Smart Sensing Using Wavelets
These further refinements to the FOSS technologies are focusing on smart sensing techniques that adjust parameters as needed in real time so that only the necessary data are acquired-no more, no less. Traditional FOSS signal processing is based on Fourier transforms that break up the length of the fiber into equal-length analysis sections.
If high resolution is required along one portion of the fiber, the whole fiber must be processed at that resolution. Wavelet transforms make it possible to efficiently break up the length of the fiber into analysis sections that vary in length. If high resolution is required along one
portion of the fiber, only that portion is processed at high resolution, and the rest of the fiber can be processed at the lower resolution.
Work to date: The team has developed a C-language prototype of a wavelet-based signal processing algorithm. This static form currently operates at half the speed of the Fourier-based algorithm, but it will be able to operate three to four times faster once optimized.
Looking ahead: Next steps involve developing an adaptive form of the wavelet algorithm and optimizing the code. An adaptive algorithm would automatically change the resolution of sensing based on real-time data. For example, when strain on a wing increases during flight, the software will automatically increase the resolution on the part of the fiber that is under strain.
Improved efficiency: Offers precision measurement only where it is needed rather than on the entire fiber
Faster signal processing: Processes data at different resolutions for specific fiber segments
Fiber Optic Sensing
Armstrong's portfolio of Fiber Optic Sensing System (FOSS) technologies offers unparalleled options for high-resolution sensing in applications that require a unique combination of high-powered processing and lightweight, flexible, and robust sensors. The system measures real-time strain, which can be used to determine two-dimensional and three-dimensional shape, temperature, liquid level, pressure, and loads, alone or in combination. Initially developed to monitor aircraft structures in flight, the system's capabilities open up myriad new applications for fiber optics-not just in aerospace but also for civil structures, transportation, oil and gas, medical, and many more industries.
The Armstrong approach employs fiber Bragg grating (FBG) sensors, optical frequency domain reflectometry (OFDR) sensing, and ultra-efficient algo-rithms (100 samples/second). Engineers are continually seeking new ways of looking at information and determining what is important. Armstrong's FOSS technologies focus on critical research needs. Whether it is used to determine shape, stress, temperature, pressure, strength, operational load, or liquid level, this technology offers ultra-fast, reliable measurements.