New Fiber Bragg Grating Three-Dimensional Accelerometer Based on Composite Flexure Hinges

Abstract

Multi-dimensional acceleration sensors are used in important applications in the aerospace, weapon equipment, and nuclear fields and have strict requirements in terms of performance, volume, and mass. Fiber Bragg grating acceleration sensors use optical wavelength signals as a medium for information transmission to effectively eliminate the influence of electromagnetic interference between multi-dimensional sensors. In this study, we designed a composite flexure hinge three-dimensional acceleration sensor. To this end, we investigated the coupling mechanism between a new integrated elastomer structure and fiber grating to determine the influence of structural parameters on the static and dynamic characteristics, volume, and mass of the sensor. By optimizing the strain distribution, amplitude, and frequency and coupling characteristics between dynamic dimensions, a design theory and a method for integrating the three-dimensional acceleration sensor were developed. The size of the optimized accelerometer is only 25 mm × 25 mm × 30 mm. Performance testing revealed that, along the three spatial dimensions, the sensor had sensitivities of 51.9, 39.5, and 20.3 pm/g, respectively, resonance frequencies of 800, 1125, and 1750 Hz, respectively, and a measurable frequency range of 0–250 Hz.

Multifunctional Integration of Optical Fibers and Nanomaterials for Aircraft Systems

“…This approach is based on the strain produced in the FBG, due to the inertial displacement of the proof mass under acceleration [ 149 ]. For this reason, it is possible to develop 2- and 3-axis [ 150 ] accelerometers using different assembly conditions and using the multiplexing capabilities of the FBGs. Thus, it is possible to develop FBG-based accelerometers for multipoint measurement, which play an important role not only in navigation systems, but also in structural monitoring in aircrafts.…”

Optical Interferometric MEMS Accelerometers

“…To avoid the chirping effect of the FBG accelerometer, researchers proposed several improved design solutions, including that the Bragg grating is not directly glued to the cantilever beam but forms a fixed connection with the leaf spring and the structural base, [31,37,38,45] or connects the two ends of the Bragg grating element to both ends of the hinge with a flexible hinge structure, [47][48][49] or treats the fiber directly as an elastomer and fixed the inertial mass in the middle of the fiber. [49][50][51] Through the above methods, the Bragg grating is uniformly tensioned to achieve a constant strain distribution. However, the chirping effect also has advantages, which can be applied to solve the problem of wavelength shift with the temperature.…”

A Low-Frequency Fiber Bragg Grating Acceleration Sensor Based on Spring Support and Symmetric Compensation Structure with Flexible Hinges

“…Although these sensors have a wide measurement frequency range, they are not suitable for low-frequency measurements. In another study, Wang, H et al (2021) [18] proposed a composite bending hinge three-dimensional accelerometer. In the three spatial dimensions, the sensitivities of the sensor are 51.9, 39.5, and 20.3 pm/g, respectively, with resonant frequencies of 800, 1125, and 1750 Hz.…”