2D and 3D Shape Sensing Based on 7-Core Fiber Bragg Gratings

Abstract

A fiber-optic shape sensing based on 7-core fiber Bragg gratings (FBGs) is proposed and experimentally demonstrated. The investigations are presented for two-dimensional and three-dimensional shape reconstruction by distinguishing bending and twisting of 7-core optical fiber with FBGs. The curvature and bending orientation can be calculated by acquiring FBG wavelengths from any two side cores among the six outer cores. And the shape sensing in three-dimensional (3D) space is computed by analytic geometry theory. The experiments corresponding of two-dimensional (2D) and 3D shape sensing are demonstrated and conducted to verify the theoretical principles. The resolution of curvature is about 0.1m−1 for 2D measuring. The error of angle in shape reconstruction is about 1.89° for 3D measuring. The proposed sensing technique based on 7-core FBGs is promising of high feasibility, stability, and repeatability, especially for the distinguishing ability on the bending orientation due to the six symmetrical cores on the cross-section.

On-Chip Sub-Picometer Continuous Wavelength Fiber-Bragg-Grating Interrogator

“…Several approaches for FBG interrogation have been reported in the literature, such as the scanning Fabry-Pérot (FP) cavity [8,9], tunable lasers [10,11], and volume phase grating-based spectrometers [12,13]. However, most traditional interrogators usually suffer from the high price and bulky volume, which limits their applications in some emerging fields, such as unmanned aerial vehicle (UAV) monitoring, lithium-ion battery status monitoring [14], and in-situ three-dimensional (3D) shape sensing [15][16][17][18]. On-chip FBG interrogators based on the photonic integrated circuit (PIC) technology have been extensively studied recently due to its advantages of the small size and low power consumption.…”

Strain measurement with multiplexed FBG sensor arrays: An experimental investigation

“…Historically, sensing technologies based on Fibre Bragg Grating (FBG) [ 15 ] have been applied to a vast range of applications, such as shape sensing [ 16 , 17 ], healthcare [ 18 ], magnetic field detection [ 19 , 20 ], as well as in the hydrocarbon industry [ [21] , [22] , [23] , [24] ]. More recently, the intrinsic properties of the FBG, such as its low electromagnetic interference (EMI), natural waterproofness, multiplexing capability, small size, acoustic emission capabilities, resistance to high pressures and high temperatures (HPHT), wavelength-encoded characters and linearity with pressure [ [25] , [26] , [27] , [28] ], have been seen as outstanding advantages for using FBG to measure strain, temperature, pressure and ultrasonic waves effectively in a laboratory environment [ [29] , [30] , [31] , [32] ].…”

Shape Sensing Based on Longitudinal Strain Measurements Considering Elongation, Bending, and Twisting

“…Often, the fibers are arranged in parallel to the centerline of the sensor array which we denote as a longitudinal arrangement. With the help of the known geometrical relations of the array's cross-section, the shape of the deformed array can be reconstructed [10], [11], [12]. Various researchers apply this approach to reconstruct the centerline of continuum robots, e.g.…”