Effect of Uncertainties on UCAV Trajectory Optimisation Using Evolutionary Programming

There is a recognised need for an automated trajectory planning to guide manned or unmanned aircraft against an agile adversary such as a missile. Evolutionary programming approaches provide an alternative to classical functional optimisation methods with the capability of incorporating multiple optimisation goals and in the same time tolerating aircraft constraints. In this study, an evolutionary flight path planning algorithm capable of mapping aircraft trajectories in three dimensions under several aerodynamics constraints is developed. The task of the trajectory was to guide the aircraft away from interception. The calculations assumes that the aircraft states are accurate. Good trajectories were found under this assumption. But in reality, states are measured in an environment that has uncertainties, such as instrument error, atmospheric disturbances, etc. This paper studies the effect of the presence of errors to the accuracy of the algorithm. Two state variables were studied, i.e. altitude and velocity for both players. From the simulation, the effect of noises and interception radius can influence the sensitivity of the optimiser.