MINIMUM TIME SWING UP AND STABILIZATION OF ROTARY INVERTED PENDULUM USING PULSE STEP CONTROL

This paper proposes an approach for the minimum time swing upof a rotary inverted pendulum. Our rotary inverted pendulum is supported bya pivot arm. The pivot arm rotates in a horizontal plane by means of a servomotor. The opposite end of the arm is instrumented with a joint whose axisis along the radial direction of the motor. A pendulum is suspended at thejoint. The task is to design a controller that swings up the pendulum, keepsit upright and maintains the arm position. In the general intelligent hybridcontroller, a PD controller with a positive feedback is designed for swinging upand a fuzzy balance controller is designed for stabilization. In order to achievethe swing up in a minimal time, a controller named Minimum Time IntelligentHybrid Controller is proposed which is precisely a PD controller together witha pulse step controller for swinging up along with the fuzzy balance controllerfor stabilization. The impulsive control action is tuned by trial and errorto achieve the minimum-time swing-up. An energy based switching controlmethod is proposed to switch over from swing up mode to stabilization mode.Extensive computer simulation results demonstrate that the swing up timeof the proposed minimum-time controller is significantly less than that of theexisting general hybrid nonlinear controller.

Keywords:

Fuzzy logic control (FLC) , Rotary inverted pendulum (RIP) , Swing up control , PD control , Energy based switching control , Hybrid control and Minimum-time control