請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/10133
標題: | 應用於虛擬實境之六自由度並聯式液壓平台之姿態
控制與沖淡濾波器設計 Posture Control of a 6-DOF Parallel Hydraulic Manipulator and Washout Filter Design for Virtual Reality Application |
作者: | Sung-Hua Chen 陳聖化 |
指導教授: | 傅立成(Li-Chen Fu) |
關鍵字: | 非線性控制,史都華平台,前向運動學,遞回步階控制,液壓驅動器,動感法則,感知誤差, Nonlinear Observer,Stewart Platform,Forward Kinematics,Backstepping Control,Hydraulic Actuator,Motion Cueing Algorithm,Sensation Error, |
出版年 : | 2011 |
學位: | 博士 |
摘要: | 駕駛模擬機是一個整合系統,其組成包含運動平台系統、電腦圖學,三維物理模擬及動感演算法。本篇論文對應用於駕駛模擬機之液壓驅動史都華平台的非線性控制問題進行探討,並且也討論動感法則之設計問題。
在本篇論文的第一部份,對於一般的6-6史都華平台,我們提出了一個以觀測器為基礎的前向運動學解法,並且將此解法應用於設計一個輸出回授的滑動模式控制。傳統的前向運動學解法若非計算負荷太重就是太複雜,因而無法使用於線上控制的架構中。將本論文所提出的解法應用於輸出回授控制架構上,不須加裝額外的感測器便可以達成運動平台的六自由度姿態控制。傳統所使用的控制方法乃是控制每一個驅動器長度,相對的,我們提出的輸出回授控制器是直接在卡式座標系上控制平台姿態。我們亦提出此設計的穩定性證明以確保控制誤差的收斂。 接著,我們提出了一個遞回步階控制策略,並結合了前述之觀測器為基礎的前向運動學解法,以控制此六自由度之並聯式液壓平台。與傳統控制方法不同的是,我們所提出的控制不只考慮平台動態,並且包含液壓驅動器的動態。此控制器的計設目的在於移動平台追尋給定的姿態軌跡。我們對此控制亦驗證其穩定性以確保誤差收斂。對前述之輸出回授控制與此遞回步階控制,我們皆呈現了數值模擬和實驗結果以驗證設計的效能。 駕駛模擬機的擬真運動乃是由動感法則所產生的。本論文中應用了最佳沖淡濾波器設計將人體感知誤差最小化以提供擬真的運動行為,此設計並考慮了模擬機的運動空間限制。此濾波法則基於人體內耳庭系統,比較了模擬機駕駛者與真實載具駕駛者的感受。成本函數包含駕駛者的感受誤差及平台的運動,將其最小化以達成最佳設計。為補償最佳沖淡濾波器固定參數的缺點,我們應用了運動感知的模糊控制法則在線上調整過濾之信號。模擬結果驗證了平台工作空間的使用效率以及相對於傳統沖淡濾波器小的感知誤差。 The vehicle simulator is an integrated system which is a synthesis of motion platform system, computer graphs, 3-dimensional physics, and a motion cueing algorithm. This dissertation investigates the nonlinear control issues of a hydraulic actuated Stewart platform used as the motion platform in the vehicle simulator system, and the motion cueing algorithm. In first part of this dissertation, an observer-based forward kinematics solution of a 6-6 Stewart platform is proposed and this algorithm is applied to implement an output feedback sliding mode control. The conventional forward kinematics solutions take too much computational load or are too complex to be carried out in the on-line control scheme. With the proposed solution, 6-DOF posture control of the moving platform can be achieved without installation of any external sensor after applying an output feedback control. In contrast with the conventional control scheme which aims to control individual leg length in actuator domain, the output feedback controller is proposed here to control the posture in Cartesian coordinates directly. The stability is proved to ensure convergence of the tracking errors. After that, a backstepping control strategy is proposed to control the 6-DOF parallel hydraulic manipulator while incorporating the observed-based forward kinematics solver. Different from conventional control methods, the proposed control considers not only the platform dynamics but also the dynamics of the hydraulic actuators. The objective of controller design is to drive the moving platform such that its posture tracks a given trajectory. The stability of the whole system is thoroughly proved to ensure convergence of the tracking errors. Simulations and experimental results of the output feedback control in first part and the backstepping control are presented to validate the effectiveness of the design. The realistic motion of the vehicle simulator is produced by the motion cueing algorithm. An optimal washout filter, taking into account the limitation of the simulator’s workspace, is applied here to minimize human’s perception error in order to provide realistic behavior. The filtering algorithm compares the human’s perception of driving simulator with that driving actual vehicle obtained based on the human vestibular model. The cost function accounting for both the pilot’s sensation error and the range of platform motion is minimized. To compensate the drawback of fixed parameters in optimal washout filter, the fuzzy control rules of motion perception are applied to online adjust the filtered signals. The simulation results verify the efficient utilization of the platform workspace and less sensation error in comparison with that obtained by the classical washout filter. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/10133 |
全文授權: | 同意授權(全球公開) |
顯示於系所單位: | 電機工程學系 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
ntu-100-1.pdf | 16.88 MB | Adobe PDF | 檢視/開啟 |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。