雙轉(zhuǎn)臺(tái)五軸數(shù)控機(jī)床旋轉(zhuǎn)軸位置無關(guān)幾何誤差辨識(shí)

張文斌 劉煥牢 王宇林 周恒宇

摘要：

針對(duì)雙轉(zhuǎn)臺(tái)五軸數(shù)控機(jī)床旋轉(zhuǎn)軸幾何誤差辨識(shí)精度問題，提出一種在機(jī)床坐標(biāo)系下的旋轉(zhuǎn)軸位置無關(guān)幾何誤差（PIGEs）辨識(shí)模型。建立了刀具球與工件球在機(jī)床坐標(biāo)系下的實(shí)際初始坐標(biāo)，通過逆矩陣得到工件球在所測(cè)軸的實(shí)際初始位置，基于4種測(cè)量模式建立了包含球桿儀安裝誤差與旋轉(zhuǎn)軸PIGEs的桿長(zhǎng)變化量數(shù)學(xué)模型。仿真分析了PIGEs對(duì)測(cè)量模式的影響，結(jié)果表明刀具球在兩旋轉(zhuǎn)軸軸線交點(diǎn)位置時(shí)，平行度誤差不影響球桿儀桿長(zhǎng)變化量。最后，通過實(shí)驗(yàn)辨識(shí)出旋轉(zhuǎn)軸8項(xiàng)PIGEs，并對(duì)旋轉(zhuǎn)軸PIGEs的4項(xiàng)位置誤差進(jìn)行補(bǔ)償。實(shí)驗(yàn)結(jié)果表明，補(bǔ)償后的位置誤差最大絕對(duì)值由203.5 μm減小至5.1 μm，所提出的辨識(shí)模型可以有效提高五軸機(jī)床精度。

關(guān)鍵詞：五軸數(shù)控機(jī)床；旋轉(zhuǎn)軸；位置無關(guān)幾何誤差；機(jī)床坐標(biāo)系；球桿儀

中圖分類號(hào)：TH161

DOI：10.3969/j.issn.1004132X.2024.06.008

開放科學(xué)（資源服務(wù)）標(biāo)識(shí)碼（OSID）：

Identification of Rotary Axes PIGEs of Five-axis CNC Machines with

Double Rotary Tables

ZHANG Wenbin? LIU Huanlao? WANG Yulin? ZHOU Hengyu

School of Mechanical Engineering，Guangdong Ocean University，Zhanjiang，Guangdong，524088

Abstract： Aiming at the problems of the accuracy in identifying geometric errors of rotation axis of five-axis CNC machines with double rotary tables， an identification model of PIGEs of rotation axis on absolute coordinate system was proposed. The actual initial coordinates of the tool ball and the workpiece ball in the machine coordinate system were established， and the actual initial position of the workpiece ball in the measured axis was obtained by the inverse matrix. The mathematical model of the double ball bar length changing included installation errors and the PIGEs of the rotation axis was established based on the four measurement patterns. The effects of PIGEs on the measurement pattern were analyzed by simulation. The results show that the parallelism error may not affect double ball bar length changing when the tool ball is at the intersection of the two rotation axis. Finally， 8 PIGEs of the rotary axis were identified through experiments， and 4 positional deviations of the rotary axis PIGEs were compensated. The experimental results show that the maximum absolute value of the compensated positional error is reduced from 203.5 μm to 5.1 μm， and the proposed identification model may effectively improve the accuracy of five-axis CNC machines.

Key words： five-axis CNC machine； rotation axis； position-independent geometric error（PIGE）； machine coordinate system； double ball bar

收稿日期：20230915

基金項(xiàng)目：國家自然科學(xué)基金（52175458）；廣東省自然科學(xué)基金（2021A15150110591）；廣東省教育廳項(xiàng)目（2022ZDZX3006）

0? 引言

五軸機(jī)床在加工形狀復(fù)雜的零部件時(shí)有獨(dú)特的優(yōu)勢(shì)，提高五軸機(jī)床的精度是提高加工精度的關(guān)鍵［1］。在加工過程中，影響加工精度的因素包括幾何誤差［2］、熱誤差［3］、伺服誤差［4］和切削力［5］引起的誤差。根據(jù)標(biāo)準(zhǔn)ISO 230-1［6］、ISO 230-7［7］和ISO 10791-1［8］中的定義，機(jī)床幾何誤差是加工過程中影響加工精度的主要來源。目前已知五軸機(jī)床的幾何誤差多達(dá)41項(xiàng)，其中旋轉(zhuǎn)軸的幾何誤差成為加工過程中的主要誤差源，包括12項(xiàng)位置相關(guān)幾何誤……