This book systematically explains the theoretical issues related to the dynamic characteristics, performance calculations, and flight control system design of multirotor aircraft, drawing on theories and methods from flight (dynamic) mechanics and flight control.

This book systematically explains the theoretical issues related to the dynamic characteristics, performance calculations, and flight control system design of multirotor aircraft, drawing on theories and methods from flight (dynamic) mechanics and flight control. It aims to equip readers with foundational flight dynamics knowledge and practical methods for theoretical design and mathematical simulation of flight control systems, while addressing unresolved questions—such as why PID control is necessary for attitude control and its relationship to vehicle dynamics. Although this book is not a specialized treatise on multirotor flight dynamics, the knowledge it provides is sufficient for general design. From the standpoint of force, torque balance, and control, using fixed-pitch blades requires at least four rotors arranged symmetrically around the center of mass; the quadrotor is the most fundamental configuration. More generally, as long as rotors are arranged around the center of mass and symmetrically with respect to the body's longitudinal symmetry plane (i.e., the plane of the body coordinate system), the configuration can be considered a generalized quadrotor aircraft, which serves as the subject of this book under the assumption that it does not fall into the low-Reynolds-number small-scale category. For convenience, this generalized quadrotor is simply referred to as a quadrotor, and the results can be extended to any even-numbered rotor layouts (e.g., six-rotor, eight-rotor) with symmetric arrangements about the center of mass or the body coordinate system plane.