在进行高精度曲率半径测量时, 三点支撑方式会引入测量误差。对该误差进行了理论分析及有限元仿真, 并通过实验对仿真结果进行了验证。结果表明, 支撑形变中的旋转对称误差项导致测量结果失准。在特定实验条件下, 得到的补偿量小于70 nm, 基于此对三点支撑下的曲率半径测量值进行补偿, 可以提高测量精度。

When the high-precision measurement of the curvature radius is performed, the measurement error is introduced under three-point support. The theoretical analysis and the finite element simulation of the errors are carried out and the simulation results are verified by experiments. The results show that the rotationally symmetric error of support deformation leads to the inaccurate radius. The compensation is less than 70 nm under the specific experimental conditions. Based on this, the measurement accuracy can be increased when the measured value of the curvature radius under three-point support is compensated.