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- Unmanned Aerial Systems: Theoretical Foundation and ApplicationsPublication . Koubaa, Anis; Azar, AhmadUnmanned Aerial Systems: Theoretical Foundation and Applications presents some of the latest innovative approaches to drones from the point-of-view of dynamic modeling, system analysis, optimization, control, communications, 3D-mapping, search and rescue, surveillance, farmland and construction monitoring, and more. With the emergence of low-cost UAS, a vast array of research works in academia and products in the industrial sectors have evolved. The book covers the safe operation of UAS, including, but not limited to, fundamental design, mission and path planning, control theory, computer vision, artificial intelligence, applications requirements, and more. This book provides a unique reference of the state-of-the-art research and development of unmanned aerial systems, making it an essential resource for researchers, instructors and practitioners.
- A Drone Secure Handover Architecture validated in a Software in the Loop EnvironmentPublication . Vasconcelos Filho, Ênio; Gomes, Filipe; Monteiro, Stéphane; Penna, Sergio; Koubaa, Anis; Tovar, Eduardo; Severino, RicardoThe flight and control capabilities of uncrewed aerial vehicles (UAVs) have increased significantly with recent research for civilian and commercial applications. As a result, these devices are becoming capable of flying ever greater distances, accomplishing flights beyond line of sight (BVLOS). However, given the need for safety guarantees, these flights are increasingly subject to regulations. Handover operations between controllers and the security of the exchanged data are a challenge for implementing these devices in various applications. This paper presents a secure handover architecture between control stations, using a Software in the Loop (SIL) model to validate the adopted strategies and mitigate the time between simulation and real systems implementations. This architecture is developed in two separate modules that perform the security and handover processes. Finally, we validate the proposed architecture with several drone flights on a virtual testbed.
- Cooperative Vehicular Platooning: A Multi- Dimensional Survey Towards Enhanced Safety, Security and ValidationPublication . Vasconcelos Filho, Ênio; Santos, Pedro Miguel; Koubaa, Anis; Tovar, Eduardo; Severino, RicardoCooperative Vehicular Platooning (Co-VP) is a paradigmatic example of a Cooperative Cyber-Physical System (Co-CPS), which holds the potential to vastly improve road safety by partially removing humans from the driving task. However, the challenges are substantial, as the domain involves several topics, such as control theory, communications, vehicle dynamics, security, and traffic engineering, that must be coupled to describe, develop and validate these systems of systems accurately. This work presents a comprehensive survey of significant and recent advances in Co-VP relevant fields. We start by overviewing the work on control strategies and underlying communication infrastructures, focusing on their interplay. We also address a fundamental concern by presenting a cyber-security overview regarding these systems. Furthermore, we present and compare the primary initiatives to test and validate those systems, including simulation tools, hardware-in-the-loop setups, and vehicular testbeds. Finally, we highlight a few open challenges in the Co-VP domain. This work aims to provide a fundamental overview of highly relevant works on Co-VP topics, particularly by exposing their inter-dependencies, facilitating a guide that will support further developments in this challenging field.
- Car Detection using Unmanned Aerial Vehicles: Comparison between Faster R-CNN and YOLOv3Publication . Benjdira, Bilel; Khursheed, Taha; Koubaa, Anis; Ammar, Adel; Ouni, KaisUnmanned Aerial Vehicles are increasingly being used in surveillance and traffic monitoring thanks to their high mobility and ability to cover areas at different altitudes and locations. One of the major challenges is to use aerial images to accurately detect cars and count-them in real-time for traffic monitoring purposes. Several deep learning techniques were recently proposed based on convolution neural network (CNN) for real-time classification and recognition in computer vision. However, their performance depends on the scenarios where they are used. In this paper, we investigate the performance of two state-of-the art CNN algorithms, namely Faster R-CNN and YOLOv3, in the context of car detection from aerial images. We trained and tested these two models on a large car dataset taken from UAVs. We demonstrated in this paper that YOLOv3 outperforms Faster R-CNN in sensitivity and processing time, although they are comparable in the precision metric.
- Micro Air Vehicle Link (MAVLink) in a Nutshell: A SurveyPublication . Koubaa, Anis; Allouch, Azza; Alajlan, Maram; Javed, Yasir; Belghith, Abdelfettah; Khalgui, MohamedThe micro air vehicle link (MAVLink in short) is a communication protocol for unmanned systems (e.g., drones and robots). It specifies a comprehensive set of messages exchanged between unmanned systems and ground stations. This protocol is used in major autopilot systems, mainly ArduPilot and PX4, and provides powerful features not only for monitoring and controlling unmanned systems missions but also for their integration into the Internet. However, there is no technical survey and/or tutorial in the literature that presents these features or explains how to make use of them. Most of the references are online tutorials and basic technical reports, and none of them presents comprehensive and systematic coverage of the protocol. In this paper, we address this gap, and we propose an overview of the MAVLink protocol, the difference between its versions, and it is potential in enabling Internet connectivity to unmanned systems. We also discuss the security aspects of the MAVLink. To the best of our knowledge, this is the first technical survey and tutorial on the MAVLink protocol, which represents an important reference for unmanned systems users and developers.
