光學顯微鏡中的自動對焦技術已廣泛應用於精密量測、生醫檢測及工業檢測等領域。 然而，傳統自動對焦方法多採用停止－掃描策略，導致對焦過程需耗費較長的移動與等 待時間。另一方面，連續掃描雖可提升掃描效率，但在掃描方向切換時容易激發壓電平 台之高頻振動，進而影響影像品質與對焦精度。為改善上述問題，本論文提出一種應用 於光學顯微鏡自動對焦系統之最佳化方法，包含軌跡規劃與精密控制兩個部分。在軌跡 規劃方面，提出時間優化的最小化抖動軌跡設計。所提出之軌跡可根據不同掃描需求， 在移動時間與抖動限制之間進行調整，使粗搜尋階段優先縮短移動時間，而細搜尋階段 則優先降低振動，以提升對焦效率與穩定性。 在控制器設計方面，由於壓電平台具有遲滯與潛變等非線性特性，容易降低軌跡追 蹤性能，因此本論文建立一套複合式控制架構，結合 Prandtl-Ishlinskii逆模型與改 良式快速趨近律滑模控制器，以提升軌跡追蹤精度並抑制追蹤過程中的振動現象。最後， 透過模擬與實驗驗證所提出自動對焦策略與控制方法之有效性，並與傳統方法進行比較。;Autofocus techniques in optical microscopy have been widely applied in precision measurement， biomedical inspection， and industrial inspection. However， conventional autofocus methods generally adopt a stop-and-scan strategy， which requires considerable movement and waiting time during the focusing process. Continuous scanning can improve scanning efficiency， but it may excite high-frequency vibrations of the piezoelectric stage during direction reversals， thereby degrading image quality and focusing accuracy. To address these issues， this thesis proposes an optimization framework for optical microscope autofocus systems， consisting of trajectory planning and precision control. In the trajectory planning part， a time-optimized minimum-jerk trajectory is developed. The proposed trajectory can be adjusted according to different scanning requirements， allowing the coarse search stage to prioritize movement speed while the fine search stage focuses on vibration reduction， thereby improving autofocus efficiency and stability. In the controller design， the nonlinear characteristics of piezoelectric stages， including hysteresis and creep， can significantly degrade tracking performance. Therefore， a compound control framework integrating a Prandtl-Ishlinskii (PI) inverse model and a Modified Fast Reaching Law Sliding Mode Controller (MFRLSMC) is proposed to enhance tracking accuracy and suppress vibration during the tracking process. Finally， simulations and experiments are conducted to validate the effectiveness of the proposed autofocus strategy and control method.
