Modeling and Control of an Unmanned Aerial Vehicle with Tilt Rotors Equipped with a Camera In this work, we present a control law for an unmanned aerial vehicle (UAV) carrying a camera through a two degrees of freedom (2DOF) gimbal mechanism. The vehicle is an H shaped quadrotor with an additional mechanism that allows the independent projection, along the longitudinal direction, of the thrust generated by each rotor. This particular characteristic shows useful during the execution of some specific tasks, especially the ones that require high velocity. A control law is designed to deal with the underactuation and nonlinearities behavior of the vehicle, that are expressed mathematically by the EulerLagrange formulation. The control structure is arranged in four subsystems, designed to control the dynamics of the UAV position, attitude, rotors inclination, and camera pointing. For the position control, the inverse dynamic is used to linearize the translation subsystem, and then a robust Hxe2x88x9e controller is applied. For the remaining subsystems, the SuperTwisting Sliding Mode Control is applied. We present, through simulation, the performance of the designed control structure, proving that the controlled UAV is stabilized and able to track given trajectories even in the presence of unmodeled dynamics, parametric uncertainties and external disturbances (such as wind gusts).

Mathematical modeling and control of a quadrotor aerial vehicle with tiltrotors aimed for interaction tasks With a wide spectrum of applications ranging from entertainment to military use, quadrotors, in their conventional construction with four fixed rotors, have proven to be sufficiently capable of robustly performing numerous tasks. However, the capability to generate thrust just in one direction, i.e., normal to its main plane, is very restrictive and drastically reduces the maneuverability and agility of the vehicle. In this paper, an alternative model of the quadrotor is presented. Constructively, the difference lies in the addition of a mechanism that tilts the rotors in the longitudinal direction, which in practice adds maneuverability by enabling the longitudinal translation uncoupled from the pitching movement. In addition to this new thrust component in the longitudinal direction, this configuration also yields a significant increase in the yaw torque. These are highly desired features in a UAV used to execute tasks that require physical interaction with the surrounding environment. The mathematical model of the entire system is obtained by employing the EulerLagrange formalism and a multibody approach. In addition, a basic control scheme is used to verify, through simulation, the obtained model.