Research On Ultrasonic Flowmeter Based On Correlation Algorithm

Ultrasonic flowmeter is widely applied to the fields of meteorology, petroleum chemical, medicine, water resource management, for the advantages non-contact, high accuracy, ease-to-use and so on. Great progress has been made on Ultrasonic Flowmeters, in recent years, with the development of digital signal processing technology and microprocessor. A new kind flowmeter based on ARM is introduced in the dissertation, which accords with the embedded system development.This dissertation introduces the history, present status and trend of flowmeter, explains the theory and characters of ultrasonic flowmeters and discusses the usual methods of measuring the flow by ultrasonic as well as both correlation and interpolation principles. Furthermore, the designing of an ultrasonic flowmeter, the application of correlation principle in measuring flow by phase difference method are explored and the calculating approach of key parameters in correlation algorithm are given, and the effect of interpolation algorithm on improving measurement precision are investigated.The theory of correlation principle in ultrasonic flowmeter and the hardware based on ARM S3C2410 will be introduced. In system hardware, the ultrasonic transmitting, receiving and amplifying circuits are designed, and the ultrasonic signal is digitalized by high speed A/D converter. The S3C2410 ARM system circuits including system power, memory, communication faces are introduced as well as the software analyse the linux system migration and the software design for ultrasonic transceiver module, communication module, and control module on ARM9.