Analyzing structural properties of composite system in frequency domain over F(z) with computer

The signal flow diagram is inputted into the computer and then transfer function matrix is derived by the Mason rule. Two scenarios are taken to analyze the structural properties of the composite systems. One is to get the state and output equations by the subsystems´ transfer function matrices and their connections and then to estimate the structural controllability (observability) according to the rank of the controllable (observable) matrix. The other way is to analyze the co-primeness of the denominators or nominators of the subsystems´ transfer function matrices. The input and topology analysis of the signal flow diagram are realized in Visual C++ 6.0 and the calculation of the transfer function matrices and analysis of structural properties are performed with Matlab symbolic computing.