Multi-Wavelength Optical Sensing for Wind Turbine Ice Detection

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Solution Overview

Problem

Existing wind turbine systems require multiple sensors to monitor ice on rotor blades and objects below the turbine, complicating the system and making it difficult to reliably assess ice thickness, posing a safety risk.

Innovation Solution

A wind turbine equipped with a single optical sensor that emits light at multiple wavelengths to simultaneously detect ice on rotor blades and objects below the turbine, using intensity ratios to identify materials like ice and objects, and optionally classifying them.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple sensors are used to monitor ice on rotor blades and objects below the turbine, then detection coverage is improved, but device complexity increases

Engineering Contradiction:
Improvedetection coverageVSAvoidsensor system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The optical sensor is designed to perform multiple functions: it detects ice on rotor blades and simultaneously monitors for objects below the turbine using the same sensor unit. This multi-functionality reduces the need for separate sensor systems while maintaining comprehensive detection coverage.

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

Solution Approach 2:

The patent combines ice detection and object detection functions into a single optical sensor system. By merging these previously separate monitoring tasks into one integrated sensor, the system reduces complexity while achieving reliable detection of both ice conditions and objects in the danger zone.

Inventive Principle:
Principle #5Merging (Combining)

2Device complexity

If a single optical sensor is used to monitor both ice and objects, then device complexity is reduced, but measurement precision for ice thickness assessment deteriorates

Engineering Contradiction:
Improvesensor system complexityVSAvoidice thickness detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The optical sensor uses multiple wavelengths of light to probe the ice on rotor blades. By analyzing the reflection or absorption characteristics at different wavelengths, the system can determine ice thickness with sufficient precision despite using a single sensor, avoiding the need for multiple specialized sensors.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces physical contact-based ice measurement methods with optical detection. The optical sensor uses light interaction with the ice to infer thickness, eliminating the need for mechanical probes while maintaining adequate measurement precision for safety decisions.

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

3Measurement precision

If multiple wavelengths are emitted by the light source, then material detection accuracy is improved, but energy consumption increases

Engineering Contradiction:
Improvematerial identification accuracyVSAvoidlight source energy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The light source emits light at multiple wavelengths in a periodic or sequential manner rather than continuously at all wavelengths simultaneously. This approach allows the sensor to gather spectral information needed for accurate material identification while reducing overall energy consumption by activating only the necessary wavelengths at appropriate intervals.

Inventive Principle:
Principle #19Periodic 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 reduces sensor complexity, accurately detects and classifies ice and objects, enabling safer operation by preventing ice-related hazards through precise monitoring and controlled shutdowns.

Implementation Method 1

a receiving and evaluation unit configured to detect at least one object within the monitoring area based on received light emitted by the light source and remitted (in particular, reflected) by the object

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4653696B1Wind turbine with an optical sensor
Publication Date: 2026.04.15 SICK AG
  • EP4653696B1 patent drawingFigure 1
  • EP4653696B1 patent drawingFigure 2
  • EP4653696B1 patent drawingFigure 3~3B

AI summary

An optical sensor, which may be used for a wind turbine, comprises a light source that emits light into a predetermined monitoring area and a receiving and evaluation unit configured to detect at least one object within the monitoring area based on received light emitted by the light source and reflected by the object. The light source is further configured to emit light at at least two different wavelengths, while the receiving and evaluation unit is additionally configured to determine the respective intensity of the light reflected by the object for each of the at least two wavelengths and, based on the ratio of at least two intensities at different wavelengths, to detect at least one predetermined material on the object. A wind turbine with such an optical sensor and a method for operating such a wind turbine are also described.