Modeling and Control of Bisymmetric Aerial Vehicles Subjected to Drag and Lift

The modeling and control of a class of thrust propelled aerial vehicles subjected to lift and drag aerodynamic forces is addressed. Assuming a rotational symmetry of the vehicle's envelope about an axis and the alignment of the thrust force with this axis, one shows that the resultant of aerodynamic forces can be decomposed as the sum of a term in the direction of the air velocity and a term in the direction of the thrust force. Conditions allowing for the derivation of a family of models of aerodynamic forces for which the first term does not depend on the vehicle's orientation are pointed out. When such a model applies, pre-compensation of the latter term with the thrust input allows one to recast the control problem into the simpler case of a spherical vehicle subjected to drag only for which nonlinear feedback controllers endowed with strong stability and convergence properties have been reported in prior studies. Beside the adaptation of these control results, the paper extends a previous work by the authors in two directions. First, the 3D case is addressed whereas only motions in a single vertical plane was considered. Secondly, the family of models of aerodynamic forces for which the aforementioned transformation holds is enlarged