This study aimed at finding simple algorithms to identify three different movements registered by accelerometer and to detect differences in the acceleration signals of people with and without visual impairments. The Tactile Acoustical Navigation and Information Assistant (TANIA) is construed to provide persons suffering from visual impairments support for an independent navigation indoors and outdoors. Attaining this goal, TANIA uses vertical acceleration signal extrema to assess its user's walking distance. This study investigated first the sit-to-stand movement, stumbling and walking up- and down stairs of 25 subjects with visual impairments using TANIA sensor system. The objective was to improve the user's movement detection using sensors to get valid and reliable data. In a second step of the study it was investigated if there is a difference between the above-mentioned movements in people with or without visual impairments (n=10). The acceleration signals of the subjects were compared. Three simple algorithms were found, which are able to separate the movement signals based on accelerometers of the respective daily movements. The second step analysis revealed a detectable difference in the second phase of stumbling (p=.034), where the subjects had to get back into walking forward. No differences in the other acceleration signals were found.

Purpose. This study describes the development of a multi-functional assistant system for the blind which combines localisation, real and virtual navigation within modelled environments and the identification and tracking of fixed and movable objects.Method. The approximate position of buildings is determined with a global positioning sensor (GPS), then the user establishes exact position at a specific landmark, like a door. This location initialises indoor navigation, based on an inertial sensor, a step recognition algorithm and map. Tracking of movable objects is provided by another inertial sensor and a head-mounted stereo camera, combined with 3D environmental models. This study developed an algorithm based on shape and colour to identify objects and used a common face detection algorithm to inform the user of the presence and position of others.Results. The system allows blind people to determine their position with similar to 1 metre accuracy. Virtual exploration of the environment can be accomplished by moving one's finger on a touch screen of a small portable tablet PC. The name of rooms, building features and hazards, modelled objects and their positions are presented acoustically or in Braille.Conclusions. Given adequate environmental models, this system offers blind people the opportunity to navigate independently and safely, even within unknown environments. Additionally, the system facilitates education and rehabilitation by providing, in several languages, object names, features and relative positions.

The system was originally developed to provide visually impaired people with a navigation device which could be used independently indoors and outdoors, without any pre-installed infrastructure. TANIA utilizes a movement sensor, a GPS sensor, and detailed maps of the current environment. Its maps are augmented by guiding grids to insure safe navigation even in large open areas without physical cues, and by text information specific to each environment. Navigation and environmental information is presented acoustically or in Braille [5].

The use of a small, portable Tactile Acoustical Navigation and Information Assistant (TANIA) by ambulatory blind people in complex environments is presented. TANIA utilizes an inertial sensor, tablet computer, and enhanced mapping to provide precise navigation of up to one-step accuracy. Its operation is relatively simple, even for elderly people with no computer experience. Previously-installed beacon or tag infrastructure is not required, which expands environmental access for blind users to any area where adequate digital mapping has been done. Current development in pilot locations is described, including examples of how maps are augmented with specific, location-based information. Such data can be presented to the user acoustically or in Braille. Given the ever-increasing availability of global positioning and information services, systems such as TANIA suggest the potential for independent and precise worldwide navigation by blind people.

A small Braille display with Active Tactile Control (ATC) Braille technology was developed in association with the Handy Tech Company. With ATC technology text information can be read without pressing a scrolling button, as the system automatically shifts to the next line when the reading finger is detected at the end of the last word. This Braille display was connected to two compatible systems. The first is the TANIA (Tactile Acoustical Navigation and Information Assistant) navigation system, based on detailed maps, a movement sensor, and the Global Positioning System (GPS). The second is an object recognition system, which uses 3D environmental models, a movement sensor and stereo camera. Either system, or both in combination, provide information acoustically or in Braille. Blind and deafblind users report that the use of the portable ATC display technology combined with these systems represents an additional step toward increasing independent orientation and mobility.

A navigation assistant based on a tactile-acoustical interface and augmented map information is presented, affording blind people real and virtual explorations of the 2007 CSUN Conference environment. By tapping on a touch screen, hotel layout and conference-related data are provided. Introduction Negotiating new environments can be challenging for all of us, but blind people face far greater navigation and orientation difficulties in such situations. At conferences, for example, the environment must be learned quickly and may even change from day to day. Information about the location of meeting rooms, restrooms, lunch and break areas, booths, company representatives, and products is especially difficult to obtain. This author's experience at the last CSUN Conference stimulated the development of a specialized application of our electronic Tactile-Acoustical Navigation and Information Assistant (TANIA) system to this year's meeting. Unlike commercially available navigation systems, which are usually inoperable indoors without installation of a time and/or cost intensive signal or marker infrastructure, the TANIA system does not require infrastructure. It provides indoor navigation support for blind and visually-impaired people based on a step-recognition method and simple building maps. These maps have been augmented with additional information supplied by hotel management, conference organizers, and exhibitors.

