Research On Phase Detection Methods In Laser Range Finder

Nowadays, with the development of science and technology, the demand for distance measurement is indispensable. And the ranging accuracy requirements are also increasing. The research on precision distance measuring has attracted particular interests.Comparing with other light sources, laser has many advantages, such as good monochromaticity, high luminance, good coherence and good collimation. Because of these advantages, laser has been widely used. The role of laser range finder has become increasingly prominent in the modernization and national defense construction of China.Laser ranging according to different principles, it can be divided into pulsed laser ranging technology and phase laser ranging technology. Pulsed laser ranging technology is mainly used in the field of ultra-long-distance measurement, while phase laser ranging technology has played a significant role in the field of medium-range and short-range. In order to improve the accuracy of distance measuring in further, in-depth exploration and research are conducted.Phase laser ranging system is mainly composed of signal transmitting unit, signal receiving unit and signal processing unit. The accuracy of this ranging method depends on the accuracy of the phase detection. Therefore the phase difference measurement is the key technique of phase laser ranging technology. On this basis, the methods of phase detection are compared and analyzed.The purpose of this paper is to improve the accuracy of phase detection, and thus the accuracy of phase laser range finder is improved. So in this paper, the major tasks are as follows:1. The background of distance measuring is introduced. The importance of laser ranging is introduced. Many different methods for distance measuring are discussed.2. The principle of phase laser range finder is introduced in detail. And this paper gives an overview of key technique of phase laser ranging. Which is included the choice of modulation frequencies and the method of measurement of phase difference.3. Several phase difference detection techniques and methods are introduced. The advantages and disadvantages of these methods are analyzed. The phase detection methods of zero-crossing and maximum-crossing are compared.4. Based on the method of zero-crossing detection and maximum-crossing detection, the numerical simulations are made to evaluate their performances. And the simulation results are analyzed and compared.5. The analysis of the shortage of this paper is investigated. And the future of phase laser ranging technology is prospected.With the development of science and technology, we believe that phase laser ranging technology will play an important role in the ranging field in the future. And it will make people’s lives more comfortable and convenient.