Active Vibration Control of Beam-Pointing-Sensitive Modes in Large Space Deployable Antennas

Abstract

Large space deployable antennas play a critical role in satellite microwave communications, remote sensing, and deep space exploration due to their high-precision, light weight, and reliability. However, their large size and extremely low stiffness and damping make them susceptible to vibrations, which degrade the stability of antenna beam pointing under continuous external excitation. To mitigate the effects of such vibrations on beam pointing stability, this paper proposes an active hybrid control method targeting beam-pointing-sensitive vibration modes which significantly degrade beam pointing accuracy. First, the dynamic model of the antenna is established, and finite element computing is used to solve the mode shapes and identify the sensitive modes. A model-independent hybrid control method, based on independent modal space control approach, is then designed to control the specific modes, with initial effectiveness verified through numerical simulations. To further validate the practical feasibility of the proposed control method, active vibration control experiments are conducted on a 10 m aperture antenna prototype for a specific beam pointing sensitive mode (approximately 4.6 Hz). Experimental results indicate that steady state vibration is achieved within 1.1 s after initiating active control, with root-mean-square acceleration suppression exceeding 77% at monitoring points. These results demonstrate that the active control method effectively suppresses vibrations in beam-pointing-sensitive modes.