Variable-order fractional operators for adaptive order and parameter estimation

Abstract

Adaptive parameter estimation schemes for linear fractional-order processes of commensurate type are illustrated in the present note. A gradient-based scheme for commensurate order estimation is outlined first, and a combined gradient/least-squares scheme for simultaneously estimating the commensurate order and the remaining process parameters is finally considered. A key feature of the proposed schemes is the utilization of appropriate variable-order fractional filters. Theoretical results are validated by means of thoroughly discussed simulation examples. © 2013 IEEE.