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.

由于表面的复杂性和高长宽比，检查高梯度自由曲面是制造自动化中的一项艰巨任务。机上测量在超精密制造中显示出显著成就。本文提出了一种使用彩色共聚焦探头在高梯度自由曲面上进行机上非接触扫描的方法。首先，建立了基于超精密金刚石车床的扫描坐标采样模型。然后，定义陡峭角度以引导扫描曲线分布，并通过控制计划偏差生成全局网格扫描线。设计探针的分段运动轨迹时要考虑光轴的矢量方向和传感器偏移误差。最后，确定扫描参数并生成NC检查程序。所提出的方法可以在准确性和效率之间取得平衡。通过机上检查实验验证了其有效性。