On the guidance of fully-actuated multirotor aerial vehicles under control allocation constraints using the receding-horizon strategy

Abstract

The present work is concerned with the wayset-based guidance of a very general class of fully-actuated multirotor aerial vehicles which can be equipped with fixed or vectorable rotors. The problem is tackled by means of a hierarchical guidance and control framework containing two nested loops. For the outer loop, a guidance strategy based on the nonlinear model predictive control paradigm is proposed. It steers the vehicle through a sequence of position-attitude waysets, while guaranteeing the satisfaction of the control allocation constraints. For the inner loop, a single multi-variable inverse-dynamic force-torque control law is designed to stabilize the translational and rotational dynamics, and an optimal control allocator is formulated, by means of a convex program, to distribute the required control efforts among the available actuators. The asymptotic stability of the inner and outer loop, the recursive feasibility of the guidance algorithm, as well as the feasibility of the control allocator are proved to hold. The proposed method is numerically illustrated with a quadrotor containing two-degrees-of-freedom vectorable rotors and shows to be effective to guide the vehicle while respecting all the rotor constraints.

Keywords: Control allocation; Model predictive control; Multirotor aerial vehicle; Wayset-based guidance.