基于间接法在线能力评估和自主规划技术研究

针对运载火箭推力故障条件下的自主救援任务，研究了一种基于间接法的在线能力评估和自主规划方法。构建了以入轨点能量最大为最优性能指标的最优控制问题。通过数值方法探讨了在满足轨道倾角和入轨点路径角约束条件下，入轨点速度、远地点和近地点跟入轨高度之间的关系，设计了一种与入轨高度相关的特征量来对入轨能力进行评估。以近地点最高为救援轨道选取准则，结合能力评估，研究了一种自主在线规划策略，当判断能够进入圆轨道时，割线法求解最大圆轨道，否则采用牛顿法求解近地点最高的椭圆轨道。仿真结果表明，提出的自主规划方法在有效性、收敛性和实时性上均能满足在线制导需求。

Research on online capability assessment and autonomous planning technology based on indirect method

Aiming at the autonomous rescue mission under the thrust failure condition of the launch vehicle, an online capability assessment and autonomous planning method was studied based on the indirect method. The optimal control problem with the maximum energy at the orbit injection point was constructed. Under the constraints of the inclination of the orbit and the path angle of the orbit injection point, the relationship between the speed of the orbit injection point, the height of the apogee, the height of perigee and the height of the orbit injection point was discussed through a numerical method. A feature quantity was designed to perform the orbital capability evaluation. Taking the highest perigee height as the selection criterion for rescue orbit, an autonomous online planning strategy was proposed based on the orbital capability evaluation. When it was judged that it can enter the circular orbit, the secant method was used to solve the largest circular orbit. Otherwise, the Newton method was used to solve the highest elliptical orbit. Simulation results show that the autonomous planning method proposed meets the requirement of online guidance in terms of effectiveness, convergence and real time performance.