適應滑動模式控制於基座干擾下之減振研究

Adaptive Sliding Mode Control of a Pan/Tilt Platform for Vibration Suppression

徐聖閔(Hsuan-Hung Hsu)

指導教授 ： 蕭俊祥

國立臺北科技大學/機電學院/機電整合研究所/碩士(2007年)

摘要

本論文使用主動式振動控制的方法，利用感測器獲得平台轉動之角速度值，再經過電腦假積分的運算轉換成為角度值，當作所需的回授訊號。同時並導入了適應滑動模式控制來做為主要的控制原理基礎，憑藉著史都華六軸平台所產生的擾動源以及環境影響，估測出整體系統隨著時間變化之干擾量，即時更新系統參數。控制器便能依據當時振動情況，主動產生出反振動訊號輸出給伺服馬達，讓控制系統進入至滑動平面來達到控制的目的。此外，理論中還使用了 Lyapunov 穩定法則來確保控制過程中之漸進穩定性，並更新系統所需之參數。

本實驗將由史都華六軸平台對於yaw/pitch兩軸產生激振干擾源。在單頻訊號結果部分，對於單軸平台的控制約可達到超過 20 dB以上的減振量，雙軸同動平台同時控制的效果可達 17 dB 以上的減振量；在複頻結果部份，對於單軸平台的控制約可達到超過 10 dB以上的減振量，雙軸同動平台同時控制的效果可達 9 dB 以上的減振量，因此，實驗證明適應滑動模式控制能在各種不同的低頻振動干擾條件下有顯著的減振效果，也比使用線性系統之Filtered-X LMS控制法擁有較好之性能及響應。

關鍵字

適應滑動模式控制 ； 史都華平台 ； 假積分

並列摘要

This thesis applies active vibration control method by feeding back rate sensor signal to computer, where angular displacement of the platform can be obtained by pseudo-integration. Adaptive sliding mode controller is used for vibration suppression, where external disturbance to the pan/tilt platform is supplied by a Steward platform. In addition, the Lyapunov theorem is applied to have the asymptotic stability of the closed loop system with system parameters updated on line.

In the experiments, a Steward platform disturbs the pan/tilt platform in yaw and pitch directions. Over 20 dB vibration attenuations can be obtained in the pan and tilt platform each independently under pure sinusoidal excitation, whereas over 17dB vibration reduction is observed for simultaneously pure sinusoidal excitation. In the case under two-frequency sinusoidal excitations, over 10 dB vibration suppression is obtained for each independently excited pan and tilt platform, and over 9 dB attenuations for simultaneously excited pan/tilt platform. Therefore, the adaptive sliding mode controller proves to be effective in suppressing the low-frequency vibration of the pan/tilt platform and has superior performance than does the linear controller using the filtered-X LMS algorithm.

並列關鍵字

Adaptive Sliding Mode Control ； Steward Platform ； Pseudo-Integration

參考文獻

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