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This paper presents a new holistic vision-based mobile assistive navigation system to help blind and visually impaired people with indoor independent travel. The system detects dynamic obstacles and adjusts path planning in real-time to improve navigation safety. First, we develop an indoor map editor to parse geometric information from architectural models and generate a semantic map consisting of a global 2D traversable grid map layer and context-aware layers. By leveraging the visual positioning service (VPS) within the Google Tango device, we design a map alignment algorithm to bridge the visual area description file (ADF) and semantic map to achieve semantic localization. Using the on-board RGB-D camera, we develop an efficient obstacle detection and avoidance approach based on a time-stamped map Kalman filter (TSM-KF) algorithm. A multi-modal human-machine interface (HMI) is designed with speech-audio interaction and robust haptic interaction through an electronic SmartCane. Finally, field experiments by blindfolded and blind subjects demonstrate that the proposed system provides an effective tool to help blind individuals with indoor navigation and wayfinding. [ABSTRACT FROM AUTHOR]

We present a novel collaborative mapping and autonomous parking system for semi-structured multi-story parking garages, based on cooperative 3-D LiDAR point cloud registration and Bayesian probabilistic updating. First, an inertial-enhanced (IE) generalized iterative closest point (G-ICP) approach is presented to perform high accuracy registration for LiDAR odometry, which is loosely coupled with inertial measurement unit using multi-state extended Kalman filter fusion. Second, the IE G-ICP is utilized to reconstruct the 3-D point cloud model for each vehicle, and then the individual model maps are merged and updated into a global probabilistic 2-D grid map. A collaborative multiple layer semantic map is constructed to support autonomous parking. Finally, we propose a collaborative navigation approach for path planning when there are multiple vehicles in the parking garage through vehicle-to-vehicle communication. A global path planner is designed to explore the minimum cost path based on the semantic map, and local motion planning is performed using a random exploring algorithm for obstacle avoidance and path smoothing. Our pilot experimental evaluation provides a proof of concept for indoor autonomous parking by collaborative perception, map merging, and updating methodologies. [ABSTRACT FROM PUBLISHER]

Google's Project Tango has made integrated depth sensing and onboard visual-intertial odometry available to mobile devices such as phones and tablets. In this work, we explore the problem of large-scale, real-time 3D reconstruction on a mobile devices of this type. Solving this problem is a necessary prerequisite for many indoor applications, including navigation, augmented reality and building scanning. The main challenges include dealing with noisy and low-frequency depth data and managing limited computational and memory resources. State of the art approaches in large-scale dense reconstruction require large amounts of memory and high-performance GPU computing. Other existing 3D reconstruction approaches on mobile devices either only build a sparse reconstruction, offload their computation to other devices, or require long post-processing to extract the geometric mesh. In contrast, we can reconstruct and render a global mesh on the fly, using only the mobile device's CPU, in very large (300 m $$^2$$ ) scenes, at a resolutions of 2-3 cm. To achieve this, we divide the scene into spatial volumes indexed by a hash map. Each volume contains the truncated signed distance function for that area of space, as well as the mesh segment derived from the distance function. This approach allows us to focus computational and memory resources only in areas of the scene which are currently observed, as well as leverage parallelization techniques for multi-core processing. Furthermore, we describe an on-device post-processing method for fusing datasets from multiple, independent trials, in order to improve the quality and coverage of the reconstruction. We discuss how the particularities of the devices impact our algorithm and implementation decisions. Finally, we provide both qualitative and quantitative results on publicly available RGB-D datasets, and on datasets collected in real-time from two devices. [ABSTRACT FROM AUTHOR]