Research on Distance Ranger with Electroptical Modulation

• Main Author: 曾仕傑
• Other Authors: 沈志雄
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/58765298446449962661

碩士 === 國立彰化師範大學 === 機電工程學系 === 99 === Abstract In this thesis, we propose a new PLL technique by using a position sensitive detector (PSD) and laser-triangle-projected measurement to evaluate the distance. The different positions of the sensing object induce the variation of the transmission intensity which are detected by sensors and is transferred to the corresponding analog signal. We utilize a position sensitive detector (PSD) in the receiving circuits to produce photocurrent and then transform photocurrent to voltage by a trans-impedance amplifier. To increase the accuracy and reduce the interference of the noise, the differential measurement method uses the electroptical modulation for the laser driving. The new measuring technique is an innovative measurement method that can be done by phase-lock loop measurement. The main purpose is to reduce noise, light environment interference and enhances the measured signal level, which can effectively eliminate noise and improve noise ratio with better than traditional measurements.