CAJ | 학술논문

大型机床工作台在往复运动过程中，丝杠螺母会产生大量的热，一部分热量从螺母传入工作台导致工作台两侧翘曲，使工作台不同位置产生不同热误差。为提高大尺寸机床工作台的纵向热误差补偿精度，提出分段拟合热误差建模预测方法。该方法是沿工作台横向在多个位置建立对应点的纵向热误差模型，然后由各点单模型预测值进行分段拟合建立工作台整体预测模型，利用分段拟合模型实现对工作台任意位置热误差预测。同时为了提高热误差模型预测精度和鲁棒性，采用粒子群优化算法根据实时反馈热误差数据对模型参数辨识，使热误差模型能适应机床最新的工作状态。在一台三坐标铣床工作台上进行试验，建立X轴快速运动时工作台纵向热误差模型，试验结果表明：该方法鲁棒性好预测精度高，能够实现大尺寸工作台任意位置的热误差补偿，且具有一定的通用性。
대형궤상공작태재왕복운동과정중，사강라모회산생대량적열，일부분열량종라모전입공작태도치공작태량측교곡，사공작태불동위치산생불동열오차。위제고대척촌궤상공작태적종향열오차보상정도，제출분단의합열오차건모예측방법。해방법시연공작태횡향재다개위치건립대응점적종향열오차모형，연후유각점단모형예측치진행분단의합건립공작태정체예측모형，이용분단의합모형실현대공작태임의위치열오차예측。동시위료제고열오차모형예측정도화로봉성，채용입자군우화산법근거실시반궤열오차수거대모형삼수변식，사열오차모형능괄응궤상최신적공작상태。재일태삼좌표선상공작태상진행시험，건립X축쾌속운동시공작태종향열오차모형，시험결과표명：해방법로봉성호예측정도고，능구실현대척촌공작태임의위치적열오차보상，차구유일정적통용성。
When worktable is traveling along the X,Y, orZ axis of machine tool back and forth, due to frictional interaction between moving parts, a great amount of heat is generated in ball–screw drive systems, and part of it is transferred to the worktable, by which two sides of the worktable parallel to the guide way will be warped. So the thermal deformations of various positions on the worktable are different. In order to improve the accuracy of thermal error compensation of large size worktable, a multi-location forecasting model with piecewise fitting compensation method is proposed. The corresponding thermal error model of the multi-point on the worktable is established, and piecewise fitting of multi-point prediction model is used to implement a thermal error compensation for whole worktable. Furthermore, to improve prediction accuracy and robustness of the thermal error model, particle swarm optimization algorithm is utilized to identify the model parameters based on the real-time feedback data, and thus the thermal error model could adapt to the latest working condition of the machine tools. The thermal error compensation experiment of the worktable in a three coordinate milling machine is carried out under the condition ofX-axis’s fast movement. The experimental results indicate that this method has a good robustness and a high precision, which can compensate thermal error of large size worktable at any position, and this method is of universal applicability.