Model based control of a quadrotor with tiltable rotors

Abstract

Micro Aerial Vehicles (MAV) with vertical takeoff and landing capabilities such as quadrotors are often used as sensor platforms. The carried equipment like cameras or LASER range finders has to be aligned to some point of interest. In this article a modified type of a quadrotor will be presented: a quadrotor with tiltable rotors which in contrast to common quadrotors is able to perform independent velocity and attitude movements. This ability makes additional aligning equipment to move the payload redundant. After a system description, the used control algorithm based on Nonlinear Inverse Dynamics (NID) is explained. In this article an extension of this approach is presented. The pseudo control hedging method removes the influence of the actuator dynamics from the control loop. The extension and its integration into the control algorithm are explained and the influence on the quality of control is demonstrated by simulation results.