多声路高精度超声波流量测量系统

为了满足大管径流量的测量精度,研制了基于现场可编程门阵列器件FPGA和锁相环路的多声路超声波流量测量系统。系统以FPGA为主要逻辑控制芯片,计算机为操作控制平台,单片机AT89C52为计算机与FPGA的通信中转枢纽,AT89C52将FPGA测得的基于锁相环路的多个超声波声路测量数据传送给计算机,由计算机负责对流量进行计算和数据处理。锁相环路的采用提高了时钟相位的精度,从而提高了传播时间的测量精度,根据对系统精度分析得出系统测量误差小于0.25%。

Multi-paths ultrasonic flow measurement system with high precision

In order to satisfy the flow measurement precision for big-pipe,multi-paths ultrasonic flow measurement system based FPGA(Field Programmable Gate Array) and phase lock loop(PLL) was developed.The system used FPGA as the main logic control chip,computer as the operation consol,and singlechip AT89C52 as the communication hinge between the computer and FPGA.AT89C52 transfered the the measurement data of multiple ultrasonic paths based PLL from FPGA to computer,and the computer then calculated the flow.The adoption of PLL improves the clock phase precision leading to improving the measurement precision of the travel time.The system precision analysis showed that the flow measurement error is less than 0.25%.