Design And Research Of Multi-channel Ultrasonic Flow Meter

In recent years,ultrasonic technology has been widely used in the field of flow measurement,which has promoted the development of ultrasonic flowmeters.Ultrasonic flow meter has the advantages of convenient installation,wide measurement range and no influence on fluid flow field.It plays an important role in the field of hydrological survey and industrial measurement in my country.At present,my country’s ultrasonic flow meter still has many problems to be solved urgently,such as low measurement accuracy and high overall power consumption,which restrict the development of ultrasonic flow meter.In response to the above problems,this article designed a multi-channel ultrasonic flow meter based on a full understanding of the ultrasonic technology and the principle of time difference flow measurement,analyzed the factors that affecting the measurement accuracy,and proposed a new flow measurement algorithm,the algorithm can reduce the influence of temperature changes on the accuracy of flow rate measurement to a certain extent.At the same time,the hardware analog switch is controlled by the software program to realize the multi-channel flow rate measurement,which further improves the measurement accuracy.For the hardware circuit design part,the single-chip microcomputer,timing chip and signal strength indicator that used in this article all have the characteristics of high precision and low power consumption.The specific implementation process is that realize multi-channel selection and transducer drive through analog switch and push-pull drive circuit respectively firstly,then use adjustable LC frequency selective amplification network to select frequency,filter and amplify the signal,and then use signal strength indicator and comparator accurately judge the echo signal,and finally use the timing chip TDC-GP22 to measure the ultrasonic propagation time with high precision,which realizes the hardware circuit design with high accuracy,strong stability and low power consumption.For the software programming part,firstly,the data communication between the PC and the single-chip microcomputer,the single-chip microcomputer and the timing chip is realized through RS485 and SPI,and then the channel switching in the measurement process is realized through the program design,the data parsing program is designed to realize the fast reading and writing of the timing chip finally.Based on the hardware circuit design and software program design,this article completed the prototype production,and verified the flow rate measurement function of the prototype through static water experiments.At the same time,for the measurement accuracy and power consumption indicators,a comparative experiment was carried out with the acoustic doppler current profiler.The results show that the multi-channel ultrasonic flow meter designed in this paper can achieve multi-layer measurement of fluid flow rate.It can ensure high measurement accuracy,while having the characteristics of low power consumption and fast measurement speed,and meet the expected design goals.