The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Aircraft control system is designed to provide adequate stability during transition flight of a quad-tilt wing (QTW) UAV. The dynamic inversion method, which is a linearization method without an approximation algorithm, is applied to a control problem of the UAV, because of strong nonlinearity of its dynamical behavior. The validity of the proposed control system is verified through numerical simulation...
This paper presents a visual Simultaneous Localization And Mapping (SLAM) method for temporary satellite dropout navigation for an unpowered fixed-wing aircraft. It is designed for flight altitudes beyond typical stereo ranges, but within the range of distance measurement sensors. The proposed visual SLAM method consists of a common localization step with monocular camera resectioning, and a mapping...
We propose the structured two-loop flight control system of a novel tandem ducted fan vehicle for near hover flight in consideration of actuator saturations on its dynamics. The prescribed controller architecture consists of static output feedback inner loop and four PI outer loop, which is a desirable and intuitive structure for practical implementation. The effect of a limited control activity on...
Formation control is concerned with the problem of arranging or rearranging agents into a target configuration (such as a line or surface of a sphere) while preserving threshold distances that enable communication and avoid collisions. In this work, a decentralized algorithm for formation control of a multi vehicle fault-tolerant system is proposed. By using computational geometry techniques, a novel...
This paper presents an experiment to evaluate the effects of immersive displays in a multi-UAV context in which the operator may need to understand not only the 3D spatial relationships between the UAVs but also where the UAV is with respect to mountains or other obstacles. To this end, a 3D simulator was developed and displays were selected based on their Field-of-Regard (FoR). Participants supervised...
This paper describes the design of model predictive control (MPC) for an unmanned aerial vehicle (UAV) used to track objects of interest identified by a real-time camera vision (CV) module in a search and track (SAT) autonomous system. A fully functional UAV payload is introduced, which includes an infra-red (IR) camera installed in a two-axis gimbal system. Hardware-in-loop (HIL) simulations are...
Visual odometry and mapping methods can provide accurate navigation and comprehensive environment (obstacle) information for autonomous flights of Unmanned Aerial Vehicle (UAV) in GPS-denied cluttered environments. This work presents a new light small-scale low-cost ARM-based stereo vision pre-processing system, which not only is used as onboard sensor to continuously estimate 6-DOF UAV pose, but...
This paper considers the design and control of a Remotely Operated Aerial System Remotely Operated (ROAS) with force feedback to pilot in order to increase the perception level. The force experienced by the pilot through a Human Machine Interface (HMI) considers and it is proportional to the translational speed and proximity to objects located in the environment where the UAV evolves. In order to...
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...
In this paper, we propose an Integrated Fault Tolerant Controller (IFTC) for quadrotor UAVs based on Sliding Mode Passive and Active FTCs, along with Trirotor conversion maneuver. A Sliding Mode Observer is used to detect and estimate actuator faults affecting rotors, and a fault severity based decision station activates the suitable controller. The new controller not only ensures fault tolerance,...
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...
This article proposes a methodology for enabling Unmanned Aircraft Systems (UASs) to avoid obstacles. The strategy, which makes use of a Robust Exact Differentiation (RED), relies on spiral trajectory tracking maneuvers, and is based on a backstepping controller with disturbance compensation. The RED strategy has been adopted since it enables the exact estimation of disturbances from the first moment,...
In this paper, an unmanned aerial vehicle (UAV) based forest fire detection and tracking method is proposed. Firstly, a brief illustration of UAV-based forest fire detection and tracking system is presented. Then, a set of forest fire detection and tracking algorithms are developed including median filtering, color space conversion, Otsu threshold segmentation, morphological operations, and blob counter...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.