Design And Application Of Digital Broadband Ultrasonic Detection Circuit System

Currently, most common ultrasonic detection applications use the echo information in time field and the detecting signals they use are generated by analog signal generators. These systems could only get limited information with low accuracy and poor mobility. Digital broadband ultrasonic detection circuit system owns strong anti-jamming capability by using digital detecting signals. Any types of signals can be generated, complex analysis methods are usually employed in echo signal processing as well. Then on this base, National Engineering Technology Research Center for Mobile Ultrasonic Detection where the author belongs considers realizing mobile ultrasonic detection as its research direction by using WBFM to raise quantity of information, detecting precision and efficiency. The thesis is mainly about constructing high-speed and high-accuracy digital broadband ultrasonic detection circuit system to provide test platform for the research of the center.In the second chapter, the thesis introduced the characteristics and applications of ultrasonic and different types of ultrasonic sensors. In the third chapter, the thesis introduced the structure of digital broadband ultrasonic detection circuit system in detail and made a performance comparison with traditional analog ultrasonic detection system. Then the thesis put up an algorithm to get the intrinsic frequency response of the digital ultrasonic testing system. In the fourth chapter, the thesis attempted to design and construct a digital wired broadband ultrasonic detection circuit system and verified its practicability and reliability with tests of ultrasonic sensors’ frequency response and ultrasonic ranging. In the fifth chapter, due to the low mobility of the digital wired broadband ultrasonic detection circuit system, the thesis then designed a digital wireless broadband ultrasonic detection circuit system which has become an effective solution to the mobile ultrasonic detection. It separates the data processing module and the detection front-end and the lower power consuming detection front-end realizes cutting down the costs of testing applications. The thesis also made some related tests on the wireless system and then gave a comparative analysis with tests results in the fourth chapter. The innovation of this thesis lay in:1. Using LFM as the detecting signal to own high accuracy by raising quantity of information. 2. The two systems constructed all use digital signal. Hence the optimum signal and matched ultrasonic sensors are chosen depending on different measured objects and complex analysis method is adopted for furthest information reversion while conducting the echo signal. The systems are no longer limited to single application scenario. The two systems could be extended easily for more efficient independent channels by increasing the quantity of chips to meet the simultaneous detecting requirements of multi channels. 3. Digital wireless broadband ultrasonic detection circuit system realizes separating its signal processing module and detecting front-end. There is a high-speed wireless data transmission scheme between these two modules. The data processing is run in background. Mobile ultrasonic detection would be realized.