Indoor Human Navigation Systems: A Survey <s> System Feedback <s> We outline the design for a navigation system for the visually impaired and describe the progress we have made toward such a system. Our long-term goal is for a portable, self-contained system that will allow visually impaired individuals to travel through familiar and unfamiliar environments without the assistance of guides. The system, as it exists now, consists of the following functional components: (1) a means of determining the traveler's position and orientation in space, (2) a Geographic Information System comprising a detailed database of the surrounding environment and functions for automatic route planning and for selecting the database information desired by the user, and (3) the user interface. <s> BIB001 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> This paper presents the research for the development of a new travel aid to increase the independent mobility of blind and elderly travellers. This aid will build on the technologies of geographical information systems (GIS) and the Global Positioning System (GPS). The MOBIC Travel Aid (MOTA) consists of two interrelated components : the MOBIC Pre-journey System (MOPS) to assist users in planning journeys and the MOBIC Outdoor System (MooDs) to execute these plans by providing users with orientation and navigation assistance during journeys. The MOBIC travel aid is complementary to primary mobility aids such as the long cane or guide dog. Results of a study of user requirements are presented and their implications for the initial design of the system are discussed. <s> BIB002 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> Metronaut is a novel wearable computer which captures information, senses position, provides wide range communications, consumes less than one watt of power, and weighs less than one pound. Metronaut employs a bar code reader for information input and position location, a two-way pager for communications, and an ARM processor for computation. Metronaut's application is schedule negotiation and guidance instructions for a visitor to the CMU campus. The visitor's position is determined from reading bar codes at information signs around campus. Modifications to the schedule are negotiated using the two-way pager for communications with the campus computing infrastructure. Metronaut is alternatively powered by a mechanical flywheel converting kinetic energy to electrical energy. <s> BIB003 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> This paper proposes a walking navigation system for the blind. The system is based on a comparison of data obtained by a pedometer and a terrestrial magnetic sensor and prearranged teaching data of a route to a destination. The system gives an appropriate instruction (using voice and buzzer sound) during a user's walk. This paper mainly describes experiments designed to clarify the characteristics of the system. The results show that the nodes of a walking route for teaching should be less than 50 m, since the maximum error of the system is about 10% in a walking distance of 50 m. The experiments also show that the walkers (sighted men with eye masks) were guided by the system along a course of about 900 m, taking about 40 to 50 mins. © 1998 Scripta Technica. Syst Comp Jpn, 28(13): 36–45, 1997 <s> BIB004 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> This paper describes a wearable navigation system based on a haptic directional display embedded in the back of a vest. The system consists of a 4-by-4 array of micromotors for delivering haptic navigational signals to the user's back, an infrared-based input system for locating the user in an environment, and a wearable computer for route planning. User testing was conducted to evaluate the effectiveness of this system as a navigation guide for sighted users in an unfamiliar lab area. It is hoped that such a system can be a useful navigation guide for individuals with severe visual impairments in an unfamiliar environment. Future work will address the specific issues concerning blind navigation. <s> BIB005 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> The position-tracking accuracy of a location-aware mobile system can change dynamically as a function of the user’s location and other variables specific to the tracker technology used. This is especially problematic for mobile augmented reality systems, which ideally require extremely precise position tracking for the user’s head, but which may not always be able to achieve the necessary level of accuracy. While it is possible to ignore variable positional accuracy in an augmented reality user interface, this can make for a confusing system; for example, when accuracy is low, virtual objects that are nominally registered with real ones may be too far off to be of use. To address this problem, we describe the early stages of an experimental mobile augmented reality system that adapts its user interface automatically to accommodate changes in tracking accuracy. Our system employs different technologies for tracking a user’s position, resulting in a wide variation in positional accuracy: an indoor ultrasonic tracker and an outdoor real-time kinematic GPS system. For areas outside the range of both, we introduce a dead-reckoning approach that combines a pedometer and orientation tracker with environmental knowledge expressed in spatial maps and accessibility graphs. We present preliminary results from this approach in the context of a navigational guidance system that helps users to orient