Introduction Remarkable advances have been made in the development and technical optimisation when considering stationary solutions of assistant systems for the visually impaired. For example, recent progress in web accessibility allows sensory handicapped people to receive in many cases the same amount of information as sighted persons. While looking at mobile solutions, there are still many other challenges to achieve equal opportunities concerning information access. In 2004 we presented a design for a new type of an indoor navigation and object identification system for the blind [1]. The basic idea of this system is to combine local sensor information with 3D environment models. The local sensor information can be acquired using a hand-guided sensor module. This sensor module consists of a stereo camera, a 3D direction sensor, and a keyboard. It is also possible to attach the sensor module to the cane. By pressing keys, inquiries can be sent either to the connected portable computer or to a platform of one or more servers distributing information about the closer and distant environment. The location of the user can be determined using conventional WiFi installations. The system enables users to recognise modelled objects, i.e. the closest object in front of the user. The name of this object is transmitted to the user over a text-to-speech engine.

In previous work we have presented a prototype of an assistant system for the blind that can be used for self-localization and interactive object identification of static objects stored within 3D environment models. In this paper we present a new method for interactive tracking of various types of movable objects. The state of fixed movable objects, like doors, can be recognized by comparing the distance between sensor data and a 3D model. For the identification and model-based tracking of free movable objects, like chairs, we have developed an algorithm that is similar to human perception, based on shape and color comparisons to trained objects. Further, using a common face detection algorithm, our assistant system informs the user of the presence of people, and enables the localization of a real person based on interactive tracking of virtual models of humans.

Summary We present an improved prototype for the interactive localization and recognition of objects for the blind by matching stereo images, orientation and 3D model information.

In this paper we present a concept for a wide-ranging indoor navigation support for the blind and people with impaired vision. Parts of this work were realized within a new prototype of an indoor navigation and object identification system for the blind. With the previous orientation assistant it is possible for blind persons to orientate themselves and to detect objects within modeled indoor environments. By pressing keys, the user’s inquiries concerning their environment are acoustically answered through a text-to-speech engine. The previous system’s limitation was that it was necessary to hit an object precisely using a picking ray within a 3D model in order to allow proper object identification. Our new prototype now includes the option to receive augmented navigation hints automatically just by walking in virtual corresponding navigation areas.

Children and adults often find it difficult to learn basic foreign language vocabulary through conventional teaching methods. This is especially true for blind learners, who lack the benefit of environmental cues. While sighted individuals gain valuable information by noting the position of objects and their association with other objects (e.g., clock on the wall, chairs with the table, etc.), such cues are unavailable to blind learners. We have developed an orientation assistant for the blind that allows both blind and sighted individuals to learn basic vocabulary in their own or different languages while simply exploring their environment. Our device consists of a sensor module and a portable computer, and requires the generation of a 3D model of a specific indoor environment. A database is created which names all objects of interest in several different languages. The user can point the sensor module in any direction, press a key, and the closest object within the modelled environment is announced via text-to-speech engine. Thus, blind children, as they explore their surroundings, gain the environmental cues that facilitate vocabulary development. Blind and sighted individuals of all ages can utilize our device to learn foreign vocabulary, with sighted learners benefiting from the pairing of auditory and visual cues. Additionally, our orientation assistant allows blind individuals to navigate independently and safely within the modelled environment.

In this paper we present a new system that assists blind users in orienting themselves in indoor environments. We developed a sensor module that can be handled like a flashlight by a blind user and can be used for searching tasks within the three-dimensional environment. By pressing keys, inquiries concerning object characteristics, position, orientation and navigation can be sent to a connected portable computer, or to a federation of data servers providing models of the environment. Finally these inquiries are acoustically answered over a text-to-speech engine.

A voice control program was integrated into our portable navigation and object recognition system for the blind and visually impaired. So far, a keyboard or touch screen was required to control this system. Trials at pilot locations have shown that there are many situations where the use of hands and fingers is inconvenient or sometimes impossible. To expand usability voice-operated selection of destinations and voice commands for enhanced navigation support were added. 1. INTRODUCTION Various products exist to provide navigational help for the blind in specific locations. Most common, perhaps, are Braille markers on doors, elevators and bank machines. Less common are tactile environmental maps at building or park entrances. Although helpful, such aids cannot announce their presence, and blind navigators must depend upon others to direct them to the Braille information. More technical devices provide auditory cues, such as announcing building floors or traffic light changes, but these are unavailable in many areas. To support more independent ambulation by blind people, complex indoor location and navigation systems have been developed. Most require installation of a special infrastructure, such as optical beacons or Radio Frequency Identification (RFID) tags. The impressive accuracy achieved by some of these systems is offset by several disadvantages. Installation is time-consuming and costly. Beacons can be occluded by environmental changes, like door position, and signals impeded by weather conditions, like temperature and humidity. Outdoor navigation systems based on the Global Positioning System (GPS) have proven similarly unsatisfactory. Maps used in such systems are made for car navigation, resulting in low accuracy and low resolution. Further, as with most indoor