Vision-Based Autonomous Following of a Moving Platform and Landing for an Unmanned Aerial Vehicle

Interest in Unmanned Aerial Vehicles (UAVs) has increased due to their versatility and variety of applications, however their battery life limits their applications. Heterogeneous multi-robot systems can offer a solution to this limitation, by allowing an Unmanned Ground Vehicle (UGV) to serve as a recharging station for the aerial one. Moreover, cooperation between aerial and terrestrial robots allows them to overcome other individual limitations, such as communication link coverage or accessibility, and to solve highly complex tasks, e.g., environment exploration, infrastructure inspection or search and rescue. This work proposes a vision-based approach that enables an aerial robot to autonomously detect, follow, and land on a mobile ground platform. For this purpose, ArUcO fiducial markers are used to estimate the relative pose between the UAV and UGV by processing RGB images provided by a monocular camera on board the UAV. The pose estimation is fed to a trajectory planner and four decoupled controllers to generate speed set-points relative to the UAV. Using a cascade loop strategy, these set-points are then sent to the UAV autopilot for inner loop control. The proposed solution has been tested both in simulation, with a digital twin of a solar farm using ROS, Gazebo and Ardupilot Software-in-the-Loop (SiL); and in the real world at IST Lisbon’s outdoor facilities, with a UAV built on the basis of a DJ550 Hexacopter and a modified Jackal ground robot from DJI and Clearpath Robotics, respectively. Pose estimation, trajectory planning and speed set-point are computed on board the UAV, using a Single Board Computer (SBC) running Ubuntu and ROS, without the need for external infrastructure.This research was funded by the ISR/LARSyS Strategic Funding through the FCT project UIDB/50009/2020, the DURABLE project, under the Interreg Atlantic Area Programme through the European Regional Development Fund (ERDF), the Andalusian project UMA18-FEDERJA-090 and the University of Málaga Research Plan. Partial funding for open access charge: Universidad de Málag

Earthmoving construction automation with military applications: Past, present and future

© ISARC 2018 - 35th International Symposium on Automation and Robotics in Construction and International AEC/FM Hackathon: The Future of Building Things. All rights reserved. Amongst increasing innovations in frontier engineering sciences, the advancements in Robotic and Autonomous Systems (RAS) has brought about a new horizon in construction applications. There is evidence of the increasing interest in RAS technologies in the civil construction sector being reflected in construction efforts of many military forces. In particular, Army or ground-based forces are frequently called upon to conduct construction tasks as part of military operations, tasks which could be partially or fully aided by the employment of RAS technologies. Along with recent advances in the Internet of Things (IoT) and cyber-physical system infrastructure, it is essential to examine the current maturity, technical feasibility, and affordability, as well as the challenges and future directions of the adoption and application of RAS to military construction. This paper presents a comprehensive survey and provides a contemporary and industry-independent overview on the state-of-the-art of earthmoving construction automation used in defence, spanning current world’s best practice through to that which is predicted over the coming years

A Control Architecture for Unmanned Aerial Vehicles Operating in Human-Robot Team for Service Robotic Tasks

In this thesis a Control architecture for an Unmanned Aerial Vehicle (UAV) is presented. The aim of the thesis is to address the problem of control a flying robot operating in human robot team at different level of abstraction. For this purpose, three different layers in the design of the architecture were considered, namely, the high level, the middle level and the low level layers. The special case of an UAV operating in service robotics tasks and in particular in Search&Rescue mission in alpine scenario is considered. Different methodologies for each layer are presented with simulated or real-world experimental validation

The Effects of Remotely Piloted Aircraft Command and Control Latency during Within-Visual-Range Air-To-Air Combat

The type of military missions conducted by remotely piloted aircraft continues to expand into all facets of operations including air-to-air combat. While future within-visual-range air-to-air combat will be piloted by artificial intelligence, remotely piloted aircraft will likely first see combat. The purpose of this study was to quantify the effect of latency on one-versus-one, within-visual-range air-to-air combat success during both high-speed and low-speed engagements. The research employed a repeated-measures experimental design to test the various hypothesis associated with command and control latency. Participants experienced in air-to-air combat were subjected to various latency inputs during one-versus-one simulated combat using a virtual-reality simulator and scored on the combat success of each engagement. This research was pursued in coordination with the Air Force Research Laboratory and the United States Air Force Warfare Center. The dependent variable, combat score, was derived through post-simulation analysis and scored for each engagement. The independent variables included the input control latency (time) and the starting velocity of the engagement (high-speed and low-speed). The input latency included six different delays (0.0, 0.25, 0.50, 0.75, 1.0, and 1.25 seconds) between pilot input and simulator response. Each latency was repeated for a high-speed and low-speed engagement. A two-way repeated-measures analysis of variance was used to determine whether there was a statistically significant difference in means between the various treatments on combat success and determine if there was an interaction between latency and fight speed. The results indicated that there was a statistically significant difference between combat success at the various latency levels and engagement velocity. There was a significant interaction effect between latency and engagement speed, indicating that the outcome was dependent on both variables. As the latency increased, a significant decrease in combat success occurred, decreasing from .539 with no latency, to .133 at 1.250 seconds of latency during high-speed combat. During low-speed combat, the combat success decreased from .659 with no latency, to .189 at 1.250 seconds of latency. The largest incremental decrease occurred between 1.00 and 1.25 seconds of latency for high-speed and between 0.75 and 1.00 at low-speed. The overall decrease in combat success during a high-speed engagement was less than during the low-speed engagements. The results of this study quantified the decrease in combat success during within-visual range air-to-air combat and concluded that, when latency is encountered, a high-speed (two-circle) engagement is desired to minimize adverse latency effects. The research informs aircraft and communication designers of the decrease in expected combat success caused by latency. This simulation configuration can be utilized for future research leading to methods and tactics to decrease the effects of latency

