Research On Invisible Two-dimensional Code Design And Scanning System Based On Ultrasonic Phased Array

Because of various advantages, such as large information capacity, error correction, goodsecrecy, scanning fast, high flexibility and low system cost, two-dimensional code technologyhave been widely applied. Because of easily be blocked and damaged, invisibletwo-dimensional code technology based on optical is difficult to meet the demand for securityand confidentiality of the data information. Recent years, ultrasonic phased array technology isgaining great attention in the international, which has the characteristics of maneuverablesteering beam and dynamic focusing beam. Combining the ultrasonic phased array technologywith two-dimensional code technology, a new kind of invisible two-dimensional code wasdesigned. It provides a more concealed and more confidentiality invisible two-dimensionalcode technology. In comparison with the conventional ultrasonic testing technology，theultrasonic phased array technology provides a method of rapid beam steering and sequentialaddressing of a large area without requiring mechanical or manual scanning. Applying theultrasonic phased array technology to the invisible two-dimensional code scanning system canimprove the invisible the two-dimensional code scanning speed and reading accuracy.This dissertation firstly analyses the two-dimension code technology, Summarizing thecharacteristics and deficiencies of the two-dimension code technology. According to thecharacteristics of ultrasonic detecting technology, this dissertation provides a new design ideafor invisible two-dimensional code.This dissertation introduces the status of researches on Ultrasonic phased array technology,elaborates the principle of Ultrasonic phased array technology in detail. Via the research of thelinear phased arrays ultrasonic field, the model of acoustics directivity was built. A simulationstudy on the influence of each parameter to the directivity of the linear phased arrays wascarried out, including the number of array elements, control angle, element spacing and widthof the array element.Based on analyzing the defect characteristics of the invisible two-dimensional code, thescan methods and scan process of the two-dimensional code was studied. Ultrasonic phasedarray scanning algorithm was studied. As an example of two-dimension code array parallel to the surface, this dissertation did researches on the measurement theory and method by usingultrasonic phased array technology, gave the two-dimensional code scanning systemarchitectures. The research result provides a new design idea for invisible two-dimensionalcode, and promotes the further application for the ultrasonic phased array technology intwo-dimensional code areas.