A new synchronous error control method for CNC machine tools with dual-driving systems

摘要

Driving an object along one axis with two driving systems is a common method for obtaining high acceleration and high trust force for a large CNC machine tool. However, if large synchronous movement error exists between the two driving systems, the machine will not be able to achieve high acceleration. Moreover, it may also cause serious structure deformation and damage to the machine. To solve this problem, a new control method integrating the model reference adaptive control and variable structure control was developed and verified in this study. The proposed method can determine and compensate on-line the synchronous movement errors between two driving systems so that the master driving unit and the slave driving unit of a dual-driving system can synchronously move with no large drag force and reach the desired acceleration. Experiments were performed on a gantry-type two-axis platform with a sliding 5-Kg metal block attached on the X-axis. The experimental results showed that the maximum and the average synchronous movement errors were reduced from 0.061 mm to 0.040 mm and from 0.032 mm to 0.013 mm, respectively.