Position Control of Single Link Flexible Manipulator by Variable Structure Model Following Control

A variable structure model following controller (VSMFC) is designed for the tip position control of a single flexible link. The design is done for the system model in which only the first two flexible modes are included. Due to the simplicity in choosing second order models for the subsystems representing the dynamics of the various flexible modes, the design can be easily extended to include any desired number of flexible modes. The tip position response is made to assume a second order step response by suppressing the flexible modes very quickly. Hence the tip position response can be easily controlled by a suitable choice of the damping factor and natural frequency of the second order model which the rigid body mode of the link is made to follow. The controller is robust to parameter variations and disturbances.