科研之友
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摘要
Optical fiber using for displacement measurement has the characteristics of high resolution, high responsibility, small size and has been widely used, but it';s only suit for single point measurement. So combining with optical communication technology, a new optical fiber displacement measurement system with multi-channel is proposed. Based on the principle of reflective light intensity modulation, light of the single laser source is modulated by LiNbO3 electro-optical crystal. The modulated light, via a 3-Port circulator, is injected into a 1 × n optical switch quickly, different measuring channels, measuring channel and reference channel can be switched alternately by the optical switch, then the light is injected to a common photo detector and lock-in amplifier circuit, this can avoid the parameter inconsistent of multi-processing circuits and reduce the cost. Voltage of the output signal is directly proportional to the reflective light intensity and then converted into digital form by an A/D module. The digital signal is processed by software to get the final measured displacement. The common reference channel is adopted to revise the variation of the light source. Stability of the system is so as to be improved. The experimental results show that the resolution of the system is 0.1 μm, repeatability is up to 0.5%. The system is simple in configuration and has great expansibility. It';s flexible to increase or decrease the measuring channels by changing the number of the optical switch channels and the measuring optical fibers.
- 出版日期2009
- 单位北京交通大学
