Model-based friction compensation scheme for the linear inverted pendulum

Generally, studies on inverted pendulum system only considered the viscous friction, the system with controllers designed based on this model was stable in simulations. However, when the controller was implemented in experimental system, small oscillation resulted. This paper give strong evidence that stickslip friction between the cart and the track is the source of the small amplitude oscillations. To offset the impact of friction and eliminates this oscillation, Gauss and LuGre friction model were employed, respectively, and the friction parameters are measured experimentally. The feedback controller is employed to stable the inverted pendulum in the upright position. Finally, simulation results are given to prove the validity of the proposed friction compensation strategy.