考虑控制饱和的编队飞行卫星姿态协同控制

Attitude Coordination Control of Formation Flying Satellites under Control Saturation

研究了考虑控制输入饱和的编队飞行卫星姿态协同控制问题,提出了一种非线性饱和协同控制器。与单颗卫星输入受限控制中通常选用双曲正切函数不同,引入了一个新的连续可微的非线性饱和函数向量,以保证连续控制输入的有界性,并便于姿态协同系统的稳定性分析。基于闭环姿态协同系统在期望跟踪角速度不同取值情况下属于自主或非自主系统的特点,分别采用LaSalle不变原理和Barbalat引理对不同情况下的协同控制系统的稳定性进行了分析,得出了系统渐近稳定的结论。仿真结果表明,这种非线性协同控制器,既能实现编队卫星的姿态协同,又能确保控制输入的有界性。

The problem of the attitude coordination control under control input saturation for formation flying satellites is investigated,and a nonlinear saturated coordination controller is proposed.Different from the case of the attitude control for single satellite under input constraints,in which a hyperbolic tangent function is usually chosen,a new continuously differentiable nonlinear saturation function vector is introduced to ensure that the continuous control input is bounded and make the stability analysis of the attitude coordination system available.Based on the feature that the closed-loop attitude coordination system belongs to autonomous systems or non-autonomous systems respectively according to different values of the desired and tracked angular velocity,LaSalle＇s invariance principle and Barbalat＇s lemma are utilized correspondingly to analyze the stability of the attitude coordination controlled system in different cases,then the result of the asymptotical stability is obtained.Simulation results show that this kind of nonlinear coordination controller can achieve the purpose of attitude coordination for formation flying satellites,and guarantee the control input is bounded as well.