SYSTEM AND METHOD OF IN SITU WIND TURBINE BLADE MONITORING
Systems and methods are disclosed for monitoring parameters such as the material properties or structural integrity of a wind turbine blade on a wind turbine. An example method comprises detecting light reflected from a wind turbine blade, generating a value based on the detecting, comparing the value to a threshold value and determining a parameter of the wind turbine blade based on the comparing. A further embodiment comprises determining a wind velocity by detecting reflected light from a target area in front of the wind turbine blade. An example system comprises a detector configured to detect light reflecting from a turbine blade and to produce a value representative of the detected light. The system also comprises a comparator configured to compare the value to a threshold value and to determine a parameter of the turbine blade.
1 .- 18 . (canceled)
19 . A method comprising:
receiving at a laser Doppler velocimeter at least a portion of light transmitted to a blade of a wind turbine as reflected light;
calculating a reflection signature of the blade based on the reflected light received at the laser Doppler velocimeter; and
determining a wellness indicator of the blade based on a comparison of the reflection signature of the blade with a plurality of stored reflection signatures.
20 . The method of claim 19 , further comprising determining that the wellness indicator satisfies a threshold value; and indicating that the blade should be replaced.
21 . The method of claim 19 , wherein the laser Doppler velocimeter is located on a nacelle of the wind turbine.
22 . The method of claim 19 , wherein the plurality of reflection signatures correspond to reflection signatures of a material that is the same as the material of the blade of the wind turbine.
23 . The method of claim 19 , wherein the reflection signature represents a vibration pattern of the blade.
24 . The method of claim 19 , further comprising a laser Doppler velocimeter located on a nacelle of the wind turbine.
25 . The method of claim 19 , further comprising transmitting the light from the laser Doppler velocimeter to the blade of the wind turbine.
26 . The method of claim 25 , wherein the laser Doppler velocimeter transmits the light during operation of the wind turbine.
27 . The method of claim 19 , wherein the reflection signature comprises a fundamental frequency.
28 . The method of claim 27 , wherein the reflection signature comprises higher order harmonics of the fundamental frequency.
29 . The method of claim 27 , wherein the reflection signature comprises a third harmonic of the fundamental frequency.
30 . The method of claim 19 , further comprising determining a remaining lifespan of the blade.
31 . The method of claim 30 , wherein the remaining lifespan of the blade is further determined based on a type of material used to construct the blade.
32 . A system comprising:
a machine-readable storage medium comprising a plurality of reflection signatures;
a light detector configured to detect light reflected from a blade of a wind turbine;
a computing device configured to calculate a reflection signature of the blade based on the light reflected from the blade and determine a wellness indicator of the blade based on a comparison of the reflection signature of the blade with the plurality of reflection signatures stored in the machine-readable storage medium.
33 . The system of claim 32 , wherein the wellness indicator of the blade is further determined based on a type of material used to construct the blade.
34 . The system of claim 32 , wherein the plurality of reflection signatures correspond to reflection signatures of a material that is the same as the material of the blade of the wind turbine.
35 . The system of claim 32 , wherein the reflection signature represents a vibration pattern of the blade.
36 . The system of claim 32 , further comprising a light transmitter configured to transmit the light to the blade of the wind turbine.
37 . The system of claim 36 , wherein the light transmitter transmits the light during operation of the wind turbine.
38 . The system of claim 32 , wherein the reflection signature comprises a fundamental frequency.
39 . The system of claim 38 , wherein the reflection signature comprises higher order harmonics of the fundamental frequency.
40 . The system of claim 38 , wherein the reflection signature comprises a third harmonic of the fundamental frequency.
41 . A method comprising:
receiving at a laser Doppler velocimeter at least a portion of light transmitted to a blade of a wind turbine as reflected light;
calculating a reflection signature of the blade based on the reflected light received at the laser Doppler velocimeter; and
identifying a structural change of the blade based on an identified change in the reflection signature of the blade.
42 . The method of claim 41 , wherein the structural change comprises at least one of damage to the blade, a crack in the blade, and blade fatigue.