在液壓系統中,針對不同的動態特性檢測需要有不同的壓力波訊號,其中以方波與步階波為最常用的壓力訊號。依據過去的研究顯示,壓力方波產生器於高頻狀態下,方波波形特性逐漸變差且不穩定,因此影響高頻狀態液壓元件鑑別時之準確性。本研究以直線式運動機制作為液壓方波產生器,其構造是由閥體與滑軸所組成,實驗的方法探討閥軸速度、工作壓力與壓力腔容積對波形的影響,因此本研究利用漸進式輸入方式提供極為穩定之壓力源。目的為縮短反應之上升時間與暫態響應及降低系統超越量,並獲得更方的波形以提供較佳的壓力波激振源。 由實驗結果得知,輸入端液壓源之穩定性,是會影響輸出波形之動態特性,尤以暫態響應為最直接。滑軸速度愈快愈有助於暫態響應時間的縮短,而蓄壓容腔的容積越小也越能增加反應速度及縮短暫態時間。
In hydraulic system, various signals of pressure wave would be used for testing dynamic characteristics. However, square and step waves are most commonly used. Previous papers show that the pressure waves form could not be obtained and unstable at high frequency range. In this study, a straight-motion mechanism was used to generate square and step wave. This generator is composed of spool valve. The speed of spool, working pressure, and chamber volume will affect the waveform by use of experimental method. The goal of this study is to decrease the rising time, transient state, and overshoot. And the more square of waveform can be obtained to supply pressure wave source. As a result, the stability of pressure source will affect the dynamic characteristic of output waveform. And the speed of spool is quicker then the transition state will be shorter. The chamber volume of pressure is smaller can increase the reaction rate and reduce the period of transition state.