Academic literature on the topic 'Counterfeit coin detector'

With the widespread using of coins, in order to solve the troubles brought by counterfeit money, it is of great significance to develop a system for real-time identification of coins. In the analysis of image processing technology, the hardware and software in this field, this paper has verified the recognition algorithm in the MATLAB and VC, and it had set up an coin image processing system with the DSP chip as a platform. In this system not only the surface information of the coin can be achieved and processed in real time, but also a practical hardware and software basis for the further application of DSP for image processing can be built.

The period during which the Ukrainian lands were ruled by the Romanov and Habsburg monarchy dynasties within the Russian and Austro-Hungarian empires was also a noticeable problem of the existence of counterfeit money in the circulation, as well as fraudulent processes related to or involved in counterfeiting. The article deals with the special cases of fraud and cheatings that took place around the process of counterfeiting and sale of the money forgeries in the Ukrainian lands during their stay included in the Russian and Austro-Hungarian empires, based on the little-known and previously unpublished sources of study. Particularly interesting are cases of fraud around the sale of counterfeit credit bills, where trusted scammers were offered to buy high-quality counterfeit money at a discounted price, with only such pieces of paper where the top and bottom sides contained genuine banknotes when issuing such an illegal transaction. With the increase in the number of counterfeits of Russian credit bills detected, since the first quarter of the XIX century, the investigation has established the fact that counterfeits were imported from England, where a factory for the production of counterfeits was organized in London. Information about the counterfeiters has gained such publicity, and rumors about the stuffing of counterfeit English banknotes throughout Russia have become so entrenched in the imagination of the population that they have spawned a new kind of fraud – offering to buy high-quality «English» counterfeits for easy sale. The counterfeiting was also the manufacture of the postage stamps, the illicit manufacture or erosion of the repayment of which was pursued by the state. Traditional crime against the money supply, which by the time of the late modern times was directly equated with counterfeiting, was the cutting the edge of coins in various ways. With the introduction of new money into circulation, fraudsters often used this kind of deception on the part of the trusted population, like paying by old coins telling they are the new ones. Often, reports of counterfeiting are accompanied by information about fantasy technologies, not only in the focus of the special devices, but also in the equipment of the premises. Interesting evidence of fraud and fraud involved in counterfeiting can be attributed to «shuler» coins, the two sides of which are identical, which served to deceive gullible gamblers.

STC89C52 single-chip microcomputer is used as control core of the system, and characteristics of photoelectric switch is used to design a scheme for detection of face value of coins based on different sizes of coins. Genuine coins and counterfeit coins have different size and mass, based on which the combination of strain sensor and photoelectric switch is put forward to design a scheme for identifying genuine coins and counterfeit coins. In this paper, hardware and software design of the system is introduced in a detail way and system testing is conducted at last, the result of which indicates that the system can realize the identification, classified statistics, sound and light prompting for coins with different face values as well as identification of genuine coins and counterfeit coins, and thus has a certain degree of prospect for application and value of promotion.

The article deals with the processes of counterfeiting and the attempts to sell the forgery coins and banknotes during the 19th – early 20th centuries in the Kyiv region, which were analyzed basing on files of historical archival funds and materials of the press of that time. The peculiarities of counterfeiters activity in the specified region were determined, the main centers and areas of counterfeiters manufacturing were established, as well as the places and conditions of their sale. Most of the sources cited in this article are published for the first time. There were also periods of increase in counterfeiters activity in Kyiv and in the provinces. In addition to the data over the circulating money counterfeits (coins, assignations and credit notes), we also provide the data on the revealed facts of counterfeiting of treasury bills, tax stamps and money surrogates. The conclusions obtained in the article allow us to imagine the extent of the problem of counterfeiting money in the Kyiv region and to make the topography of the main areas of counterfeiting detection. The research is highly relevant and has high scientific significance not only for the history of money circulation and numismatics, but also for the history of criminalistics and jurisprudence.

