NONLINEAR STABILITY CONTROL OF INVERTED PENDULUM ON A CART USING LQR-BASED T-S FUZZY CONTROL

Abstract

The inverted pendulum on a cart is a challenging and widely studied control problem in the fields of control systems and robotics. To address the need for more effective control strategies, this article presents a novel approach that combines the strengths of two powerful control techniques: Linear-Quadratic Regulator (LQR) and Takagi-Sugeno (T-S) fuzzy control. LQR control is well-established for stabilizing linear systems, but it faces limitations with nonlinear systems like the inverted pendulum. On the other hand, T-S fuzzy control excels in handling nonlinearities by approximating the system's behavior with local linear models. Our proposed approach leverages T-S fuzzy systems to approximate complex nonlinearities, while using LQR control for each local linear subsystem. The combined method's efficacy is substantiated by simulation results, specifically considering criteria such as stability under disturbance conditions, variations in the initial angle of the pendulum, and a comparative analysis between stability-only scenarios and those involving both swing-up and stability control.