带零动量轮航天器的逆系统方法姿态控制

为满足带零动量轮航天器姿态响应的快速性与准确性,将航天器姿态模型和飞轮机构及其补偿器视为广义控制对象,采用广义逆系统方法与内模原理相结合设计了复合控制器。在分析动量轮的摩擦阻力效应基础上,设计了基于飞轮非线性观测器的低、高速补偿器,在改变航天器惯量与加入干扰的情况下,通过仿真分析了复合控制的鲁棒性。逆系统实现了广义控制对象的解耦,内模闭环控制器弥补了解耦的非理想性,补偿器加快了姿态响应速度。仿真结果表明,逆系统与内模控制组成的复合控制器对带零动量轮航天器姿态控制是有效的,并且该控制器对航天器惯量参数和干扰具有较强的鲁棒性。

Attitude control based on inverse system for a spacecraft with zero-momentum wheels

In order to satisfy celerity and veracity of spacraft attitude responses,an attitude control method based on inverse system for a spacecraft with zero-momentum wheels is discussed.The spacecraft attitude model with wheel dynamics and its compensator was viewed as a generalized plant,and an attitude controller,which combined inverse system method with internal model principal,was presented.The friction effect for the momentum wheel was analyzed and a low-speed and high-speed compensator based on an observer was designed.Some simulations about the method were done under the circumstance of changing inertia and adding disturbances.The generalized model was decoupled into three single-input-single-output systems via inverse system method based on state feedback.The closed loop controller based on internal model principal remedied nonideal decoupling.The compensator mades attitude response be quicker.Simulation results show that the combined controller is valid to control spacecraft attitude,and system robustness is strong for inertia parameters and disturbances.