En aquesta memòria es presenten diversos treballs relacionats amb la utilització dels sensor de flux òptic de baix cost pel desenvolupament de nous sistemes de mesura compactes i de molt baix cost. Les aplicacions plantejades permeten aprofitar tot el potencial industrial d’aquest tipus de sensors. Els sensors de flux òptic tenen la peculiaritat d’incorporar dins d’un únic encapsulat un sistema d’adquisició d’imatges i un processador digital preprogramat per a realitzar el còmput de flux òptic (optical flow) de la imatge. D’aquesta manera, aquest tipus de sensors no requereixen cap sistema processador addicional i, en alguns casos, poden funcionar sense cap altre element addicional de control. Actualment, l’èxit dels sensors de flux òptic ha facilitat la seva producció industrial massiva amb costos de fabricació molt baixos el que ha incentivat el desenvolupament de noves aplicacions en camps tan diversos com la robòtica on el cost és un element fonamental en les aplicacions destinades a un mercat de consum. En aquesta memòria es presenta, per una banda, l’anàlisi de l’estat de l’art dels sensors de flux òptic i les seves aplicacions, i per l’altra, el treball de recerca realitzat sobre l’ús d’aquest sensor per a desenvolupar un codificador rotatiu incremental, un codificador absolut, un sistema de detecció de monedes falses de 2 euros, i per a realitzar el seguiment de la pupil•la de l’ull d’una persona amb discapacitat. Els resultats obtinguts a partir de les proves experimentals realitzades amb els diferents sensors de flux òptics utilitzats als dispositius proposats han permès validar les propostes realitzades i la versatilitat del disseny del sensor.
En esta memoria se presentan diversos trabajos de investigación relacionados con la utilización de sensores de flujo óptico de bajo coste para el desarrollo de nuevos sistemas de medida compactos y de muy bajo coste. Las aplicaciones planteadas permiten aprovechar todo el potencial industrial de este tipo de sensores. Los sensores de flujo óptico tienen la particularidad de incorporar dentro de un único encapsulado un sistema de adquisición de imágenes y un procesador digital preprogramado para realizar el cómputo de flujo óptico (optical flow) de la imagen. De esta manera, este tipo de sensores no requieren ningún sistema procesador adicional y, en algunos casos, pueden funcionar sin ningún otro elemento adicional de control. Actualmente, el éxito comercial de los sensores de flujo óptico ha facilitado su producción industrial masiva con costes de fabricación muy bajos lo que ha incentivado el desarrollo de nuevas aplicaciones en campos tan diversos como la robótica donde el coste es un elemento fundamental en las aplicaciones destinadas a un mercado de consumo. En esta memoria se presenta, por un lado, el análisis del estado del arte de los sensores de flujo óptico y sus aplicaciones, y por el otro, el trabajo de investigación realizado sobre la utilización del sensor para el desarrollo de un codificador rotativo incremental, un codificador absoluto, un sistema de detección de monedas falsas de 2 euros y para realizar el seguimiento de la pupila del ojo de una persona con el fin de desarrollar un dispositivo apuntador que pueda ser de utilidad para una persona con discapacidad. Los resultados obtenidos en las pruebas experimentales realizadas con los diferentes sensores de flujo óptico utilizados en los dispositivos propuestos han permitido validar las propuestas realizadas y la versatilidad del diseño del sensor.
This work presents the research performed with optical flow sensors and the proposal of several new compact and low cost applications developed to take full advantage of the industrial potential of these sensors. Optical flow sensors include into the same chip an image acquisition system and a digital signal processor programmed to compute the optical flow of the image acquired. These sensors do not require additional post-processing and can operate without any other additional external control or processing device. Currently, the commercial success of the optical flow sensors has fostered its massive industrial production and has reduced its final cost. This characteristic, combined with the versatility of the design of the sensor, has also fostered the development of a huge range of new applications in different areas, such as robotics, where the cost is a fundamental factor that prone the development and commercialization of new consumer applications. This works presents, in one hand, a review of the state of the art of the research and development related with optical flow sensors and, in the other hand, a set of new applications proposed to take full advantage of the characteristics of the sensor. The new applications proposed are: a relative encoder, an absolute encoder, a counterfeit system for the 2€ case, and an accessibility device that tracks the pupil of the user to control pointer displacement in a computer screen. This device has been designed specifically to help people with mobility impairments in the upper extremities that cannot use the computer mouse. In all cases, the experimental results achieved with the different optical flow sensors used in the new applications proposed have validated the utility and versatility of each proposal and the utility and versatility of the design of this optical sensor.

碩士
國立高雄應用科技大學
電機工程系博碩士班
101
Abstract The purpose of this research is to combine mechanical, electronic and image analysis systems in order to achieve a better ratio of coin recognition. The experimental materials being used are NT dollars, counterfeit coins and tokens which are verified by some kind of coin validator(CVR) with true coin results. Using a microphone and webcam, the experimental materials were recorded, capturing their tap iron sounds and both sides of images. The main system framework recognized the coins by writing programs to get feature values of sounds, images and uses a propagation neural network. CVR was used in the experiment which was combined with the mechanical and electronic systems. This system was widely used in vending machine devices around the world since the year 2000. It used a condenser microphone to test the waveform, infrared light to test the diameter of the coin; and coils to measure the coin materials for frequencies and permeability. The microprocessor compares the data extracted from the measurements with data previously programmed into its memory during the manufacturing process. This allows it to verify the validity or nullity of the inserted coin. Therefore, CVR can eliminate efficiently the counterfeit coins and tokens. Since the skills and technology of making counterfeit coins are getting better and better, the coin validator, system combining with the mechanic and electronic, might not be able to recognize the coins completely. In our system, we use MATLAB -R2010b to develop our program. As for the image, the front and the back images of the New Taiwan dollar is captured by WEBCAM, followed by doing image processing: first, use circle detect of Gaussian function to get the image’s position and size; second, zoom in or out to adjust the image size to 100 x100; third, do the erosion and expansion; fourth, rotate the coin’s image every five degrees to increase the samples; and finally, every image is divided into 25 image’s blocks(20 x20), then the average values of the image’s blocks are vectorized as a 1 x400 feature vector. As for the audio, the microphone records the sound of the coin hitting the iron, then followed by system processing: first, detect start and end point; second, measure audio frames; third, enhance high-frequencies; fourth, execute Hamming window; and finally, use Mel-Frequency Coefficients to extract 13-dimensional features. After the processing, using the obtained features of sound and image feature vector as the input value of the back-propagation neural network, they can then be conducted into the Artificial Neural Network for training and classification. Through the experimental evidence of this study, it can indeed effectively enhance the identification of authentic coins. Keywords: coin recognition、Ann.、images、audio、feature vector(value).