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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...
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...
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...
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...
This paper presents an optimal conflict resolution method for multiple unmanned aerial vehicles based on pseudospectral collocation which solves numerically optimal control problems by using non-linear programming. The trajectory of each aerial vehicle is defined by a set of waypoints and the time of arrival at each waypoint. The maneuvers allowed to solve the conflicts are the changes of speed of...
This paper proposes a nonlinear vision based flight control law for the automatic landing of an aircraft. Although a number of methods have been proposed in this domain, our method differs by the following features. First, we do not assume knowledge of the runway size or distance from the aircraft, or the help of a ground technology to guide the aircraft. Second, this design addresses the model nonlinearities,...
This paper describes the theory and implementation of a trajectory optimization layer operating within an energy-aware, airborne, dynamic data-driven application system (EA-DDDAS). The work addresses wind field data estimation, trajectory optimization, and implementation of communication protocols to increase sUAS endurance in persistent sensing missions. The trajectory optimization layer acts as...
This paper presents a real-time path planning algorithm for UAVs to avoid collision with other aircraft. Reachable sets are used to represent the collection of possible trajectories of obstacle aircraft. It is used in collision prediction for UAVs in path planning. Once a collision is detected, a sampling-based method is used to generate a collision avoidance path. A second collision check is performed...
This paper details a method to ascertain the reachability of known emergency landing sites for any fixed wing aircraft in a forced landing due to engine failure in steady uniform wind conditions. With knowledge of the aircraft's state and parameters, and landing site location and landing direction, the minimum height loss path can be defined. This uses glide performance calculations and a trajectory...
The crescent diversity and heterogeneity of vehicles increases the importance of simulation platforms that can reproduce missions using several kinds of vehicles. A platform is being developed at LIACC for this purpose, using Microsoft Flight Simulator X as the simulation engine. Because this simulator has some constraints involving its active simulation area around the player's central aircraft,...
This paper presents implementation of a novel guidance logic for multi-agent fixed-wing unmanned aerial systems using a moving mesh method. The moving mesh method is originally designed for use in the adaptive numerical solution of partial differential equations where a high proportion of mesh points are placed in the regions of large solution variation and few points in the rest of the domain. In...
In recent years, special interest has been paid to the solution of sector design problem. The airspace is partitioned into sectors, each of them being controlled by a group of controllers. Airspace sectors should be designed cautiously, ensuring that no sector would be overloaded during the day. The objective of an airspace design process is to adapt the airspace according to the evolution of the...
It is proposed a navigation system based on the unmanned aerial vehicle (UAV) onboard camera that can land on a moving naval platform. It is considered that, besides the usual sensors, the aircraft is equipped with a RGB digital camera capable of detecting markers located on the ship's deck. The proposed method uses a framework based on a Kalman filter (KF) and an efficient perspective-n-point (EPnP)...
We present the design and implementation of an aircraft collision avoidance algorithm for Unmanned Aerial Vehicles (UAVs). Automatic Dependent Surveillance-Broadcast (ADS-B) is used to detect aircraft. The UAV needs to fly through pre-assigned waypoints while avoiding collisions with other aircraft. The aircraft are indifferent to the UAV. A collision with aircraft are detected by simulating the UAV's...
This paper presents a novel method for moving object tracking in different scales. There are researches in tracking objects but most of them focus on specific subject and fail in some conditions such as changing position, moving camera, changing scale because of the distance variations. Camera movement is one of the most challenging events which causes to have a lot of fake moving objects in scenes...
In order to foreseen, within the next decade, the traffic at busy airports, the main objective is to automate all the ground motions from the gates to a given position of the runway exit in the near future. To this purpose, it is therefore first given the modeling of the automated vehicles in order to determine the control strategies. In this work, which is the first stage of a project referenced...
A stochastic linear hybrid system is said to be observable if the hybrid state of the system can be uniquely determined from its output. In this paper, we derive conditions for the observability of stochastic linear hybrid systems by exploiting the information obtained from system noise characteristics. Having established the necessary criteria for observability, we study the effect of these conditions...
The requirements, design and simulation of a control system for a precision tracking task, called a Pitch-rate Control Augmentation System (CAS), for the F-16 fighter aircraft model, is considered. This control system is designed over the entire flight envelope using one of the nonlinear Model Based Predictive Control techniques (MBPC), which is called Non-linear Generalized Predictive Control (NLGPC)...
Edge bundling methods reduce visual clutter of dense and occluded graphs. However, existing bundling techniques either ignore edge properties such as direction and data attributes, or are otherwise computationally not scalable, which makes them unsuitable for tasks such as exploration of large trajectory datasets. We present a new framework to generate bundled graph layouts according to any numerical...
This paper proposes a novel approach to aircraft conflict resolution where the design of an optimal conflict resolution manoeuvre based on the aircraft intent information is robustified against the uncertainty affecting the aircraft future positions by a randomized stochastic optimization method. The goal is to account for a probabilistic description of the uncertainty affecting the aircraft motion,...
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