虛擬實境應用下運動平台之滑模控制與以人類感知系統為基礎之沖淡濾波器設計

Sliding Mode Control of Motion Platform and Human-Perception-Systems Based Washout Filter Design for Virtual Reality Simulation.

黃勤鎰(Chin-I Huang)

指導教授 ： 傅立成

國立臺灣大學/電機資訊學院/電機工程學研究所/博士(2007年)

https://doi.org/10.6342/NTU.2007.01705

摘要

虛擬實境模擬機是由四個主要次系統所組成的龐大整合系統，分別是運載器(如車輛、飛機或船等)的動態系統、電腦圖學系統、運動平台系統及沖淡濾波器系統。而在本論文的研究上，主要是針對運動平台提出一高性能的控制方法以使藉由人類感知系統為基礎所建立之沖淡濾波器系統得以有效率而及時的展現出來。
在六自由度的史都華運動平台控制上，首先我們推導出完整系統的動態方程。並在未知系統參數下，只能量測到位置及速度的條件下，利用平滑滑模倒進(smooth sliding-mode backstepping)控制法逹到高性能的運動控制效果。最後藉由各種的實驗結果得以驗證控制器確實逹到優秀的性能。
之後，我們提出了同時結合人類內耳庭數學模型、平台工作空間限制及無感知策略補償器之整合性最佳沖淡濾波演算法。利用此方法所設計出來的沖淡濾波器藉由數據模擬及實驗驗證確實能使運動平台更有效率利用工作空間，做出駕駛員所應感受的内耳庭平衡感知(線性加速度及角速度)。
但前述的方法未考慮視覺感知，而易造成内耳庭平衡感知與視覺感知不同步易而頭暈。為了改善此一現象，我們建立了視覺内耳庭互動數學模型，並以此模型為基礎藉由適應調整機制修正沖淡濾波器的各個參數，一樣藉由數據模擬及實驗驗證確實能改善駕駛員長時間駕駛模擬器所產生的不合理的暈眩的情形，得到極佳的效能結果。

關鍵字

滑模控制 ； 史都華平台 ； 人類感知系統 ； 沖淡濾波器 ； 視覺與內耳庭互動模型 ； 虛擬實境

並列摘要

The driving simulator is a great integrated system which can be divided into four subsystems, including vehicle dynamics systems, computer graphs, motion platform systems, and washout filter systems. This dissertation focuses on the construction of a high-performance motion platform system with a more realistic washout algorithm for human sensation.
A smooth sliding mode backstepping control approach for the motion control of a Stewart platform is proposed. The control scheme is proposed provided that the overall system parameters are subject to uncertainties and only the positions and velocities of the links are measurable. To achieve high-performance tracking control of a 6 DOF Stewart platform normally requires the full knowledge of the system dynamics. In this dissertation, some important properties of the dynamics of the Stewart platform have been derived and exploited to develop a smooth sliding mode backstepping controller which can drive the motion tracking error to zero asymptotically. Stability analysis based on Lyapunov theory is performed to guarantee that the controller design is stable. Finally, the experimental results confirm the effectiveness of our control design.
After that, a new approach is presented to develop washout filters for the simulators. It is based on the human vestibular model, limited workspace of the motion platform, and the senseless maneuver compensator at the same time for designing a washout filter such that a cost function constraining the pilot’s sensation error (between the simulator and the simulated vehicle) is minimized. The strong sensations experienced by the pilot can be curtailed, and the platform workspace for presenting the desired scenario is more efficient than others. Finally, the simulation and experimental results confirm the effectiveness of our algorithm designed, and hence the merits of the present approach can be manifested.
To avoid dizzy feeling caused by the conflict between the visual and the vestibular systems, a novel integrated model is proposed which includes models of both vestibular and visual motion sensation and incorporates the nonlinear interaction between the vestibular and visual stimuli. Models for both rotational and translational motions are developed, producing responses that explain the characteristics of self-motion. Based on this novel model, we propose a human vestibular-visual based (HVVB) adaptive washout algorithm to avoid dizzy feeling caused by the conflict between visual and vestibular systems. Finally, the simulation and experimental results confirm the effectiveness of our proposed algorithm, thus manifesting the advantages of the present approach.

並列關鍵字

Sliding Mode Control ； Stewart Platform ； Washout Filter ； Human Perception Systems ； Visual-Vestibular Interaction ； Virtual Reality ； Simulator

參考文獻

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