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This paper details the design and performance assessment of a unique collision avoidance decision and control strategy for autonomous vision-based See and Avoid systems. The general approach revolves around re-positioning a collision object in the image using image-based visual servoing, without estimating range or time to collision. The decision strategy thus involves determining where to move the...
This paper is about a control design for the lateral-directional dynamics of a fixed wing aircraft. The objective is to command the lateral-directional dynamics to the equilibrium point that corresponds to a coordinated turn. The proposed control is inspired by the total energy control system technique; with the objective of mixing the ailerons and the rudder inputs. The control law is developed directly...
A conceptual third party risk (TPR) model is developed, implemented, and tested to demonstrate the capability of determining the risk to the population in a metropolitan city exposed to personal aerial vehicles (PAVs) and unmanned aerial vehicles (UAVs) traffic operations. The conceptual model that is primarily based on the methodology and experience of risk modelling for conventional aircraft is...
The objective of this research is to demonstrate how adaptive wings improve the overall performance of conventional micro air vehicles (MAVs). This will allow MAVs to fulfill missions with different range and endurance requirements, and therefore to perform a wider range of missions than conventional MAVs. These adaptive wings are achieved with the use of macro-fiber composites devices, a low-cost,...
Small UAS have highly constrained payload capacity, which dictates what sensors and transmitters can be selected as part of the electronics suite. We present elements of a sense and avoid (SAA) system which enables UAVs to track intruder aircraft not broadcasting ADS-B. Such SAA methods help assure safety in cases of late encounters with non-cooperative threats. This paper presents an approach to...
This paper presents the key design features, the numerical simulations and the experimental ground/flight test activities performed to verify the functionalities of an obstacle detection and avoidance system suitable for various classes of manned and unmanned aircraft. The Laser Obstacle Avoidance and Monitoring (LOAM) system is proposed as one of the key non-cooperative sensors adopted for avoiding...
Night time flights are a relatively untouched field of application for small unmanned aerial systems (sUASs) in part due to the risks associated. However, there are many opportunities for agricultural, environmental or surveillance applications when night flying missions can be valuable or necessary. Undoubtedly, there are many risks associated with flying a sUAS at night that must be thoroughly addressed...
This work proposes an obstacle avoidance strategy for UAV navigation in indoor environments. The proposal is able to compute the distance among the UAV and the obstacles (which change their position dynamically), and then to select the closest one. When a collision risk is pointed out, the algorithm establish some escape points, whose orientation is aligned tangentially to the obstacle edge or to...
This paper describes the development of a Sense and Avoid (S&A) algorithm that can ensure an Unmanned Aerial Vehicle (UAV) being able to avoid collisions autonomously. Firstly, the Closest Point of Approach (CPA) can predict the conflict. Secondly, the developed path planner generates the feasible path using differential geometric guidance and flatness techniques, where the constraints of UAV...
This paper is about solar irradiation estimation on a solar powered UAV over its mission course [1]. Solar irradiation estimation and maximizing the solar energy collection are critical for solar powered UAVs and their performance. In this paper main focus is on solar irradiation calculations and comparison of two possible flight paths for solar energy collection during a transport or inspection mission.
We address a cooperative motion control problem for a fleet of Unmanned Aerial Vehicles (UAVs). The problem partially decouples in two tasks: path-following and coordination control. The former requires the vehicle to converge and follow a desired path with no temporal constraints. The latter coordinates the elements in a fleet to travel on a desired pattern. In this paper we provide a practical and...
Optimizing energy consumption of Micro Aerial Vehicles is one of several problems that remains to be solved in the domain of UAVs. In a recent work, a novel quadrotor was introduced that was able, when possible, to roll on the ground thanks to a tilting propeller and caster wheels. In the following work, we build upon this idea with a trirotor helicopter where all the rotors are independently tilting...
The integration of Global Navigation Satellite System (GNSS) integrity augmentation functionalities in Unmanned Aerial Systems (UAS) has the potential to provide an integrity-augmented Sense-and-Avoid (SAA) solution suitable for cooperative and non-cooperative scenarios. In this paper, we evaluate the opportunities offered by this integration, proposing a novel approach that maximizes the synergies...
This work proposes the representation of the high level dynamicmodel of a quadrotor UAVwith a suspended load, through Euler-Lagrange equations. The rotorcraft movement is restricted to the XZ plane of the Cartesian space, so that it performs like a PVTOL machine. A nonlinear controller is proposed to stabilize the quadrotor and the load, during positioning and trajectory tracking tasks. Finally, simulated...
This paper addresses the problem of designing and experimentally validating a nonlinear disturbance observer, focus on the attitude regulation control problem of a quad-rotor in presence of external disturbances. The proposed nonlinear observer scheme is based on the angular velocity measurements and the control inputs in order to compensate external disturbances. The stability analysis of the nonlinear...
The continued growth of unmanned aircraft systems (UAS) is driving innovation from delivery techniques to military surveillance. Cost and knowledge barriers are major limiting factors to general UAS adoption. A UAS controlled by an onboard smartphone is proposed to leverage consumer understanding and transform the emergent industry. Based upon user-supplied GPS flight path coordinates, the UAS can...
The aim of this paper is the description of the CIRA's (Italian Aerospace Research Center) vision about GN&C (Guidance, Navigation and Control) technologies for RPAS (Remotely Piloted Aircraft System). Specifically, the architecture (limiting to GN&C functions) of on-ground and on-board segments realized for the experimental CIRA RPAS will be described and compared with the recommendations...
This paper presents the algorithms enabling real-time 4-Dimensional Flight Trajectory (4DT) functionalities in Next Generation Mission Management Systems (NG-MMS), which are the core element of future Remotely Piloted Aircraft Systems (RPAS) avionics. In particular, the algorithms are employed for multi-objective optimisation of 4DT intents in various operational scenarios spanning from online strategic...
Detect and Avoid (DAA) technology is widely acknowledged as a critical enabler for unsegregated Remote Piloted Aircraft (RPA) operations, particularly Beyond Visual Line of Sight (BVLOS). Image-based DAA, in the visible spectrum, is a promising technological option for addressing the challenges DAA presents. Two impediments to progress for this approach are the scarcity of available video footage...
In this article, the dynamic model for an Unmanned Aircraft System (UAS) enhanced with morphing capabilities is presented. The developed model describes three different modes of operation, which are: horizontal body flight configuration, vertical body flight configuration, and morphing stage. The proposed dynamic model considers a multi-rotorcraft which makes use of eight rotors for flying in the...
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