Ultrasonic Measurement and Beamforming using Optical Sensors

该提案描述了用于超声监测应用的灵敏、轻便的光学传感器的基本发展和响应量化。主要研究内容集中在对超声波应变场和光纤布拉格光栅(FBG)传感器之间的基本相互作用提供全面的理论和实验理解。这项技术的两个潜在开发实例为本研究提供了背景和应用背景：声纳阵列中的超声波波束形成和结构健康监测中的声发射检测。这些区域经过精心选择，因为它们涵盖了工程应用中常见的超声信号的典型幅度范围(在发射声纳阵列中，位移场是高幅度的，通常为10‘S纳米级，而在声发射应用中，位移场幅度可能低于100微微米)。泰利斯水下系统(声纳系统)和空中客车英国(结构健康监测)的支持函也包括在内，以帮助证明这项工作的价值。当然，超声波阵列监测的机会并不局限于声纳系统。在声纳、无损检测和医学超声领域，对提高测距精度和分辨率的需求日益增长。这种阵列中的轻量级、非侵入性超声场监测能力的潜力提供了一种独特的能力，以提供对这些阵列输出处的幅度和相位特性的绝对测量(对照光学波长校准)。这样的测量有助于校准、优化波束形成算法，以及在运行条件下连续监控实时变化的能力。如果研究成功，除了相关领域外，这项研究还将使这两个应用领域发生阶段性变化。

The proposal describes the fundamental development and response quantification of sensitive, lightweight optical sensors for ultrasonic monitoring applications. The principal research components centre on providing a comprehensive theoretical and experimental understanding of the basic interactions between ultrasonic strain fields and optical fibre bragg grating (FBG) sensors. Two potential exploitation examples of the technology provide the background and application context for this research: ultrasonic beamforming in sonar arrays, and acoustic emission detection in structural health monitoring. These areas were carefully selected as they encompass the typical amplitude range of ultrasonic signals commonly encountered in engineering applications (in transmit sonar arrays the displacement fields are of high amplitude, often many 10's of nanometres, whereas in acoustic emission applications, the displacement field amplitudes may be lower than 100 picometres). Letters of support from THALES Underwater Systems (Sonar systems) and AIRBUS UK (Structural Health Monitoring) are included to help demonstrate the value of this work. Of course the opportunities for ultrasonic array monitoring are not confined to sonar systems. The increasing use of complex coded sequence actuation for ultrasonic arrays demonstrates a growing demand for improved ranging accuracy and resolution in sonar, non destructive testing and medical ultrasound fields. The potential for a lightweight, non-intrusive ultrasound field monitoring capability in such arrays provides a unique capability to provide absolute (calibrated against optical wavelength) measurement of the amplitude and phase characteristics at the output of these arrays. Such measurements facilitate calibration, optimisation of beamforming algorithms, and the capability to continuously monitor real-time changes under operational conditions. If successful the research will enable a step change for both areas of application in addition to related fields.