Two-Step Controller for 3-D Flexible Link Manipulators: Bandwidth Modulation and Modal Feedback Approach

Abstract

For joint tracking control of flexible robots, this paper presents a two-step design of controller: the bandwidth modulation with modal feedback approach. First, we focus on the design of rigid part’s motion controller considering the bandwidth of the rigid subsystem. We investigate the relationship between macro joint tracking performance and vibration suppression capability using the bandwidth parameter. After adjusting the bandwidth of rigid motion, the composite control, which is the second step consisting of rigid and flexible sub-controllers, is applied like singular perturbation approach. As the flexible sub-controller, we propose a direct modal feedback controller that is very simple, but effective to suppress the vibration. The validity and effectiveness of the proposed method are verified by experiments using a POSTECH 3-D flexible robot.