Isolation Control of Micro Vibration to Realize Micro and Fine Manufacture

We have designed controllers for two kinds of magnetically levitated isolators from micro vibration of installation floors。Since the magnetically levitated isolators are non-contact，no-friction and controllable，they are expected to have an ability to reduce vibration level to many kinds of semi-conductor inspection or manufacture apparatuses from the installation floor.One of the designed isolator is a large-sized isolator carrying up to 200 kg mass such as a Scanning Electron microscopy(SEM)and another is a small-ized isolator carrying up to 200 kg mass such as a Scanning Electron microscopy(SEM)and another is a small-ized isolator carring up to the mass such as a Scanning Electron microscopy(SEM)。4 magnetically levitated actuators support the large-sized isolator，and 3 actuators support the small-sized isolator。A decentralized controller in vertical direction has been designed using a relative displacement sensor in the actuator and an accelerometer on the levitated table as sensors for levitation and isolation control.We employed the H I D1∞ⅡD1 robust control theory in the control…More ler design because dynamic specifications of the loaded apparatus is uncertain，magnetic actuator has large non-linearity and the flexibility of the levitated table was ignored.After estimation of the designed controller by numerical simulations，we implemented the controller in DSP and measured the isolation performance of the isolator。But the experimental results did not show efficient isolation performance。Accordingly，we dopted a centralized considering vertical motion and two angular motion around 2 horizontal axes and implemented the controller in DSP。But we could not get good isolation performance.Afterward we have adopted the sub-space method for the identification of dynamic model of the isolator and control of the isolator as we worried that a cause of the bad performance was the error in the dynamics of the levitated table and the magnetic actuator.We also studied a new control method for vibration isolation of SEM manipulating the electron beam in using the image shift of SEM by the aptive feed forwe control method for vibration isolation of SEM manipulating the electron beam in using the image shift of SEM by the feive forward of the fibrating of the ibrol。Less：Less

We have designed controllers for two kinds of magnetically levitated isolators from micro vibration of installation floors. Since the magnetically levitated isolators are non-contact, no-friction and controllable, they are expected to have an ability to reduce vibration level to many kinds of semi-conductor inspection or manufacture apparatuses from the installation floor.One of the designed isolator is a large-sized isolator carrying up to 200kg mass such as a Scanning Electron microscopy (SEM) and another is a small-sized isolator carrying up to 20kg mass such as an Atomic Force Microscopy (AFM). 4 magnetically levitated actuators support the large-sized isolator, and 3 actuators support the small-sized isolator. A decentralized controller in vertical direction has been designed using a relative displacement sensor in the actuator and an accelerometer on the levitated table as sensors for levitation and isolation control.We employed the HィイD1∞ィエD1 robust control theory in the control … More ler design because dynamic specifications of the loaded apparatus is uncertain, magnetic actuator has large non-linearity and the flexibility of the levitated table was ignored.After estimation of the designed controller by numerical simulations, we implemented the controller in DSP and measured the isolation performance of the isolator. But the experimental results did not show efficient isolation performance. Accordingly, we dopted a centralized considering vertical motion and two angular motion around 2 horizontal axes and implemented the controller in DSP. But we could not get good isolation performance.Afterward we have adopted the sub-space method for the identification of dynamic model of the isolator and control of the isolator as we worried that a cause of the bad performance was the error in the dynamics of the levitated table and the magnetic actuator.We also studied a new control method for vibration isolation of SEM manipulating the electron beam in SEM using the image shift coil of SEM by the adaptive feed forward control of the floor vibration. Less