- Adaptive Terminal-Integral Sliding Mode Force Control of Elastic Joint Robot Manipulators in the Presence of HysteresisPublication . Taher Azar, Ahmad; Serrano, Fernando E.; Koubaa, Anis; Ahmad Kamal, Nashwa; Vaidyanathan, Sundarapandian; Fekik, ArezkiIn this paper, an adaptive terminal-integral sliding mode force control of elastic joint robot manipulators in the presence of hysteresis is proposed. One of the most important issues that is solved in this study is that the hysteresis phenomenon is considered something that provokes losses in the manipulator motion and controller errors. Force control is necessary because it can be implemented and very useful in the area of industrial robotics such as collaborative and cooperative robotics. Therefore, it can be implemented for precise control in which robot-operator or robot-robot interaction is needed. An adaptive terminal-integral sliding mode force control is proposed by considering the hysteresis and the effects between the end effector and a flexible environment. Force control has not been studied extensively nowadays and even less for elastic joint robot manipulators. Thus, to improve the system precision control, the adaptive sliding mode controller (ASMC) is designed by a Lyapunov approach obtaining the adaptive and controller laws, respectively. As an experimental case study, two links elastic joint robot manipulator is considered by obtaining the elastic joint model with hysteresis using a Bouc-Wen model.
- RosDrive: An Open-Source ROS-Based Vehicular Simulator for STEM Control Systems Classes TutorialPublication . Vasconcelos Filho, Ênio; Yudi, Jones; Abdelkader, Mohamed; Koubaa, Anis; Tovar, EduardoThe study of control systems in the engineering courses is quite complex, given the difficulty of some teachers in exemplifying and allowing the student to understand how such systems affect the environment. In this context, the STEM methodologies aim to fill this gap between the traditional classes and the student comprehension of the topic through the active learning process. Realistic open-source simulators can be interpreted as one solution for this STEM implementation, allowing students to test, modify and create different configurations and sensors with a low-cost environment. This work presents a flexible open-source 3D simulation framework, based on ROS, of a line follower vehicle, using an embedded PID controller, a camera for processing and detecting lines, and sonars for detecting and avoiding obstacles. This simulator integrates several controller systems, allowing the student to build consistent skills in control and related areas, analyze the impacts of models configurations, and extends its knowledge to new techniques.
- Towards a Realistic Simulation Framework for Vehicular Platooning ApplicationsPublication . Vieira, Bruno; Severino, Ricardo; Koubaa, Anis; Tovar, EduardoCooperative vehicle platooning applications increasingly demand realistic simulation tools to ease their validation, and to bridge the gap between development and real-word deployment. However, their complexity and cost, often hinders its validation in the real-world. In this paper we propose a realistic simulation framework for vehicular platoons that integrates Gazebo with OMNeT++ over Robot Operating System (ROS) to support the simulation of realistic scenarios of autonomous vehicular platoons and their cooperative control.
- A Cloud Based Disaster Management SystemPublication . Cheikhrouhou, Omar; Koubaa, Anis; Zarrad, AnisThe combination of wireless sensor networks (WSNs) and 3D virtual environments opens a new paradigm for their use in natural disaster management applications. It is important to have a realistic virtual environment based on datasets received from WSNs to prepare a backup rescue scenario with an acceptable response time. This paper describes a complete cloud-based system that collects data from wireless sensor nodes deployed in real environments and then builds a 3D environment in near real-time to reflect the incident detected by sensors (fire, gas leaking, etc.). The system’s purpose is to be used as a training environment for a rescue team to develop various rescue plans before they are applied in real emergency situations. The proposed cloud architecture combines 3D data streaming and sensor data collection to build an efficient network infrastructure that meets the strict network latency requirements for 3D mobile disaster applications. As compared to other existing systems, the proposed system is truly complete. First, it collects data from sensor nodes and then transfers it using an enhanced Routing Protocol for Low-Power and Lossy Networks (RLP). A 3D modular visualizer with a dynamic game engine was also developed in the cloud for near-real time 3D rendering. This is an advantage for highly-complex rendering algorithms and less powerful devices. An Extensible Markup Language (XML) atomic action concept was used to inject 3D scene modifications into the game engine without stopping or restarting the engine. Finally, a multi-objective multiple traveling salesman problem (AHP-MTSP) algorithm is proposed to generate an efficient rescue plan by assigning robots and multiple unmanned aerial vehicles to disaster target locations, while minimizing a set of predefined objectives that depend on the situation. The results demonstrate that immediate feedback obtained from the reconstructed 3D environment can help to investigate what–if scenarios, allowing for the preparation of effective rescue plans with an appropriate management effort.
- A traffic differentiation add-on to the IEEE 802.15.4 protocol: implementation and experimental validation over a real-time operating systemPublication . Severino, Ricardo; Batsa, Manish; Alves, Mário; Koubaa, AnisThe IEEE 802.15.4 is the most widespread used protocol for Wireless Sensor Networks (WSNs) and it is being used as a baseline for several higher layer protocols such as ZigBee, 6LoWPAN or WirelessHART. Its MAC (Medium Access Control) supports both contention-free (CFP, based on the reservation of guaranteed time-slots GTS) and contention based (CAP, ruled by CSMA/CA) access, when operating in beacon-enabled mode. Thus, it enables the differentiation between real-time and best-effort traffic. However, some WSN applications and higher layer protocols may strongly benefit from the possibility of supporting more traffic classes. This happens, for instance, for dense WSNs used in time-sensitive industrial applications. In this context, we propose to differentiate traffic classes within the CAP, enabling lower transmission delays and higher success probability to timecritical messages, such as for event detection, GTS reservation and network management. Building upon a previously proposed methodology (TRADIF), in this paper we outline its implementation and experimental validation over a real-time operating system. Importantly, TRADIF is fully backward compatible with the IEEE 802.15.4 standard, enabling to create different traffic classes just by tuning some MAC parameters.