| With the rapid development of modern processing industry and precision manufacture, high-level equipment manufacturing demands for new micro-devices with complex structure widely. However, the available detection technology can not evaluate this kind of micro-devices directly and effectively, which restricted the development of processing and related field seriously. With the continuous development of probe sensor technology, Multi-core fiber probe sensor can achieve three-dimensional decoupling measurement of micro-scale with CMM because of its advantage of decoupling. But existing Multi-core fiber probe sensor has many problems, such as signal crosstalk, low signal demodulation efficiency and high production costs.To deal with the problems above, this paper proposes a self-assembled optical fiber grating sensor for measurement of micro scale and demodulation system. The probe sensor fabricated by four single mode fibers based on the theory of self-assembly, can reduce the production cost and overcome the problem of singal crosstalk effectively. At the same time, a high speed signal demodulation system is designed for the probe sensor, realizing the rapid demodulation of the sensor output signal. In this paper, the principle of fiber Bragg grating probe self-assembly, sensor packaging production, signal demodulation and measurement system is thoroughly investigated, and the performance of the probe sensor is verified by experiments. The main research works of this paper are as follows:1. Packaging study self-assembly optical fiber grating sensor. A method of fabricating multicore fiber grating probe sensor based on the self-assembly priciple is proposed, to solve the problems of the existing multicore fiber grating probe sensor, such as high cost, signal crosstalk and transmission loss. the model of self-assembly fiber grating is established and analyzed, the feasibility of single mode fiber form multicore fiber by liquid bridge is validated; a self-assembly optical fiber grating probe sensor is produced.2. Design optical power demodulation system. Design optical power demodulation system based on the principle of differentical compensation, to realize the rapid demodulation of two lines output sianal in probe senso, raising the efficiency of demodulation by 10 times. A new prestressed adjustment device is designed, to solve the problems such as air turbulence and mechanical vibration, the stablity of a minute is improved from the original 0.25 % to 0.07 %. And the power resolution is 7 p W.3. Design self-assembly fiber grating probe measurement system. In view of self-assembly fiber grating probe microscale measurement requirement, the measurement framework is optimized. And the measurement software for self-assembly fiber grating probe is wrote, through the piezoelectric control, motor drive control and serial interface communication subprogram, to realize the function of probe posture adjustment and microscal automatic measurement.4. Test the self-assembled fiber grating microscal measurement system. The attitude adjustment function of the measurement system and measurement software is validated base on the designed microscale measurement system, the result shows that the initial attitude of probe is adjusted by automatic. Then, the performance of the probe measurement system is tested: the sensor is verifield with orthogonal decoupling ability. the stability of the measurement is 30 nm within 1 minutes and 60 nm within 10 minutes, a radial resolution of 30 nm and an axial resolution of 10 nm can be achieved. The repeatability precision is less than 0.09 μm. Last, a micro hole in the engine is measured. The average diameter of the hole is 282.8 μm, and the expanded uncertainty is 0.4 μm for k=2.This paper has researched the fiber grating self-assembly principle and fabricated the probe sensor, which solves the problems of the existing multicore fiber grating probe sensor in the microscale measurement. It provides a new way for microscale measurement. |
PDF Full Text Request