Model Matching and Passivation of MIMO Linear Systems via Dynamic Output Feedback and Feedforward

Abstract

A model matching and passivating control architecture for MIMO linear systems, comprising dynamic feedback and feedforward, is proposed. The approachessentially without any restriction on the relative degree and the zeroes of the underlying system and by relying only on input/output measurements-provides a closed-loop system the transfer matrix of which matches any desired matrix of rational functions. An alternative implementation of the above design allows to achieve an arbitrary approximation accuracy of a desired transfer matrix while also preserving structural properties-in particular observability-of the overall interconnected system. Such a construction can be then specialized to provide input/output decoupling or a system that is passive from a novel control input to a modified output. The result is achieved by arbitrarily assigning the relative degree and the location of poles and zeros on the complex plane of the interconnected system in a systematic way. It is also shown that similar ideas can be employed to enforce a desired, arbitrarily small, L 2-gain from an unknown disturbance input to a modified output, while preserving the corresponding gain from the control input to the same output. The paper is concluded with applications and further discussions on the results.

On the Stability of Volts-per-Hertz Control for Induction Motors

“…The complete passivity of G(s) in every operating point is not guaranteed since the rotorflux deviation also affects the passivity. Nonetheless, complete passivation does not seem possible by means of simple V/Hz control due to the underlying non-minimum phase system [24]. Fig.…”