Research And Design Of Portable Ultrasonic Flow Meter

China is a country with severe water shortage,the water resources per capita is 2300 cubic meters,but China's water consumption is the largest in the world.Statistics on the distribution of water resources in our country is not very perfect,so it is necessary to record the distribution and flow of water resources,and it plays an important role in urban water,industrial development,agricultural production,ecosystem and biodiversity.In addition,the acceleration of the process of modernization and the development of smart city into the national strategy,so it is very important to study the velocity and distribution of water resources by using ultrasonic velocity.In this paper,the ultrasonic velocity measurement method is used to measure the flow velocity with no damage to the flow field,high measuring speed and high sensitivity.The purpose is to study and design a set of portable,intelligent,high precision,energy saving,high stability,the use of a wide range of flow velocity measuring instrument.The design is divided into sensor parts and data collector parts,sensor measures the velocity,temperature and depth of the water,data collector can process and store the collected water data in real time.According to the latest research trends of velocity measurement at home and abroad,based on acoustic Doppler principle and Single-chip technology,ultrasonic measurement method is put forward.The sensor is designed with STM32F407 as the core,and the peripheral circuit is an ultrasonic transmitting and receiving circuit,The data collector based on the STM32F103 kernel,with function in data display,storage,GPRS transmission and 4-20 mA,complete the hardware design of portable ultrasonic flow meter.In the part of system software,the ZoomFFT algorithm of the velocity core algorithm is completed and optimized,and the bottom drive of the data collector is realized.This paper introduces the design principle and calculation formula,the important parameters of the hardware and software,the specific requirements and procedures of the joint debugging,the Comparison of data obtained in the actual environment and design requirements.The hardware and software of the equipment are debugged in the ideal environment of the laboratory,then the actual test is carried out in the river,and the data are analyzed and compared,Finally,the flow rate of the device is higher and the stability is better.The experimental results show that the system meets the requirements of predetermined accuracy.