Driving and tilt-hovering-An agile and manoeuvrable aerial vehicle with tiltable rotors

Driving and tilt-hovering help unmanned aerial vehicles extend their time of operation and the visible range of the equipped sensors.Standard quadrotors are underactuated,whose translational and rotational motions are strongly coupled.As a result,it is impossible to maintain the attitude invariably while changing position.Meanwhile,larger flying speed results in greater air resistance,which is also not desirable.A novel aerial platform with tiltable rotors is proposed.Compared with standard quadrotors,the aerial vehicle has three special capabilities:vector-flying,tilt-hovering,and driving.The platform consists of two tilting-axes to change the direction of thrusts with respect to the aircraft body.To guarantee flexible manoeuvres,a geometric tracking control scheme that adapts on the fly to the thrust vectoring is exploited.Manoeuvrability of the proposed vehicle in different manoeuvres is demonstrated,such as flight with vectoring thrust that can reduce the flight resistance,tilt-hovering expanding the reachable set of the equipped sensors.The prototype equipped with an electromechanical controller is constructed,and several associated preliminary experiments are performed.The feasibility of the mechanical design and the geometric control strategy are demonstrated.