Swing-up Control of a Double Inverted Pendulum by Combination of Q-Learning and PID Algorithms

The double inverted pendulum is a nonlinear system with unstable balance and rapid response. When two pendulums are allocated vertically, and there is no movement, the system is stable. In this article, we propose a control mechanism based on reinforcement learning. The system can improve its performance and balance by implementing the Q-Learning techniques besides the PID control scheme. The Q-Learning algorithm balances the pendulum to its inverted vertical position in the first step. In the second step, the Q-Learning algorithms are combined with classical PID to balance the double inverted pendulum and perform swing-up control. Eventually, simulation findings showed the efficiency of the proposed controller.