Thermal Characteristic Analysis And Fitting Algorithm Research Of CNC Form Grinder Movable Upright Column

In order to improve thermal characteristic of form-grinding process and further enhance machining accuracy, a step-by-step recu(?)sive fitting algorithm has been presented to predict the variation trend of form grinder movable upright column based on the analysis of non-linear and time-lagging features. To measure temperature distribution on column, a multi-channel temperature measuring device was developed on the platform of virtual instrument LabVIEW (Laboratory Virtual Instrument Engineering Workbench), and then finite element analysis was carried out. High fitting precision has been proved by comparing the fitting curve with the test curve. The fitting algorithm is suitable for temperature characteristic analysis, thermal error prediction modeling and error elimination.Chapter One. Developing situation of high-performance form grinder both at home and abroad was introduced. Negative influence caused by thermal error and deformation was then explained. The research progress on temperature field analysis and thermal error modeling conducted by foreign developed countries and domestic key universities was clarified. At the end, the significance, content and structure of this study were presented.Chapter Two. Detailed design plan of temperature measurement device by virtual instrument LabVIEW was presented, including hardware configurations and software parameter settings. And then, the design process of this device was explained, including the function of each module, programming method, data acquisition and exchange, man-machine interface and operation principle, and thus laying solid foundation for the following temperature measurement test and algorithm application.Chapter Three. Finite element theory of steady-state and transient-state temperature field based on heat transfer principle was explained. Then operating condition and thermal source analysis of movable upright column was iterated through temperature contrast between the front and back profile of column. Temperature field distribution of each thermal source was analyzed by ANSYS, which further proved that temperature distribution on upright column was unbalanced and paved the way for the subsequent study on thermal data fitting of movable upright column on high-performance form grinder.Chapter Four. Thermal error of form grinder column possessed non-linear, time-lagging and multi-parameter characteristics based on the analysis of temperature field distribution on column. Based on the analysis of data, a step-by-step recursive fitting algorithm was presented to process multi-order exponential function with large span of time constant. In accordance with the feature that exponential function with various time constants has different equilibrium time, first-order exponential function fitting algorithm was adopted; then time constant and corresponding amplitude of multi-order exponential function through step-by-step fitting. High fitting precision has been proved by comparing the fitting curve with the test curve. The fitting algorithm is suitable for temperature characteristic analysis, thermal error prediction modeling and error elimination, which were proved by practical applications.Chapter Five. The study ideas were reviewed and results summarized. And the prospect of this thesis was also presented for further study.