考虑输出约束及外部干扰的柔性航天器振动控制

Vibration control of flexible spacecraft with output constraints and external disturbances

针对具有输出约束及外部干扰的柔性航天器系统,提出一种直接关节力矩输入的振动控制方法。利用哈密顿原理,系统动力学特性由偏微分方程(PDE)和常微分方程(ODE)耦合组成的分布参数模型来描述。设计了非线性干扰观测器补偿外界干扰,并基于正切型障碍李雅普诺夫函数解决了航天器姿态角度误差和振动误差的多输出约束问题。利用扩展的拉塞尔不变集原理和半群理论证明了系统的渐近稳定性。不仅实现了姿态角的位置控制,还抑制了柔性航天器的弹性振动。通过对比仿真验证了所提方法的有效性。

A vibration control with direct joint torque input is presented for flexible spacecraft systems subject to external disturbances and output limits.Firstly,the dynamic characteristics of the system are described by a distributed parameter model which is composed of partial differential equation(PDE)and ordinary differential equation(ODE).Secondly,the tangential barrier Lyapunov function is used to ensure that the output constraints of vibration errors and attitude angle errors are met by a nonlinear disturbance observer that is intended to adjust for external disturbances.The asymptotic stability of the system is proved by extended LaSalle’s invariance principle and semigroup theory.It not only realizes the position control of attitude angle,but also restrains the elastic vibration of flexible spacecraft.Finally,the effectiveness of the proposed control method is verified by comparison simulations.