Microvibration Control in Precision Equipments and Structures

This reserach project aimed at solving the microvibration problems in precision equipments such assemiconductor lithography systems，原子force microscopes， high-speed color printers，大空间结构，三个主要结构已经适应了和谐的和谐effects of vibrations，which are the following: Suppression of vibration at the sources. Suppression of vibrationtranmissions by using passive isolation materials or active isolation systemsor changing structures of transmission routes. Application of disturbance rejection control toprecision equipments or whole systems including vibration sources.To suppress vibrations at thesources,the present research has proposed application of feedforward control input to cancel the directdisturbance caused by a stepper on an active isolation system这是computed beforehand using experimental data.这是公认的计算机方法the optimal reference input which achieves high-speed movement in good accuracy without generatingvibrations.To suppress vibration transmissionsthis research has considered modeling and control of an active vibration isolation system. Couplingsin the six degrees of freedom of translations and rotations of its table have been identified. H*control is applied to strongly coupled subsystems decentrally for the attitude control.这是可行的considered optimal结构设计for suppression of vibration transmissions using the H* norm asthe transmission gain.To suppress vibrations by control of the whole system，this paper has been proposed optimal regulation of large space structures under the sumption ofsensors/actuators collocation. Both static feedback of velocity and displacement and simple dynamicfeedback of displacement have been considered，and tuning methods for controller gains have been presented。

This reserach project aimed at resolving the microvibration problems in precision equipments such as semiconductor lithography systems, atomic force microscopes, high-speed color printers, etc. and large space structures. Three major strategies have been considered to remove the harmful effects of vibrations, which are the following :・Suppression of vibrations at the sources.・Suppression of vibration tranmissions by using passive isolation materials or active isolation systems, or by changing structures of transmission routes.・Application of disturbance rejection control to precision equipments or whole systems including vibration sources.To suppress vibrations at the sources, the present research has proposed application of feedforward control input to cancel the direct disturbance caused by a stepper on an active isolation system, which is computed beforehand using experimental data. It has proposed also computaion methods for the optimal reference input which achieves high-speed movement in good accuracy without generating vibrations.To suppress vibration transmissions, this research has considered modeling and control of an active vibration isolation system. Couplings in the six degrees of freedom of translations and rotations of its table have been identified. H* control is applied to strongly coupled subsystems decentrally for the attitude control. It is also considered optimal structural design for suppression of vibration transmissions using the H* norm as the transmission gain.To suppress vibrations by control of the whole system, this paper has been proposed optimal regulation of large space structures under the assumption of sensors/actuators collocation. Both static feedback of velocity and displacement and simple dynamic feedback of displacement have been considered, and tuning methods for controller gains have been presented.