Robust control stability using the error loop
by Enrico Canuto; Wilber Acuña-Bravo; Carlos Perez Montenegro
International Journal of Mechatronics and Automation (IJMA), Vol. 3, No. 2, 2013

Abstract: This paper formulates the error loop as a tool for designing robust stability control systems in the presence of structured and unstructured uncertainties. The error loop indicates that uncertainties can be accommodated through the design of the noise estimator, which is the unique feedback channel from plant to control. The real-time model that is embedded in the control unit and the noise estimator constitute a state predictor. The embedded model consists of a controllable dynamics plus a disturbance dynamics fed by the noise estimator. It is shown that causality constraint prevents perfect cancellation of causal uncertainties (unknown disturbance), but makes the control law which is fed by the state predictor to play a role, thus offering a further degree of freedom. Employing asymptotic expansions of the closed-loop transfer functions, simple, explicit design formulae derive from stability inequalities. They relate closed-loop eigenvalues to model parameters and requirements, and define an admissible frequency band for the state predictor bandwidth. This paper restricts formulation to the univariate case. A simple example is provided with simulated and experimental data.

Online publication date: Wed, 30-Apr-2014

The full text of this article is only available to individual subscribers or to users at subscribing institutions.

 
Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.

Pay per view:
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.

Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Mechatronics and Automation (IJMA):
Login with your Inderscience username and password:

Username:        Password:          Forgotten your password?

Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.

If you still need assistance, please email subs@inderscience.com