一种CPLD+ARM齿轮流量计变送器的设计  

Design of Gear Flowmeter Transmitter Based on CPLD + ARM

作　　者：徐巧玉[1] 毛鹏 王军委 朱佩 

机构地区：[1]河南科技大学机电工程学院,河南洛阳471003 [2]洛阳银杏科技有限公司,河南洛阳471003

出　　处：《河南科技大学学报（自然科学版）》2018年第4期16-21,共6页Journal of Henan University of Science And Technology:Natural Science

基　　金：国家自然科学基金项目(51205108);河南省高等学校重点科研基金项目(15A535001)

摘　　要：为了有效地消除齿轮流量计的原始脉冲信号误差,提高其测量精度,设计了一种基于复杂可编程逻辑器件(CPLD)和高级精简指令集处理器(ARM)的齿轮流量计变送器。通过CPLD获取流量计脉冲信号的相位差,确定流体方向;采用状态比较法设计软件,进行滤波整形,消除脉冲信号的原始误差,并输出方向电平与计数脉冲信号。以ARM为处理核心采集计数脉冲的个数和方向电平信号,将流量信号转换成标准信号并输出。实验结果表明:利用光耦和CPLD滤波能够有效减小流量计输出信号中的误差,减小后的误差在0.1%以内,适应不同黏度的液体。To improve the measurement precision of gear flowmeter effectively,and eliminate the original pulse signal error,a gear flowmeter transmitter based on complex programmable logic device( CPLD) and advanced RISC machines( ARM) was designed. The phase difference of the flow meter pulse signal was obtained through CPLD to determine the direction of the flow. The state comparison method was used to design the software for shaping filter,which can eliminate the original error of pulse signal,and output directional level and counting pulse signal. The number of the counting pulse and direction level signal were collected by the ARM processing core,then the flow signal was converted to flow parameter and was output. The experimental results show that opto-isolator and CPLD filter can effectively reduce the error in the output signal of the flow meter. The reduced error of pulse signal acquisition is within 0. 1%,which adapts to the liquid with different viscosity.

关 键 词：复杂可编程逻辑器件 高级精简指令集处理器 光耦隔离 状态比较法 

分 类 号：TP274[自动化与计算机技术—检测技术与自动化装置] TP273[自动化与计算机技术—控制科学与工程]