Studies On Key Control Technology And Application Of Electronic Gearbox

Electronic gearbox transmission is characterized by high precision, wide transmission ratio and flexibility. Mechanism transmission link can be replaced by electronic gearbox to realize exact transmission. Electronic gearbox plays an important role in gear making machine tool transmission and other fields that need synchronization motion. The electronic gearbox system structure, information processing, servo control and application in cam CNC turning were discussed comprehensively in this dissertation. It includes such contents as follows: 1. The comparisons of electronic gearbox and normal NC was listed. It concludes that electronic gearbox is a special NC system. By control principle and mode, electronic gearbox was divided into Master-slaver structure based on variable-value control and parallel structure based on fixed-value control. The electronic gearbox transmission precision was studied. The selective principle of structure was illuminated. 2. Electronic gearbox based on PLL synchronization control was studied. Information processing approach adopting space-division and time-division combination was presented. The precision of information processing is improved by counting integer and fraction of pulse, and extends transmission ratio as well as. To improve motion measurement precision, the error average principle was utilized to eliminate the AM and FM effect of encoder installation eccentricity and gradient by symmetrical distribution of double sense organs. 3. Address the characteristics of non-uniform speed transmission, position function control and transmission ratio function control were presented to realize electronic gearbox. The differences between position function curve interpolation and general NC interpolation were analyzed. Considering the effect of uncontrollable continuous principal motion, interpolation slope and position function precompensation interpolation were presented. The relationship among interpolation, servo dynamic response and transmission precision was studied. The coordinate linkage relationship and electronic gearbox scheme in noncirclar gear hobbing were studied. 4. To improve electronic gearbox static and dynamic perfi)rmances, trace error and tracking leg, robust in parameters change and load disturbance, PU) control, adaptive control, predict feedforward control, H0. control were discussed. Theoretic analysis and digital simulation results demonstrated that these control strategies had good effectiveness in tracking performance, rejecting model parameters excursion and disturbance. 5. Motion synchronization between tool in X direction and principal axis rotation was controlled by electronic gearbox in cam turning. And profiling mechanism could be superseded by servo tool-holder. Linear motor direct drive servo tool-holder was designed, and host-slave control system with PC and DSP was developed for the require of high-speed and realtime servo. The technical process was analyzed in cam turning. Servo tool holder with tool swinging and principal axis variable rotate speed were presented to keep constant cutting angle and speed.