Vibration control study of large deployable reflector antenna based on Stewart platform

The loop deployable antenna in Tandem-L is a large, flexible, low damping, low modal frequency space structure, which has a large vibration response after being disturbed by the outside world in space. When using intelligent piezoelectric actuators to control the vibration, there are adverse effects such as insufficient driving force and difficulty of antenna deployment after actuator installation, etc. This paper proposes a method to control the vibration of reflective antenna by installing Stewart platform at the root of antenna. Meanwhile, considering the modelling uncertainty of Stewart platform dynamics and reflective antenna dynamics, a composite dynamics model with Stewart platform tracking error and reflective antenna modal displacement as state quantities is established. The control law of the composite dynamics model is designed by using LQR control method to obtain the desired attitude of the Stewart platform, and then the sliding mode controller of the Stewart platform motion is designed to track the desired attitude and realize the vibration control of the antenna. The composite control simulation study is carried out for a large deployable reflector antenna. The results show that the adopted composite control method of antenna vibration based on Stewart platform can effectively suppress the flexural vibration of the deployable reflector antenna.