Aerial refueling is an important capability to increase the endurance and flight range of aircraft, but it often suffers from a low success rate. The altitude and speed of the tanker aircraft in the docking phase play a great role in the docking success rate. According to this, the optimal trim state, namely the optimal speed and altitude of the tanker aircraft, is investigated through the reachability analysis method in this paper. The optimal problem is transformed to find the trim state corresponding to the maximum volume of the reachable set. First, a relative motion model of the receiver aircraft with respect to the drogue is proposed. Then, based on reachability analysis, an optimization problem is formulated and a solution procedure is given in detail. In the simulation, the volumes of reachable sets are plotted with respect to the given discrete speeds and altitudes, based on which the optimal trim state of the docking phase is determined. Finally, the determined optimal trim state is verified by using numerous docking control simulations and the degree of controllability from another aspect. The effectiveness of the proposed method is demonstrated.

空中加油是提高飞机续航能力和飞行范围的一项重要能力，但其成功率通常很低。在对接阶段，空中加油机的高度和速度在对接成功率中起着重要作用。据此，本文通过可达性分析方法研究了最优的调整状态，即油轮飞机的最佳速度和高度。转换最佳问题以找到与可到达集合的最大体积相对应的修整状态。首先，提出了接收机相对于锥套的相对运动模型。然后，基于可达性分析，提出了一个优化问题，并给出了详细的求解过程。在模拟中 相对于给定的离散速度和海拔高度绘制可到达集合的体积，基于此确定对接阶段的最佳调整状态。最后，通过使用大量的对接控制仿真和另一方面的可控制性程度来验证确定的最佳修整状态。证明了所提方法的有效性。