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In this chapter, two multi-rate iterative learning control (ILC) schemes, pseudo-downsampled ILC and two-mode ILC are proposed for good learning performance. In pseudo-downsampled ILC, error and input signals are downsampled before they are used in ILC learning law. The output of ILC is then upsampled to the original rate for the next cycle. In two-mode ILC, different learning mechanisms are used on low and high frequency bands, respectively. On low frequency band, a conventional ILC with the original sampling rate is used. While on the high frequency band, a pseudo-downsampled ILC is used. Experimental results are presented to demonstrate the effectiveness of the proposed multi-rate ILC schemes.
KeywordsDown-sampling Convergence Robustness Anti-imaging Anti-aliasing
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