Optimal Digital Modal Vibration Suppression of a Cantilever Pipe Conveying Fluid

• Main Authors: Wei-Liang Hsu, 徐維良
• Other Authors: Yih-Hwang Lin
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/60259608262787332135

碩士 === 國立臺灣海洋大學 === 機械與機電工程學系 === 99 === The purpose of this research is to investigate digital vibration control of a cantilever pipe conveying fluid considering modal observer dynamics. Firstly, with the classical beam theory being considered, the pipe and the actuator dynamics are taken into account for establishing the system's equations of motion for the control formulation. The computation of the feedback gain is realized by discrete time optimal control theory. A method for generating the close loop eigenvectors with the target values is also proposed. It is impractical to measure all the system states. The application of an observer can be used to alleviate the burden by estimating the required modal states used for feedback control. This study used a single sensor, along with the application of a modal space observer, and applied the modified IMSC (independent modal space control) formulation for structural vibration suppression. The advantage of being able to direct the control on the unstable mode only can reduce the computation cost significantly. From the numerical evaluation, the proposed method using only the controlled modal feedback signals can stabilize the originally unstable system and provides great control performance.