Optimal Placements of Actuators and Robust ADP-Based Vibration Control for Large Flexible Space Structures

Purpose: A control scheme is presented to attenuate the vibration of the large flexible space structures (LFSS), which includes the optimization of actuator positions and the design of the robust vibration control algorithm. In contrast to the existing literature, the optimization criterion does not depend on the controller parameters, and robust adaptive dynamic programming (RADP) can effectively suppress the vibration of the LFSS under mixed continuous disturbance and model uncertainties. Method: First, the optimization criteria of optimal placements of the actuator, which can maximize the actuating efficiency, decoupling input voltage and modal contribution factor, are proposed. On this basis, the adaptive parameter differential evolution (APDE) algorithm is employed to speed up the optimization process. Subsequently, the RADP is designed to enhance the control effect and robustness of the system under external disturbances and model uncertainties. Finally, the RADP-based vibration control performance under optimal and random placement layouts is compared. Results and Conclusion: The effectiveness of the proposed optimization criterion, APDE method and RADP-based vibration control algorithm is verified by simulation. The proposed optimization criteria save the actuator energy consumption and enhance the adaptability of the optimization. The optimal actuator positions can be swiftly identified by the APDE algorithm. In addition, the RADP-based vibration control algorithm improves the control effect, reduces decay time and enhances the robustness of the LFSS under mixed continuous excitation and model uncertainties.