Development of A Risk Alert System on Railroad Platform for Blind Person Using VSLAM Technology

A blind support system utilizing VSLAM (Visual Simultaneous Localization And Mapping) technology has been developed to alert blind persons the risks on railroad platforms. In Japan, one or two fatal accidents involving blind persons occur each year in average, which is ten times higher probability of accident compared with sighted persons. This requires a significant challenge in the transportation of blind persons in our society. To improve their mobility within the public transportation system, a high-fidelity risk alarm system is desired. To address this problem, we have been developing a sound alert system specifically designed for detecting risks on railroad platforms, using VSLAM. VSLAM is a kind of 3D robot vision, which construct a characteristic Point Cloud (PC) map from video image. A newly captured video image is compared with the PC map and the camera's location and direction is estimated with precision of some centimeter. By assigning hazardous area, such as the platform's edge, on the PC map, the system can provide proximity alerts with high accuracy. The direction and distance of the risk point are informed by stereo sound. Experiments of blind subjects have demonstrated that the system can effectively alert the potential danger in advance.