ABSTRACTUbiquitous computing systems have often suffered the crit-icism of providing only marginal value and not justifying the serious amount of money spent for research in this area [1]. In this extended abstract, we describe the vision and the prototype of a ubiquitous computing environment for visu-ally impaired people. The aim is to help them orient them-selves in new, unknown environments and thereby enable them to lead a more independent life.KeywordsUbiquitous computing, visually impaired.INTRODUCTIONEveryday Problems for Visually ImpairedVisually impaired people encounter many problems during their daily routine that sighted people wouldn’t neccessarily think of. Take for example shopping in the local supermar-ket. Thousands of items, feeling all the same, spread over dozens of shelves, all the same shape. Visually impaired people will typically only go shopping to their local super-market and buy only few products in well known locations. Or think of a modern airport terminal. Where is the check-in counter for a certain airline? Where does one collect the luggage after landing? Without external help, these issues are almost unsolvable for the visually impaired.The Basic IdeaThe common source of these problems is that the world reveals itself to us mostly over visual stimuli, which are being withheld from visually impaired people. To cope with some of these problems, we propose the paradigm of a chatty environment. In this environment, the world uses an alternative channel, namely audio, to reveal itself to the user. While walking by, entities in the environment keep talking to the user, thereby revealing their existence: “Here is the shelf with milk products, down the next aisle are the fridges with meat and ice”, “Here is track 9, do you want more informations on the departing trains?”This (at first sight rather naive looking) feature of the sys-tem will probably seem annoying to most sighted people. An environment talking endlessly to the user sounds like a headache to many of us that we would surely turn off after a few minutes. However, speaking to members of the Swiss Association of the Blind, it turns out that for visually impaired people there can almost never be too much audio stimuli. This is comparable to the huge amount of visual informations sighted people pick up every second, few of which they really use. Here, too, it feels far from annoying to continuosly receive that much unneccessary information since one has learned to focus on the interesting aspects only.THE SYSTEMWe are currently in the process of building a prototype of the chatty environment as part of the ETH Zurich campus. The prototype consists of several components: a large num-ber of tagged entities in the environment, a world explorerin form of a portable device for the visually impaired user, and a tag reader connected to the world explorer to pick up the tags.Smart EntitiesThe objects of the chatty environment are electronically tagged, either by passive tags – using radio frequency iden-tification (RFID) technology – or active tags – these could for example be active RFID tags, Berkeley TinyOS Motes [3], or Smart-Its [4]. The main requirement is that the com-munication between the tags and the user device does not need line of sight. Not only do we want to follow Weiser’s vision of a ubiquitous computing system that works unob-trusively in the background without requiring explicit inter-action [2], we also need to make sure that a system for the visually impaired does not require the user to point the por-table device to a certain object for triggering an action. Therefore, infrared beacons are not suited for tagging the environment objects. In our prototype, we use the Berkeley Motes.World ExplorerThe portable device carried by the user receives the data transmitted by the environment objects. It can be either a stand-alone device carried by the user in her pocket or backpack, or an extension of the user’s cane.The most important data the smart entities send is their identity, such as “ticket booth”, “escalator”, “men’s restrooms”, “track 9”, or “train to Geneva”.The device we are currently using as world explorer is an iPaq PocketPC, which will be replaced in a later project phase by a PDA especially designed for the visually impaired. These devices have the advantage of providing Braille input and output.User InterfaceThe chatty environment keeps revealing itself to the user until she chooses to investigate one of the environment’s objects. By pressing a button on the device shortly after an The Chatty Environment – A World Explorer for the Visually ImpairedVlad CoroamaInstitute for Pervasive ComputingSwiss Federal Institute of Technology (ETH) Zurich8092 Zurich, Switzerland+41 1 63 26087coroama@inf.ethz.ch
