Wyniki 1-10 spośród 19 dla zapytania: authorDesc:"ANDRZEJ KOS"

Ultrasonic white stick for detecting holes for blind people


  Most blind people use white sticks as a main aid while walking outside. This simple object helps them to navigate, avoid obstacles and also to inform other people about their disability. It comes very handy, especially in cities. When blind people are moving, they are likely to encounter a number of obstacles that can be very dangerous for them. From the visual impaired people’s perspective we can divide obstacles into three main categories: - obstacles rising from the ground; - hanging obstacles; - holes in the ground. Luckily enough, blind people are able to detect and avoid all of these categories of obstacles, however each category of obstacles can be detected in a different way. By simply moving a while stick not far from the ground, a visual impaired person can sense various obstacles from the ground to approximately their waistline. As for hanging obstacles, they are harder to detect for a blind person who uses a white stick in a conventional way. In such a case electronic applications come handy. Researchers have experimented with ultrasonic sensors for detecting obstacles [1]. They have been able to detect a number of objects and compute the distance, but they had problems with detecting small obstacles or ones with soft surface. Some of these problems can be solved with replacing ultrasonic sensors with infrared sensors [2, 3]. On the market, there are also aids for blind people designed for an obstacle detection like for example “Ultracane" [4]. As for the last category, it is very difficult to detect any holes or excavations in pavements or roads in real-time. These defects are usually present only a little bit below the ground level. If we want to detect an obstacle in front of us, we just send a signal (infrared or ultrasound) and wait[...]

Low-power logic design based on gate driving way considering interconnections capacitances

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This paper presents design method of low-power integrated circuits based on information on primary inputs vectors changes, considering interconnections in real chip. The tested chip was designed in CMOS AMS 0.35m technology. Taking advantage of gate driving way - the reason of a gate switching - two-level logic functions were synthesized. Previously developed design methods for low power synthesis have been modified. Now interconnection capacitance is evaluated and taken into consideration during logic synthesis. Post layout simulations were done for verification. Streszczenie. W artykule przedstawiono metodę projektowania cyfrowych układów scalonych o obniżonym poborze mocy z uwzględnieniem pojemności pasożytniczej połączeń między bramkami. Wykorzystano informacje o zmianie wektorów wejściowych układu oraz wektorów wejściowych bramek - prawdopodobieństwo sterowania bramki. Zaprojektowano układ scalony w technologii CMOS AMS 0.35m. (Prawdopodobieństwo sterowania bramek jako podstawa projektowania układów cyfrowych o obniżonym poborze mocy z uwzględnieniem pojemności pasożytniczej połączeń) Keywords: low-power logic design, interconnections, gate placement, chip design, gate driving way. Słowa kluczowe: układy cyfrowe o obniżonym poborze mocy, połączenia, rozmieszczanie bramek, projektowanie układów scalonych. Introduction Power consumption is one of major problems in today’s design of digital IC. Interconnections have strong influence on timing properties of circuits and also on amount of consumed energy. So, place and routing stage during design is more and more important. During years many methods for placing and routing were worked out, but development of submicron technology forces designers to modify existing methods and search new ones [1, 2]. In this paper authors present observations and remarks on interconnection influence on power consumption during a chip design. Authors intention was design of a chip [...]

Device for road holes and obstacles detection


  Today’s life as we know it is based on visual signs. Practically all the important information needed to go independently through an average person’s day is provided by their sight. Let us focus on some urban environment. A person is able to see objects, determine their approximate distance, distinguish between a hole and a bump on a road, detect and recognize an important element from its background or simply read some text information from books, posters, etc. Most of these actions, if not all, allow people to gather information and give them time to react before they approach some objects. Furthermore, there are many devices that help people gain more important for them information than they would be able to learn from a closest environment in their field of view, such as navigation systems. There are also many devices that help people keep safe and avoid some accidents, like for instance, street lights and road signs. But neither of them is well suited for visually impaired people. Of course, there are special audio signals for blind people near some pedestrian crossings and there are devices which help visual impaired people avoid obstacles [1], but they are still not sufficient to keep them safe and well informed about their surrounding environment [2]. This is mostly due to a change of sensors positions while a blind person is moving. That is why we develop a MOBIAN© project - Mobile Safety System for the Blind [3]. This project is supported by The National Centre for Research and Development under: NR13-0065-10. A part of the MOBIAN© project is to create a highly reliable device for detecting obstacles and holes of various length and depth, as it is presented in Fig. 1. There is no doubt that special algorithms have to be designed, tested and implemented for this purpose. Fig. 1. Holes and other obstacle detection Rys. 1. Wykrywanie dziur, usk[...]

