State-space modeling, system identification and control of a 4th order rotational mechanical system

Abstract

In this thesis, a 4th order rotational mechanical plant provided by Educational Control Products is modeled from first principles and represented in state-space form. Identification of the state-space parameters was accomplished using the parameter estimation function in Matlab's System Identification Toolbox utilizing experimental input/output data. The identified model was then constructed in Simulink and the accuracy of the identified model parameters was studied. The open loop stability of the plant, as well as its controllability and observability were analyzed to determine the applicability of a pole placement control strategy. Based on the results of this analysis, a full state variable feedback controller was investigated to place the system's poles such that a rotational disk would perfectly track a step angle input with less than five percent overshoot and have less than a one second settling time, with no steady-state error. A refinement of this controller, to include an observer to estimate the system states, was also investigated. Finally, the results of this work are summarized and presented as a series of laboratories applicable to a course in state-space design.