关键词: 信息处理技术, 飞行时间, 双边沿计数器, 相位延迟内插, 现场可编程逻辑门阵列

Abstract: A new high-precision echo flight time of measuring algorithm was presented by analyzing the advantages and disadvantages of high-precision digital time interval measuring algorithms, which combines the pulse counting method with the phase delay interpolation. The pulse counting method is used to ensure a large dynamic measuring range, and the double-edge triggering counter is designed to improve the accuracy and reduce the counting quantization error. The phase delay interpolation is used to reduce the quantization error of pulse counting for further improving the time measurement resolution. A n-fold phase delay interpolation was performed to raise the time measurement resolution to 1/2n of the quantized error. Test data show that the echo flight time measurement system with this algorithm as its core and implemented on Xilinx FPGA has a shorter conversion time, and a measured error is less than 55 ps.

Key words: information processing, time of flight, double edge counter, phase delay interpolation, field programmable gate array