Title :
High-Speed Digital Realizations of Fractional Operators in the Delta Domain
Author_Institution :
Dept. of Environ. Eng. & Sustainable Dev., Tech. Univ. of Bari, Taranto, Italy
fDate :
3/1/2011 12:00:00 AM
Abstract :
The realization of fractional-order controllers is based on the approximation of the irrational operators by continuous or discrete transfer functions. However, at high sampling frequencies, discrete z-transfer functions approximations can be very sensitive even to small changes in coefficient values. This technical note proposes a realization of sν , in terms of transfer functions in the complex delta-domain, which improves considerably the robustness of the approximation to parameter changes and then to truncation in transfer function coefficients applied for implementation with finite word length.
Keywords :
approximation theory; discrete systems; robust control; roundoff errors; transfer functions; complex delta domain; continuous transfer function; discrete transfer function approximation; finite word length; fractional order controller; high-speed digital realization; irrational operator; sampling frequency; $delta$ operator; Delta-domain; differential operator; discretization; fractional calculus; fractional-order control (FOC);
Journal_Title :
Automatic Control, IEEE Transactions on
DOI :
10.1109/TAC.2010.2101134