植基於橢圓邊界滑動模式之弦波振盪器
Abstract
本研究利用可變結構控制理論的滑動模式於數位弦波產生系統的設計，其中系統所產生出來的數位弦波其頻率與振幅均可由可變結構的滑動圓來加以控制，藉著調整滑動圓便可任意產生所需頻率與振幅的數位弦波訊號。
可變結構控制系統的到達模式容易受到系統擾動的影響，由於系統的不確定性、切換元件的延遲等因素，使滑動模式存有不良的顫動現象，於是本研究提出指數趨近的方法提昇到達模式品質。
並設計橢圓邊界區間滑動模式來改善傳統不連續控制的缺點，藉由加入內外的兩個邊界使可變結構控制系統的狀態控制軌跡被限定在這兩邊界區間內切換，使可變結構控制系統大大減少切換的次數，也因此切換元件不致因過度切換而造成疲勞，使整個系統提早損壞，藉由本研究的設計確實能產生穩定的數位弦波。
關鍵詞： 可變結構控制系統、數位弦波振盪器、指數趨近、
橢圓邊界滑動模式
Sinusoidal nonlinear oscillators are designed in this dissertation ,in which a sliding ellipse is used instead of the conventional switching hyperplane. Both the desired amplitude and frequency of the sinusoidal oscillator are simply dependent on the equation of sliding ellipse and are independent of plant parameter. In the traditional variable structure system, hitting time reduction and chattering attenuation are two important but contradictory issues. The thesis employ exponential approach control rule and sector boundary sliding mode to resolve this conflict. A system should be reduced approach time and sensitivity to parameter variance and external disturbance by the exponential approach control rule. The dynamic response of the exponential approach time can be designed by the user himself. The control rule based on the sector boundary sliding mode can successfully attenuate the chattering phenomena and avoid steady-state of the system error. Finally, we apply this property of this VSS system to design a digital sinusoidal generator system which can generate more stable sinusoidal signal. Keywords : Variable Structure System, Sinusoidal Oscillators, Ellipse Boundary Sliding Mode , Exponential Approach Rule
Sinusoidal nonlinear oscillators are designed in this dissertation ,in which a sliding ellipse is used instead of the conventional switching hyperplane. Both the desired amplitude and frequency of the sinusoidal oscillator are simply dependent on the equation of sliding ellipse and are independent of plant parameter. In the traditional variable structure system, hitting time reduction and chattering attenuation are two important but contradictory issues. The thesis employ exponential approach control rule and sector boundary sliding mode to resolve this conflict. A system should be reduced approach time and sensitivity to parameter variance and external disturbance by the exponential approach control rule. The dynamic response of the exponential approach time can be designed by the user himself. The control rule based on the sector boundary sliding mode can successfully attenuate the chattering phenomena and avoid steady-state of the system error. Finally, we apply this property of this VSS system to design a digital sinusoidal generator system which can generate more stable sinusoidal signal. Keywords : Variable Structure System, Sinusoidal Oscillators, Ellipse Boundary Sliding Mode , Exponential Approach Rule
Description
Keywords
可變結構控制系統, 數位弦波振盪器, 指數趨近, 橢圓邊界滑動模式, Variable Structure System, Sinusoidal Oscillators, Ellipse Boundary Sliding Mode, Exponential Approach Rule