Research Of Development And Measurement Methods Of Mechanical&Thermal Multi-parameter Testing Platform Based On Optical Fiber Technology

With the continuous development of science and technology,optical fiber sensors have attracted extensive attention because of their anti-electromagnetic interference,high sensitivity,high and low temperature resistance,and have been used in the detections of various parameters.In order to meet the requirements of detecting mechanical and thermal parameters in extreme environments,we have designed and developed the mechanical & thermal multi-parameter testing platform based on optical fiber technology to realize the multi-point detection of pressure,temperature,strain and acoustic vibration.On the basis of reviewing the development status of related fields at home and abroad,the main work is as follows:1.The overall design scheme of the mechanical & thermal multi-parameter testing platform is proposed in term of the modular design idea.Based on the principle of fiber Fabry-Perot sensing and fiber grating sensing,the thesis presents the multichannel fiber optic pressure sensing subsystem,fiber optic temperature/strain sensing subsystem and fiber optic acoustic vibration sensing subsystem.2.The mechanical & thermal multi-parameter testing platform is developed on account of the modular design concept,including the design and implementation of optical circuit module,drive control module,data acquisition and processing module,and the whole machine structure and interface.The method of instrument assembly and debugging is standardized,and the common causes and solutions are analyzed and summarized,which guarantee the basic functions of the platform.3.A demodulation algorithm based on all-phase filters is proposed,in view of the problem that the noise affects the demodulation accuracy.The algorithm is verified by using the fiber optic temperature/strain sensing subsystem.The results show that the proposed algorithm has good noise reduction effect.Compared with the traditional centroid method,the demodulation stability is improved by 30%,and it can meet the real-time processing requirements of the experimental site.4.The measurement methods of measuring performance and quality characteristics of the mechanical & thermal multi-parameter testing platform are studied.We tested the multi-parameter measurement performance and the multichannel real-time acquisition and processing capability.And the environmental adaptability and the reliability index were achieved.The test results have proved that the mechanical & thermal multi-parameter testing platform can make accurate and reliable measurements.