Geometry Enhanced Finite Time Near Optimal Control Strategy for Acrobatic Flip Motion of Quadcopter Unmanned Aerial Vehicles

A nonlinear optimal control strategy, named the geometry enhanced finite time
$\theta-\mathrm{D}$
technique, is proposed to manipulate the acrobatic flip flight of variable pitch (VP) quad-copter unmanned aerial vehicles (abbreviated as VP copter). A unique superiority of the VP copter, which can provide the thrust in both positive and negative vertical directions by varying the pitch angles of blades, facilitates the acrobatic flip motion. The finite time
$\theta-\mathrm{D}$
technique can offer a closed-form near-optimal state feedback control law with online computational efficiency as compared with the finite time state-dependent Riccati equation (SDRE) technique. Meanwhile, by virtue of the geometric technique, the singularity issue of the rotation matrix in the acrobatic flip maneuver can be avoided. The simulation experiments verify the proposed control strategy is effective and efficient.