themselves in an unfamiliar environment. Our system uses inferencing and path planning to guide users toward targets that they choose. <s> BIB006 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> Drishti is a wireless pedestrian navigation system. It integrates several technologies including wearable computers, voice recognition and synthesis, wireless networks, Geographic Information System (GIS) and Global positioning system (GPS). Drishti augments contextual information to the visually impaired and computes optimized routes based on user preference, temporal constraints (e.g. traffic congestion), and dynamic obstacles (e.g. ongoing ground work, road blockade for special events). The system constantly guides the blind user to navigate based on static and dynamic data. Environmental conditions and landmark information queried from a spatial database along their route are provided on the fly through detailed explanatory voice cues. The system also provides capability for the user to add intelligence, as perceived by, the blind user, to the central server hosting the spatial database. Our system is supplementary to other navigational aids such as canes, blind guide dogs and wheel chairs. <s> BIB007 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> We have previously proposed a portable navigation system for the visually impaired (see Nakamura, K. et al., IEICE Trans. of Japan, vol.J79, p.1610-18, 1996; Takuno, S. et al., IEICE Trans. of Japan, vol.J83, p.293-302, 2000). However, there are some places where this system is unable to provide proper guidance. Since the traveling direction of the traveler in this system is measured by a terrestrial magnetism sensor, there is a possibility that the wrong direction is measured, due to the distortion of the terrestrial magnetism by vehicles, etc. Road markings, e.g., pedestrian crossing, white line of the road, are reliable information to measure the correct direction. Furthermore, street landmarks, e.g., electric pole, traffic-control sign and post box, are also useful for a traveler to confirm his position. Therefore, we have now adequately applied image processing to our portable navigation system to make it more reliable. <s> BIB008 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> The design of mobile navigation systems adapting to limited resources will be an important future challenge. Since typically several different means of transportation have to be combined in order to reach a destination, the user interface of such a system has to adapt to the user's changing situation. This applies especially to the alternating use of different technologies to detect the user's position, which should be as seamless as possible. This article presents a hybrid navigation system that relies on different technologies to determine the user's location and that adapts the presentation of route directions to the limited technical resources of the output device and the limited cognitive resources of the user. <s> BIB009 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> Abstract: In this paper we describe a prototype spatial audio user interface for a Global Positioning System (GPS). The interface is designed to allow mobile users to carry out location tasks while their eyes, hands or attention are otherwise engaged. Audio user interfaces for GPS have typically been designed to meet the needs of visually impaired users, and generally, though not exclusively, employ speech-audio. In contrast, our prototype system uses a simple form of non-speech, spatial audio. This paper analyses various candidate audio mappings for location and distance information. A variety of tasks, design considerations, design trade-offs and opportunities are considered. The findings from pilot empirical testing are reported. Finally, opportunities for improvements to the system and for future evaluation are explored. <s> BIB010 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> 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. <s> BIB011 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> A location-aware navigation system has been developed and implemented for the visually disabled or visually impaired; the system is designed to improve individuals' independent mobility. This self-contained, portable system integrates several technologies, including mobile personal digital assistants, voice synthesis, a geographic information system (GIS), and a differential Global Positioning System (DGPS). The system is meant to augment the various sensory inputs available to the visually impaired user. It provides the user with navigation assistance, making use of voice cues iterating contextual building and feature information at regular intervals, through automatic GPS readings and a GIS database. To improve the efficiency of the retrieval of contextual information, an indexing method based on road segmentation was developed to replace the exhaustive search method. Experimental results show that the performance of the system on searching the buildings, landmarks, and other features around a road has been significantly improved by using this indexing method. <s> BIB012 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> In this paper, we discuss application possibilities of augmented reality technologies in the field of mobility support for the deaf blind. We propose the navigation system called virtual leading blocks for the deaf-blind, which consists of a wearable interface for Finger-Braille, one of the commonly used communication methods among deaf-blind people in