Title :
A modified method for closed-loop identification of transfer function models
Author_Institution :
Sch. of Quantitative Methods & Math. Sci., Univ. of Western Sydney, Penrith South DC, NSW, Australia
fDate :
4/1/2002 12:00:00 AM
Abstract :
Substantial revisions on the newly proposed bias correction based method are made in the framework of indirect identification of a linear (possibly unstable) plant operating in closed loop with a low-order stabilizing controller. By making a new formulation of a least-squares estimate of an intermediate parameter vector purposely introduced, the modified algorithm is able to achieve a direct yet unbiased closed-loop system estimate in the presence of misspecified noise model. With no identification of a high-order augmented closed-loop system, the computational complexity of the algorithm is significantly reduced. Simulations of identifying an open-loop unstable plant illustrate the promising performance of the modified algorithm in low signal-to-noise ratio environments
Keywords :
closed loop systems; control system synthesis; feedback; identification; least squares approximations; parameter estimation; transfer functions; bias correction based method; closed-loop identification; closed-loop system estimation; computational complexity reduction; control systems design; indirect identification; intermediate parameter vector; least-squares estimate; linear plant; low SNR environments; low signal-to-noise ratio environments; low-order stabilizing controller; misspecified noise model; modified algorithm; parameter estimation; transfer function models; unstable plant; Australia; Computational complexity; Computational modeling; Control systems; Instruments; Open loop systems; Parameter estimation; Transfer functions; Vectors; Working environment noise;
Journal_Title :
Circuits and Systems I: Fundamental Theory and Applications, IEEE Transactions on
