Basic study on step detection system for the visually impaired

We proposes a step detection system as a supporting system for the visually impaired. A small laser range sensor, which is attached to the user´s chest, obtains distance information in the vertical cross-sectional plane of the front of the user. Points obtained through the range sensor are analyzed based on coordinates and classified into horizontal and vertical segments. The system judges whether there are steps or stairs by examining combination of the segments and informs the existence of the step to the user by voice and beep sound. Experimental trials show the basic validity of the proposed system. The system detects steps with the accuracy of over 95% even if the user is walking.