Portable Robotic Navigation Aid for the Visually Impaired

This dissertation aims to address the limitations of existing visual-inertial (VI) SLAM methods - lack of needed robustness and accuracy - for assistive navigation in a large indoor space. Several improvements are made to existing SLAM technology, and the improved methods are used to enable two robotic assistive devices, a robot cane, and a robotic object manipulation aid, for the visually impaired for assistive wayfinding and object detection/grasping. First, depth measurements are incorporated into the optimization process for device pose estimation to improve the success rate of VI SLAM\u27s initialization and reduce scale drift. The improved method, called depth-enhanced visual-inertial odometry (DVIO), initializes itself immediately as the environment\u27s metric scale can be derived from the depth data. Second, a hybrid PnP (perspective n-point) method is introduced for a more accurate estimation of the pose change between two camera frames by using the 3D data from both frames. Third, to implement DVIO on a smartphone with variable camera intrinsic parameters (CIP), a method called CIP-VMobile is devised to simultaneously estimate the intrinsic parameters and motion states of the camera. CIP-VMobile estimates in real time the CIP, which varies with the smartphone\u27s pose due to the camera\u27s optical image stabilization mechanism, resulting in more accurate device pose estimates. Various experiments are performed to validate the VI-SLAM methods with the two robotic assistive devices. Beyond these primary objectives, SM-SLAM is proposed as a potential extension for the existing SLAM methods in dynamic environments. This forward-looking exploration is premised on the potential that incorporating dynamic object detection capabilities in the front-end could improve SLAM\u27s overall accuracy and robustness. Various experiments have been conducted to validate the efficacy of this newly proposed method, using both public and self-collected datasets. The results obtained substantiate the viability of this innovation, leaving a deeper investigation for future work

Design, modeling and analysis of object localization through acoustical signals for cognitive electronic travel aid for blind people

El objetivo de la tesis consiste en el estudio y análisis de la localización de objetos en el entorno real mediante sonidos, así como la posterior integración y ensayo de un dispositivo real basado en tal técnica y destinado a personas con discapacidad visual. Con el propósito de poder comprender y analizar la localización de objetos se ha realizado un profundo estado de arte sobre los Sistemas de Navegación desarrollados durante las últimas décadas y orientados a personas con distintos grados de discapacidad visual. En el citado estado del arte, se han analizado y estructurado los dispositivos de navegación existentes, clasificándolos de acuerdo con los componentes de adquisición de datos del entorno utilizados. A este respecto, hay que señalar que, hasta el momento, se conocen tres clases de dispositivos de navegación: 'detectores de obstáculos', que se basan en dispositivos de ultrasonidos y sensores instalados en los dispositivos electrónicos de navegación con el objetivo de detectar los objetos que aparecen en el área de trabajo del sistema; 'sensores del entorno' - que tienen como objetivo la detección del objeto y del usuario. Esta clase de dispositivos se instalan en las estaciones de autobús, metro, tren, pasos de peatones etc., de forma que cuando el sensor del usuario penetra en el área de alcance de los sensores instalados en la estación, éstos informan al usuario sobre la presencia de la misma. Asimismo, el sensor del usuario detecta también los medios de transporte que tienen instalado el correspondiente dispositivo basado en láser o ultrasonidos, ofreciendo al usuario información relativa a número de autobús, ruta etc La tercera clase de sistemas electrónicos de navegación son los 'dispositivos de navegación'. Estos elementos se basan en dispositivos GPS, indicando al usuario tanto su locación, como la ruta que debe seguir para llegar a su punto de destino. Tras la primera etapa de elaboración del estaDunai ., L. (2010). Design, modeling and analysis of object localization through acoustical signals for cognitive electronic travel aid for blind people [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8441Palanci

