Gravity/Inertia Force Error Compensation for Optical Free-Form Surface Milling Machines

doi:10.12068/j.issn.1005-3026.2025.20230266

Abstract

Abstract:

In order to improve the machining accuracy of optical free-form surfaces， given the shortcomings of traditional machine tools in heat and force， a new five-axis machine tool topology is constructed， which can effectively reduce the influence of thermal deformation on the accuracy of machine tools， and a synchronous compensation method of gravity/inertial force error is proposed. The error compensation effect of different error compensation methods are compared and analyzed. The results show that the accuracy of milling machines can be greatly improved by using gravity balance combined with mechanical shunt column， and the error compensation effect of variable force （VF） is significantly better than that of constant force （CF）， the error compensation effect of two-dimensional motion gravity balance （TMGB） is significantly better than that of fixed gravity balance （FGB）. The worst compensation method is FGB combined with CF， while the best compensation method is TMGB combined with VF. The combination of FGB combined with VF and TMGB combined with CF have their own advantages and disadvantages under different conditions.

Key words: optical free-form surface, thermal error, inertia force error, gravity error, error compensation, error prevention

CLC Number:

TP 20

Qi LI, Chao ZHANG, Tian-biao YU, Wan-shan WANG. Gravity/Inertia Force Error Compensation for Optical Free-Form Surface Milling Machines[J]. Journal of Northeastern University(Natural Science), 2025, 46(2): 104-110.

Figures/Tables 14

Fig. 1 Optical free-form surface milling machine

Fig. 2 Gravity/inertia force transfer path of the optical free-form surface milling machine

Fig. 3 Working principle of gravity balance

Fig. 4 Error compensation model of the optical free-form surface milling machine

Fig. 5 Space errors of the spindle end at different positions （gravity load）

Fig. 6 Space errors of the spindle end at different positions （gravity load+cutting load）

Fig. 7 Space errors of Z-axis guide rail adopting different compensation methods at the origin

Fig. 8 Straightness of Z-axis guide rail adopting different compensation methods at the maximum travel limits

Fig. 9 Space errors of Z-axis lead screw adopting different compensation methods at the origin

Fig. 10 Straightness of Z-axis lead screw adopting different compensation methods at the maximum travel limits

Fig. 11 Space errors of Y-axis guide rail adopting different compensation methods at the origin

Fig. 12 Straightness of Y-axis guide rail adopting different compensation methods at the maximum travel limits

Fig. 13 Space errors of X-axis guide rail adopting different compensation methods at the origin

Fig. 14 Straightness of X-axis guide rail adopting different compensation methods at the maximum travel limits

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