高空太阳能无人机三维航迹优化

为提升高空太阳能无人机的飞行性能和载荷能力，综合考虑无人机运动状态和能量获取、存储、消耗之间的耦合关系，建立了三维航迹优化模型。采用高斯伪谱法在离散点上近似状态变量和控制变量，且在一系列配点上满足动力学方程的约束，将最优控制问题转化为非线性规划问题。针对典型的点到点飞行任务开展了航迹优化，并与常规定高定速航迹进行了对比。结果表明:通过调整飞行姿态，可以使高空太阳能无人机的净吸收能量提高9.2%；综合调整飞行姿态和改变飞行高度两种措施可以获得更大的能量优势，使储能电池剩余电量提高18.8%。 

Three-dimensional optimal path planning for high-altitude solar-powered UAV

In order to enhance the flight performance and load capacity of high-altitude solar-powered UAV, a three-dimensional optimal path planning model that examines the interaction between flight status, energy acquisition, storage, and consumption was established. The Gauss pseudo-spectral method was employed to transform the optimal control problem into a nonlinear programming problem through approximating the state variables and control variables on discrete points and satisfying the constraints of dynamic equations on a set of collocation points. Then optimization and simulation were carried out for a typical point-to-point mission and the optimum path was compared with current constant-altitude constant-velocity path. The results indicate that appropriate changes of flight attitude angle increase the net energy of solar-powered UAV by 9.2%. By comprehensive utilization of changing flight attitude angle and flight altitude, the proposed optimum path brings more energy profits, which improves the battery pack final state of charge by 18.8%.