This paper presents control and coordination algorithms for groups of vehicles. The focus is on autonomous vehicle networks performing distributed sensing tasks where each vehicle plays the role of a mobile tunable sensor. The paper proposes gradient descent algorithms for a class of utility functions which encode optimal coverage and sensing policies. The resulting closed-loop behavior is adaptive, distributed, asynchronous, and verifiably correct.

Coverage control for mobile sensing networks

In the real world, a realistic setting for computer vision or multimedia recognition problems is that we have some classes containing lots of training data and many classes contain a small amount of training data. Therefore, how to use frequent classes to help learning rare classes for which it is harder to collect the training data is an open question. Learning with Shared Information is an emerging topic in machine learning, computer vision and multimedia analysis. There are different level of components that can be shared during concept modeling and machine learning stages, such as sharing generic object parts, sharing attributes, sharing transformations, sharing regularization parameters and sharing training examples, etc. Regarding the specific methods, multi-task learning, transfer learning and deep learning can be seen as using different strategies to share information. These learning with shared information methods are very effective in solving real-world large-scale problems. This special issue aims at gathering the recent advances in learning with shared information methods and their applications in computer vision and multimedia analysis. Both state-of-the-art works, as well as literature reviews, are welcome for submission. Papers addressing interesting real-world computer vision and multimedia applications are especially encouraged. Topics of interest include, but are not limited to:  • Multi-task learning or transfer learning for large-scale computer vision and multimedia analysis • Deep learning for large-scale computer vision and multimedia analysis • Multi-modal approach for large-scale computer vision and multimedia analysis • Different sharing strategies, e.g., sharing generic object parts, sharing attributes, sharing transformations, sharing regularization parameters and sharing training examples, • Real-world computer vision and multimedia applications based on learning with shared information, e.g., event detection, object recognition, object detection, action recognition, human head pose estimation, object tracking, location-based services, semantic indexing. • New datasets and metrics to evaluate the benefit of the proposed sharing ability for the specific computer vision or multimedia problem. • Survey papers regarding the topic of learning with shared information.  Authors who are unsure whether their planned submission is in scope may contact the guest editors prior to the submission deadline with an abstract, in order to receive feedback.

IEEE transactions on pattern analysis and machine intelligence

Morphometric tools for landmark data: geometry and biology

In recent years there have been excellent results in visual-inertial odometry techniques, which aim to compute the incremental motion of the sensor with high accuracy and robustness. However, these approaches lack the capability to close loops and trajectory estimation accumulates drift even if the sensor is continually revisiting the same place. In this letter, we present a novel tightly coupled visual-inertial simultaneous localization and mapping system that is able to close loops and reuse its map to achieve zero-drift localization in already mapped areas. While our approach can be applied to any camera configuration, we address here the most general problem of a monocular camera, with its well-known scale ambiguity. We also propose a novel IMU initialization method, which computes the scale, the gravity direction, the velocity, and gyroscope and accelerometer biases, in a few seconds with high accuracy. We test our system in the 11 sequences of a recent micro-aerial vehicle public dataset achieving a typical scale factor error of 1% and centimeter precision. We compare to the state-of-the-art in visual-inertial odometry in sequences with revisiting, proving the better accuracy of our method due to map reuse and no drift accumulation.

/pdf/visual-inertial-monocular-slam-with-map-reuse-qzzpcqq1e3.pdf

Visual-Inertial Monocular SLAM With Map Reuse

Over the past few years, the application of camera-equipped Unmanned Aerial Vehicles (UAVs) for visually monitoring construction and operation of buildings, bridges, and other types of civil infrastructure systems has exponentially grown. These platforms can frequently survey construction sites, monitor work-in-progress, create documents for safety, and inspect existing structures, particularly for hard-to-reach areas. The purpose of this paper is to provide a concise review of the most recent methods that streamline collection, analysis, visualization, and communication of the visual data captured from these platforms, with and without using Building Information Models (BIM) as a priori information. Specifically, the most relevant works from Civil Engineering, Computer Vision, and Robotics communities are presented and compared in terms of their potential to lead to automatic construction monitoring and civil infrastructure condition assessment.

