THE ANALYSIS OF DIGITAL PHASE-SHIFT MEASURING METHODS FOR DUAL-FREQUENCY LASER RANGE FINDER |
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| Li Menglin, Xie Wenfeng, Zhu Jingguo, Ren Jianfeng, Xiao Fang, Meng Zhe |
- Abstract:
- Phase-shift range finder is to measure the phase-shift of the modulation wave during its propagation. The precision of traditional phase-shift range finder is limited by measurement rate and the modulation depth. Usually the modulation depth of laser diode decreases with the increase of modulation frequency which is crucial for high precision with sinusoidal modulation. A new phase-shift range finder with dual-frequency He-Ne laser is introduced. The error model is built in order to analyze the factors influencing the precision of phase-shift laser range finder.
Two digital phase-shift measuring methods are discussed through the principle simulation. The white noise, the frequency offset and other error factors are introduced during the simulation. Then the measurement performances on all-phase spectrum analysis method and a new sub-sampling spectrum analysis are analyzed. The simulation results indicate that all-phase spectrum analysis method is advantageous for high speed and high accuracy measurement, owing to its better performance in error immunity. The sub-sampling spectrum analysis method reduces the hardware requirement and the simulation results show that the accuracy of phase-shift measurement can reach to the Cramer-Rao limit. - Keywords:
- phase-shift range finder, dual-frequency laser, all-phase spectrum analysis, sub-sampling spectrum analysis
- Download:
- IMEKO-TC14-2014-27.pdf
- DOI:
- -
- Event details
- IMEKO TC:
- TC14
- Event name:
- TC14 LMPMI Symposium 2014
- Title:
11th Symposium on Laser Metrology for Precision Measurement and Inspection in Industry
- Place:
- Tsukuba, JAPAN
- Time:
- 03 September 2014 - 05 September 2014