Sequence planning of on-machine measurement and re-machining

Abstract

In order to realize autonomous machining, it is necessary not only to automate the preparation tasks for machining but also to verify the machining results during the process. Therefore, this study realized the automation of planning for on-machine measurement, where measurement is conducted at the necessary time during the machining process based on process planning. Furthermore, when a machining abnormality is detected based on the measurement results, the proposed system automatically judges whether to stop machining or to re-machine the affected region. In the proposed system, measurement is conducted after the machining of a region that has an influence on the next machining process according to the association chart, which shows the subordination relationships of the geometrical constraints among removal volumes. If measurements indicate excess cutting, the system immediately stops machining because it is impossible for the workpiece to be modified. If measurements indicate incomplete cutting, the system re-machines the affected region and continues the machining process by recursively applying the NC program for the target removal volume. A case study was conducted in order to validate the proposed method of automated planning of on-machine measurement and re-machining. The result showed that the proposed system can automatically determine whether to stop or continue machining according to the measurement results.

Keywords

• on-machine measurement
• re-machining
• automation
• process planning
• nc program