Development of a cane with a haptic interface using IC tags for the visually impaired

It is often difficult for visually impaired persons to walk outside to his or her destination. In this paper, we develop a cane with a built-in haptic interface for use by visually impaired persons. The cane is paired with IC tags buried underground (e.g., under street pavement). The haptic interface is controlled with a position and velocity control system that accurately indicates four directions (forward, backwards, right and left). After evaluating the vibration in the haptic interface, we determined the optimal vibration frequencies indicating a specific direction were combinations of 5 (Hz) and 1 (Hz). Furthermore, the optimal repetition of vibrations was determined to be two times. By using these conditions, the four directions were recognized more than 95% of the time. It was also confirmed that the visually impaired person recognized the presented direction even when an IC tag was buried underground. In the future, a mechanism will be developed that will allow visually impaired persons to recognize directions more accurately even if they swing the cane in a controlled manner. In addition, we will integrate a route decision system into the cane equipped with the haptic interface.