Optical-fiber Bragg grating sensor query instrument

Abstract

The invention discloses a kind of fiber boolager grating sensor inquiring device. The centre data processing control model is connected to the model communication bus, the narrowband scanning light source connects to the model light source allocating device, the allocating device is at least connected to a sensor inquiring channel model, and the channel model connects to the model communication bus. The invention may use extensible structure, only need to insert in one or several functional model. It can enhance the load bandwidth greatly; the device has a centre control model and several extensible functional model, each functional model is a independent data collecting and processing subsystem, the function will not decreases along the extension of system, it solves the problem that the increment of sensors will lead to the decrease of updating frequency. The cost is decreased greatly. The device not only can measure the shift of centre wavelength of each sensor, but also can provide the change information of waveform and carry on the wave spectrum analysis of real-time data.

Description

Technical field: [0001] The invention relates to the technical field of query equipment, in particular to a fiber Bragg grating sensor query device. Background technique: [0002] With the development of optical communication technology, some technologies in optical communication gradually provide a technical platform for applications in the sensing field, and fiber grating is one of them. The fiber grating sensor based on fiber grating technology is becoming another hot spot in the field of sensor research. Compared with traditional electrical sensors, fiber Bragg grating sensors have very obvious technical advantages in sensor network applications: 1. Good reliability and strong anti-interference ability, because fiber Bragg grating encodes the sensed information with wavelength, and the wavelength is An absolute parameter, it is not affected by the system loss caused by factors such as light source power fluctuations and fiber bending, so the fiber grating sensor has ver...

AI Technical Summary

Problems solved by technology

This type of interrogator can only measure the real-time data of the peak reflection wavelength of the sensor, but cannot provide information on its spectral shape. However, in many applications, the sensor reflection waveform and its changes are very important information. Therefore, MOI Company also Developed a Si720 query instrument using a high-speed AD switching circuit as a data acquisition unit, which has two channels with a query bandwidth of 50nm and a data update frequency of 5Hz

Although it is currently the most widely used and comprehensive query instrument, it is still far from meeting the requirements of modern engineering applications. It has the following main shortcomings: 1. The equivalent query bandwidth is too small. Currently, the best performance is MOI The Si425 is about 200nm. Calculated based on the dynamic range of the 2nm sensor, about 100 sensors can be queried. However, many modern mechanical research measurements and monitoring, such as the application of long-span bridge structures, require more than 1,000 measurement points, which is equivalent to 10. The sum of the above Si425 equivalent query bandwidth, more importantly, in many applications, such as wave propagation and mode analysis in mechanical structures, the data of all measurement points must be synchronized, therefore, multiple query instruments cannot be used together To solve the problem of insufficient query bandwidth, there is still no query instrument of any form with a query bandwidth exceeding 200nm

2. The expansion capability of the query bandwidth is small or almost non-existent. Since the expansion of the query bandwidth is limited by the data processing capability of the central control processing unit, it has actually reached saturation in the Si425 of MOI Company, that is, when the number of sensors reaches more than 100 , the data update frequency drops from 250Hz to 25Hz, and the C signal processing ability is weak. Modern high-performance interrogators still use general-purpose microprocessors (MPUs) instead of dedicated digital signal processors (DSPs) as signal spectrum processing components. , it is impossible to analyze and process a large number of high-speed scanning spectra in real time. For example, the data update frequency of MOI's Si720 is only 5Hz, which greatly limits the application

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