Linear inverted pendulum control based on improved ADRC

Abstract

An improved active disturbance rejection control (ADRC) strategy is proposed for the control precision improvement of the trolley position and the pendulum angle of the linear inverted pendulum. First, a new nonlinear function with improved continuity and conductivity around the zero point is designed. On the basis of this new function, the control rates of the extended state observer (ESO) and the nonlinear state error feedback (NSEF) of the traditional ADRC controller are improved. Second, with the improved ESO, the various disturbances of the trolley position and the swing angle of the first-order linear inverted pendulum are expanded into two states. These two states are then observed in real time and linearly compensated. Third, with the improved control rate of the NSEF, the nonlinear integration method is adopted to nonlinearly combine the differential and the error differentials and subsequently provide high quality control to the system. Finally, simulation and experimental verification of the linear inverted pendulum control system based on the improved ADRC are conducted. Results show that the proposed control strategy has higher control precision and robustness than the double-closed-loop PID.

Keywords

• Improved active disturbance rejection control strategy
• first-order linear inverted pendulum
• improved extended state observer
• improved nonlinear state error feedback