Earticle

Structural controllability is an important concept of linear systems, and problems relating to this concept have recently become the subject of a great deal of research. In this paper, two different structures of control are proposed that are based on the servo control system. An analysis is conducted on the structural controllability of two control systems, the differences of which relate to the structural controllability criterion in the frequency domain over F(z). Due to the fact that the system is not structurally controllable, the first servo control system is not completely manageable no matter what values the parameters take; therefore, the reasons for this are investigated. Conversely, the second system becomes structurally controllable by changing the structure of the control system. Thus, it is made fully stable by the feedback compensation even if it has an unstable mode. Accordingly, this research on the structural controllability of a system not only provides a deeper understanding of the system’s nature, but is also important for explaining why a system is not structurally controllable and how changing its structure can resolve this.