Minyoung Lee, Sooyong Lee*
The Journal of Mechanical Science and Technology, vol. 25, no. 4, pp.1043-1050, 2011

Abstract : Most blind and vision-impaired people use a white cane or a guide dog to aid their walking. The conventional white cane helps the user to perceive the environment simply by identifying the presence of nearby obstacles. In the present study, three infrared range sensors were used to identify the floor state. The sensor system, affixed to the user’s belt, does not require swinging motion or any other movement by the user. The three sensors are configured radially, and the design parameters are selected based on the sensor characteristics. The main difference from the conventional range sensor system for the blind is that the infrared range sensor system identifies three discrete states (even surface, ascending stair, descending stair). The condition for the state transition was derived from a sensor system model. Additionally, the effects of sensor system movement were verified by covariance analysis.

Keyword : Covariance analysis; Floor sensing; Range sensor; State estimation