  The quadrotor task of negotiating aggressive attitude maneuvers while
adhering to motor constraints is addressed here. The majority of high level
quadrotor Nonlinear Control System (NCS) solutions ignore motor control
authority limitations, especially important during aggressive attitude
maneuvers, generating unrealizable thrusts and negating the validity of the
accompanying stability proofs. Here, an attitude control framework is
developed, comprised by a thrust allocation strategy and a specially designed
geometric attitude tracking controller, allowing the quadrotor to achieve
aggressive attitude maneuvers, while complying to actuator constraints and
simultaneously staying "close" to a desired position command in a
computationally inexpensive way. This is a novel contribution resulting in
thrusts realizable by available quadrotors during aggressive attitude
maneuvers, and enhanced performance guaranteed by valid stability proofs. Also,
it is shown that the developed controller can be combined with a collective
thrust expression in producing a position/yaw tracking controller. Through
rigorous stability proofs, both the position and attitude frameworks are shown
to have desirable closed loop properties that are almost global. This
establishes a quadrotor control solution allowing the vehicle to negotiate
aggressive maneuvers position/attitude on SE(3). Simulations illustrate and
validate the effectiveness and capabilities of the developed solution.
