Numerical Simulation of a Small Size Rotor With Selfinduced Instability Using Sliding Mode and Fopid Controller and Their Comparison

Abstract

Dynamic systems like gyro-pendulums and tippe-tops behave in a peculiar unstable manner due to material or internal damping. Dynamic systems beyond certain critical threshold spinning speed may become unstable due to rotating dampers. There have been several efforts in the past to stabilize such systems but most of the earlier efforts to stabilize such rotors had difficulty in stabilizing extremely small size, mini or micro rotors although one may find some efforts to stabilize medium to large size rotors using some heavy actuators like squeeze film dampers etc. The underlying problems with the small size rotors is that if the selection of the actuators is not proper than the actuator size may be heavier than the rotor itself therefore the choice of actuators remains always a challenge in a rotor with micro or mini size. Since in the present work the control, sensing and actuation all are embedded within a single embedded coupling due to obvious practical reasons as discussed in the paper the challenge is to see the entire dynamics from a moving frame or rotating coordinate system. Design and practical implementation of these smart structures always remains a big challenge.