軸向磁氣混合軸承系統控制研究

Control Design on the Hybrid Magnetic-Aerostatic Thrust Bearing

李應村(Ying-Tsun Lee)

指導教授 ： 范憶華

中原大學/工學院/機械工程研究所/碩士(2009年)

https://doi.org/10.6840/cycu200900270

摘要

近年來，由於精密化工業的需求越來越高，對於軸承的要求不只需要負載大，更需要能夠精準定位且具有避震效果。針對需求，本研究整合氣靜壓軸承與磁浮軸承這兩種非接觸式軸承，製作一套混合式止推軸承系統。系統主要利用兩種非接觸式軸承的優點，在機構設計上是以氣靜壓軸承系統提供主要負載力，搭配磁浮軸承與控制器針對動態負載及干擾進行主動式控制。
設計時首先針對軸承的規格進行軸向力分析，分析軸承設計對承載力及剛性的影響，藉此決定軸承的設計規格。在確定系統承載力及規格後，可建立系統之模型方程式，並根據此方程式建立適用之控制器。主動式磁浮系統的控制器部分採用可變結構控制系統，由於可變結構控制系統為一個非常強健性的控制系統，對於外界干擾及參數不確定性具有非靈敏的特性，因此本研究選取此控制器並與傳統PD控制器進行比較以選取較適用之控制器。
本研究模擬分成穩定懸浮狀態及加入外力干擾等兩部分，由穩定懸浮狀態可
知本系統若單純使用氣靜壓系統時其穩態誤差約在3*10__m左右，而加入磁浮系統後，經由可變結構控制器的調整，可使系統的穩態誤差減小至1__。在加入外力干擾及負載的部分，顯示當系統承受500N之負載並受到瞬間外力的干擾時，經由加入可變結構控制器之混合式軸承系統，可使系統保持在穩定懸浮的狀態，且穩態誤差接近1__，證明本研究加入磁浮系統與可變結構控制器的想法可使系統具有阻尼性及高負載的能力，並有效改善系統穩定度。

關鍵字

磁浮 ； 氣靜壓 ； 混合式軸承 ； 可變結構

並列摘要

Recently, the demand of the precision device is reaching the sub-micrometer level, the requirement for the bearing is not only needs larger load capacity but also needs higher stiffness coefficient. The aim of the research is to design and develop an aerostatic-magnetic hybrid bearing system. The system mainly utilizes the advantages of the two kinds of non-contact bearings. The aerostatic bearing provides the main function to supply supporting force to the rotating shaft, and the active magnetic bearings with the controller are applied to stabilize the operational condition, using electromagnetic force to suspend gravity and isolate vibration force from the system.
The axial force is derived and modified to analyze the influences of the design and operational parameters of the aerostatic-magnetic hybrid bearing on the load capacity and the stiffness. Then the dynamic model of the overall system is established and analyzed. Next, a sliding mode controller which system would not be affected completely by parameter uncertainties and external disturbances is designed to regulate the attitude in this system. So this research chooses sliding mode controller and compares with the traditional PD controller in order to choose the more applicable controller.
Simulation of this research is divided into two parts of steady state and joining the external force interfering with stability. From the simulation result can demonstrate that joining a magnetism system with sliding mode controller can make system have better damping coefficient and larger load capacity, and improve the stability of the system effectively.

並列關鍵字

Aerostatic ； Magnetic ； Hybrid Bearing ； Sliding Mode Controller

參考文獻

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