Wind Turbine Blade Motion Tracking Using Modulated Light Sensing
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Solution Overview
Problem
Existing wind turbine blade monitoring systems are inadequate in measuring torsion and are vulnerable to operational factors such as vibrations and gravity, and are power-consuming.
Innovation Solution
A blade motion tracking system using frequency-modulated light sources and position sensitive detectors (PSDs) to measure bending and torsion of wind turbine blades, employing non-discrete PSDs for accurate, real-time monitoring with minimal ambient light interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If cameras and inclinometers are mounted on the blades for monitoring, then blade deflection can be detected, but the systems become vulnerable to vibrations, gravity and centrifugal accelerations
Solution Approach 1:
The patent replaces mechanical sensors (cameras and inclinometers mounted on blades) with an optical measurement system using light sources and position-sensitive detectors. This substitution eliminates the vulnerability of mechanical systems to vibrations, gravity, and centrifugal accelerations while maintaining measurement capability through optical field-based detection.
2Measurement precision
If known monitoring systems are used, then blade deflection can be monitored, but they are not capable of monitoring blade torsion
Solution Approach 1:
The patent creates a universal monitoring system that can detect both blade deflection and torsion using the same optical components. By strategically positioning multiple light sources on the blade and using position-sensitive detectors, the system achieves multi-functionality, monitoring both bending and twisting motions without requiring separate specialized systems.
Solution Approach 2:
The patent extends monitoring from one dimension (deflection only) to multiple dimensions by adding torsion detection capability. The position-sensitive detectors measure light source positions in both x and y directions, enabling detection of both deflection and torsional movements through multi-dimensional position analysis.
3Adaptability or versatility
If multiple light sources are used on the blade, then both bending and torsion can be measured, but the system complexity increases
Solution Approach 1:
The patent divides the blade monitoring function into segmented light sources positioned at specific locations (leading edge, trailing edge, and intermediate positions). Each light source monitors a specific aspect of blade motion, and the position-sensitive detector processes these segmented signals to reconstruct complete blade behavior, simplifying the overall system architecture.
4Reliability
If frequency-modulated light sources are used, then ambient light interference is reduced, but the system requires more complex signal processing
Solution Approach 1:
The patent changes the frequency parameter of the light sources to create frequency-modulated signals. This parameter change allows the system to distinguish modulated light from ambient light through frequency discrimination, improving reliability while the frequency modulation serves as a simple tagging mechanism that requires straightforward signal processing.
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
Provides reliable, fast, and cost-effective monitoring of blade motion, enabling load reductions and power enhancements, suitable for both prototype testing and long-term operation with minimal impact on aerodynamics.
Implementation Method 1
an optical measuring device which is adapted to receive light emitted from the first light source(s)... a position sensitive detector identifying the position of the first light source
Data Source
AI summary
A method and system is for tracking motion of a wind turbine blade. A blade motion tracking system is for installation on a wind turbine blade with a blade root and tip. The system has at least one light module with at least a first light source, preferably adapted to emit light in the blade root direction. An optical measuring device at the blade root may receive light emitted from the first source. The optical measuring device may be a position sensitive detector identifying the first light source position relative to the position sensitive detector. A single light source located at, close to, or towards the tip, is sufficient to measure blade deflection. The first light source is modulated with a predefined frequency such that light from the first light source can be distinguished from ambient light and thereby minimize the influence of the ambient light conditions during detection.