Hierarchical Modal Control of a Novel Manipulator

This paper focuses on the development and implementation of an intelligent hierarchical controller for the vibration control of a deployable manipulator. The emphasis is on the use of knowledge-based tuning of the low-level controller so as to improve the performance of the system. To this end, first a fuzzy inference system (FIS) is developed. The FIS is then combined with a conventional modal controller to construct a hierarchical control system. Specifically, a knowledge-based fuzzy system is used to tune the parameters of the modal controller. The effectiveness of the hierarchical control system is investigated through numerical simulation studies. Examples are considered where the system experiences vibrations due to initial disturbance at the flexible revolute joint or due to maneuvers of a deployable manipulator. The results show that the knowledge-based hierarchical control system is quite effective in suppressing vibrations induced due to the above mentioned disturbances. Results suggest that performance of the modal controller could be significantly improved through knowledge-based tuning.