Dynamic characteristic is presented by identifying the model and the dynamic parameters of a precise long stroke linear motor （PLSLM） with the air-bearing in optical lithography. The PLSLM is supported by air-bearin...Dynamic characteristic is presented by identifying the model and the dynamic parameters of a precise long stroke linear motor （PLSLM） with the air-bearing in optical lithography. The PLSLM is supported by air-bearing on the stator, and is driven by on-board two large linear motors in a cross-configuration. Firstly, a model of the PLSLM is established by finite element method （FEM）. Secondly, based on the model, the natural frequencies and model shapes are discusse＆ And the contribution of each active mode is evaluated by computing the modal participation factors （MPF）, which indicates the major vibration direction. Furthermore, by the experimental modal analysis, the experimental results are in agreement with simulation results, which it is sure that the FEM is reasonable. What＇s more, comparing with the effects on the frequency due to the air-bearing stiffness, the relations of the natural frequencies with the air-bearing stiffness are found. It is found that the frequency response curve is fluctuant with the air-bearing stiffness in each direction. Finally, it is conclusion that the natural frequency of the PLSLM is largely affected by the air-bearing stiffness variety. This research is contributed to the dynamic characteristics resulted from the air-beating stiffness. Further work will include better optimization on the dynamic parameter in the controller design through the control algorithm for the precise long stroke motor.展开更多
China is a transitional and developing country with the largest population and number of farmers in the world, and shows a striking feature of urban-rural dual structure. The major content in China's rising modern...China is a transitional and developing country with the largest population and number of farmers in the world, and shows a striking feature of urban-rural dual structure. The major content in China's rising modernization is the process of urbanization transformation, urbanization of small and middle-sized city in China should become the basic path selection. Which involves three important issues: concept, people, and institution. Only based on the modernization of concept, people and institution, there will automatically generate the modernization of industry, agriculture, technology and national defense, and thus consistently developing prosperous of both the country and the citizens.展开更多
基金National Basic Research Program of China (973 Program,No.2003CB716206)National Natural Science Foundation of China (No.50605025)
文摘Dynamic characteristic is presented by identifying the model and the dynamic parameters of a precise long stroke linear motor （PLSLM） with the air-bearing in optical lithography. The PLSLM is supported by air-bearing on the stator, and is driven by on-board two large linear motors in a cross-configuration. Firstly, a model of the PLSLM is established by finite element method （FEM）. Secondly, based on the model, the natural frequencies and model shapes are discusse＆ And the contribution of each active mode is evaluated by computing the modal participation factors （MPF）, which indicates the major vibration direction. Furthermore, by the experimental modal analysis, the experimental results are in agreement with simulation results, which it is sure that the FEM is reasonable. What＇s more, comparing with the effects on the frequency due to the air-bearing stiffness, the relations of the natural frequencies with the air-bearing stiffness are found. It is found that the frequency response curve is fluctuant with the air-bearing stiffness in each direction. Finally, it is conclusion that the natural frequency of the PLSLM is largely affected by the air-bearing stiffness variety. This research is contributed to the dynamic characteristics resulted from the air-beating stiffness. Further work will include better optimization on the dynamic parameter in the controller design through the control algorithm for the precise long stroke motor.
文摘China is a transitional and developing country with the largest population and number of farmers in the world, and shows a striking feature of urban-rural dual structure. The major content in China's rising modernization is the process of urbanization transformation, urbanization of small and middle-sized city in China should become the basic path selection. Which involves three important issues: concept, people, and institution. Only based on the modernization of concept, people and institution, there will automatically generate the modernization of industry, agriculture, technology and national defense, and thus consistently developing prosperous of both the country and the citizens.
