Abstract
The thesis investigates and implements the adaptive gap control for CNC EDM. It enables CNC adapt the parameters of real-time gap control module automatically,according to the change of the gap condition, to achieve stable, continuous, andefficient machining. In the investigation, we first experiment to confirm that relative electrode wear is correlative with abnormal discharge number, and removedworkpiece volume is proportional to normal discharge number. Then, the relationshipbetween machining efficiency, abnormal discharge rate and adaptive parameters,the reference value of discharge retarding period and servo gain, are identified experimentally. finally, we take machining efficiency and abnormal discharge rateas sensing variables to develop the algorithm of adaptive parameters optimization,and then have a successful test on the real machine. In comparison with the traditional EDM, the developed CNC adaptive control algorithm can adapt machining parameters, according to the change of the gap condition. It's machining process is stable and low abnormal discharge rate. In contrast, the traditional EDM causes serious arcing in the same test condition with CNC