Fuzzy (PI+D)/sup 2/ control for flexible robot arms

This paper continues the investigation of a "shoulder-elbow-like" single flexible robot arm model with damping, previously discussed by the authors (1996), to develop a new design of a fuzzy (PI+D)/sup 2/ control scheme for both vibration suppression and set-point tracking. Computer simulation results are included to show that the fuzzy-logic-based controllers perform very well for this flexible-link model described by a couple of higher-order partial differential equations with initial-terminal and boundary value conditions. Graphical stability analysis of the controlled system is also given in this paper, which has very good agreement with theoretical analysis results.