This paper presented the use of ultrasonic and infrared
sensors for distance measurement in the development of an
obstacle detection system for elderly and people with vision
impairment. Experimental results show that ultrasonic and
infrared sensors have different characteristics in terms of
output voltage measurements. It is clearly indicated that
ultrasonic sensor gives a linear output characteristic whereas
infrared sensor shows a nonlinear output characteristic. Both
sensors are able to detect an obstacle at the distances within
their usable range with percentage of accuracy between 95%
and 99%. The experimental result indicates that the US and
IR sensors are able to provide reliable distance
measurements even with different colors and materials of
obstacles. It has been shown that IR sensor has slightly
higher resolution than that of the US sensor, especially for
small distance measurement within their usable ranges.
Future work, the system should determine the sensor
location on the shoe, and the sensors only detect the obstacle
when the foot fully touching to the ground.