Smartphone application for accessible navigation

Διπλωματική εργασία--Πανεπιστήμιο Μακεδονίας, Θεσσαλονίκη, 2018.The main aim of this study is to investigate how the modern smartphone technology can assist people with visual impairments in indoor navigation tasks. We use the free and open indoor navigation service Anyplace, to design an indoor guidance system that is accessible, inexpensive, simple and user-friendly to different user groups disregarding their disabilities. The Android application that Anyplace offers, was extended and modified to serve also the needs of visually impaired users. The presented system works well with the assistive applications that Android platform offers and provides various ways for interaction between the user and the system. The system is communicating with Anyplace server to inform the user about the information of the surrounding environment and guide him/her to the desired place in the building with accessible messages. The application can process, specific pre-defined user commands and location information from existing QR labels in the building. This thesis is focusing on assisting the impaired users on indoor navigation tasks, but not on replacing the assistive means that the visually impaired user is already using. (e.g. long cane, guide dog) Experimental results show the ability of the system to effectively communicate with the user and assist him/her in way-finding tasks in the building of the University of Macedonia

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

Exploring the Use of Wearables to Enable Indoor Navigation for Blind Users

One of the challenges that people with visual impairments (VI) have to have to confront daily, is navigating independently through foreign or unfamiliar spaces.Navigating through unfamiliar spaces without assistance is very time consuming and leads to lower mobility. Especially in the case of indoor environments where the use of GPS is impossible, this task becomes even harder.However, advancements in mobile and wearable computing pave the path to new cheap assistive technologies that can make the lives of people with VI easier.Wearable devices have great potential for assistive applications for users who are blind as they typically feature a camera and support hands and eye free interaction. Smart watches and heads up displays (HUDs), in combination with smartphones, can provide a basis for development of advanced algorithms, capable of providing inexpensive solutions for navigation in indoor spaces. New interfaces are also introduced making the interaction between users who are blind and mo-bile devices more intuitive.This work presents a set of new systems and technologies created to help users with VI navigate indoor environments. The first system presented is an indoor navigation system for people with VI that operates by using sensors found in mo-bile devices and virtual maps of the environment. The second system presented helps users navigate large open spaces with minimum veering. Next a study is conducted to determine the accuracy of pedometry based on different body placements of the accelerometer sensors. Finally, a gesture detection system is introduced that helps communication between the user and mobile devices by using sensors in wearable devices

Empowering and assisting natural human mobility: The simbiosis walker

This paper presents the complete development of the Simbiosis Smart Walker. The device is equipped with a set of sensor subsystems to acquire user-machine interaction forces and the temporal evolution of user's feet during gait. The authors present an adaptive filtering technique used for the identification and separation of different components found on the human-machine interaction forces. This technique allowed isolating the components related with the navigational commands and developing a Fuzzy logic controller to guide the device. The Smart Walker was clinically validated at the Spinal Cord Injury Hospital of Toledo - Spain, presenting great acceptability by spinal chord injury patients and clinical staf

Development of Obstacle and Pit-Detecting Ultrasonic Walking Stick for the Blind

This project focused on improving mobility for a blind person by creating an obstacle and pit detecting walking stick using ultrasonic sensors. The project comprised of both hardware and software. The hardware consists of ultrasonic sensors, buzzers and a microcontroller, while the software consists of Arduino Integrated Development Environment (Arduino IDE), which was used to program the microcontroller. A Polyvinyl Chloride (PVC) casing was used to house the hardware components. The ultrasonic sensor that detects obstacles was programmed to detect obstacles at a distance of 100 cm or below and causes the buzzer to sound so as to alert the blind person. Another ultrasonic sensor was programmed to identify pit at a depression of 18 cm and above. This stick was tested to detect obstacles by 80 different blindfolded individuals within a room with different objects placed at different positions. Results showed that the percentage reduction of collision rate when comparing the developed ultrasonic walking stick to a normal white cane is 90.1%. This shows that the ultrasonic walking stick is reliable for domestic use by a blind person. Keywords— Arduino, ATmega328 Microcontroller, Blind walking stick, Mobility aid, Smart cane, Ultrasonic sensor