For model-based control design, closed-loop identification gives better performance

• We compare open loop versus closed loop identification when the identified model is used for control design, and when the system itself belongs to the model class, so that only variance errors are relevant. Our measure of controller performance (which is used as our design criterion for identification) is the variance of the error between the output of the ideal closed loop system (with the ideal controller) and that of the actual closed loop system (with the controller computed from the identified model). Under those conditions, we show that, when the controller is a smooth function of the input-output dynamics and the disturbance spectrum, the best controller performance is achieved by performing the identification in closed loop with an operating controller that we characterize. For minimum variance and model reference control design cirteria, we show that this 'optimal operating controller for identification' is the ideal controller. This then leads to a suboptimal but feasible iterative scheme. Copyright © 1996 Elsevier Science Ltd.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Reglerteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Control Engineering (hsv//eng)

Keyword

Closed-loop identification

Experiment design

Identification for control

Closed loop control systems

Control system synthesis

Dynamics

Errors

Mathematical models

Optimal control systems

Performance

Closed loop identification

Model based control design

Identification (control systems)

SRA - ICT

SRA - Informations- och kommunikationsteknik

Publication and Content Type

ref (subject category)

art (subject category)