Marimuthu Minimum Time Swing up and Stabilization of Rotary Inverted Pendulum Using Pulse Step Control

This paper proposes an approach, for the minimum time swing up of a rotary inverted pendulum. Our rotary inverted pendulum is supported by a pivot arm. The pivot arm rotates in a horizontal plane by a servo motor. The opposite end of arm is instrumented with a joint whose axis is along the radial direction of the motor. A pendulum is suspended at the joint. The task is to design a controller that swings up the pendulum and maintains it upright and maintains the arm position. In the general intelligent hybrid controller, a PD controller with a positive feedback is designed for swinging up and a fuzzy balance controller is designed for stabilization. In order to achieve the swing up in a minimal time, a controller named Minimum Time Intelligent Hybrid Controller is proposed in this paper which is nothing but a PD controller plus a pulse step controller for swinging up along with the fuzzy balance controller for stabilization. By trial and error, tuning of the impulsive control action is done to achieve the minimum-time swing-up. To switch over from swing up mode to stabilization mode energy based switching control method is proposed. Compared to the existing general hybrid nonlinear controller, the swing up time is significantly reduced in the proposed minimum-time controller as demonstrated by extensive computer simulation results.