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Time-domain aircraft system identification is applied to flight test data obtained using a motion capture system. Longitudinal aerodynamic force and moment time histories are obtained using the estimation-before-modeling approach, in which forces and moments are modeled as Gauss-Markov processes and estimated concurrently with the aircraft state histories using an extended Kalman filter. Quasi-steady...
This paper addresses the problem of autonomous navigation of a quadrotor helicopter using state estimators when the GPS signal is not available. The main objective is to estimate the translational position and velocity of the flying machine. The observer proposed uses a double integral approximation of the acceleration defined in the mathematical model in order to estimate the states previously mentioned...
This paper presents a trajectory tracking non-linear controller for the quadrotor that compensates external forces and moments. The external forces, their first and second time derivatives, as well as the external moments, are reconstructed using an estimator based on the immersion and invariance technique. The evaluation of the proposed controller is performed with the aid of a series of experimental...
An Unmanned aerial vehicle (UAV) guidance law is addressed as an optimal regulator (LQR) problem. An adaptive optimal path following nomenclature is derived and defined. The state weighting matrix of the LQR is defined in term of intrinsic parameter error thereby enabling the guidance law to regulate the UAV disturbance errors effectively. The state weighing matrix is tuned using a genetic algorithm...
This paper describes the tracking guidance for the autonomous UAV landing and the vision-based detection of the marker on the moving vehicle with the real-time image processing system. The detection of the marker is based on the color detection algorithm with morphological filter and the tracking guidance is based on the relative distance between the UAV and the vehicle. In order to track and land...
This paper presents a feasibility study for end-body positioning maneuvers using a towed cable-body system where a fixed wing Unmanned Aerial Vehicle (UAV) is stabilized in a steady-state circular motion. As high precision maneuvers such as object pickup/dropoff are typically performed by rotorcraft UAVs, a successful fixed-wing concept would greatly increase the possible range for this type of operation...
Airships present many interesting opportunities for transport, surveillance and inspection but have seen little to no use in commercial or military unmanned applications. Generally underpowered, underactuated, and large in size, airships express difficulties in adverse atmospheric conditions or situations requiring rapid or precise maneuvers. In this paper, a miniature unmanned airship with a moving...
This paper presents a decentralized multi-agent motion planning method for aerial robots moving among 3D polygonal obstacles. The algorithm combines a prioritized A∗ algorithm for high-level (global) planning along with a barrier functions-based method for low-level (local) coordination and control. We first extend the barriers function method developed in earlier work to treat arbitrary polygonal...
Modeling and identification of an aerial vehicle will allow engineers to design and implement guidance and control systems using the mathematical model acquired on flight. Using the mathematical model, several improvements and benefits shall be obtained, such as designing control subsystem using Modern Control Theory; the expected results at the workbench test will correspond more accurately to the...
The paper presents a tube based Model Predictive Control (MPC) strategy for robust tracking control of PVTOL aircraft. PVTOL system is considered as a benchmark for investigating dynamics and control related issues for unmanned aerial vehicles (UAVs). Due to non-linear dynamics and under actuated nature of this system, the task of building control algorithm for such systems becomes challenging. Here,...
In this paper a fractional-order (or alternatively known as a non-integer) FOPID type controller (that gives better performance than classical, integer-order PID type) was proposed for tracking of the rotational speed reference signal of propeller in electric propulsion system used in multirotor flying robots and platforms. For propulsion system (electronic speed controller, brushless direct current...
Multirotor aerial vehicles are extensively employed in applications requiring a stationary surveillance platform to monitor a situation on the ground for a specific duration. In most cases, these systems are small in size and weigh < 10Kgs. This paper presents a design methodology employed to develop a multirotor system exceeding the conventional size and weight category. The study includes modelling...
Two missile guidance laws viz. Pursuit Guidance (PG) and Trajectory Shaping (TS), have been adopted to aggressively follow curved, compact trajectories using a quadrotor. The concept of virtual target navigation has been utilized to generate the required curved trajectories. Simulations and flight tests have been performed using a quadrotor and the performance characteristics obtained have been compared...
An optimization problem based on discrete-integer and continuous variables in order to design a multirotor for a specific application (maximum thrust-to-weight and maximum flight time) is developed. We considered the length and the diameter of the rods as continuous variables and the selection of the motors, propellers, and battery as discrete-integer variables, the components selected are available...
Speed, agility, maneuverability, range and efficiency of birds and insects are far beyond the conventional flying mini vehicles. There are various research works to create vehicles that imitate these amazing creatures. In this paper, a wing mechanism is designed for a micro aerial vehicle using four flapping wings. In this system, a four-bar mechanism is preferred as the wing mechanism. In order to...
Unmanned aerial vehicles (UAVs) are widely applied in both civil and military fields, such as rescue, surveillance, exploration, navigation, precision agriculture and etc., because of small size, low cost and easy maintenance. However the autonomous flight of UAVs under unstructured environment is still open, especially when GPS is unavailable or indoor task is scheduled. Furthermore, GPS-based navigation...
This paper presents a novel obstacle avoidance scheme for UAVs. This scheme is based on the use of a technique recently developed by one of the authors, which is based on a transformation of a variable constraint into an input saturation. In the case of obstacle avoidance, this saturation is designed so as to ensure a safe trajectory around the obstacles, offering a proof of this desired behavior...
The increasing civilian demand for autonomous aerial vehicle in the professional markets led to an abundance of inexpensive navigational hardware platforms and vehicle prototypes. Current photogrammetry-based applications require crisp and precise positioning of images so that the process does not fails. Also systems adaptable to the circumstances for better effectiveness, vehicles capable of vertical...
The design and testing of unmanned aerial vehicles is a difficult task due to the high risk of damage to property during testing, to prevent accidents from happening it is indeed necessary to perform extensive simulation of controllers to ensure good stability and performance. We have been working to solve this problem by developing a realistic simulator by using a complete mathematical model of the...
In this paper, we investigate the problem of fault tolerant for a group of multiple autonomous cooperative unmanned aerial vehicles (UAVs) during execution their mission in a desired geometrical pattern. A decentralized linear model predictive control (LMPC) is designed and implemented on a team of cooperative UAVs to achieve the desired formation in the absence of faults (normal/fault-free cases)...
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