The development of electronic sensing devices for the visually impaired requires knowledge of the needs and abilities of this class of people. In this project we present a rough analysis that can be used to properly define the criteria to be adopted for the design of such devices. In particular, attention will be focused on clear-path indicators, highlighting their role in orientation and mobility tasks. A new device belonging to this class is presented. The detector is based on a multisensor strategy and adopts smart signal processing to provide the user with suitable information about the position of objects hindering his or her path. Experimental trials demonstrate the efficiency of the device developed.
About 1% of the human population is visually impaired, and amongst them about 10% is fully blind. One of the consequences of being visually impaired is the limitations in mobility. For global navigation, many tools already exist. For instance, in outdoor situations, handheld GPS systems for the blind are now available. These tools are not helpful for local navigation: local path planning and collision avoidance. The traditional tools, i.e. the guide dog and the cane, are appreciated tools, but nevertheless these tools do not adequately solve the local navigation problems. Guide dogs are not employable at a large scale (the training capacity in the Netherlands is about 100 guide dogs yearly; just enough to help about 1000 users). The cane is too restrictive. The goal of this research is to develop a wearable tool that assists the blind to accomplish his local navigation tasks. Fig shows the architecture of the proposed tool. It consists of a sensory system controlled by the user. The primary data needed for local navigation is range data (which is not necessarily obtained from visual data alone; at this point, the type of sensors is still an open question). The mapper...