Virtual Omnidirectional Perception for Downwash Prediction within a Team of Nano Multirotors Flying in Close Proximity

Teams of flying robots can be used for inspection, delivery, and construction tasks, in which they might be required to fly very close to each other. In such close-proximity cases, nonlinear aerodynamic effects can cause catastrophic crashes, necessitating each robots' awareness of the surrounding. Existing approaches rely on multiple, expensive or heavy perception sensors. Such perception methods are impractical to use on nano multirotors that are constrained with respect to weight, computation, and price. Instead, we propose to use the often ignored yaw degree-of-freedom of multirotors to spin a single, cheap and lightweight monocular camera at a high angular rate for omnidirectional awareness of the neighboring robots. We provide a dataset collected with real-world physical flights as well as with 3D-rendered scenes and compare two existing learning-based methods in different settings with respect to success rate, relative position estimation, and downwash prediction accuracy. We demonstrate that our proposed spinning camera is capable of predicting the presence of aerodynamic downwash with an $F_1$ score of over 80% in a challenging swapping task

Research studio for testing control algorithms of mobile robots

In recent years, a significant development of technologies related to the control and communication of mobile robots, including Unmanned Aerial Vehicles, has been noticeable. Developing these technologies requires having the necessary hardware and software to enable prototyping and simulation of control algorithms in laboratory conditions.The article presents the Laboratory of Intelligent Mobile Robots equipped with the latest solutions. The laboratory equipment consists of four quadcopter drones (QDrone) and two wheeled robots (QBot), equipped with rich sensor sets, a ground control station with Matlab-Simulink software, OptiTRACK object tracking system, and the necessary infrastructure for communication and security.The paper presents the results of measurements from sensors of robots monitoring various quantities during work. The measurements concerned, among others, the quantities of robots registered by IMU sensors of the tested robots (i.e., accelerometers, magnetometers, gyroscopes and others)

Open-Source Drone Programming Course for Distance Engineering Education.

This article presents a full course for autonomous aerial robotics inside the RoboticsAcademy framework. This “drone programming” course is open-access and ready-to-use for any teacher/student to teach/learn drone programming with it for free. The students may program diverse drones on their computers without a physical presence in this course. Unmanned aerial vehicles (UAV) applications are essentially practical, as their intelligence resides in the software part. Therefore, the proposed course emphasizes drone programming through practical learning. It comprises a collection of exercises resembling drone applications in real life, such as following a road, visual landing, and people search and rescue, including their corresponding background theory. The course has been successfully taught for five years to students from several university engineering degrees. Some exercises from the course have also been validated in three aerial robotics competitions, including an international one. RoboticsAcademy is also briefly presented in the paper. It is an open framework for distance robotics learning in engineering degrees. It has been designed as a practical complement to the typical online videos of massive open online courses (MOOCs). Its educational contents are built upon robot operating system (ROS) middleware (de facto standard in robot programming), the powerful 3D Gazebo simulator, and the widely used Python programming language. Additionally, RoboticsAcademy is a suitable tool for gamified learning and online robotics competitions, as it includes several competitive exercises and automatic assessment toolspost-print5214 K

A Broad View on Robot Self-Defense: Rapid Scoping Review and Cultural Comparison

With power comes responsibility: as robots become more advanced and prevalent, the role they will play in human society becomes increasingly important. Given that violence is an important problem, the question emerges if robots could defend people, even if doing so might cause harm to someone. The current study explores the broad context of how people perceive the acceptability of such robot self-defense (RSD) in terms of (1) theory, via a rapid scoping review, and (2) public opinion in two countries. As a result, we summarize and discuss: increasing usage of robots capable of wielding force by law enforcement and military, negativity toward robots, ethics and legal questions (including differences to the well-known trolley problem), control in the presence of potential failures, and practical capabilities that such robots might require. Furthermore, a survey was conducted, indicating that participants accepted the idea of RSD, with some cultural differences. We believe that, while substantial obstacles will need to be overcome to realize RSD, society stands to gain from exploring its possibilities over the longer term, toward supporting human well-being in difficult times