In-process measuring method for the size and roundness of workpiece with discontinuous surface in cylindrical grinding process

On-line metrology is widely applied in manufacturing which not only contributes to improving the working efficiency but also helps to ensure the surface quality of machined parts. However, for cylindrical workpieces with discontinuous surface such as spline shaft, the accurate measurement method is still the key challenge. This paper proposes a novel in-process measuring method of geometrical characteristics of discontinuous surface based on extreme value memory strategy and predictive regression algorithm. The invalid measured size data in the keyways can be effectively replaced by the computed data. Based on the in-process measuring method and the established evaluation mathematical models, the roundness of the manufacturing workpieces can be obtained by using the continuous and valid measurement data. Experimental investigations for machining multi-keyway shaft are carried out based on the proposed method. The experimental results show that the proposed measurement method has a high accuracy for discontinuous surfaces. (C) 2020 Elsevier Ltd. All rights reserved.