ABSTRACT
\section*{Abstract}
Flight planning is defined as finding a sequence of actions that transform some initial state into some desired goal state. This chapter begins with path and trajectory planning: \AQ{planning of trim}{-1pc}{AU: Please confirm if edit in this sentence is appropriate.} trajectories and time optimal trajectories and non-holonomic motion planning. Trajectory generation refers to determining a path in free configuration space between an initial configuration of the aircraft and a final configuration consistent with its kinematic and dynamic constraints. The optimal approach can be used to realize the minimum time trajectory or minimum energy to increase the aircraft’s endurance. Zermelo problem is then considered; it allows the study of aircraft’s trajectories in the wind. In the middle of the chapter, guidance and collision/obstacle avoidance are considered. Planning trajectories is a fundamental aspect of autonomous aircraft guidance. It can be considered as a draft of the future guidance law. The guidance system can be said to fly the aircraft on an invisible highway in the sky by using the attitude control system to twist and turn the aircraft. Guidance is the logic that issues the autopilot commands to accomplish certain flight objectives. Algorithms are designed and implemented such that the motion constraints are respected while following the given command signal. Flight planning is also the process of automatically generating alternate paths for an autonomous aircraft, based on a set of predefined criteria, when obstacles are detected in the way of the original path. Aircrafts operate in a three-dimensional environment where there are static and dynamic obstacles as well as other aircrafts, and they must avoid turbulence and storms. As obstacles may be detected while the aircraft moves through the environment or their locations may change over time, the trajectory needs to be updated and satisfy the boundary conditions and motion constraints. Then, mission planning is introduced by route optimization and fuzzy planning.
