高速电主轴精度损失的热力影响机理及调控方法研究

Accuracy preservation is one of the most important contents to evaluate the accuracy and reliability of high-speed motorized spindles, and the thermodynamic characteristics are important factors affecting accuracy preservation. It is of great significance for high efficiency, high speed, and high precision of machining to grasp the law of accuracy loss and seek the methods of accuracy preservation through investigation on thermo-mechanical mechanism of high-speed motorized spindles..The thermal network model of motorized spindle system is established based on thermal resistance. The influence mechanism of the temperature field of spindle system affected by the variation of structural constraints, contact characteristics between surfaces, operating conditions, cooling and lubrication is analysised.The effect of non-uniform temperature field on the friction/wear and accuracy decline of high-speed motorized spindles is obtained. After collecting the precision loss data based on time series, the precision loss evaluation and.prediction model based on the thermal characteristics of high-speed motorized spindle system is established through identifying the sensitive factors and the sensitive feature parameters. To achieve robust control of the spindle precision recession, the look-ahead algorithm based on multi-fields/multi-characteristics，and active control method integrated deeply with CNC system and NC programs and adjustment technologies are proposed..The main innovation of this research is devoted to establish a complete set of precision loss evaluation, prediction and robust control method for high-speed motorized spindle system based on thermodynamics.

精度保持性是评价高速电主轴工作精度和可靠性的重要内容，热力特性是影响主轴精度保持性的重要因素。研究主轴系统热力影响机理，掌握精度损失规律，寻求精度保持方法，对实现高效、高速、高精加工意义重大。.基于热阻热容法，建立电主轴系统热传递网络模型，分析结构约束、接合面接触特性、气/液流场、工况变化对主轴系统温度场的影响机制，找出非均匀温度场对高速电主轴摩擦/磨损和精度损失的影响规律；基于时间序列采集精度退化数据，通过对敏感因素和敏感特征参数的辨识研究，建立高速电主轴系统基于热力特性的精度损失评价与预测模型；提出基于多场/多特性的精度损失前瞻计算方法，与数控系统和数控加工程序深度融合的主动调控以及离线调整方法，实现对精度损失的稳健调控。.本项目主要创新：建立一套完整的、基于热力特性的高速电主轴系统精度损失评价、预测、稳健控制方法。

开展高速电主轴系统的热力特性分析，进行复杂工况下高速电主轴多场耦合热力特性机理及耦合效应研究，掌握主轴精度损失规律，寻求精度保持技术和方法，对实现高效、高速、高精乃至智能加工具有重要理论意义和应用价值。.首先，开展了主轴轴承热位移、考虑振动效应的热生成以及考虑结构和装配约束的热作用机理研究，对轴承热阻网络进行了改进，并且在此基础上分析了轴承配置形式和主轴工况参数对轴承温度场变化的影响规律和耦合关系；建立了基于热力特性的高速主轴精度损失模型，研究了高速主轴精度损失评价规划和方法。.其次，开展了对主轴系统的稳态热分析，求解了主轴系统温度场信息，并在此基础上完成了对主轴系统热位移误差建模；完成了主轴系统回转误差辨识与检测系统设计；研究了主轴结构配置、气/液流场结构和工作参数、主轴工况参数对于精度损失的影响规律；提出了基于响应面和NSGA-II的主轴精度损失模型多目标参数修正方法，完成了模型的优化。.最后，开展了对数控铣床系统铣削工件时的精度损失的试验分析，利用试验数据，建立了基于BP神经网络的数控加工精度损失预测模型，提出了利用遗传算法对数控加工工艺参数进行优化的稳健调控方法；完成了对预紧力作用下角接触球轴承刚度理论的分析计算；搭建了基于压电陶瓷预紧装置的主轴系统精度损失离线调控平台，实现了以跳动和振动为主要控制量的离线轴承预紧。