Delay-aware decoupling of multivariable control systems with observers

In multivariable control systems internal coupling leads to undesired influences on controlled quantities. When decoupling is achieved by disturbances feedforward, compensation takes effect after a delay induced by filtering, leading to insufficient suppression of coupling influences. This paper presents a delay-aware prediction method that enhances disturbance feedforward by dynamical compensation of filtering delays using a two-step model based prediction routine. With disturbance observers for state and parameter estimation, full state measurement and time invariance are no longer prerequisites. The design procedure for the proposed method is illustrated by means of an application example.