在這篇論文裡提出了一個可以消除伺服系統的摩擦力或是未知干擾的強健型補償器和另一個限制增益(Gain Limit)補償器。在第一個補償器裡，包括了一個預估系統數學模型的倒數、一個濾波器、與輸入命令的扣抵和一個積分項。這個補償器有效的抵消伺服系統裡的摩擦力和未知的干擾， 除此之外，再透過一個滑差模式控制器(Sliding Mode Controller)消除補償器未完全消除的干擾項。這個控制的方法可以有效的消除摩擦力和未知的干擾項且不需要事先知道摩擦力的模型和預估。模擬和實驗的結果可以證明這個方法可以有效的且實際的利用到實際的伺服系統中。 在高精度的定位系統中， 控制器的高增益引起的極限循環(Limit Cycles)明顯的減低伺服系統的定位性能。在第二個補償的方法， 包括一個Dead-Zone 函式和一個積分項， 可以使系統維持在穩定的狀態。這個補償器不但可以確保系統在穩定的狀態，更提供了一個簡單又有效的方法使得使用者在設定增益的時候，避免因為不預期的設定， 使得系統產生極限循環的現象， 讓系統的性能減低。模擬的結果證明此一方法可以有效的避免極限循環，且可以在實際的例子中使用。 A novel friction and modelling uncertainty compensation and a gain limitcompensator for a ball-screw table system are presented. The first scheme consisting of an inverse of the nominal model with an input deduction, a filter, and an integral term. This control scheme can compensate for frictional effects and modelling uncertainty inherent in the ball-screw mechanism. In addition, when further combined with a conventional sliding-mode controller (SMC), this controller can help to counteract the effects of residual frictional torque and residual modelling uncertainty.The proposed control scheme successfully compensates for frictional effects and modeling uncertainty without requiring any prior knowledge of the friction model. Simulation and experimental results confirm the ability of the proposed scheme to compensate for the effects of friction and modelling uncertainty in a practical application. In high-precision positioning systems, the limit cycles induced by friction effects result in a significant reduction in the positioning performance; particularly when the servo system utilizes a high gain controller. Accordingly, the second scheme presents a compensation scheme consisting of a dead-zone function and an integral term to limit the equivalent gain of unspecified controllers to the stable range. The proposed compensation scheme not only ensures that the feedback loop system remains stable, but also provides a simple and effective mechanism for preventing the users from inadvertently setting control gains which degrade the positioning performance of the system. The simulation results confirm the ability of the gain limit compensation scheme to suppress the effects of limit cycles and therefore demonstrate its feasibility for practical applications.
