A method of 3D path planning for solar-powered UAV with fixed target and solar tracking

Abstract

To harvesting the more net energy, a method of 3D path planning for solar-powered UAV with fixed target and solar tracking has been presented in this paper. However, how to deal with the coupling between UAV motion, mission constraints, energy production, and the energy consumption is the key to 3D path planning for solar-powered UAVs to continuously monitor fixed targets. Hence, in this study, the flight paths of SUAV will be planned on a virtual cylinder surface in 3D space, with the fixed target center as the origin. In order to realize the UAV path planning based on the virtual cylinder surface, firstly, the UAV motion is re-modeled, and the UAV's motion characteristics and force are analyzed based on this model. Then, based on the motion trajectory characteristics in relation to the force balance, the state variables at each waypoint of the UAV are parameterized in the form of the variables to be optimized and their first and second derivatives, and a spline interpolation function is introduced three times to obtain the first and second derivatives of the solution variables. Finally, with reference to the UAV's minimum power flight strategy, the horizontal plane component of the UAV flight speed is set to the minimum power level flight speed, while the yaw rate is solidified and the sun position is assumed to be unchanged for a short period of time to simplify the optimization process and thus obtain the final optimal solution. The simulation experiment shows that unlike the UAV that flies at a fixed height, the UAV herein will climb or descend to seek a more favorable attitude to maximize energy production.