Range Finder With Pulse Reflection Oscillation Method

• Main Authors: Wen-Chieh Liu, 劉文傑
• Other Authors: Mao-Hong Lu
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/64121824428828339033

博士 === 國立交通大學 === 光電工程所 === 91 === For either one of the two conventional methods, the phase method or the pulse method, employed in usual laser range-finders, more and more sophisticated circuit is needed when higher and higher precision is to be performed. The purpose of this thesis is to present a new method, the pulse reflection oscillation method, and to verify its feasibility by designing and operating a prototype system based on its principle. The pulse reflection oscillation method works by measuring the period of oscillation waves in the emission-reflection loop to decide the propagation time between the target point and the reference point. It employs a frequency counter to measure the period. It can perform very high precision measurement with very simple circuit. In this thesis, the system’s optical path configuration is defined and the principle of pulse reflection oscillation is discussed. Based on the configuration, the system is applied in the measurement of the propagation delay in optical fibers and in the determination of the fault point in electric cables. The results verify the feasibility of the method.