基于θ-D方法的在轨操作相对姿轨耦合控制

Coupled Control of Relative Position and Attitude Based on θ-DTechnique for On-orbit Operations

针对诸如模块更换、燃料加注等在轨操作任务中的相对动力学与控制问题,建立了描述航天器间近距离相对运动的轨道姿态耦合动力学模型,结合轨道摄动和姿态干扰力矩分析了耦合项对模型的影响。考虑到基于状态相关系数形式模型的非线性和时变性,采用θ-D次优控制算法设计了相对姿轨耦合控制器。以在轨加注任务最终逼近段为背景,针对目标航天器失控旋转的情况进行了数值仿真,仿真结果表明了θ-D控制算法能够实现对相对轨道和姿态的同步控制,简化对控制器的求解并具有较高的控制精度。

For the problems of relative dynamics and control in the on-orbit operations such as module replacement, fuel charge and so on, coupled dynamics model of relative orbit and attitude was established to describe the relative motion of two spacecrafts in close range. Orbit perturbation and attitude disturbed torque was used to illustrate the impact of the coupled terms on the model. With the consideration of the nonlinear and time-varying of dynamic model based on the state dependent coefficient form, 0-D suboptimal control algorithm was adopted to design the controller of the coupled model of the relative translation and rotation. For the mission of space refuel during the final approach of an uncontrolled rotating satellite, the θ-D method is validated to be capable to realize the synchronization control of the relative orbit and attitude through the numerical simulation, which simplifies the calculation of controller and achieves a comparatively high precision.