LABGSM - system ewaluacyjny modułu GSM/GPRS


  Telefonia bezprzewodowa w ciągu bardzo krótkiego czasu odmieniła oblicze świata. W ciągu niespełna dwóch dekad sieć GSM/GPRS zyskała na świecie miliardy abonentów i liczba ich wciąż wzrasta. Telefony i usługi stają się dostępne dla ogółu społeczeństw w wielu krajach. Wraz z upowszechnieniem się telefonii komórkowej coraz intensywniej rozwija się i wykorzystywane są dodatkowe funkcje jakie może realizować technologia GSM/ GPRS. Łączność komórkowa jest obecnie podstawą wielu kluczowych systemów dla gospodarki. Począwszy od kontroli, dozoru, archiwizacji danych na zewnętrznych serwerach po sterowanie maszynami i procesami. Łączność GSM/GPRS wydaje się być niezastąpioną w aplikacjach gdzie urządzenia operują globalnie (np. archiwizacja danych o położeniu i parametrach jazdy pojazdu). Rozwój zarówno sieci telefonii bezprzewodowej, gwałtowny spadek cen usług i postęp w dziedzinie elektroniki sprawiają, że układy wykorzystujące GSM/GPRS stały się bardzo popularne również wśród elektroników-entuzjastów. Przedstawiany system ewaluacyjny LABGSM pozwala na przetestowanie i zapoznanie się z funkcjonalnością modułu przemysłowego GSM/GPRS w sposób nie wymagający ciągłego nadzoru eksperta. Zastosowane procedury czuwają nad prawidłowością wykonywanych procesów, a wyniki etapów prac są zapisywane w bazie danych. Prezentowany system dydaktyczny umożliwia przedstawienie podstawowych możliwości modułu GSM, transmisji GPRS i wykorzystanie innych protokołów transmisji udostępnianych przez zastosowany moduł przemysłowy.Moduł GSM/GPRS HiLo Głównym elementem platformy sprzętowej systemu LABGSM jest moduł GSM/GPRS HiLo firmy Sagem Communication (rys. 1). Główne części użytego w LABGSM modułu przedstawia rys. 2 [1]. Interfejs modułu do komunikacji ze środowiskiem zewnętrznym stanowi 40-pinowe złącze na którym dostępne są wszystkie wyjścia oprócz gniazda anteny i styków interfejsu JTAG. K[...]

Behavioural modelling of dynamic frequency scaling with prediction of the integrated circuit temperature


  Considering the aspiration to make modern digital circuits faster and scaling down the technology the researchers must take into account thermal effects [3]. The goal is to find the trade off between keeping the throughput of the system on the possible maximum level and decreasing the power consumption of the device. Assuming that circuit cannot exceed acceptable maximum temperature for proper work it should be controlled in the way keeping its temperature as close to the permissible limit as possible with minimal fluctuations. To achieve that some dynamic control systems have been developed including: Dynamic Voltage Scaling (DVS) - scaling the supply voltage, Dynamic Clock Throttling (DCT) - shutting off the clock when overheating and Dynamic Frequency Scaling (DFS) - scaling clock frequency, which are often combined [4]. Idea of frequency control origins from the fact that circuit working with higher frequency consumes more power. In order to cool it down it has to be slowed down. When the chip returns to safe temperature range it can work faster again. This frequency- temperature feedback can be used to stabilize the temperature and ensure safe work of the circuit. Despite former achievements on the field some further investigations must be done to improve thermal behaviour of the circuit and find the optimal control system [5]. Popular electronic simulators are not suitable for thermal transient simulations of electronic circuits. That causes the need to create an environment in which temperature of the circuit can be examined. Presented MATLAB models have been created to verify several different implementations of the dynamic frequency control systems before fabrication of the ASIC (Application Specified Integrated Circuit). In addition Predictive Frequency Scaling (PFS) method which is based on DFS and DCT but predicts changes in temperature in nearest future will be introduced and its advantages will be motivated [1][...]

3D environment modeling - hybrid system for blind people DOI:10.15199/ELE-2014-147


  Today’s world is filled with electronics that are now more sophisticated and what is important they can be really small reaching microscopic (MEMS) or even nanoscopic sizes (NEMS) [1]. Therefore, future generations are going to be aided by nearly impossible to see with the human eye devices in many fields, for instance, nanorobotics [2], medicine [3]. As for the field of medicine and rehabilitation researchers all over the world are successfully implementing electronic and electro-mechanic systems into disabled people’s lives to help them to cope with every day’s existence. There are always improving artificial pacemakers [4], digital hearing aids [5], active prostheses [6], etc. There are prostheses almost for everything. However, the difficulties occur with designing medical and rehabilitation aids for the visually impaired people taking into account their disability and the fact that humans percept and recognize environment mainly using sight. The full restoration of vision is not possible with the knowledge we have at present, however researchers are working on it [7]. Without supplying the blind with the information about the environment they are unable to live fully independently and what is most important they are unsafe while travelling between locations especially in unfamiliar environments and almost every blind person depends only on a white stick and remaining senses in those situations. Naturally, devices and systems for navigating visual impaired people exist [8], although their main goal is to help with obstacles avoidance rather than create the model of the surrounding environment in the way that blind people could rely on, while moving for instance, inside an unknown room - even in the dark. State of the art The model of the close environment should be as detailed as possible. Which information would be passed to the blind person is subjective and this aspect is supposed to be customizable. N[...]

Peltier modules array on common alumina substrate for the blind - thermal and electrical tests

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Blind people can read characters by touching convex paper or by using Braille charts based on piezoelectric crystals. The main disadvantage of a piezoelectric chart is a limitation to two lines of a text because of the necessary crystal length. This results in impossibility of displaying graphics. Recently there were news about the special device for blind people that can transfer informatio[...]

