Among many constraints faced by a blind person, the challenge of independent mobility is the paramount. Widely, the white cane is the most popular tool for mobility aid, but it also has constrains too. For example, when it is used to detect obstacles up to the knee-level, the upper body is left unattended. This leaves the risk of the user of being hit from a raised platform or from high horizontal bars. The SMC’s Obstacle Detection division has implemented a cane to detect and measure the distance of any obstacles present in knee-above areas. This is based on an Ultrasonic Range Finder sensor which can acquire range data’s between any obstacle and the user within 2.5 meters. Using the LABVIEW (visual programming language), the URF sensor (SRF05) is triggered with minimum 10uS pulse every 250 millisecond to start the range. Simultaneously, data of echo pulse generated from the output of the sensor is acquisitioned to calculate the distance of the obstacle. At the end, the range of distance is numerically displayed in real-time on the LABVIEW block diagram. The distance of the obstacle is then used by SMC’s Signal Integration division to alert the user depending on the range. In this report, detailed description of the hardware aspect of the Ultrasonic Range Finder sensor, the LABVIEW’s visual block programming of triggering pulse periodically and echo pulse analysis from sensor, and the experiments on reducing beams width are elaborated.
Kanagaratnam, Kajatheepan, "Smart Mobility Cane: Design of Obstacle Detection" (2009). EE 4BI6 Electrical Engineering Biomedical Capstones. Paper 8.