The last decades a variety of portable or wearable navigation systems have been developed to assist visually impaired people during navigation in known or unknown, indoor or outdoor environments. There are three main categories of these systems: electronic travel aids (ETAs), electronic orientation aids (EOAs), and position locator devices (PLDs). This paper presents a comparative survey among portable/wearable obstacle detection/avoidance systems (a subcategory of ETAs) in an effort to inform the research community and users about the capabilities of these systems and about the progress in assistive technology for visually impaired people. The survey is based on various features and performance parameters of the systems that classify them in categories, giving qualitative-quantitative measures. Finally, it offers a ranking, which will serve only as a reference point and not as a critique on these systems.

/pdf/wearable-obstacle-avoidance-electronic-travel-aids-for-blind-2bjofqudfi.pdf

Wearable Obstacle Avoidance Electronic Travel Aids for Blind: A Survey

Indoor Human Navigation Systems {a Survey

Navigating complex routes and finding objects of interest are challenging tasks for the visually impaired The project NAVIG (Navigation Assisted by artificial VIsion and GNSS) is directed toward increasing personal autonomy via a virtual augmented reality system The system integrates an adapted geographic information system with different classes of objects useful for improving route selection and guidance The database also includes models of important geolocated objects that may be detected by real-time embedded vision algorithms Object localization (relative to the user) may serve both global positioning and sensorimotor actions such as heading, grasping, or piloting The user is guided to his desired destination through spatialized semantic audio rendering, always maintained in the head-centered reference frame This paper presents the overall project design and architecture of the NAVIG system In addition, details of a new type of detection and localization device are presented This approach combines a bio-inspired vision system that can recognize and locate objects very quickly and a 3D sound rendering system that is able to perceptually position a sound at the location of the recognized object This system was developed in relation to guidance directives developed through participative design with potential users and educators for the visually impaired

NAVIG: augmented reality guidance system for the visually impaired

In this paper, we describe interdependence for assistive technology design, a frame developed to complement the traditional focus on independence in the Assistive Technology field. Interdependence emphasizes collaborative access and people with disabilities' important and often understated contribution in these efforts. We lay the foundation of this frame with literature from the academic discipline of Disability Studies and popular media contributed by contemporary disability justice activists. Then, drawing on cases from our own work, we show how the interdependence frame (1) synthesizes findings from a growing body of research in the Assistive Technology field and (2) helps us orient to additional technology design opportunities. We position interdependence as one possible orientation to, not a prescription for, research and design practice--one that opens new design possibilities and affirms our commitment to equal access for people with disabilities.

https://dl.acm.org/doi/pdf/10.1145/3234695.3236348

Interdependence as a Frame for Assistive Technology Research and Design

Spatial navigation in the absence of vision has been investigated from a variety of perspectives and disciplines. These different approaches have progressed our understanding of spatial knowledge acquisition by blind individuals, including their abilities, strategies, and corresponding mental representations. In this review, we propose a framework for investigating differences in spatial knowledge acquisition by blind and sighted people consisting of three longitudinal models (i.e., convergent, cumulative, and persistent). Recent advances in neuroscience and technological devices have provided novel insights into the different neural mechanisms underlying spatial navigation by blind and sighted people and the potential for functional reorganization. Despite these advances, there is still a lack of consensus regarding the extent to which locomotion and wayfinding depend on amodal spatial representations. This challenge largely stems from methodological limitations such as heterogeneity in the blind population and terminological ambiguity related to the concept of cognitive maps. Coupled with an over-reliance on potential technological solutions, the field has diffused into theoretical and applied branches that do not always communicate. Here, we review research on navigation by congenitally blind individuals with an emphasis on behavioral and neuroscientific evidence, as well as the potential of technological assistance. Throughout the article, we emphasize the need to disentangle strategy choice and performance when discussing the navigation abilities of the blind population. For further resources related to this article, please visit the WIREs website.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/wcs.1375

Spatial navigation by congenitally blind individuals.

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.

Design and development of an indoor navigation and object identification system for the blind

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.

/pdf/interactive-tracking-of-movable-objects-for-the-blind-on-the-ef7y8ahsom.pdf

Interactive tracking of movable objects for the blind on the basis of environment models and perception-oriented object recognition methods

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.

Augmented Indoor Modeling for Navigation Support for the Blind.

The foundation of any orientation and navigation system for the blind is an accurate determination of the user’s position and the location of objects within his environment. This is also the reason why most available systems have weaknesses or even fail. In order to address this problem, we previously focused on indoor environments. One reason for this approach is that localization within indoor environments is more difficult, since GPS signals are normally unavailable. The second reason is that, if we can solve the localization problem indoors, it should also be possible to solve it outdoors by combining our assistant with the global positioning system.

Interactive localization and recognition of objects for the blind

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 (eg, 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

Andreas Hub

Papers

Design and development of an indoor navigation and object identification system for the blind

Interactive tracking of movable objects for the blind on the basis of environment models and perception-oriented object recognition methods

Augmented Indoor Modeling for Navigation Support for the Blind.

Interactive localization and recognition of objects for the blind

Learning Foreign Languages by Using a New Type of Orientation Assistant for the Blind