Japan, and a ubiquitous environment for barrier-free application, which consists of floor-embedded active radio-frequency identification (RFID) tags. The wearable Finger-Braille interface using two Linux-based wristwatch computers has been developed as a hybrid interface of verbal and nonverbal communication in order to inform users of their direction and position through the tactile sensation. We propose the metaphor of "watermelon splitting" for navigation by this system and verify the feasibility of the proposed system through experiments. <s> BIB013 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> In this paper the design, development and evaluation of a GPS-based auditory navigation system is presented that implicitly guides a user by a contextualized rendering of personal audio files. The benefit of this navigation system is that the user can listen to his own audio contents while being navigated. Wearing headphones, the user listens to audio contents which are located in a virtual environment. The user simply walks in the direction where the sound seems to have its origin. A formal evaluation under field conditions proved that navigation with contextualized audio contents is efficient and intuitive and that users are highly satisfied with the navigation support given by the evaluated auditory display. <s> BIB014 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> We present a robot-assisted wayfinding system for the visually impaired in structured indoor environments. The system consists of a mobile robotic guide and small passive RFID sensors embedded in the environment. The system is intended for use in indoor environments, such as office buildings, supermarkets and airports. We describe how the system was deployed in two indoor environments and evaluated by visually impaired participants in a series of pilot experiments. We analyze the system's successes and failures and outline our plans for future research and development. <s> BIB015 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> Digital maps and route descriptions on a PDA have become very popular for navigation, not the least with the advent of the iPhone and its Google Maps application. A visual support for wayfinding, however, is not reasonable or even possible all the time. A pedestrian must pay attention to traffic on the street, a hiker should concentrate on the narrow trail, and a blind person relies on other modalities to find her way. To overcome these limitations, we developed a non-visual support for wayfinding that guides and keeps a mobile user en route by a tactile display. We designed a belt with vibrators that indicates directions and deviations from the path in an accurate and unobtrusive way. Our first user evaluation showed that on an open field without any landmarks the participants stayed well to given test routes and that wayfinding support is possible with our Tactile Wayfinder. <s> BIB016 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> Almost 2 million Japanese citizens use Navitime, a mobile phone-based navigation service that incorporates various modes of transportation. User experiences reveal implications for designing urban-computing services. Location-based services are a key pervasive computing application that could deeply influence urban spaces and their inhabitants. Recent advances in mobile phones, GPS, and wireless networking infrastructures are making it possible to implement and operate large-scale location- based services in the real world. <s> BIB017 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> Many navigation systems for visually impaired people have been developed, but few can provide dynamic interactions and adaptability to changes. The aim of this working life project is to create an innovative navigation service solution that will improve the quality of life of the visually impaired. For example, a university campus might be such a large and rambling place that visually impaired people can not always find the services or rooms they want to. Therefore, we are devising new service solutions that exploit the technical features of modern WLAN systems in an innovative way. This paper describes the LaureaPOP system that focuses on the indoor navigation service design in a wireless local area network environment. <s> BIB018 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> A challenge to individuals with cognitive impairments in wayfinding is how to remain oriented, recall routines, and travel in unfamiliar areas in a way relying on limited cognitive capacity. According to psychological model of spatial navigation and the requirements of rehabilitation professionals, a novel wayfinding system is presented with an aim to increase workplace and life independence for people suffering from diseases such as traumatic brain injury, cerebral palsy, mental retardation, schizophrenia, Down syndromes, and Alzheimer's disease. This paper describes an approach to providing distributed cognition support of travel guidance for persons with cognitive disabilities. The unique strength of the system is the ability to provide unique-to-the-user prompts that are triggered by context. As this population is very sensitive to issues of abstraction (e.g. icons) and presents the designer with the need to tailor prompts to a 'universe-of-one' the use of images specific to each user and context is implemented. The key to the approach is to spread the context awareness across the system, with the context being flagged by the QR-code tags and the appropriate response being evoked by