| An approach to improve the productivity and surface quality of the grinding process is presented. It describes the development and implementation of a high-frequency micro-actuation system for vibratory modulation in grinding process. The approach is based on the fact that ground surface texture has dominant roughness in the cross feed direction of the surface grinding process. High-frequency vibratory movement of the workpiece in the cross feed direction can reduce the surface roughness in this direction and therefore reduce the overall surface roughness. A three dimensional model for the surface texture generated by a surface grinding process is developed based on the kinematics of the process. A simulation procedure is developed to check the effectiveness of this approach. Some rules for selecting the process parameters are studied by simulations. A prototype workpiece actuator that incorporates magnetostrictive actuation has been developed. It has been tested and implemented on a conventional surface grinding machine. A series of experiments have been conducted to demonstrate the viability of this method. The results show that it offers an effective means of improving the quality of the ground surface texture and improving the grinding process efficiency.; An analysis method, multi-resolution analysis which is based on the wavelet transform, is proposed in the study of a grinding wheel surface. Using wavelet transformations, the measurement noise can be effectively eliminated in the wheel measurement process, the measured profile can be decomposed according to different scales. The wheel surface can be reconstructed from the multi-resolution profile using a combination of different scales according to the practical needs, particularly in this thesis, the characteristic wavelength of the wheel can be obtained from the multi-resolution study of the wheel. The characteristic wavelength associated with their characteristic grain can be used in the prediction of ground surface roughness. Wavelet transformation method can also be used to compress the measurement data, which provides an efficient method for modeling the grinding wheel surfaces.; The precision surface evaluation is usually limited by the accuracy and resolution of the measurement method. In order to improve the lateral resolution, a confocal system is developed.; A laser interferometric microscope is developed for surface measurement. This microscope is based on the phase shift laser interferometry principles so as to obtain sub-micrometer accuracy in the surface height axis. Methods for improving the measurement accuracy in both of the lateral axes and the axis perpendicular to the surface are suggested. (Abstract shortened by UMI.)... |
