Differential Incremental External Ultrasound Research And Implementation Of Liquid Level Precision Measurement System

With the rapid development of measuring technology, in some situations the accuracy of liquid level measurement is also increasing. External type and intelligent and high precision measurement is the development trend of current level measurement technology. Therefore, the differential complement and external ultrasonic liquid level measuring system has been attached more and more importance.By viewing and researching on the information of the liquid level measurement, this topic designs a kind of high-precision ultrasonic level measurement system based on FPGA. The project has realized the design of the ultrasonic transmitting and receiving system and the production of PCB circuit board, then the project analyzes and processes the data of the later stage.The experimental results show that in the tank under the condition of body temperature and oil density variable, and within 0.1 ~ 1m’s system measurement range, this measuring system is highly accurate and practical. This topic mainly researches the following aspects: First of all, the ultrasonic wave is introduced briefly, including the generation and use of ultrasonic, ultrasonic ranging system and ultrasonic ranging principle and other basic knowledge. The hardware circuit of ultrasonic liquid level measurement system is designed, which includes power module, transmitter module and receiver module. After the completion of the module design, we use Multisim to simulate this circuit and finally make PCB board. Secondly, the main factors of affecting the ultrasonic ranging accuracy, including temperature, echo the timing of measurement accuracy and measuring blind area, are described. And we get the differential complement and external ultrasonic model, and the model is based on Matlab simulation. In the end, this paper introduces the function of the differential complement and external ultrasonic distance algorithm on FPGA. The system is divided into pulse transmitting module, high speed counting module, echo receiving module, the distance calculation module. The design verification is carried out for each sub module, then designs the top sequence, finally realizes the echo receiver function.