充液航天器姿轨耦合预设性终端滑模控制

Liquid-Filled Spacecraft Attitude-Orbit Coupling Preconditioned Terminal Sliding Mode Control

主要研究充液航天器在存在参数不确定和外部扰动的情况下,姿轨耦合一体化运动与控制问题。将液体晃动等效为一阶弹簧质量模型,基于对偶四元数建立了充液航天器姿轨耦合动力学模型,按照动量与动量矩守恒定律推导充液航天器姿轨耦合动力学方程与运动学方程;考虑外界干扰和模型耦合特性,提出了一种基于指数形式的预设性能终端滑模控制策略,采用干扰观测器对综合扰动进行估计;并利用Lyapunov理论证明闭环系统的稳定性;最后,数值仿真结果表明,在设计的控制器作用下,充液航天器可以实现精确的姿轨控制,验证了控制器的有效性。

The integrated motion and control problem of attitude-orbit coupling for fluid-filled spacecraft in the presence of parameter uncertainties and external perturbations is focused in this paper.The liquid shaking is equivalent to a first-order spring-mass model,and a coupled dynamics model for the attitude-orbit of the liquid-filled spacecraft based on the dyadic quaternion is established,and the coupled dynamics equations for the attitude-orbit of the liquid-filled spacecraft and the equations of kinematics are deduced according to the laws of conservation of momentum and momentum moments.Regarding the external disturbances and model coupling characteristics,a preset performance terminal sliding mode control strategy based on an exponential form is proposed,which employs a disturbance observer to estimate the integrated disturbances and prove the stability of closed-loop systems by using Lyapunov theory.Finally,the numerical simulation results show that the fluid-filled spacecraft can realize accurate attitude-orbit control through the actions of the designed controller,which verify the effectiveness of the controller.