基於零相位誤差追蹤與虛擬微分迴授法則之前饋式強健控制器應用於翹板式懸臂致動器

Abstract

由於光碟機機構經常受到週期性干擾或擾動影響，針對此干擾問題來設計伺服控制器，本論文提出一數位控制架構ZPET-PDF以提升系統的性能與抗干擾能力，將預測干擾之ZPET-FF 控制理論應用於穩定的伺服系統，搭配PDF control架構，改善超越量(overshoot)以及干擾(disturbance)之影響。本論文提出的控制架構分為兩部分：閉迴路為虛擬微分回授法則(Pseudo-Derivative Feedback, PDF)，用以抑制確定性干擾，包括步階、正弦干擾；外迴路為前饋式零相位誤差追蹤補償控制理論(zero phase error tracking feed-forward,ZPET-FF)，對消除週期性干擾更為顯著，並且改善系統伺服響應。由於在現實中，模型誤差是不可避免的，並且影響閉迴路系統的穩定性。故利用小增益理論分析系統控制架構，提高系統強健性(robustness) ，使其滿足強健穩定性(robust stability)。藉由本研究結果驗證了ZPET-PDF控制器其響應速度與抗外加干擾的能力都較PI 控制器佳。

Because optical disk driver usually suffers the periodic disturbance or the perturbation when reading the data from disk. Therefore, this thesis presents a discrete control structure ZPET-PDF to improve the performance and disturbance rejection to stabilize the system. The proposed structure consists of two parts: the inner loop and the outer loop. First, the PDF control can be designed to reject external disturbances, including step disturbance and sine disturbance. Second, the ZPET-FF structure is capable to enhance disturbance rejection performance especially for periodic disturbance. Seeing that the stability is influenced by the model mismatch, and model mismatch will always exist in the process. In this thesis, small gain theorem was used to analyze the control structure of system, and raise the robustness of system to satisfy the robust stability. This paper shows that the response and disturbance rejection capacity of the ZPET-PDF controller is better than the PI controller by the result of the simulations.