Attitude control system design for a clustered launch vehicle in the presence of vibration in direct sub-band space

Vibration control of clustered launch vehicles has been significantly encountered with many challenges as a result of multi degree of freedom. The control system must cover all degrees of freedom to approach desired performances. In this regards, frequency response methods play an important role in vibration control of multi body dynamic systems. In this view, vibration control is implemented via dominant frequency estimation and filtering. In several activities used full band adaptive filters, the filtering system cannot apply to complicated vehicles. Powerful properties of signal processing toolboxes lead to design practical and useful vibration control systems. In this paper, vibration reduction is implemented in subband frequency and this is one the main contributions of this study. In this way, high delay made from the subband filtering may lead to degradation of the control system. In this paper, a method is presented for reducing the delay based on the Smith predictor and model reference adaptive approaches. The results of numerical simulation show the proposed approach can satisfactory compensate the problem of delay in the online sub-band filtering. This performance is carried out for a clustered launch vehicle with convenient responses