Title: A Priori Identifiability of Closed Loop Subsystems for Correlated Outer Signals
Abstract: For interconnected systems consisting of closed loop subsystems the a priori identifiability of the subsystems is considered. for the general case that each closed loop configuration has four outer signals which are mutually correlated a general procedure for testing the a priori identifiability is given. for different experimental conditions which up to now have not been considered in the literature this procedure is used to determine the corresponding solutions for the unknown subsystem characteristics. The results obtained show that only some definite correlations of the outer signals and not all possible correlations have to be known for guaranteeing the a priori identifiability. This is of practical relevance for an optimum experiment design.