A new method for trajectory optimization in Terrain Following flight

In this paper, the problem of two dimensional Terrain Following / Terrain Avoidance trajectory optimization has been considered for an Unmanned Aerial Vehicle (UAV) in vertical flight plane. This problem is formulated as an optimal control problem, and then Direct Collocation method is employed as a solver tool for generating flyable path. Chebyshev polynomial has been used to model the geographical data of the terrain in a given route. The results indicate that the method is suitable for the terrain following problem especially in the case of producing more reliable flyable path based on the system dynamics, physical limitations and also the mission requirements.