Design And Development Of Liquid Level Test Radar

As the key equipment in industrial observation,the precision of liquid level gauge plays a vital role in the measurement of materials.Traditional non-contact measurement methods mainly include ultrasonic ranging and laser ranging.The ultrasonic ranging system is simple and low in cost,but the air decay rate is fast,and easy to be affected by environmental factors and affect its accuracy.Although laser ranging accuracy is high,it is also affected by environmental factors.Microwave measurement is a non-contact liquid level measurement method that is not constrained by too many environmental factors and can be used in a harsh environment.The pulse radar made by PTOF(Pulse Time-Flight)method can be used as the basis of the design of the liquid level height test radar,which has the advantages of high precision,high resolution,and so on.It is the research hotspot of liquid level detection.In this thesis,under the condition of studying the application of PTOF radar level gauge,a PTOF radar level gauge with Raspberry Pi as the upper computer and Xethru X4 is designed,the overall design scheme is put forward,the related hardware and software systems are studied,and the matching antenna is designed for this system.The main research work is as follows:1.Investigate the current research status of non-contact ranging,research trends at home and abroad,and preliminarily propose the research objectives of this paper.2.Introduced and compared PTOF and FMCW’s two popular ranging principles and the factors that affect their accuracy.Combined with the actual situation to determine the overall plan.3.The hardware collocation scheme of the system is determined,the transmitting signal model of the transmitter is selected,and the main sampling algorithm is judged,so the sweep threshold algorithm is selected as the sampling algorithm of the receiver,and Xethru X4 is taken as the core chip of the design,and the working principle of the system is introduced.4.The design and simulation of the antenna with the radar system,through the introduction of the basic principle of the antenna,the antenna is gradually optimized to meet the needs of the system.5.The overall system was built and tested by Raspberry Pi.The test results showed that the overall error of the PTOF radar level gauge in 5m was 12.6cm,and the measurement accuracy was 2.5%.The experimental results meet the requirement of a general liquid level meter for measuring accuracy.