Multi DoF system modelling-Transfer Function and State variable approaches

Multiple degrees of freedom (Multi DoF) system modeling from analytical equations is the preliminary and essential step for mechanical and mechatronics system analysis and design. In general two major approaches are followed - Transfer function and state variable methods. In this paper, a Multi DoF system (4 mass-spring-damper cantilever beam structure) model is formulated using both approaches. The paper serves as an analysis of the step by step procedure for both approaches and a short discussion on fundamental model characteristics. Matlab ® code is utilized to analyze the models. The developed models are discussed from aspects of stability, noise control and disturbance rejection.