Research On CNC Machine Tool Global Error Compensation System

With the development of advanced manufacturing and machining technologies, the researchers are facing a new challenge for improving precision of numerical control processing equipments.In order to improve the accuracy of machine tools, there are usually two methods, hard and soft compensation. Some mechanical adjustment and structural changing are involved in hard compensated schemes so that the wider research on promotion is prevented due to high cost and low efficiency. Soft compensation usually uses algorithms or software methods to improve machine tools accuracy, and this method is much more simple and easy to operate, which has been widely used and studied.For simplifying modeling and operating, a novel error compensation approach is presented, main contributions are as follows:(1) The global error of a CNC machine tool is measured by a laser interferometer, and its global error model is established for compensation purpose.(2) The global error database of CNC machine tools is designed.(3) The software for modifying G code is designed and implemented so that the accuracy of CNC machine tools is improved obviously.The software of the system above is designed. The software can modify the G code file and store the error compensation data to the database, and error decomposition is not necessary in this system. The effectiveness of the proposed approach is demonstrated by some experiments, which the accuracy of X axis is increased more than 50%, and Z axis more than 40%.