On-machine noncontact scanning of high-gradient freeform surface using chromatic confocal probe on diamond turning machine.

• An on-machine noncontact scanning method for high-gradient surface is presented. • Segmented motion is designed considering steepness angle and planning deviations. • The chromatic confocal probe is integrated into the diamond turning machine. Inspecting a high-gradient freeform surface is a challenging task in manufacturing automation due to its complexity of the surface and high-aspect-ratio. On-machine measurement has shown remarkable achievements in ultra-precision manufacturing. In this paper, an on-machine noncontact scanning method using chromatic confocal probe for high-gradient freeform surface is proposed. First, a coordinate sampling model of scanning based on an ultra-precision diamond turning machine is established. Then, the steepness angle is defined to guide the scanning curves distribution, and global mesh scanning lines are generated by controlling planning deviations. Segmented motion trajectory of the probe is designed considering the vector direction of optical axis and sensor offset error. Finally, the scanning parameters are determined and the NC inspection program is generated. The proposed method can make a balance between accuracy and efficiency. Its effectiveness is verified by the on-machine inspection experiments. [ABSTRACT FROM AUTHOR]