Vibration and input tracking control of flexible manipulator using hybrid fuzzy logic controller

This paper presents investigations into the development of hybrid fuzzy logic control schemes for end-point vibration suppression and input tracking of a flexible manipulator. A constrained planar single-link flexible manipulator is considered and the dynamic model of the system is derived using the assumed mode method. To study the effectiveness of the controllers, initially a proportional-derivative (PD)-type fuzzy logic controller (FLC) is developed for control of rigid body motion. This is then extended to incorporate a non-collocated PID controller for control of vibration (flexible motion) of the system. Simulation results of the response of the manipulator with the controllers are presented in time and frequency domains. The performances of the control schemes are assessed in terms of level of vibration reduction, input tracking capability and time response specifications. Finally, a comparative assessment of the control techniques is presented and discussed.