基于多体系统理论的机床几何误差预测模型

Machine Tool Geometric Error Prediction Model Based on Multi-Body System Theory

针对五轴机床几何误差建模,首先,从分析误差产生机制和建立精度误差补偿模型的角度,提出了基于多体系统理论的平动轴几何误差模型;其次,依据误差模型,对运动轴联动所产生的圆弧轨迹进行了预测,并与球杆仪实测圆轨迹进行对比验证;同时,依据三角函数法对球杆仪偏置误差进行了分离和辨识,还原出实际的几何误差;最后,实验表明所提方法能有效地去除球杆仪检测时引入的偏置误差,经误差模型预测的圆度与球杆仪实测值的误差百分比为4.2%,所提预测方法效果显著。

Aiming at the geometric error modeling of five-axis machine tools, firstly, a translational axis geometric error model based on multi-body system theory was proposed from the angle of analyzing error generation mechanism and establishing accuracy error compensation model. Secondly, according to the error model, the arc trajectory generated by the motion axis linkage was predicted, and compared with the measured circle trajectory of the cue instrument. At the same time, according to trigonometric function method, the bias errors of the cue apparatus are separated and identified, and the actual geometric errors are restored. Finally, the experimental results show that the proposed method can effectively remove the bias errors introduced by the rod tester, and the error percentage between the roundness predicted by the error model and the measured value of the rod tester is 4.2%, indicating that the proposed method is effective.