Numerical Control System Development For Rotary Precision Synthetic Carbon Film Potentiometer Linearity Trimming Machine

The major way to improve the linear precision of Rotary Synthetic Carbon Film Potentiometer is to trim resistance using the advanced equipments. The dissertation deals with some key issues relevant to numerical control system for Rotary Synthetic Carbon Film Potentiometer trimming machine based on the domestic and overseas corresponding researches. The following works have been completed:The general plan for industrial PC based Rotary Synthetic Carbon Film Potentiometer linearity trimming machine open NC system is designed by analyzing the working principle, output performance, the developmental trend of numerical control and function requirement of trimming machine.Based on the general plan, the hardwares are chosen by the capability analyse. The hardwares are connecting and setting according to the capability and system fuction.Applying the position control strategy, the sysem servo stiffness is adjusted and parameters are optimized in order to insure that system works stably, exactly and quickly. The basic fuctions including machine coordinate, home, limit, external pulse driving and emergency stop are set up.According to the module design method, the software structure is design: the module of data acquisition is improved using a shielding method in order to reduce the data acquisition card's disturbance from direct driving motor; the module of searching zero point and thimming are designed based on the structure characteristic and trimming process of Synthetic Carbon Film Potentiometer and lots of experiments; The linear precision is improved by linearity regression during the testing.