Implementation of an LQR-based swing-up and stabilization controller for the furuta pendulum using an STM32 microcontroller

Abstract The Furuta pendulum is an interesting subject for some researchers, especially control engineers. Its nonlinear and underactuated characteristic make it challenging to stabilize it. It is used as a benchmark model for validating linear and nonlinear control strategies. Here, in this paper, we present an implementation of a real-time controller for the Furuta Pendulum using an STM32 microcontroller. The controller combines an energy-based swing-up strategy and a Linear Quadratic Regulator (LQR) for stabilization at the upright position. A full-state feedback control law is derived from a linearized state-space model of the system. The algorithm is deployed on an STM32F411RE microcontroller using encoder feedback and PWM-based motor control. Simulation and experimental results demonstrate the effectiveness and robustness of the proposed system under varying initial conditions, with the controller achieving faster stabilization (0.6–1.9 s), reduced oscillation frequency, and smaller steady-state deviation from the reference value.