Triangle method of laser range finding based on twosection beam technology

ZHANG Lingbao, ZHU Hua
(College of Science, Zhejiang University of Technology, Hangzhou 310032, China)

Abstract: Aiming at realizing the fabrication of miniaturized laser range finder with low cost, a new triangle method for laser range finding based on the twosection Gaussian beam was proposed. Double PIN photodiode was used to acquire two section beams, replacing CCD or PSD for traditional triangle method in laser range finder. The relationships among the power ratio of two section beams, the corresponding range and the emission angle were derived from the photometry and Gaussian beam theory. Some figures for the above relations were plotted by using numerical methods, and the range to the target could be calculated from the measured power ratio. The test results indicate that this method is possessed of the merits of simple structure, high resolution and less sensitive to the darkness of the target object.
Key words: laser range finding; triangle method; power ratio; background noise