Abstract of Thesis presented at COPPE/UFRJ as a partial fulfillment of the requirements for the degree of Master of Science (M.Sc.)

Smooth Robust Control Applied to Quadrotor Landing

Paulo Roberto Yamasaki Catunda

March/2016

Advisor:

Alessandro Jacoud Peixoto

Department:

Eletrical Engineering

      In this work the problem of autonomous landing of a quadrotor on a vertically oscillating platform is addressed. It is prop osed an adaptive robust altitude control scheme based on a smo oth sliding mo de controller to deal with the aero dynamic Ground Effect and the mass variation during a pick and place task. The stability analysis assuming that velocity is available for feedback is provided. For the case where the Ground Effect can be parameterized, a Normalized Least Squares (NLS) algorithm is used for estimate the unknown paramaters. In this case, a proportional derivative controller with time-varying gains is developed based on the NLS algorithm. For position and attitude control a hierarchical control approach which is common for quadrotors is employed in two nested loops. The inner loop is the vehicle attitude control, while the outter loop is the position control along a trajectory. Proportional derivative type controllers along with feedforward and feedback linearization are considered. In addition, it is developed a nonlinear model of a quadrotor following the Newton-Euler and Euler-Lagrange formalisms for rigid bodies. The traditionals approximations used in the development of the models are evaluated. The performance of the proposed methods are illustrated through numerical simulations and experimental results obtained with the developed quadrotor and experimental setup.