Affiliations: [a] State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, China | [b] School of Aerospace Engineering, Xi’an Jiaotong University, Xi’an, China | [c] Shanghai Institute of Spaceflight Control Technology, Shanghai, China
Correspondence:
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Corresponding author: Shilin Xie, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China. E-mail: [email protected]
Abstract: The loop antenna is a kind of large and flexible space truss structure commonly with weak damping and low modal frequencies. It is recognized the active vibration control performance of loop antenna structure is limited with use of piezoelectric stack actuator due to small actuating displacement. Besides, the introduction of piezoelectric stack actuator may obstruct the unfolding of antenna. A new active control way is thus put forward in the work where the voice coil motor is used as actuator and connected to the antenna structure by Kevlar fiber. This kind of actuation mode has the advantages of large output displacement, fast response, large output power and convenient installation. The governing equation of vibration control system of loop antenna employing the voice coil motor - Kevlar fiber actuator is firstly established according to finite element theory. In practical engineering, the first modal frequency of antenna is such low that it might be very close to the operational frequency of attitude adjusting equipment. As a result, the first modal vibration of antenna is easy to be stimulated and thus is often of most concerned in vibration control of antenna structure. Accordingly, aiming to suppress effectively the first modal vibration of loop antenna, the active vibration control strategies with PD and Fuzzy control algorithm are studied respectively. Moreover, PD-Fuzzy composite controller is also designed to improve the control effects near equilibrium position. The numerical and experimental results show that the voice coil motor - Kevlar fiber actuator can suppress the first modal vibration response of the antenna significantly and the performance of Fuzzy control is better than that of PD control. The control performance near equilibrium position can be improved obviously by use of PD-Fuzzy composite control algorithm.
Keywords: Loop antenna, vibration control, voice coil motor, Fuzzy control
