Gradient approximations in iterative feedback tuning for multivariable processes

• Iterative feedback tuning (IFT) is a model free control tuning method using closed-loop experiments. For single-input single-output (SISO) systems only 2 or 3, depending on the controller structure, closed-loop experiments are required. However for multivariable systems the number of experiments increases to be proportional to the dimension of the controller. In this contribution several methods are proposed to reduce the experimental time by approximating the gradient of the cost function. One of these methods uses the same technique of shifting operators as is used in IFT for SISO systems. This method is further analysed and sufficient conditions for local convergence are derived. It is shown that even if there are commutation errors due to the approximation method, the numerical optimization may still converge to the true optimum.

Ämnesord

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

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

Nyckelord

adaptive control

controller tuning

multivariable systems

optimization

SRA - ICT

SRA - Informations- och kommunikationsteknik

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)