关键词: 复合加工机床, 运动学模型, 空间误差, 补偿, L-M算法

Abstract: The kinematic modeling of the special structure compound machine tool is carried out by D-H and H-M methods,so that the machine tool volumetric positioning error measured by the laser tracker is convenient for model parameter identification,and the forward solution of the machine theoretical model and the identification parameters of the machine kinematic error model are listed.In the kinematic error model of the machine tool,taking the theoretical volumetric position and orientation of the verification points as the basis,according to the Jacobi matrix of the volumetric position and orientation of the tool point relative to the coordinate axis of the machine tool,the block matrix combined with the L-M algorithm is used to calculate the coordinate axis compensation of the verification points,the algorithm converges quickly,and the calculation efficiency is improved compared to the Jacobi matrix iterative method,and the average value of the volumetric position and orientation error of the machine tool after the coordinate axis compensation is 0.004 22 mm and 9.99×10^-4 rad. Compared with the error before compensation,the error is reduced by 82.5 % and 16.1 %,respectively,indicating that the volumetric position and orientation accuracy of the compound machine tool has been greatly improved.

Key words: compound machine tool, kinematic model, volumetric error, compensation, L-M algorithm