高精度超声波液位测量系统设计  

Design of High Precision Ultrasonic Level Measurement System

作　　者：李泽 姜明顺[1] 吕珊珊[2] 朱友峰[1] 苏晨辉 张雷[1] 张法业[1] 隋青美[1] LI Ze;JIANG Mingshun;LYU Shanshan;ZHU Youfeng;SU Chenhui;ZHANG Lei;ZHANG Faye;SUI Qingmei(School of Control science and Engineering,Shandong University,Jinan 250061,China;Institute of Marine Science and Technology,Shandong University,Jinan 250100,China)

机构地区：[1]山东大学控制科学与工程学院,山东济南250061 [2]山东大学海洋研究院,山东济南250100

出　　处：《自动化仪表》2018年第11期56-59,共4页Process Automation Instrumentation

基　　金：国家自然科学基金资助项目(41472260);山东省自然科学基金资助项目(2014ZRE27372;ZR2017PEE023);山东大学基本科研业务费交叉培育专项基金资助项目(2016JC012);山东大学青年学者未来计划基金资助项目(2016WLJH30)

摘　　要：随着工业生产中对在线液位检测技术要求的不断提升,需要更适用于工业生产、精度更高的测量设备。对基于脉冲回波法的超声波液位检测系统进行了研究和改进,介绍了其工作原理及系统结构。以STM32F407为控制器,设计了超声波信号的产生、接收、处理、采集等电路。发射电路对脉冲宽度调制(PWM)脉冲升压驱动超声波换能器产生超声波,接收电路先对信号进行限幅和滤波处理。通过放大数据将脉冲信号处理成更易分析的低频信号,利用控制器的直接内存存取(DMA)功能实现对信号的连续采集。通过辨识回波信号起始时刻,建立渡越时间与液位之间的关系。试验结果表明,在70 mm的范围内,系统误差小于1 mm。该设计为密闭容器的液位测量提供了一种高精度的检测方法,同时为工业领域的液位在线自动检测提供了参考。Due to the increasing demand for online liquid level detection technology in industrial production,the measuring equipment with higher precision,which is more suitable for industrial production,is needed.The ultrasonic liquid level detection system based on pulse echo method is studied and improved.Its working principle and system structure are introduced.Using STM32F407 as the controller,the electric circuits are designed to generate,receive,process and acquire ultrasonic signals.Through the pulse midth modulation(PWM)pulse,the transmitting circuit boosts the ultrasonic wave to drive the ultrasonic transducer to generate the ultrasonic wave.The receiving circuit limits and filters the signal first,and then amplifies the pulse signal to a more easily analyzed low-frequency signal by logarithm amplification,to achieve continuous signal acquisition by using the direct memory access(DMA)function of controller,and to establish the relationship between the transit time and the level by identifying the beginning of the echo signal.The experiments verify that the system error is less than 1 mm in the range of 70 mm.The design provides a high-precision detection method for the airtight container level measurement and the inspiration for online automatic liquid level detection in industry.

关 键 词：超声波 液位检测 高精度 脉冲回波法 PWM脉冲 带通滤波 

分 类 号：TH86[机械工程—仪器科学与技术] TP216[机械工程—精密仪器及机械]