Guidance Strategy for Small UAVs to Extend Mission Range by Utilizing Atmospheric Energy

This paper discusses a new guidance strategy to extend mission time of small unmanned aerial vehicles (UAVs) by harvesting energy from the atmosphere. Small UAVs are getting common for people to investigate areas that are too dangerous or expensive for manned air vehicles to execute. However, their small sizes restrict their payloads, which directly leads to their poor mission range and time. One of the solutions for this problem is to extract energy from wind fields and to reduce fuel required to fly back and forth between the mission area and the ground station. The speed to fly principle and the optimization technique are common for this purpose but we have doubts about reliabilities of both methods. The former assumes only steady flight while the latter cannot deal with uncertain environments, such as wind field, which is fundamentally important for our work. In our study, a new stochastic optimization method was developed, which can handle parameter incertitude numerically. The optimal trajectory we obtained has optimal trajectory’s expected value and variance information, which may improve the operator’s decision making skills.