Fixed-pitch quadrotors are popular research and hobby platforms largely due to their mechanical simplicity relative to other hovering aircraft. This simplicity, however, places fundamental limits on the achievable actuator bandwidth and the possible flight maneuvers. This paper shows that many of these limitations can be overcome by utilizing variable-pitch propellers on a quadrotor. A detailed...

During recent years there has been growing interest in unmanned aerial vehicles (UAVs). Moreover, the necessity to control and navigate these vehicles has attracted much attention from researchers in this field. This is mostly due to the fact that the interactions between turbulent airflows apply complex aerodynamic forces to the system. Since the dynamics of a quadrotor are non-linear and the ...

The studies in UAV modeling and control have been increased rapidly recently. This paper presents the modeling and control of a four rotor vertical take-off and landing (VTOL) unmanned air vehicle known as quadrotor aircraft. The modeling of the quadrotor will be described by using Euler-Newton equations. In order to stable the quadrotor and control the attitude of that, classical PID controlle...

In this thesis, intelligent controllers are designed to control attitude for quadrotor UAV (Unmanned Aerial Vehicle).Quadrotors have a variety of applications in real time e.g. surveillance, inspection, search, rescue and reducing the human force in undesirable conditions. Quadrotors are generally unstable systems; the kinematics of quadrotor resembles the kinematics of inverted pendulum. In or...

In this paper, we present a vision based robust pose estimation system in different observed situations for a quadrotor in outdoor environments. This system could provide us with approximate ground truth of pose estimation for an outdoor quadrotor, while most of existing vision based systems perform indoors. We only use the own features of the quadrotor, while most existing systems modify the a...

Standard quadrotor UAVs possess a limited mobility because of their inherent underactuation, i.e., availability of 4 independent control inputs (the 4 propeller spinning velocities) vs. the 6 dofs parameterizing the quadrotor position/orientation in space. As a consequence, the quadrotor pose cannot track arbitrary trajectories in space (e.g., it can hover on the spot only when horizontal). Sin...

Corresponding Author: Kil To Chong Department of Electronics Engineering, Chonbuk National University, Jeonju, South Korea Email: [email protected] Abstract: This paper addressed obstacle avoidance problem of a quadrotor in outdoor environment. Path planning was finished by employing classical Dijkstra algorithm and the controller of the quadrotor adopted integral backstepping method. In orde...

In this work, the main objective is to study the Optimal Kalman Filtering (OKF) method for estimating the state vector of a small quadrotor UAV through incorporating the internal disturbances including the white Gaussian process and measurement noises. Firstly, the kinematic and dynamic model of the quadrotor is transformed into a discrete-time system via the linear extrapolation method. Second...

International Journal of Robotics, Vol. 4, No. 1, 38-46 (2015) / Gh. Alizadeh, K. Ghasemi 39 The remainder of this paper is then organized as follows. fIGThe control strategy is exposed in Section III; in this section, two approaches of nonlinear robust control design are proposed: the SMDO control for translational movements and the nonlinear H∞ control for the rotational subsystem. Section IV...

This paper presents the design, analysis, and real-time experimental evaluation results of a nonlinear sensor fault diagnosis scheme for quadrotor unmanned air vehicles (UAV). The objective is to detect, isolate, and estimate sensor bias faults in accelerometer and gyroscope measurements. Based on the quadrotor dynamics and sensor models under consideration, the effects of sensor faults are rep...