Analysis of the Friction Impact on the Performance of the Linear Quadratic Regulator Controller Applied to the Multibody Model of the Furuta Pendulum

This paper investigates the influence of dry friction on a linear control system applied to the Furuta pendulum. First, the various types of dry friction laws applicable in a multibody model are presented and categorized into two main groups, that is, static models and dynamic models. By following a detailed description of the dynamic system considered in this study, as well as a general overview of the linear-quadratic control method, the paper examines first the behavior of the multibody system at hand in the absence of friction. Subsequently, through initial theoretical exploration, the paper analyzes and discusses the response of the multibody system in the presence of several types of friction. All simulations are conducted in the MATLAB-SIMULINK environment utilizing the SIMSCAPE MULTIBODY toolbox. The obtained results contribute to a deeper understanding of how dry friction influences the control system of the Furuta pendulum in particular and underactuated nonlinear multibody systems in general.