渦輪分子真空幫浦適應性可變結構控制研究

Adaptive Variable Structure Control For Turbomolecular Pump Suspended By Active Magnetic Bearings

江彥徹(Yan-Che Jiang)

指導教授 ： 范憶華

中原大學/工學院/機械工程研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400672

摘要

本研究主要目的在針對渦輪分子真空幫浦轉子質心落在葉片端下方，其運轉特性與轉軸有很大的差異，無法利用解耦合控制簡化系統的特點，設計出一良好的回授控制器。
磁浮軸承轉子系統本身具有非線性之動態特性，以往已有許多學者專家在磁浮軸承系統模式建立與控制研究方面貢獻心力，但大部分都是對經過線性化的系統使用線性的控制器，忽略了系統本身的不確定性和外來的不預期干擾。因此本文提出適應性可變結構控制法，利用可變結構控制天生具有的強健性，來抑制因建模及線性化所造成之系統誤差及因轉速變化過大造成的系統特性變化；再結合適應性控制的優點針對參考模型與受控系統裝置間的誤差輸出加以控制，使系統在發生外力干擾時能更快速將系統拉回旋轉中心點附近運轉，進而提升系統性能。
由模擬結果得知，一般可變結構控制器，對於偏心力及外力干擾雖然有不錯的抑制效果，但當內部參數變化或外力干擾過大時，控制器為了能在瞬間將反應壓抑下來，可能會提供過大的電流量或較快的切換頻率，導致系統的不穩定。而適應性可變結構控制器則使得磁浮軸承轉子系統的輸出不論在任何情況下，皆能追循參考模型輸出，使系統快速到達穩定的狀態。經由比較兩者之控制效果，發現兩者有近似相同的性能。但使用適應性可變結構控制對外力干擾的抑制更佳，更能提高系統的強健性。

關鍵字

適應性可變結構控制 ； 可變結構控制 ； 主動式磁浮軸承

並列摘要

This study is dedicated to design a feedback controller for the turbo molecular pump, which center of gravity is located below the blades; therefore, its running property is different from the rotor and cannot be decoupled to simplify the system.
Formerly many scholars and experts establish the magnetic bearing system pattern or design the controller, and devoted in the magnetic domain, which neglect system uncertainties and external unanticipated disturbance, and simply applied linear controller to the linearized system.
Therefore, this thesis proposes the adaptive variable structure control theory, due to the advantage of its robustness. By applying this control theory, the system error and the system performance variety from the rotational speed change, which cause by the modeling and the linearization, can be reduced. Moreover, by designing an adaptive controller which base on the error between the plant output and the reference model, the controller can make the system come back to the running central when the system occurs external unanticipated disturbance.
From the simulation results, the general variable structure controller for regarding imbalance force and external force disturbance has the good suppression effect, but the system will be unstable when system works as internal parameter change or overload external force disturbance, while the controller possibly provides overload current or higher switching frequency to constraint the instantaneous response. On the other hands, the command output from adaptive variable structure controller follows the reference model in all kinds of circumstance. From the comparison between these two controllers, it is found that the performances are similar while the adaptive variable structure control has more robustness for external unanticipated disturbance.

並列關鍵字

Active Magnetic Bearings ； Adaptive Variable Structure Control ； Variable Structure Control

參考文獻

Bearings and Magnetic Transportation,” John Wiley ＆ Sons, Inc.,

New York, June 1994.

[2] F. Matsumura, and H. Kobayashi, “Fundamental Equation for

Horizontal Shaft magnetic Bearing and its Control System Design,”

Magnetic-Bearing System for Horizontal Shaft and Its Experimental