Realization and Control of a Damping Enhancement Compliant Stage by Incorporating Active and Passive Vibration Absorbers

Abstract

This thesis presents the dynamic analysis and control system design of a damping enhanced compliant stage consist of a notch-based structure and active damping enhanced scheme Generally compliant stages are usually fabricated of metallic structures Such an approach could yield excellent performance in many applications with simple feedback controls incorporated However metals have inherently very low material damping and it may be difficult to add external passive dampers due to space constraints Such a low damping capability would limit the effectiveness of controller design and even cause instability In this work we propose the use of the composite damping enhanced method consisting of passive vibration absorber which is made of polydimethylsiloxane (PDMS) and active damping controller of which recursive delayed position feedback (RDPF) is composed to enhance the effective material damping of compliant structures In order to implement the approach a compliant stage is designed and realized Essential performance and dynamic tests are conducted to examine the functional performances and dynamic characteristics of both the original and damping enhanced stages The results of frequency sweeping experiments indicate that the composite damping enhanced method can significantly increase the damping ratio of the stage from 0 0134 to about 0 5 Finally for assessing the possible advantage in precision control by using this damping enhanced approach controller systems are designed based on loop transmission shaping and sliding mode control methods The experimental results demonstrate that settling time is indeed improved and the control bandwidth is increased after the damping is enhanced

Date of Award	2020
Original language	English
Supervisor	Kuo-Shen Chen (Supervisor)