登月飞行器软着陆的非线性最优控制(英文)

Nonlinear Optimal Control for the Soft Landing of Lunar Landers

主要考虑登月飞行器软着陆控制的问题。制导律和控制器的设计分两步完成。首先,利用一个微分同胚变换和一个非线性输入补偿,可以将登月飞行器的非线性动态模型转换成一个线性系统。然后利用经典最优控制理论中的由拉方程,标准最优制导律的解析解既可给出。第二步,利用H∞控制理论,我们设计了一个最优反馈控制器保证了实际系统可以鲁棒渐进追踪最优标准轨道。最后通过仿真,可以看出飞行器实现了软着陆控制,着月速度小于给定值,说明方法的可行性和有效性。

This paper deal with the soft landing of the lunar lander. The design of the controller and guidance law had been completed in two steps. At first, having utilized a differential homeomorphic transformation and a nonlinear input compensation, we transformed the dynamics description of the lunar lander into a linear system. Then, based on the Yula equation of the classic optimal control method, a designing procedure and the general explicit solution of the normal guidance law were given. In the second steps, making use of the H∞ control approach, we designed a feedback controller for the uncertainties and disturbance such that the real system can track the normal orbit. At last, simulation results illustrate the feasibility and advantage of our approach.