A Design Of Ultra-low Power And High Precision Ultrasonic Flowmeter Based On MSP430

As one of the important parameters in the field of industrial control,how to improve the accuracy of measuring has been one of the problems studied by the industry.Ultrasonic flowmeter is developed from the 1950 s,which is a new kind of flowmeter by measuring the ultrasonic’s time of flight to get the flow without contacting with medium.Ultrasonic flowmeter have been widely welcomed because of its non-contact,wide range of applications,high precision,intelligent,low cost,strong ability to resist environmental interference and many other characteristics.However,the domestic design and development of ultrasonic flowmeter,whether in precision,circuit design rationality,stability,there’s still a big gap.At present,the domestic high-level ultrasonic flowmeter market is basically occupied by foreign products,the cost is relatively high,the domestic technical staff are difficult to maintain it due to technical constraints.Therefore,the development of localization,and the international level of the flow meter has been the field of people tireless efforts of the direction.This paper first introduces the research background of this subject,the development history of the flowmeters,introduces the various types of flowmeters and compares their advantages and disadvantages.Then we introduce the ultrasonic flowmeters’ s necessary situation both in countrys and foreigns.The influence of the time difference method on the final measurement results is analyzed by using the mathematical tools,also including the analysis of fluid motion state,the impact of temperature on the velocity of ultrasonic propagation.Real-time measurement of temperature is realized by hardware circuit,and the error of difference between line speed and surface speed,and correct it by using mathematical method,so as to achieve the purpose of improving the measurement accuracy.Secondly,this paper designs the overall hardware design of the ultrasonic flowmeter.The MSP430FR4133 is chosen as the overall control chip of the system.TDC1000 is used as thedriving chip and temperature measuring chip of the ultrasonic transducer.The TDC7200 is selected as the high precision time measuring chip and For the two chips can be normal to achieve the function of the design of the corresponding data transmission circuit,control circuit,and the necessary power and clock circuit.And the design of the replacement of the temperature sensor and ultrasonic sensor interface circuit to facilitate the installation and maintenance of the prototype.In the design of the circuit at the same time,pay attention to the optimization of the circuit,better control of the cost and reduce the power consumption of the flowmeter,to a certain extent,improve the robustness of the hardware circuit.Finally,according to the selected hardware parameters and performance,completed the corresponding software flow design and code preparation.Finally,according to the hardware circuit design scheme,the prototype circuit board and the corresponding software driver is designed.The prototype platform is set up.Under the limited experimental conditions,the error analysis,time of flight test,temperature test and flow calibration test are carried out.The Experimental results show that the design of the basic realization of the expected function.