Niskomocowy generator pierścieniowy CMOS sterowany napięciem


  Idea generatora pierścieniowego jest jedną z najprostszych, najbardziej znanych i często wykorzystywanych w projektach zarówno przez konstruktorów systemów analogowych, jak i cyfrowych. Układ ten składa się z szeregu identycznych struktur wzmacniających połączonych kaskadowo i zapiętych w pętli sprzężenia zwrotnego łączącej pierwszy i ostatni stopień, tak aby spełniony był warunek generacji drgań. Okres oscylacji równy jest podwojonej sumie czasów opóźnień wnoszonych przez poszczególne stopnie [1] i zależy od punkt pracy układu, którego kontrolowana zmiana stanowi podstawę do budowy generatorów przestrajanych. W literaturze wiele prac poświęcono konstrukcjom stopni wzmacniających poczynając od najprostszych inwerterów CMOS [1, 2, 3], a kończąc na realizacjach symetrycznych w postaci rozbudowanych par różnicowych [5]. Generatory pierścieniowe w realizacjach scalonych stanowią układy zajmujące małą powierzchnię, umożliwiające przestrajanie w zakresie obejmującym kilka dekad i pobierające niewielką moc [1]. Są przez to konkurencyjne w stosunku do generatorów LC, niemniej jednak w porównaniu z nimi wnoszą do sygnału znacznie większe szumy fazowe, będące krytycznym parametrem w systemach radiokomunikacyjnych [2, 3]. Generatory pierścieniowe stosowane są głównie w układach testowych systemów cyfrowych, w projektach szerokopasmowych pętli fazowych, a także w pomiarach czasów propagacji bramek logicznych. W niniejszym artykule przedstawiono projekt i wyniki symulacji po ekstrakcji z topografii generatora pierścieniowego wykonanego w technologii AMS 0,35 μm. W pracy do sporządzenia topografii i przeprowadzenia symulacji posłużono się pakietem Cadence. Głównym przeznaczeniem układu jest taktowanie systemów cyfrowych testowanych pod kątem zjawisk termicznych i elektrotermicznych. Nadrzędnym założeniem projektowym jest uzyskanie liniowej charakterystyki przestrajania w odpowiednio szerokim zakresie częstotliwości oraz mały pobór [...]

Mobile Safety System for the Blind


  There are many devices on the market that help the visual impaired people to walk in unknown urban environment [1- 4]. Numerous research and tests have been carried out in Special Educational Centre for Blind and Partially Sighted Children in Kraków. The results show there is still one major problem that needs to be solved. This problem concerns holes and road excavations in the ground and small yet very dangerous hanging obstacles which a blind person can encounter - Fig. 1. A device has to be designed to help the visual impaired people deal with the types of dangerous situations mentioned above There are devices designed especially for the visual impaired people that inform them about some obstacles and free space; for instance one device can inform if a seat in a train is occupied or not or if an elevator door is open or not. However, there is no such a device that could inform about holes and road excavations, especially the ones that have recently occurred on a daily road from a blind person’s home to their work place, damages in stairs or open space between an edge of a train platform and tracks [5]. Holes and road excavations are usually marked but it is very hard for blind people to spot and detect them. That is why any road hole is a serious danger for them. With some help of an electronic device for blind people or just a simple white stick, a blind person is able to determine if there is a hole ahead. But the problem is th[...]

Overheat security system for high speed embedded systems (Układ ochrony przed przegrzaniem dla szybkich systemów wbudowanych)


  Considering the aspiration to make modern digital circuits faster and scaling down the technology researchers must take into account thermal effects. The goal is to find the optimal balance state between keeping the throughput of the system on the possible maximum level and decreasing power consumption of the device. Assuming that circuit cannot exceed acceptable maximum temperature for proper work it should be controlled in the way that keeps its temperature as close to the permissible limit as possible with minimal fluctuations. To achieve that some dynamic control systems have been developed including: dynamic voltage scaling (DVS), dynamic clock throttling (DCT) and dynamic frequency scaling (DFS) [1]. Despite former achievements on the field some further investigations must be done to improve thermal behaviour of the circuit. The paper describes a structure of the wide-range oscillator which generates the frequency dependent on the present temperature of the silicon die. The structure of the circuit, designed and fabricated in CMOS LF 150 nm (1.8 V), technology will be presented in the next sections. The temperature-controlled oscillator (TCO) works with the OctaLynx 8-bit microcontroller which is a prototype implemented in the same silicon die and created for test purposes [2]. Motivation for Temperature-Controlled Oscillator The concept of temperature-controlled oscillator origins from the fact that circuit working with higher frequency consumes more power. That means that if the silicon die reaches high temperature range it is necessary to lower the clock rate and as a consequence cool the chip down. The problem is how to manage the frequency of the clock to minimize temperature fluctuations and let the circuit work possibly fast. Simpler dynamic systems sensed the temperature and when it crossed fixed reference level just divided the frequency of clock signal. This action can be not efficient enough because as it is[...]

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