High-Precision Measurement Method of Time-Interval Based on Pseudo-Random Sampling
作者单位：Opto-Mechatronic Equipment Technology Beijing Area Major LaboratoryBeijing Institute of Petrochemical Technology
会议名称：《The 2011 International Conference on Automation and Robotics(ICAR 2011)》
会议日期：2011年
学科分类：080802[工学-电力系统及其自动化] 0808[工学-电气工程] 08[工学]
关 键 词：Pseudo-random sampling Time-interval measurement Phase estimation
摘 要：Based on pseudo-random sampling a high-precision measurement method of time-interval for pulsed laser ranging is presented for the first time. In the method, time-intervals of laser pulses are controlled by a chirp signal generated using a Voltage-Controlled Crystal Oscillator. The time-intervals are unequal pseudo-random sequences. Pulse laser signals reflected from the object become sampling signals after they pass through a time discriminating circuit. Characteristics of measured signals are represented by the mapping of sampling time points on a referenced sinusoid signal. Then high-precision measurement of time-intervals can be implemented using a phase estimation algorithm. This method is simple in theory and easy to realize. In experiments using 15 MHz reference clock, it is achieved that the measurement precision of time is 16 ps.