/pdf/visual-monitoring-of-civil-infrastructure-systems-via-camera-7xo7w3ojtr.pdf

Visual monitoring of civil infrastructure systems via camera-equipped Unmanned Aerial Vehicles (UAVs): a review of related works

VIO-Swarm:: A swarm of 250g quadrotors

—Previous studies in the perimeter defense game have largely focused on the fully observable setting where the true player states are known to all players. However, this is unrealistic for practical implementation since defenders may have to perceive the intruders and estimate their states. In this work, we study the perimeter defense game in a photo-realistic simulator and the real world, requiring defenders to estimate intruder states from vision. We train a deep machine learning-based system for intruder pose detection with domain randomization that aggregates multiple views to reduce state estimation errors and adapt the defensive strategy to account for this. We newly introduce performance metrics to evaluate the vision-based perimeter defense. Through extensive experiments, we show that our approach improves state estimation, and eventually, perimeter defense performance in both 1-defender-vs-1-intruder games, and 2-defenders-vs-1-intruder games.

Vision-based Perimeter Defense via Multiview Pose Estimation

5G millimeter-wave (mmWave) cellular networks are in the early phase of commercial deployments and present a unique opportunity for robust, high-data-rate communication to unmanned aerial vehicles (UAVs). A fundamental question is whether and how mmWave networks designed for terrestrial users should be modified to serve UAVs. The paper invokes realistic cell layouts, antenna patterns, and channel models trained from extensive ray tracing data to assess the performance of various network alternatives. Importantly, the study considers the addition of dedicated uptilted rooftop-mounted cells for aerial coverage, as well as novel spectrum sharing modes between terrestrial and aerial network operators. The effect of power control and of multiuser multiple-input multiple-output are also studied.

Coexistence of UAVs and Terrestrial Users in Millimeter-Wave Urban Networks

Autonomous drone swarms are a burgeoning technology with significant applications in the field of mapping, inspection, transportation and monitoring. To complete a task, each drone has to accomplish a sub-goal within the context of the overall task at hand and navigate through the environment by avoiding collision with obstacles and with other agents in the environment. In this work, we choose the task of optimal coverage of an environment with drone swarms where the global knowledge of the goal states and its positions are known but not of the obstacles. The drones have to choose the Points of Interest (PoI) present in the environment to visit, along with the order to be visited to ensure fast coverage. We model this task in a simulation and use an agent-oriented approach to solve the problem. We evaluate different policy networks trained with reinforcement learning algorithms based on their effectiveness, i.e. time taken to map the area and efficiency, i.e. computational requirements. We couple the task assignment with path planning in an unique way for performing collision avoidance during navigation and compare a grid-based global planning algorithm, i.e. Wavefront and a gradient-based local planning algorithm, i.e. Potential Field. We also evaluate the Potential Field planning algorithm with different cost functions, propose a method to adaptively modify the velocity of the drone when using the Huber loss function to perform collision avoidance and observe its effect on the trajectory of the drones. We demonstrate our experiments in 2D and 3D simulations.

Comparative Analysis of Agent-Oriented Task Assignment and Path Planning Algorithms Applied to Drone Swarms.

Semantic edge is a geometric-aware semantic feature that can be leveraged in robotic perception systems for increased situational awareness and high-level environment understanding. This sparse representation nicely encapsulates the semantic information (object categories) within the geometric object boundaries. State-of-the-art semantic edge detection approaches require significant computation power and fail to approach real-time performance on embedded devices for robotic applications. In this paper, we present FENet (Fast Realtime Semantic Edge Detection Network), a semantic edge detection approach for robots with Size, Weight, and Power (SWaP) constraints. Specifically, we adopt MobileNetV2 as a lightweight backbone network, and we utilize joint pyramid upsampling to improve the system performance. We further reduce the model complexity and latency through network pruning and multiple upsampling strategies to adapt the model on embedded devices such as NVIDIA Jetson TX2. The proposed method is evaluated on Cityscapes with accuracy performances close to the state-of-the-art methods, but with substantially reduced computational complexity that speeds up the network by a factor of 10. To the best of our knowledge, FENet is the first real-time semantic edge detection network for robotic platforms.

Giuseppe Loianno

Papers

VIO-Swarm:: A swarm of 250g quadrotors

Vision-based Perimeter Defense via Multiview Pose Estimation

Coexistence of UAVs and Terrestrial Users in Millimeter-Wave Urban Networks

Comparative Analysis of Agent-Oriented Task Assignment and Path Planning Algorithms Applied to Drone Swarms.

FENet: Fast Real-time Semantic Edge Detection Network