Modular Heterogeneous Multi-Agent Control Framework with Integrated Payloads

Small unmanned aircraft are being used in an increasing number of applications ranging from emergency response to parcel delivery. Many of these applications are benefited when employed as a multiple-vehicle operation. Such operations often require tight cooperation between heterogeneous vehicles and often depend on integration with sensors and payloads. Multi-agent control algorithms can be implemented to control such systems but often require the development of an underlying vehicle communications framework in addition to a sensors and payloads communications framework. This thesis presents a single unified modular framework, named Clark, and supports heterogeneous multi-agent control and sensor/payload integration. Clark provides a wireless network between agents without relying on pre-existing communications infrastructure, and provides software interfaces for connecting to a variety of payloads. This thesis first reviews small unmanned aircraft systems (SUAS), multi-agent control, multi-agent control testbeds, and wireless networking technologies used on SUAS. Systems engineering is then employed to develop an Identified Need, Concept of Operations (ConOps), and requirements. All Defined, Derived, and Design Requirements are explained and justified. Some requirements are highlighted to demonstrate key features of the Clark framework. The software architecture is explained in detail in a top-down approach. Hardware is selected for prototyping and shown to meet the requirements. Bench tests, ground tests, and flight tests are conducted to verify the framework’s ability to communicate between agents and affect control. Ground testing includes a multi-agent cooperative mission while flight testing features two and three agent missions. Test results are presented and demonstrate the candidacy of Clark as a modular heterogeneous multi-agent control framework with integrated payloads

Design/Development of Mini/Micro Air Vehicles through Modelling and Simulation: Case of an Autonomous Quadrotor

Design and development of an autonomous quadrotor micro aerial vehicle is undertaken following a systematic approach. A fairly detailed model was constructed and simulations were then carried out with the purpose of refining the baseline design, building a controller, and testing the flying qualities of the vehicle on a ground-based flight simulator. Following this, a smooth transition to rig and flight testing has been enabled in a cost- and time-effective manner, meeting all the design requirements.Defence Science Journal, 2011, 61(4), pp.337-345, DOI:http://dx.doi.org/10.14429/dsj.61.108

Towards the use of unmanned aerial systems for providing sustainable services in smart cities

La sostenibilidad está en el centro de muchos campos de aplicación en los que el uso de los sistemas aéreos no tripulados (SUA) es cada vez más importante (por ejemplo, la agricultura, la detección y predicción de incendios, la vigilancia ambiental, la cartografía, etc.). Sin embargo, su uso y evolución están muy condicionados por el campo de aplicación específico para el que están diseñados y, por lo tanto, no pueden ser fácilmente reutilizados entre los diferentes campos de aplicación. Desde este punto de vista, al no ser polivalentes, podemos decir que no son totalmente sostenibles. Teniendo esto en cuenta, el objetivo de este trabajo es doble: por un lado, identificar el conjunto de características que debe proporcionar un UAS para ser considerado sostenible y demostrar que no hay ningún UAS que satisfaga todas estas características; por otra parte, presentar una arquitectura abierta y sostenible de los UAS que pueda utilizarse para construir UAS a petición para proporcionar las características necesarias en cada campo de aplicación. Dado que esta arquitectura se basa principalmente en la adaptabilidad del software y el hardware, contribuye a la sostenibilidad técnica de las ciudades.Sustainability is at the heart of many application fields where the use of Unmanned Aerial Systems (UAS) is becoming more and more important (e.g., agriculture, fire detection and prediction, environmental surveillance, mapping, etc.). However, their usage and evolution are highly conditioned by the specific application field they are designed for, and thus, they cannot be easily reused among different application fields. From this point of view, being that they are not multipurpose, we can say that they are not fully sustainable. Bearing this in mind, the objective of this paper is two-fold: on the one hand, to identify the whole set of features that must be provided by a UAS to be considered sustainable and to show that there is no UAS satisfying all these features; on the other hand, to present an open and sustainable UAS architecture that may be used to build UAS on demand to provide the features needed in each application field. Since this architecture is mainly based on software and hardware adaptability, it contributes to the technical sustainability of cities.• Ministerio de Economía y Competitividad y Fondos FEDER. Proyecto TIN2015-69957-R (I+D+i) • Junta de Extremadura y Fondo Europeo de Desarrollo Regional. Ayuda GR15098 y IB16055 • Parcialmente financiado por Interreg V-A España-Portugal (POCTEP) 2014-2020 program. Proyecto 0045-4IE-4-PpeerReviewe

