基于旋量理论的数控机床几何误差分离与补偿方法研究

Research on Geometric Error Separation and Compensation Method of CNC Machine Tools Based on Screw Theory

针对机床制造和装配过程中产生的几何误差,建殳一种通用的、系统的机床几何误差模型与补偿方法。首先以旋量理论与多体运动学理论为基础,从机床单个运动链到机床整体进行分析并建立了一种通用的误差模型,该模型可分离出影响可补偿与不可补偿位姿误差的几何误差源。然后基于得到的12项可补偿几何误差利用激光干涉仪进行几何误差测量、补偿实验。为了验证补偿效果,利用球杆仪进行了补偿前后的对比实验。实验结果表明:经过补偿后机床的垂直度提高了16%,圆度提高了37%。证明了所提出的建模和补偿方法可有效提高机床加工精度。

For the geometric errors generated during the manufacturing and assembly of machine tools,a general and systematic method for modeling and compensating geometric error of machine tools is established.Firstly,based on the screw theory and multi-body kinematics,a general error model is established from the single movement chain of the machine tool to the whole machine tool.With this model,the geometric error sources that affect the compensable and uncompensable pose errors could be separated.Then,based on the obtained 12 compensable geometric errors,the geometric error measurement and compensation experiment was performed by laser interferometer.In order to verify the compensation effect,a comparative experiment before and after compensation was performed using a ballbar instrument.The experimental results show that with compensation,the verticality of the machine tool is increased by 16%;the roundness is increased by 37%.It is proved that the machining accuracy of machine tools could be effectively improved by the proposed modeling and compensation method.