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This paper explores the interactions between environmental conditions and edge detector performance for use as a critical function for detect and avoidance (DAA) operations in the unmanned aerial systems (UAS) industry. The goal of this study was to establish the best edge detection scheme for sunny, low light, cloudy, and foggy conditions. A laboratory test chamber was developed to simulate these...
A unified approach to cooperative and non- cooperative Separation Assurance and Collision Avoidance (SA&CA) is presented addressing the technical and regulatory challenges of Unmanned Aircraft Systems (UAS) integration into all classes of airspace. Additionally, the emerging UAS Traffic Management (UTM) system requirements are captured and addressed in this novel unified framework. Uncertainties...
In this study, we investigate the feasibility of detecting small intruder aircraft through camera images obtained onboard a small unmanned aircraft. The research group (Small Unmanned Aerial Vehicle Laboratory) from NASA Langley Research Center flew a set of missions with their small UAS (sUAS) where one of those vehicles is outfitted with three 4K resolution cameras located at the tips of the wings...
A real-time vision-based object tracking system embedded in a quadrotor is presented in this paper. The integrated system is expected to enable the quadrotor to track a target object and keep with a fixed distance. A robust object tracking method via improving Kernelized Correlation Filters algorithm is proposed to achieve accurate visual tracking. In addition, a PID controller is applied to utilize...
This paper proposes a fuzzy adaptive sliding mode control for accommodating large actuator fault and maintaining system stability. Boundary layer is employed to smooth control discontinuity and eliminate control chattering. However, if the thickness of boundary layer is chosen too big, the tracking accuracy will be degraded. Whereas, if the boundary layer thickness is too small, control chattering...
Autonomous and semi-autonomous aerial systems (AES) as example of autonomous and semi-autonomous systems (AS) have to perform tasks in complex and dynamic environment, for example in logistics and transportation applications. In this context AS's behavior has to be verifyably safe. Traditionally, behavioral safety aspects are combined with mission-related tasks. The consequence of this combination...
Complexity is a measure of the difficulty that a particular air traffic situation represents to Air Traffic Controller (ATCo). This measure impacts on ATCo workload, which is an important factor for defining airspace capacity. This paper presents an evaluation of the impact of the insertion of Remotely Piloted Aircraft (RPA) on safety levels within a non-segregated airspace based on the calculation...
The primary focus of the work presented in this paper is a proof-of-concept study of a novel electro-thermal- based autonomous icing protection solution (IPS) for small unmanned aircraft. The solution includes a central control unit, where several control algorithms, ensure temperature control of electro-thermal sources, applied to exposed aircraft surfaces. The solution includes three different control...
The goal in this paper is to introduce an intuitive way to control a VTOL vehicle (Vertical Take-Off and Landing) using commands from an user, i.e., the idea is to provide a non cumbersome easy-to-handle interface that will allow even inexpert users a safe command interface for this kind of vehicles. The aerial vehicle chosen for validating this safe-control-scheme is the quadcopter vehicle. The user...
In this paper, a fully-autonomous quadrotor aerial robot for solving the different missions proposed in the 2016 International Micro Air Vehicle (IMAV) Indoor Competition is presented. The missions proposed in the IMAV 2016 competition involve the execution of high-level missions such as entering and exiting a building, exploring an unknown indoor environment, recognizing and interacting with objects,...
Recently, the complexity of control systems for autonomous Aerial Manipulators (AMs), i.e. Unmanned Aerial Vehicle (UAV) + Robot Manipulator (RM), is growing faster as per our demand of being able to perform more and more complex tasks. In the present work, we go a step forward adding an optimiser to the actual (nonlinear) control strategy, in order to comply with high-level control demands related...
Smart parking solutions for big cities are critically important for reducing traffic congestion and vehicle energy consumption in big cities. Visual-based detection methods have been proposed since their maintenance costs are typically lower. However, visual based detection methods in existing systems are not robust due to varying light intensities, occlusions, and their deployment costs can still...
This paper presents the development and field test of a novel unmanned aerial vehicle (UAV) for bridge inspections. The proposed UAV, which consists of a quadrotor, a cylindrical cage installed in it, and two spokeless wheels freely rotating around the cage, can climb and run on the bridge surface. Its structure improves durability and reduces air resistance compared with conventional UAVs with a...
Small Unmanned Aircraft Systems (sUAS) are already revolutionizing agricultural and environmental monitoring through the acquisition of high-resolution multi-spectral imagery on-demand. However, in order to accurately understand various complex environmental and agricultural processes, it is often necessary to collect physical samples of pests, pathogens, and insects from the field for ex-situ analysis...
In the context of optical-aided navigation and visual Simultaneous Localization And Mapping (SLAM) for satellite-denied aircraft navigation, this paper extends the monocular SLAM approach by the use of multiple sensors with different viewing directions. Downward optical sensors see other movements than forward-looking cameras, hence it is straightforward to combine the benefits of both. This combination...
This paper presents a theoretical and practical implementation of a Kalman Filter (KF) to obtain the attitude and angular velocity from a nine degrees of freedom (DoF) inertial measurement unit (IMU). These include three DoF from an accelerometer, three from a magnetometer and the last three from a gyroscope. It differs from other attitude filters in two main aspects, the model representation and...
A reliable estimation of the flight altitude in dynamic and unstructured indoor environments is an unsolved problem. Standalone available sensors, such as distance sensors, barometers and accelerometers, have multiple limitations in presence of non-flat ground surfaces, or in cluttered areas. To overcome these sensor limitations, maximizing their individual performance, this paper presents a modular...
This paper proposes the concept of drones capable of functioning as “Co-Archaeologists” that can map large caves and enter dangerous or hard-to-reach spaces. Using RGB-D data collected by drones, we will be able to produce accurate 3D models and semantic maps with proper lighting co-supervised by human archaeologists. This is going to be a major advance in archaeological practice, which can accelerate...
In this paper we study the localization and tracking of a radio frequency (RF) emitting target using multiple unmanned aerial vehicles (UAVs) over a large scale environment. Although localization of RF emitting targets using multiple measurements is a well studied problem, the standard approaches become inefficient when the signal power is uncertain and there is significant noise in the received signal...
Unmanned Aerial Vehicles (UAVs) exhibit great agility and usually require a trained pilot to operate them, while being restricted to line-of-sight range. This prevents their wide introduction in applications such as inspection for disaster scenarios. Our goal is to enable rescue teams untrained in piloting to teleoperate a UAV as an aid to their mission, while being able to focus on the task at hand...
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