High-Accuracy Fiber-Optic Shape Sensing
In this study we are concerned with quantifying the accuracy and precision of measurements taken from axially co-located strain sensors in a multi-core optical fiber. First, shape calculations based on Fiber Bragg Grating (FBG) strain measurements are examined and a discussion of potential error sources is provided. Then shape calculations based on Rayleigh scatter strain measurements are examined.
We describe the results of a study of the performance characteristics of a monolithic fiber-optic shape sensor array. Distributed strain measurements in a multi-core optical fiber interrogated with the optical frequency domain reflectometry technique are used to deduce the shape of the optical fiber; referencing to a coordinate system yields position information. Two sensing techniques are discussed herein: the first employing fiber Bragg gratings and the second employing the intrinsic Rayleigh backscatter of the optical fiber. We have measured shape and position under a variety of circumstances and report the accuracy and precision of these measurements. A discussion of error sources is included.
R. G. Duncan et al., "High-accuracy Fiber-Optic Shape Sensing," 14th Int. Symp.: Smart Structures and Materials & Nondestructive Evaluation and Health Monitoring, San Diego, CA 2007, pp. 65301S-11.