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Journal of Mechanical Science and Technology 24 (6) (2010) 1261~1264
www.springerlink.com/content/1738-494x
DOI 10.1007/s12206-010-0332-5
Newly developed walking apparatus for identification of obstructions by visually impaired people
Mitsuhiro Okayasu*
Department of Machine Intelligence and Systems Engineering, Akita Prefectural University, 84-4 Ebinokuchi, Tuchiya-aza, Yurihonjo-City, Akita 015-0055, Japan
(Manuscript Received August 6, 2009; Revised December 21, 2009; Accepted March 21, 2010)
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Abstract
In this work, two visual systems to help visually impaired people walk were developed: the first is a white cane with a non-contact detection system, and the second is a three-dimensional (3D) visual system. In place of the sense of sight, the sense of touch, either via vibration or of pins, can relay information on objects and obstacles around people. In a white cane non-contact detection system, two sets of ultrasonic sensors and vibrators, respectively, are employed to indicate the positions of both low- and high-level obstructions in front of the visually impaired person. When objects are detected by the sensor, the vibrator is strongly activated. In this system, the range of obstruction detection can be adjusted between 0.5 m and 5.5 m. By comparison, the 3D visual system uses two different components, an infrared camera sensor to detect obstructions and a tooling apparatus, incorporating a number of 1 mm diameter pins, by which their 3D shapes are derived. The pins are arranged in a 1010 matrix and move longitudinally between the retracted and extended positions based on the depth data between the infrared sensor and the obstruction. Pins are elongated individually, so that each pin tip represents a specific area of the outer surface of the object. This tactile 3D image can provide effective object information.
Keywords: Visually impaired person; Walking apparatus; Ultrasonic sensor; Infrared sensor; White cane ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1. Introduction
There is a large and growing number of visually impaired people in the world: 76 million worldwide by 2020, according to one estimation [1]. The visually impaired people when walking outside encounter certain dangers, such as (i) cars, (ii) holes and (iii) head-height obstructions. These dangers are the more serious due to the limited effectiveness of the standard walking aid used by the visually impaired that is the white cane. In attempts to address this issue, various devices [2-7] in which mechanical and electronic...