Abstract: A decoupling control method based on fast Fourier transform(FFT) filter is presented for deployment control of flexible deployable antennas. The deformable bodies are discretized with hypothesis displacement field structured by Rayleigh-ritz method, and combined with Lagrange method, the flexible multi-body dynamic function of the antenna is established. Considering with dynamic analysis and FFT spectrum analysis of deployment trajectory, a low-pass filter is used to decouple the movement feedback to two separated parts: rigid movement and the vibration caused by flexible factors. Based on instantaneous structure analysis of mechanism, the affiliation of eigen-frequency between mechanism and structure is discussed, thus the cut-off frequency of low-pass filter is determined. Aiming at the characteristics of the two feedbacks, the rigid and flexible controllers are designed. The rigid controller ensures the antenna to deploy as the specified trajectory and the flexible controller restrains the flexible vibration. The coupled relationship of the controller gain parameters between two controllers is discussed and a guide line for parameter selection is proposed based on energy relativity analysis. Numerical simulation of examples is given to demonstrate the feasibility and rationality of the method.

Key words: Control, Deployable antenna, Deployment