The Research Of Thickness Identification Technology In Cash Counter

With the increase of the circulation of RMB and counterfeit, the traditional manual cash count can't meet the workload of bank, in order to monitor all banknotes types, the thickness identification is indispensable.Accurate and rapid is very important for cash counter with thickness identification technology, so the thickness identification technology has became the main research and development direction. The thickness identification technology of banknotes is key technology for achieving recognition and identification of authenticity, which is selecting the abnormal thickness banknotes from the real one,the abnormal thickness banknotes refers to altered cash pasted by counterfeit and the cash adhesive by tape.At present, the counterfeit identification technology of high-end cash counter equipment has matured, but the research of thickness identification technology of cash counter is still on the way.There are still on the research between domestic universities and research institutions, the reform and the design of structure, the research and development of thickness identification of cash counter is still the focus.However, a variety of thickness measurement device of banknotes adoption mechanical equipment which is complex structure and high precision installation, there is only part of cash registers installed such device. Because the mechanical thickness measurement systems using eddy current sensor detecting amplification small thickness in banknotes, but this small thickness can't be measured by thickness measurement system in the initial process.Therefore, this paper develop a low-cost and high-precision detection method by gauging rotating speed in cash registers which is not equipped the thickness measurement systems, and research the reason and result why the thickness measurement systems produce bounce during the machine working.This study was carried out some works:(1) Develop a low-cost thickness measurement method by gauging speed. The dynamic model of cash counter show, the reverse force of friction which driving the banknotes advancing in cash counter will exert a reverse shaft torque which will lead to the decrease the speed of shaft. Based on this theories, First of all,building a test platform which is detecting the banknotes thickness by gauging shaft rotating speed. Then, processing the test data by M method and T method with using encoder calculating the shaft rotating speed. By analyzing test data, it was found that way can detect the thickness of banknotes pasted over tape, but pasted tape thickness is too small to be detected by the experimental device.(2) In order to verify the testing result which detecting the banknotes thickness by gauging the shaft rotating speed and analysis the motion of cash counter in dynamic. In this paper, exploring the relationship between the thickness of banknote and the rotating speed of the shaft by Recurdyn software. Firstly, building the model of the motion of cash counter by setting the parameters of banknotes and roller group and drive. Then simulation the model by changing the thickness of banknote which was the only variable. The simulation test results show that the shaft rotating speed will reducing and the motion time will increase while the banknote of abnormal thickness move.(3) Due to the problem that the thickness measurement system can't detect the thickness of banknotes in the initial processing of movement. In the paper, firstly, building a testing platform by high-speed camera seizure the movement of the thickness measurement system to explore the separation between the shrapnel and the bearing frame while the processing of cash counter movement. Then processing the photos by image tracking. Finally, compared with the testing result of detecting by eddy current sensor and found that there is a bounce which was emerging in the initial process is big displacement and 10% walking cycle, at the same time there is no separate between the shrapnel and bearing frame.