Refined Disturbance Utilization-Based Green Control for Spacecraft With Composite Actuator Disturbances

As the actuator of spacecraft, reaction wheels inevitably exist multiple input disturbances, such as axle friction. These disturbances are coupled with system inputs and exhibit strong composite characteristic, which significantly affect the control quality of spacecraft. To overcome the negative impact of composite disturbances, this article proposes a refined disturbance utilization-based green control scheme, focusing on the disturbance separation, estimation, and utilization. First, a deep coupled model of the spacecraft based on the reaction wheel dynamic is established, effectively separating composite disturbances according to their influence topology. Second, to effectively estimate composite disturbances, refined sliding-mode disturbance observer and adaptive sliding-mode disturbance observer are, respectively, designed based on the characteristics of the separated disturbances. Subsequently, in an effort to assess the beneficial or harmful effects of composite disturbances, disturbance discrimination operators are designed by utilizing the impact of disturbances on the system convergence. Combining the dual disturbance observers and the disturbance discrimination operators, a refined disturbance utilization-based green controller is finally constructed to compensate for harmful disturbances and utilize beneficial disturbances. Simulation and experiment validate the effectiveness of the proposed scheme, which demonstrates the characteristics of high-precision and low-energy consumption.