Enforcing safety is critical for aerial robotics. In this paper we consider the safety control problem for a 3D quadrotor with limited sensing range subject to avoiding collisions with timevarying obstacles. By using the concepts of Control Lyapunov Functions (CLFs) and Control Barrier functions (CBFs), we propose a control algorithm that explicitly considers the nonlinear and underactuated dyn...

In this paper, we consider the problem of controlling multiple quadrotor robots that cooperatively grasp and transport a payload in three dimensions. We model the quadrotors both individually and as a group rigidly attached to a payload. We propose individual robot control laws defined with respect to the payload that stabilize the payload along three-dimensional trajectories. We detail the des...

in this paper, a nonlinear model of the underactuated six degrees of freedom (6 dof) quadrotor helicopter was derived based on the newton-euler formalism. a new nonlinear robust control strategy was proposed to solve the stabilizing and path following problems in presence of external disturbances and parametric uncertainties. the proposed control structure consist of a sliding mode control base...

in this paper, a robust tracking control method for automatic take-off and trajectory tracking of a quadrotor helicopter is presented. the designed controller includes two parts: a position controller and an attitude controller. the attitude controller is designed by using the sliding mode control (smc) method to track the desired pitch and roll angles, which are the output of position controll...

In this paper, a robust control method based on the uncertainty and disturbance estimator (UDE) is developed to achieve the attitude tracking control for a quadrotor. To facilitate the control design, the coupled terms in the roll, pitch and yaw dynamics are lumped into the uncertainty term and the remained dynamics can be regarded as decoupled subsystems. As a result, for each subsystem, the l...

This paper presents nonlinear tracking control systems for a quadrotor unmanned aerial vehicle under the influence of uncertainties. Assuming that there exist unstructured disturbances in the translational dynamics and the attitude dynamics, a geometric nonlinear adaptive controller is developed directly on the special Euclidean group. In particular, a new form of an adaptive control term is pr...

A model for a quadrotor helicopter, its flatness-based parameterization, and its control are investigated. The model is transformed by expressing the configuration in terms of a reference trajectory and the deviation from the latter. A flat output for the error system is introduced. A dynamic and a quasi-static feedback for asymptotic stabilization of reference trajectories are derived. The app...

In this paper, we propose a monocular vision system for approach and landing using a low-cost micro aerial vehicle (MAV). The system enables an off-the-shelf Parrot AR.Drone 2.0 quadrotor MAV to autonomously detect a landpad, approach it, and land on it. Particularly, we exploit geometric properties of a circular landpad marker in order to estimate the exact flight distance between the quadroto...

In this paper we present the design of a platform for autonomous navigation of a quadrotor UAV based on RGB-D technology. The proposed platform can safely navigate in an unknown environment while self-stabilization is done relying only on its own sensor perception. We developed an estimation system based on the integration of IMU and RGB-D measurements in order to estimate the velocity of the q...

We propose a novel unified passivity-based adaptive backstepping control framework for ‘‘mixed’’ quadrotor-type unmanned aerial vehicles (UAVs), which consists of the translation dynamics with thrust force input λ ∈ R and the attitude kinematics with the angular velocity input w ∈ R3 evolving on SE(3). We also show how our proposed unified framework can be used for velocity field following, tim...