Experimental Study Of High Speed And High Precision Ultrasonic Temperature Measurement System Based On FPGA

Modern technology’s ongoing advancement has led to more stringent criteria for temperature measurement devices,and traditional temperature instruments due to the thermoelectric effect of sensitive elements used to detect temperature,the temperature measurement process requires full heat exchange with the measured material,resulting in the measurement results are prone to temperature lag,the upper limit of temperature measurement is constrained by the high temperature resistance of the sensitive element material,can not meet the temperature measurement needs of continuous high temperature measurement,measurement accuracy is also difficult to improve.Ultrasonic temperature measurement technology not only has various advantages of acoustic temperature measurement methods:wide temperature measurement range,fast response,with high sensitivity,coupled with the ultrasound itself has good propagation direction,the energy carried by the more concentrated,strong penetration characteristics,making ultrasonic temperature measurement methods have better anti-interference,higher accuracy.Therefore,this paper is based on ultrasonic temperature measurement method,in order to design a high-speed and high-precision temperature measurement system to carry out research,the main research content is as follows.1.First of all,the research status of ultrasonic temperature measurement technology and the study findings have been thoroughly examined.The principle of ultrasonic temperature measurement has been presented based on an investigation of the fundamental properties of ultrasound.The time difference method and phase difference method,two widely used ultrasonic measurement techniques,as well as the implementation difficulties were studied in depth,and after comparison and consideration,the one-way measurement time difference approach was selected for ultrasonic measurement,and a detailed implementation strategy was provided.2.With FPGA serving as the system’s general control center,which includes both the hardware component and the software logic control component,the design and implementation of the ultrasonic temperature measurement system are finished.The system combines the ultrasonic transducer,FPGA development platform and its peripheral circuits,voltage regulation subsystem,time measurement component,memory component,serial communication component and other hardware devices and circuits,through the Verilog hardware description language to achieve logic control and programming of each functional module,and each module’s functionality is verified using functional simulation.3.An experimental platform was constructed,experiments to confirm the viability of the system were developed,and ultrasonic time measurement experiments were carried out.The system was to be improved by filtering and amplifying the echo signal,optimizing the threshold comparison method to increase the precision of the ultrasonic wave propagation endpoint,and de-noising the measurement data after analysis of the measurement data and discussion of the causes of errors.The experiments demonstrate that after the improvement,the system’s measurement stability is enhanced,its measurement resolution can approach 1 ps,and its measurement error is decreased to within 0.01 ns.4.Experiments are conducted in a variety of different liquid media,and a high degree of fitting between propagation velocity and temperature is accomplished based on the least squares method,so that the temperature measurement function of the system is realized.The system’s resolution for measuring temperature is 0.001℃,its accuracy is superior to the 0.1℃ accuracy of the reference thermometer used in the experiment,and it has greater sensitivity and a faster response time than a conventional thermometer.