SLAM for Visually Impaired People: A Survey

In recent decades, several assistive technologies for visually impaired and blind (VIB) people have been developed to improve their ability to navigate independently and safely. At the same time, simultaneous localization and mapping (SLAM) techniques have become sufficiently robust and efficient to be adopted in the development of assistive technologies. In this paper, we first report the results of an anonymous survey conducted with VIB people to understand their experience and needs; we focus on digital assistive technologies that help them with indoor and outdoor navigation. Then, we present a literature review of assistive technologies based on SLAM. We discuss proposed approaches and indicate their pros and cons. We conclude by presenting future opportunities and challenges in this domain.Comment: 26 pages, 5 tables, 3 figure

Ambient awareness on a sidewalk for visually impaired

Safe navigation by avoiding obstacles is vital for visually impaired while walking on a sidewalk. There are both static and dynamic obstacles to avoid. Detection, monitoring, and estimating the threat posed by obstacles remain challenging. Also, it is imperative that the design of the system must be energy efficient and low cost. An additional challenge in designing an interactive system capable of providing useful feedback is to minimize users\u27 cognitive load. We started the development of the prototype system through classifying obstacles and providing feedback. To overcome the limitations of the classification-based system, we adopted the image annotation framework in describing the scene, which may or may not include the obstacles. Both solutions partially solved the safe navigation but were found to be ineffective in providing meaningful feedback and issues with the diurnal cycle. To address such limitations, we introduce the notion of free-path and threat level imposed by the static or dynamic obstacles. This solution reduced the overhead of obstacle detection and helped in designing meaningful feedback. Affording users a natural conversation through an interactive dialog enabled interface was found to promote safer navigation. In this dissertation, we modeled the free-path and threat level using a reinforcement learning (RL) framework.We built the RL model in the Gazebo robot simulation environment and implanted that in a handheld device. A natural conversation model was created using data collected through a Wizard of OZ approach. The RL model and conversational agent model together resulted in the handheld assistive device called Augmented Guiding Torch (AGT). The AGT provides improved mobility over white cane by providing ambient awareness through natural conversation. It can inform the visually impaired about the obstacles which are helpful to be warned about ahead of time, e.g., construction site, scooter, crowd, car, bike, or big hole. Using the RL framework, the robot avoided over 95% obstacles. The visually impaired avoided over 85% obstacles with the help of AGT on a 500 feet U-shape sidewalk. Findings of this dissertation support the effectiveness of augmented guiding through RL for navigation and obstacle avoidance of visually impaired users

Implementación de tecnologías RFID e IoT inalámbricas en el Modelado de información de construcción (BIM)

