An error compensation method for multi-axis machining based on the actual contour measurement

摘要

With the application of compensation for geometric error and thermal error, static and quasi-static accuracy of machine tools are significantly improved. Whereas, the accompanied disadvantage is the increased motion control error, especially the motion control accuracy in high-speed and ultra high-speed machining. Based on the actual contour measurement and the study of different control strategies for improving contour machining accuracy, this paper proposes an error compensation method for multi-axis machining. To be specific, a contour error model with different input parameters of the machining process needs to be built, and afterwards to be implemented into an open computer numerical control (CNC) system for real time calculation and compensation. Employing a 2-aix machine tool and base on aforementioned method, circular processing experiments with feed rates ranging from 0.5m/min to 10m/min and radiuses ranging from 10mm to 60mm are performed. The range of average radius error is reduced from 0.1mm to 0.006mm. The results demonstrate that high contour accuracy can be maintained even at high speed machining.