Blind Assistant System For Shopping In Supermarket

Visually impaired people face great difficulties in their daily lives. According to World Health Organization statistics, the number of global blind people is about4.5million in1995. Ninety percent of blind people are in developing countries, which is still in growth. It is expected that, in2020,the number will be7.6million. Therefore, daily assistance for blind people is an important topic in the field of biomedical engineering.The blind are living an inconvenient life due to the visual impairment, so a lot of researches have been focusing on designing guidance system which changes visual image into auditory or tactile signals so that the blind can easily understand. A variety of system, such as text-to-voice conversion system and voice recognition assistant system, have been developed to help visually impaired people.According to our interview with the blind, one of the most inconvenient activities in their daily life is shopping in supermarket. The self-service style and complex shopping environment make the blind hard to shop in supermarket. There is no currently supermarket-oriented assistant system for the blind. The aim of this thesis is to build a DSP-based system, assisting the blink to shop in supermarket.The system uses a digital signal processor (DSP) as a processing core module, consisting of three sub-modules:A) Infrared range measuring module. Four infrared photoelectric sensors are installed in the front of the system, which detects obstacles in the range of3cm to80cm with15°scanning range for each sensor in real time (in ms).B) Video capture module. A CMOS camera module with a resolution of720* 576is used to to acquire the image information and identify pre-labeled items within1.5meters in distance.C) Bar-code reading module. Honeywell MS7820barcode scanner is integrated in this system, working at up to1800scanning times per second omni-directional multi-line scanning mode by self-calibration, to obtain the item information.These three modules together can help the blind to detect the surrounding objects and retrieve the information for the bar-coded goods in a supermarket environment. Finally, the system output the information for items and the surrounding obstacles through a headphone to the blind. This prototype system aims to help the blind to avoid obstacle, and get the goods information in the supermarket.