displaying the appropriate path guidance images indexed by the intersection of specific end-user and context ID embedded in the tags. By separating the context trigger from the pictorial response, responses can be updated independently of the rest of the installed system, and a single QR-code tag can trigger multiple responses in the PDA depending on the end-user and their specific path. A prototype is built and tested in field experiments with real patients. The experimental results show the human-computer interface is friendly and the capabilities of wayfinding are reliable. <s> BIB019 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> Ad hoc solutions for tracking and providing navigation support to emergency response teams is an important and safety-critical challenge. We propose a navigation system based on a combination of foot-mounted inertial sensors and ultrasound beacons. We evaluate experimentally the performance of our dead reckoning system in different environments and for different trail topologies. The inherent drift observed in dead reckoning is addressed by deploying ultrasound beacons as landmarks. We study through simulations the use of the proposed approach in guiding a person along a defined path. ::: Simulation results show that satisfactory guidance performance is achieved despite noisy ultrasound measurements, magnetic interference and uncertainty in ultrasound node locations. The models used for the simulations are based on experimental data and the authors' experience with actual sensors. The simulation results will be used to inform future development of a full real time system. <s> BIB020 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> A location and tracking system becomes very important to our future world of pervasive computing, where information is all around us. Location is one of the most needed information for emerging and future applications. Since the public use of GPS satellite is allowed, several state-of-the-art devices become part of our life, e.g. a car navigator and a mobile phone with a built-in GPS receiver. However, location information for indoor environments is still very limited. Several techniques are proposed to get location information in buildings such as using a radio signal triangulation, a radio signal (beacon) emitter, or signal fingerprinting. Using radio frequency identification (RFID) tags is a new way of giving location information to users. Due to its passive communication circuit, RFID tags can be embedded almost anywhere without an energy source. The tags stores location information and gives it to any reader that is within a proximity range which can be up to 10-15 meters for UHF RFID systems. We propose an RFID-based system for navigation in a building for blind people or visually impaired. The system relies on the location information on the tag, a userpsilas destination, and a routing server where the shortest route from the userpsilas current location to the destination. The navigation device communicates with the routing server using GPRS networks. We build a prototype based on our design and show some results. We found that there are some delay problems in the devices which are the communication delay due to the cold start cycle of a GPRS modem and the voice delay due to the file transfer delay from a MMC module. <s> BIB021 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> We describe a body-worn sensor suite, environment representation, set of algorithms, and graphical-aural interface designed to provide human-centered guidance to a person moving through a complex space. The central idea underlying our approach is to model the environment as a graph of visually distinctive places (graph nodes) connected by path segments (graph edges). During exploration, our algorithm processes multiple video-rate inputs to identify visual features and construct the “place graph” representation of the traversed space. The system then provides visual and/or spoken guidance in user-centered terms to lead the user along existing or newly-synthesized paths. Our approach is novel in several respects: it requires no precise calibration of the cameras or multi-camera rig used; it generalizes to any number of cameras with any placement on the body; it learns the correlation between user motion and evolution of image features; it constructs the place graph automatically; and it provides only coarse (rather than precise metrical) guidance to the user. We present an experimental study of our methods applied to walking routes through both indoor and outdoor environments, and show that the system provides accurate localization and effective navigation guidance. <s> BIB022 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> In this paper, a novel tour-guiding system is introduced, based on our space-identifying ubiquitous infrastructure, where positioning devices are deployed ubiquitously to identify the place of users. In this infrastructure, we can flexibly construct information service related to the places of interest in the city by modeling the space of the real world as a set of relations among the discrete places, and attaching space-identifying devices to them. Our developed tour-guiding system introduces many art works in a large commercial complex in Japan. Based on the benefit of the infrastructure, this system can provide detailed navigation service as well as art introduction service in both indoor and outdoor environments, and can guide the users to reach their interested art works. Currently, this system is already used in