ABSTRACT: The integration and installation of innovative Radio Frequency Identification (RFID) technologies in combination with wireless Internet of Things (IoT) technologies in Building Information Modelling (BIM), assigned building elements, can create connectivity between the physical- and the virtual world. Beyond the identification of physical objects, further information can be connected, which can be made available to different user groups during the entire life cycle of the building structure. This provides a high level of transparency, in that by scanning the tagged building elements, complete associated information can be accessed and presented to users via applications, in visual and audio form. One use of an RFID and BIM-supported electronic guidance system, namely for the visually impaired, has already been investigated in my bachelor thesis at the University of Applied Sciences (Technische Hochschule Mittelhessen, THM). This Master’s Thesis focuses on the implementation of passive RFID technology into BIM models in combining them with open-source software applications. BIM represents the digital twin of building models in the digital world and can be linked to physical structures (buildings, roads, sewer systems and such others) and building materials (e.g. textiles, mineral and plastic floor coverings, concrete components) by integrating RFID tags. Connecting the parametric BIM models with the physical building elements by using RFID and wireless IoT technologies in a multi-platform application enables the BIM building models to be actively used throughout the life cycle of a building, not only by the facility management, but also by the public for various use cases. During the literature review, suitable software and hardware components were selected, and a prototype multi-platform application for a navigation and positioning system was developed as proof of concept for the Industry Foundation Classes (IFC) file. (See Demo Version at https://opennavibim.herokuapp.com/ ). The challenge was to read the RFID tags in different installation scenarios. Depending on the installation situations (under, over or in the material), various requirements were specified for RFID tags and readers (RFID, handhold personal digital assistant “PDA”). In this field, further hardware developments are necessary.RESUMEN: Mediante la integración e instalación de la innovadora tecnología de identificación por radiofrecuencia (RFID, Radio Frequency Identification) en el modelado digital de información de construcción (BIM, Building Information Modelling), con la interconexión inalámbrica del internet de las cosas (IoT, Internet of Things), es posible crear una conectividad entre el mundo físico y el virtual. Más allá de la mera identificación de objetos existentes, esta conectividad permite incorporar información adicional, que puede ponerse en disposición de los diferentes grupos de usuarios que intervienen durante el ciclo completo de vida de la estructura de la edificación. Se consigue un alto de nivel de transparencia en ese traspaso de información, accesible por medio del escaneado de los elementos etiquetados en la edificación, al tener una completa información asociada que es presentada a los usuarios vía aplicaciones en formato visual o de audio. Una investigación en la aplicación de tecnología RFID basada en BIM para un sistema de navegación electrónica, destinada a personas con discapacidad visual, ha sido desarrollada en mi trabajo fin de grado en la Universidad de Ciencias Aplicadas de Mittelhessen (THM). El presente Trabajo Fin de Master se centra en la implementación de tecnología RFID pasiva en modelos BIM combinados con aplicaciones de software libre. El modelo BIM representa el gemelo digital de los elementos de construcción en el mundo virtual, permitiendo establecer una relación del modelo con estructuras físicas (edificios, carreteras o sistemas de alcantarillado, entre otros) y materiales de construcción (por ejemplo, textiles, cubiertas de suelo minerales o plásticas, componentes de hormigón, …) por medio de la integración de etiquetas RFID. La conexión de los modelos paramétricos BIM con los elementos físicos del edificio, mediante el uso de tecnologías RFID e IoT inalámbricas en una aplicación multiplataforma, permite que los modelos de construcción BIM se utilicen activamente a lo largo del ciclo de vida de un edificio, no solo por la gestión de las instalaciones, sino también por el público para diversos casos de uso. Durante la revisión bibliográfica, se seleccionaron los componentes de software y hardware adecuados, y se desarrolló un prototipo de aplicación multiplataforma para un sistema de navegación y posicionamiento como prueba de viabilidad del concepto del modelo Industry Foundation Classes (IFC). (Véase la versión de demostración en https://opennavibim.herokuapp.com/ ). La lectura de las etiquetas RFID en diferentes en diferentes situaciones de instalación presenta un desafío, dependiendo de la instalación (debajo, encima o en el material) los requisitos impuestos a las etiquetas y lectores RFID son diferentes. Por lo tanto, es necesario seguir desarrollando el hardware en este ámbito.Máster en Ingeniería de Caminos, Canales y Puertos (Plan 2020

Wayfinding and Navigation for People with Disabilities Using Social Navigation Networks

To achieve safe and independent mobility, people usually depend on published information, prior experience, the knowledge of others, and/or technology to navigate unfamiliar outdoor and indoor environments. Today, due to advances in various technologies, wayfinding and navigation systems and services are commonplace and are accessible on desktop, laptop, and mobile devices. However, despite their popularity and widespread use, current wayfinding and navigation solutions often fail to address the needs of people with disabilities (PWDs). We argue that these shortcomings are primarily due to the ubiquity of the compute-centric approach adopted in these systems and services, where they do not benefit from the experience-centric approach. We propose that following a hybrid approach of combining experience-centric and compute-centric methods will overcome the shortcomings of current wayfinding and navigation solutions for PWDs

Indoor assistance for visually impaired people using a RGB-D camera

In this paper a navigational aid for visually impaired people is presented. The system uses a RGB-D camera to perceive the environment and implements self-localization, obstacle detection and obstacle classification. The novelty of this work is threefold. First, self-localization is performed by means of a novel camera tracking approach that uses both depth and color information. Second, to provide the user with semantic information, obstacles are classified as walls, doors, steps and a residual class that covers isolated objects and bumpy parts on the floor. Third, in order to guarantee real time performance, the system is accelerated by offloading parallel operations to the GPU. Experiments demonstrate that the whole system is running at 9 Hz

The Role of Situation Awareness Metrics in the Assessment of Indoor Orientation Assistive Technologies that Aid Blind Individuals in Unfamiliar Indoor Environments

The importance of raising user\u27s situation awareness has proven to be an important factor in the successful use of systems that involve mission-critical tasks. Indoor Orientation Assistive Technology (OAT) that supports blind individuals is one of the systems that needs to be oriented to support user\u27s situation awareness. In the tasks involved in this system, blind individuals try to maintain their spatial understanding of the environment. The current evaluation methods of Orientation Assistive Technology that aids blind travelers within indoor environments rely on the performance metrics. When enhancing such systems, evaluators conduct qualitative studies to learn where to focus their efforts. The main purpose of this thesis is to investigate the use of an objective method to facilitate blind travelers situation awareness when traveling unfamiliar indoor environments. We investigate the use of in-task probes using the Situation Awareness Global Assessment Technique (SAGAT) method, and post self-reported questionnaire using the Situation Awareness Rating Technique (SART) method. The goal of this metric is to design an objective method that can highlight design areas that need improvements when evaluating such systems. Also, we investigate the relationship between user\u27s situation awareness and user\u27s confidence, satisfaction, and stress levels