【摘要】 针对在轨挠性卫星姿态跟踪时存在参数不确定、外部干扰以及控制输入受限等问题,提出了一种自适应L2增益控制方法.首先利用神经网络来逼近系统中的未知非线性动态特性,设计自适应控制律来处理系统中的不确定参数;其次设计了一鲁棒控制器使得干扰力矩对系统性能输出具有L2增益,从而实现对干扰的抑制控制.最后通过引入附加的输入误差系统,设计自适应L2增益控制器,使得当控制输入一旦超出幅值限制时能够立刻恢复到限制范围内,实现对输入受限问题的解决.仿真结果表明,该控制方法能够实现高精度的姿态跟踪控制,具有一定的可行性和有效性.更多还原

【Abstract】 An adaptive L-two-gain controller is proposed for the attitude tracking of flexible spacecraft with external disturbances and input constraint.Neural networks are employed for the approximation of unknown system dynamics;an adaptive controller is developed to learn the undetermined parameters.Secondly,a robust controller is designed to achieve the L-two tracking performance with a desired disturbance-attenuation level.Finally,to treat the input constraint problem,the system is augmented with an auxiliary input signal error system.An improved adaptive L-two-gain controller is adopted to rapidly recover the unconstrained input signal when it goes beyond the input constraints.Simulations are carried out to study the effectiveness of the proposed control scheme;results show the theoretical and practical advantages of this approach.更多还原