基于TDC_GP2的高精度时间差测量的关键技术研究

Study on the key technology of high-precision time-difference measurement based on TDC_ GP2

时差法超声波流量计、激光测距、磁致伸缩传感器等领域要求测量开始脉冲与停止脉冲之间的时间间隔精度必须达到纳秒级以内,为此,本文基于最小分辨率达65ps的专用测时芯片TDC_GP2,采用高性能FPGA Core3S500E作为主控器,设计了一种高精度超短时间间隔的测时系统.本文详细分析了测时系统的硬件电路原理及软件设计的关键技术,为评估测时芯片不同时间间隔测量的精度,对TDC_GP2的测量范围1及范围2进行了一系列时间间隔测量实验及数据误差分析.实验结果表明,测时芯片TDC_GP2对于纳秒级时间间隔的测量,测量精度均为皮秒级,500μs以下的时间间隔测量数据极为稳定,标准差均在180 ps以下.

Some measuring instruments such as transit - time ultrasonic flow meter, laser ranging and magnetostrictive sensor require that the precision of the time difference between the begining and the ending pulse must reach nanoseconds. In the present paper a measuring system of high resolution and ultra - short time interval was developed based on the special time measurement chip -TDC_GP2 with minimum resolution of 65ps and used the high performance FPGA Core3SS00E as the host controller. The key technology of the hardware circuit principle and software flowchart was analyzed ill detail. In order to evaluate the accuracy of different time interval measurement, a series of time interval measurement experiments and error analysis in the measurement range 1 and 2 was carried out. The results showed that for the nanoseconds time interval measurement, the measurement precision level of the TDC_GP2 is picoseconds and for the time internals below 500 μs, the measuring data has higher stability and the standard deviation is all within 180 ps.