发表机构
University of Kentucky（肯塔基大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对小天体着陆中引力不确定性与执行器约束问题，提出结合扩展高增益观测器、控制障碍函数二次规划及最优分配的安全位置姿态最优控制方法，并在两种配置仿真中验证。
AI 中文摘要
在小天体上着陆具有挑战性，因为航天器必须在难以精确建模的引力作用下满足安全性和执行器约束。本文提出了一种在引力不确定性和严格执行器限制下实现安全着陆的最优控制方法。该方法处理航天器姿态控制问题，其中姿态在SO(3)上表示，并存在执行器约束以及位置、姿态、速度和角速度的状态约束。该方法结合了若干关键技术。首先，利用扩展高增益观测器估计引力不确定性，并给出了估计误差的一个新的动态上界。然后，利用该引力估计和动态界计算满足状态和执行器约束同时跟踪着陆轨迹的最优控制力和力矩。最优力和力矩由二次规划问题的闭式解获得，该二次规划具有单个控制障碍函数约束，该约束由多个控制障碍函数组合而成，这些函数分别用于强制执行每个状态和执行器约束。最后，一个最优分配将控制力和力矩映射到满足执行器约束的执行器指令。该方法在仿真中通过两种具有严重引力不确定性的飞行器配置进行了演示。
英文摘要
Landing on small celestial bodies is challenging because the spacecraft must satisfy safety and actuator constraints despite gravitational forces that are difficult to model accurately. This article presents an optimal control for safe landing with gravitational uncertainty and strict actuator limits. The approach addresses spacecraft pose control with attitude represented on SO(3), where there are actuator constraints and state constraints on position, attitude, velocity, and angular velocity. The approach combines several key techniques. First, the gravitational force uncertainty is estimated using an extended high-gain observer, and we present a new dynamic upper bound on the estimation error. This gravitational estimate and dynamic bound are then used to compute optimal control forces and torques that satisfy state and actuator constraints while tracking a landing trajectory. Optimal forces and torques are obtained from the closed-form solution to a quadratic program that has a single control barrier function constraint constructed by composing multiple control barrier functions that are designed to enforce each state and actuator constraint. Finally, an optimal allocation maps control forces and torques to actuator commands that satisfy actuator constraints. The method is demonstrated in simulation using 2 vehicle configurations with severe gravitational uncertainty.
