| Summary: | 碩士 === 國立中正大學 === 機械工程學系暨研究所 === 102 === In recent years, for high-speed high-precision machine tools, the structure resonance of drive feed system could be excited. In include the flexible effect, this thesis considers the design of interpolator, drive feed systems and servo loop by deriving the complete drive feed system model which includes the servo loop and structure response. The structure error equation is derived and used to identify the parameters of the flexible structure. Finally, the model can be utilized to determine the optimal bell shape deceleration ACC/DEE time. Through choosing the proper time constant, the vibration from structural resonance can be suppressed effectively. The proposed method can achieve high speed and high precision without using an external sensor and the method can achieve the objective of high speed and precision.
First, this thesis introduces the derivation of dynamic drive feed system model and the second part is to perform dynamic model analysis. The main content can be divided into two scheme. The first part assumed that drive feed system is a rigid body and the complete servo loop model is integrated. The second part is to derive the flexible structural model using energy method. Through this model, the axial deformation of the flexible structure is estimated and relationship between the base and the reaction force is established. The error equations of the flexible structure which describes the differences between encoder feedback and optical measurement feedback is derived. Experiments of uniaxial platform are conducted to validate the dynamic error equation which is then used to identify the structure parameters, including mass, damping, and rigidity.
The last part is to design the interpolation parameter so that the impact of structural resonance can be reduced. By adjusting the best bell-shaped acceleration time, the resonance frequency of the excitation of the structure can be reduced. The experimental results validate the derived equation can predict the dynamic response accurately.
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