawingFigure 1
  • EP4614195A1 patent drawingFigure 2
  • EP4614195A1 patent drawingFigure 3

AI summary

An optical sensor for detecting objects comprises a windscreen, a light transmitter for emitting transmitted light beams through the windscreen toward an object to be detected, a light receiver for receiving received light beams passing through the windscreen, and an electronic evaluation unit that is in signal communication with the light receiver and is configured to generate a detection signal based on an output signal of the light receiver. The evaluation unit is further configured to generate a detection impairment signal based on a comparison of the generated detection signal with an expected detection signal. This signal indicates an impairment of the detection quality due to contamination of the windscreen.