服役态下的机床进给轴热误差自适应补偿方法研究

Thermal error is the main factor that affects the accuracy stability of machine tools, and the prediction and compensation for thermal error is always a challenging problem in the field of machine tools. Earlier research found that the following problems still exist: the thermal behavior of machine tools with specific structure isn't studied clearly, resulting in the lack of scientific basis for thermal error modeling; adaptive compensation under service conditions for complex working conditions and wear of screw is still a problem to be solved. In this project, the thermo-mechanical coupling behavior of ball screw and the adaptive compensation method for thermal error are studied. The screw's thermo-mechanical coupling mechanism under multiple time-varying dynamic heat sources, thermal elastic under single time-varying heat source, and effect of screw restraint on thermal behavior are all revealed. The prediction models of screw's temperature field and thermal error under multiple time-varying dynamic heat sources are both established. Based on the analysis of screw-nut pairs' friction characteristic and its influence factors, the fuzzy adaptive adjustment method for frictional heat based on multivariate information fusion is presented to realize the adaptive compensation for thermal error. Finally, the compensation effect is verified under service conditions of machine tools. The purpose of this study is to reveal the thermo-mechanical coupling behavior of ball screw, and to establish thermal error adaptive compensation method of servo axis under service conditions to solve the theoretical and technical problems in the application of thermal error compensation.

数控机床的热误差是影响其精度稳定性的主要因素，而对热误差的预测和补偿一直是机床领域具有挑战性的难题。研究发现，目前仍存在如下问题：对特定结构机床的热行为规律认识不够清晰，热误差建模缺乏科学依据；尚未解决机床服役态下针对复杂工况及丝杠磨损等的自适应补偿问题。本项目围绕上述问题，开展丝杠的热-力耦合行为及热误差自适应补偿方法的研究。揭示多时变动态热源作用下丝杠的热-力耦合机理、单时变热源作用下丝杠的热弹性以及丝杠约束方式对热行为的影响规律，建立多时变动态热源作用下的丝杠温度场和热误差预测模型，基于对丝杠螺母副的摩擦特性及影响因素的分析，提出多元信息融合的摩擦热参数模糊自适应调整方法，实现对热误差的自适应补偿。最后，在机床服役态下验证补偿的效果。本研究旨在科学揭示滚珠丝杠的热-力耦合行为规律，创建服役态下的进给轴热误差自适应补偿方法，解决热误差补偿技术在应用中面临的理论和技术问题。

面向国产数控机床精度稳定性提升的迫切需求，针对机床进给轴丝杠热-力耦合机理不明、热误差补偿精度和鲁棒性差等关键问题，本着“接受机床环境热扰动”的思路，围绕关键科学问题“多源时变热源激励下的机床热行为规律”，系统研究了服役态下的机床进给轴热误差理论与技术。. 在理论与技术研究方面，揭示了多源时变热源作用下的丝杠热-力耦合作用机理，阐明了丝杠热弹性效应及热变形伪滞后性特征，厘清了预拉伸丝杠的完整热行为规律。揭示了进给轴原点热漂移误差的规律及成因，并提出了其测试与分离方法；建立了传热机理驱动的进给轴热误差预测模型，并研究了其热特性参数快速辨识方法。分析了丝杠螺母副的摩擦特性及其影响因素，提出了基于丝杠摩擦热变化规律的热误差自适应补偿方法，实现了机床服役态下进给轴热误差在线补偿。. 在系统开发与成果应用方面，开发了机床进给轴热误差补偿系统，研究成果应用于沈机集团、航发集团430厂、航发集团460厂和航天科工三院31所等重点企业，机床进给轴热误差降幅达到94.8%，被用户评价为“显著提高了数控机床的加工稳定性，降低了航发零件的不良品率”、“促进了CJ导弹冲压发动机进气道、燃烧室等核心关键零件的高精度加工”。. 本项目发表/录用学术论文14篇，其中发表SCI论文9篇；授权国家发明专利12项，国外发明专利2项；登记软件著作权4项。所形成的数控机床进给轴热误差理论与技术，对指导数控加工装备热特性优化设计，推动机械制造行业对数控加工装备热行为认知水平提高，助推数控加工装备精度稳定性提升具有重要作用。