A Robust Output-Feedback Control for the Cart-Pole System: A Super-Twisting Sliding-Mode approach

This paper presents an output-feedback controller for a cart-pole system via sliding-mode algorithms. Due to the fact that this system is underactuated, a coupled sliding surface is employed instead of using a transformation to the regular form. Then, a continuous sliding-mode controller is designed using the super-twisting algorithm so that robustness of the control scheme is guaranteed. Since the proposed controller requires the knowledge of the velocities, a high order sliding-mode observer is introduced to estimate such velocities. All the results are validated by means of simulations, providing also a comparison between the proposed controller, a first-order sliding-mode controller and a chattering attenuation approach.