The Study Of High-Precision LD Pulse Ranging Theory And Implementation

In recent years, the construction of structure looks the direction of large-scale and precision to develop with the state increasing investment in infrastructure. The high-precision measurement of these structures has become an urgent need to solve the key technology in engineering field. Therefore, the high-precision laser pulse ranging technology research is developed that has great significance.This paper proposes that the regular screening technology can beused to achieve mm-level high-precision laser pulse ranging drawing onthe new theories and methods in the nuclear pulse detecting technology.The high-precision laser pulse ranging theory is analyzed systematicallyin this paper, and the results show that the time walk error is the mainfactor affecting the accuracy of time. So, the technical program isproposed which is used of the zero-crossing regular screening technologyto eliminate the time walk error and the features of the zero-crossingpoint is analyzed after unipolar pulse signal forming bipolar signal bydifferential. The time interval measurement method used of "coarse" and "fine" Combination is proposed by analyzing the time interval measuring principle. The principle of using the analog-digital converter to achieve "fine" time interval measuring is analyzed emphatically and the look-up table method is proposed to solve the non-linear problem when Capacitance is charged during the analog-digital conversion process.The main errors of impacting the timing accuracy are eliminated by designing Zero-crossing regular screening circuit, pulse peak hold circuit and APD bias circuit.The circuit system of high-precision LD pulse ranging is designed by solving the key technical issues above and combines the design of software, optical and mechanism parts, Eventually, the prototype of high-precision LD pulse ranging system is developed .The prototype is tested by BEIJING BOFEI INSTRUENT CO:LTD. The testing results show that the prototype measurement range can be achieved 1200m, the repeat measurement accuracy is less than or equal to±5mm, and ranging accuracy is Less than or equal to±(3+2ppm·D) which are better than the technical indicators of development project.