Design and Test of a UAV Swarm Architecture over a Mesh Ad-Hoc Network

The purpose of this research was to develop a testable swarm architecture such that the swarm of UAVs collaborate as a team rather than acting as several independent vehicles. Commercial-off-the-shelf (COTS) components were used as they were low-cost, readily available, and previously proven to work with at least two networked UAVs. Initial testing was performed via software-in-the-loop (SITL) demonstrating swarming of three simulated multirotor aircraft, then transitioned to real hardware. The architecture was then tested in an outdoor nylon netting enclosure. Command and control (C2) was provided by software implementing an enhanced version of Reynolds’ flocking rules via an onboard companion computer, and UDP multicast messages over a W-Fi mesh ad-hoc network. Experimental results indicate a standard deviation between vehicles of two meters or less, at airspeeds up to two meters per second. This aligns with navigation instrumentation error, permitting safe operation of multiple vehicles within five meters of each other. Qualitative observations indicate this architecture is robust enough to handle more aircraft, pass additional sensor data, and incorporate different swarming algorithms and missions

Aerial Networking for the Implementation of Cooperative Control on Small Unmanned Aerial Systems

The employment of Small Unmanned Aerial Systems (SUAS) for reconnaissance and surveillance missions is a vital capability of the United States military. Cooperative control algorithms for SUAS can enable tactical multi-vehicle configurations for communications extension, intelligent navigation, and a multitude of other applications. Past research at AFIT has designed and simulated a cooperative rover-relay algorithm for extended communications and has investigated its implementation through various modem configurations. This research explores aerial networking options for implementing cooperative control and applies them to an actual SUAS. Using Commercial Off-The-Shelf (COTS) hardware, a system was designed and flight tested to implement the rover-relay algorithm and provide a testbed system for future research in cooperative control. Two different modem configurations were designed and tested. The first modem configuration was demonstrated through a series of ground and flight tests to successfully relay autopilot commands and telemetry between a ground station and a rover aircraft through a relay aircraft. This configuration effectively doubles the effective range of the rover system to 1.2 miles, together with an algorithm that autonomously navigates the relay aircraft to an optimal location. Secondly, a mesh network was configured and tested. This configuration successfully relayed aircraft telemetry to the ground station from each vehicle in the network. However, the network suffered from low throughput, which limited autopilot functionality, such as updating navigation waypoints to each aircraft. The results suggest the system be updated with more capable modems in a mesh configuration to broaden the possibilities for future research in cooperative applications

Virtual Testbed for Monocular Visual Navigation of Small Unmanned Aircraft Systems

Monocular visual navigation methods have seen significant advances in the last decade, recently producing several real-time solutions for autonomously navigating small unmanned aircraft systems without relying on GPS. This is critical for military operations which may involve environments where GPS signals are degraded or denied. However, testing and comparing visual navigation algorithms remains a challenge since visual data is expensive to gather. Conducting flight tests in a virtual environment is an attractive solution prior to committing to outdoor testing. This work presents a virtual testbed for conducting simulated flight tests over real-world terrain and analyzing the real-time performance of visual navigation algorithms at 31 Hz. This tool was created to ultimately find a visual odometry algorithm appropriate for further GPS-denied navigation research on fixed-wing aircraft, even though all of the algorithms were designed for other modalities. This testbed was used to evaluate three current state-of-the-art, open-source monocular visual odometry algorithms on a fixed-wing platform: Direct Sparse Odometry, Semi-Direct Visual Odometry, and ORB-SLAM2 (with loop closures disabled)

Captain Buzz

This is the author accepted manuscript. The final version is available from ACM at https://dl.acm.org/citation.cfm?id=2750682.Fully autonomous hobbyist drones are typically controlled using bespoke microcontrollers, or general purpose low-level controllers such as the Arduino. However, these devices only have limited compute power and sensing capabilities, and do not easily provide cellular connectivity options. We present Captain Buzz, an Android smartphone app capable of piloting a delta-wing glider autonomously. Captain Buzz can control servos directly via pulse width modulation sig- nals transmitted over the smartphone audio port. Compared with traditional approaches to building an autopilot, Cap- tain Buzz allows users to leverage existing Android libraries for flight attitude determination, provides innovative use- cases, allows users to reprogram their autopilot mid-flight for rapid prototyping, and reduces the cost of building drones.This work was supported by Google Inc., the Engineering and Physical Sciences Research Council; and CSR, Cambridge

An OpenEaagles Framework Extension for Hardware-in-the-Loop Swarm Simulation

Unmanned Aerial Vehicle (UAV) swarm applications, algorithms, and control strategies have experienced steady growth and development over the past 15 years. Yet, to this day, most swarm development efforts have gone untested and thus unimplemented. Cost of aircraft systems, government imposed airspace restrictions, and the lack of adequate modeling and simulation tools are some of the major inhibitors to successful swarm implementation. This thesis examines how the OpenEaagles simulation framework can be extended to bridge this gap. This research aims to utilize Hardware-in-the-Loop (HIL) simulation to provide developers a functional capability to develop and test the behaviors of scalable and modular swarms of autonomous UAVs in simulation with high confidence that these behaviors will prop- agate to real/live ight tests. Demonstrations show the framework enhances and simplifies swarm development through encapsulation, possesses high modularity, pro- vides realistic aircraft modeling, and is capable of simultaneously accommodating four hardware-piloted swarming UAVs during HIL simulation or 64 swarming UAVs during pure simulation