Adaptive rejection of periodic disturbances acting on linear systems with unknown dynamics

• Published in: 2016 IEEE 55th Conference on Decision and Control (CDC) pp. 1243 - 1248
• Main Authors: Shahsavari, Behrooz, Jinwen Pan, Horowitz, Roberto
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.12.2016
• Subjects: Adaptive control; Feedforward neural networks; Heuristic algorithms; Linear systems; Signal processing algorithms; Trajectory
• DOI: 10.1109/CDC.2016.7798436

This paper proposes a novel direct adaptive control method for rejecting unknown deterministic disturbances and tracking unknown trajectories in systems with uncertain dynamics when the disturbances or trajectories are the summation of multiple sinusoids with known frequencies, such as periodic profiles or disturbances. The proposed algorithm does not require a model of the plant dynamics and does not use batches of measurements in the adaptation process. Moreover, it is applicable to both minimum and non-minimum phase plants. The algorithm is a "direct" adaptive method, in the sense that the identification of system parameters and the control design are performed simultaneously. In order to verify the effectiveness of the proposed method, an add-on controller is designed and implemented in the servo system of a hard disk drive to track unknown nano-scale periodic trajectories.