practice for a commercial service. In this paper, the design of this system is described and its navigation capability is verified through a user test in the real environment to discuss the effectiveness of our approach. <s> BIB023 </s> Indoor Human Navigation Systems: A Survey <s> System Feedback <s> This paper proposes a framework to enable intuitive navigation guidance for complex buildings which are huge in size and their space boundaries contain non-convex shape including non-navigable areas inside. Our approach utilizes ‘topological’ way-finding method to generate paths. This can be done by means of the integration of building information model (BIM) with our new algorithm to subdivide the spaces. The second main principle is to improve the visual information by using a new method to render all three dimensional views possibly observed in a building beforehand. This has been realized by imaging serviced using client-server architecture with supercomputer computation power. <s> BIB024
The three main techniques for providing directions to the user are identified as: • Visual: Providing directions using a display is the most common technique for providing directions. Maps BIB017 BIB009 or photos BIB019 can be displayed and direction can be shown using arrows to the user where to go. Using this method are large amount of information can be provided to the user in a short amount of time. Providing information as such can have a high level of accuracy as realistic images are displayed and arrows can clearly mark the exact location and action the user has to perform next. This method can be beneficial for individuals with cognitive disability as they can directly correspond what they see on the screen with the environment. On the other hand storing real images is storage intensive and downloading them in real time might not be feasible. Alternatively simple text directions BIB020 BIB003 can be displayed. Displaying text is far less resource intensive but provides less information, might not be as accurate, and slows down the user. 3D models of the environments BIB024 or wireframe model of the user's surroundings and labels of objects BIB006 can be rendered and displayed to the user. This method might be as efficient as displaying images in interacting with the user and require less storage compared to images but processing power required to render such models is higher. Having users to look at the screen while following directions may impede their safety as they need to devote their full attention to the screen. Visual interaction might be usable method of interaction with individuals with cognitive problems or tourists but it is difficult or impossible to utilize displays for emergency crew or users with visual impairments. • Audio: Speech based systems BIB007 BIB004 BIB018  use recorded directions BIB021 BIB001 or speech synthesis  BIB011 BIB022 to provide directions to the user. Speech synthesis is much more flexible than the recorded directions and can be performed at runtime without major processing overhead, though recorded directions sound better. Speech based directions are widely used for interaction but they are language dependent. Lengthy speech directions may overwhelm the user and may impede the user's ability to correctly follow the provided direction. Because speech directions are language dependent, audio cues can be used as an alternative BIB014 BIB010 BIB012 BIB015 . Typically some type of sonification or different audio icons with different tones can be used to provide distance information BIB010 . Audio cues are limited and for many objects no natural audio cue is associated. Speech may be safer than using a display as it requires less attention and can be easily facilitated using a headset without impairing the user's normal navigation capabilities and surrounding awareness. Using sound for output reduces the amount of information the user can obtain from the environment. Audio-based output techniques are not suitable when the environment is noisy or when a user is hearing impaired. • Haptic: Haptic based interfaces provide output using the sense of touch and do not interfere with the user's ability to sense their immediate environment using sight or hearing. Textual directions can be provided to the user using a haptic glove approach where users wear six vibration-motors worn on fingers, such as Finger-Braille BIB013 . Haptic directions can be provided for example by using vibrotactors on a waist belt BIB016  or in a backpack BIB005 . Some form of haptification (e.g, changes in frequency and intensity) is used to indicate the angle or distance between the user and the target destination. While haptic interaction has far less interference with sensing the environment, it requires training and more concentration, as it is less natural to receive complicated information through touch. Haptic-based directions require additional hardware to be provided, which may increase the cost of the system. As each modality of feedback has some drawbacks, this can be overcome by representing information in multiple modalities. Some systems combine visual and audio BIB023 or haptic and audio  BIB008 BIB004 BIB002 feedback to provide directions to the user. To navigate the user, the planned path is converted to a set of directions and provided to the user. The type of direction provided to the user may significantly affect the cognitive load; in case the directions are to too long they may be challenging to follow as users feel overwhelmed, where shorter directions may not be as efficient. 