Nonlinear PID Control of Linear Plants for Improved Disturbance Rejection
| Authors: | Zheng Jinchuan, Data Storage Institute, Singapore
Guo Guoxiao, Data Storage Institute, Singapore
Wang Youyi, Nanyang Technological University, Singapore |
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| Topic: | 4.2 Mechatronic Systems |
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| Session: | Mechatronic Applications |
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| Keywords: | Disturbance rejection, hard disk drive, Lyapunov stability, nonlinear PID control, tracking servo. |
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Abstract
A nonlinear PID (NPID) controller for a class of linear plants with output feedback is studied. The controller gains are modulated by the control error and error rate to yield a closed-loop system for improved disturbance rejection. An optimization problem involving constraints written as linear matrix inequalities (LMIs) is solved to compute the controller parameters. A hard disk drive (HDD) control application shows that the NPID outperforms the conventional PID by 9% in disturbance rejection along with a consequent reduction by 20% in settling time while the stability robustness is maintained.
