多场耦合作用下的直驱进给系统运动误差形成机理与自适应控制研究

The development and development of high performance direct drive feed system are of great value and significance for supporting ultra-high speed/ultra-precision machining of high-grade CNC machine tools, promoting the construction of national defense capability and the development of strategic emerging industries. In the direct driven feed system, the cutting force and other external disturbances directly act on the mover of motor because of the "zero-drive" structure. The multi-field couplings, which involve electric field, magnetic field, structural displacement field and stress field, become more prominent. There are complex coupled relationship among the multi-source nonlinear disturbances and dynamic errors caused by the disturbance, affecting the machining accuracy and efficiency of the workpiece. It has become one of the main reasons restricting the application of direct driven feed system in the ultra-high speed/ultra-precision machining of high-grade CNC machine tools. In this project, aiming at the permanent magnet synchronous linear motor feed system, the mechanism of the multi-field coupling and formation mechanism of the dynamic error are studied under the multi-source disturbances. The model reference adaptive control method based on the coupled pattern recognition is produced, which provides the theoretical basis and technical support for the error tracing and performance improvement of direct driven equipment. The project starts from the representation of the frequency spectrum feature for the multi-source nonlinear disturbances. Then the multi-field coupling analysis method driven by the data and model is analyzed to reveal the mechanism of multi-field coupling and the formation mechanism of dynamic error. Based on the relationship among the coupling chain, stiffness chain and precision chain of direct drive feed system, a system integration model considering multi-field and multi-parameter coupling process is established. And then, the generation process of the motion error is analyzed. What is more, aiming at the complex working conditions, a model reference adaptive control method is constructed based on the coupled pattern recognition to improve the performance of the system under full parameters. At last, the experimental platform of direct driven feed system is built to verify the feasibility of the theoretical analysis and control method proposed in this project. In theory, the integrated modeling method for the multi-field coupling and analysis method of the motion error considering multi-source nonlinear disturbances are proposed, which will provide the theoretical basis for the performance analysis of direct drive equipment and the prediction of the motion error. In the engineering application, a model reference adaptive control method based on coupling pattern recognition is constructed, which will provide technical support for the performance improvement and product development of direct-drive motion equipment oriented to the intelligent development of high-grade CNC machine tools.

高性能直驱进给系统的开发与研制对于支撑高档数控机床超高速/超精密加工、推动国防能力建设和战略性新兴产业的发展具有重要的价值和意义。而由于直驱进给系统独特的零传动结构，伺服驱动和机械系统间存在着以应力场为媒介的机电磁力多物理场耦合现象，各场中的多源非线性扰动以及它们造成的运动误差之间存在着复杂的耦合演化关系，共同决定了系统的运动精度。尤其在零件加工过程中，多频交变切削力直接作用于电机动子，对电机输出推力特性的反向影响更加突出，加剧了直驱进给系统中的多场耦合问题，产生更加复杂多变的运动误差，影响零件加工精度和效率，这成为制约直驱进给系统在高档数控机床超高速/超精密加工中应用的主要原因之一。本项目针对永磁同步直线电机直驱进给系统，研究多源非线性扰动作用下的机电磁力多场耦合机理与运动误差形成机制，构建自适应控制方法，为直驱运动装备的误差溯源与性能改善提供理论依据和技术支撑。项目从多源非线性扰动全参数下的频谱特性建模与多维演变规律表征入手，将数据驱动技术与谱特征理论相融合，研究多源非线性扰动作用下的直驱进给系统机电磁力多物理场耦合过程与耦合机理；基于直驱进给系统的耦合链-刚度链-精度链综合作用关系，建立考虑多场多参数耦合过程的系统集成模型，分析多场耦合作用下的运动误差生成—传递—耦合—演化过程，揭示多场耦合机理与运动误差形成机制；构建基于耦合模式识别的模型参考自适应控制方法，保证系统在零件加工全过程的运动性能；最后搭建开放式直驱实验平台进行测试，验证项目提出的理论模型和控制方法的可行性。本项目在理论上，提出多源非线性扰动作用下的直驱进给系统机电磁力多场耦合问题集成建模与运动误差分析方法，为直驱运动装备的性能分析和运动误差的预测与溯源提供理论依据；在工程应用上，构建基于耦合模式识别的模型参考自适应控制方法，面向高档数控机床智能化发展，为直驱运动装备的性能改善与产品开发提供技术支撑。

永磁同步直线电机进给系统取消了所有中间机械传动环节，电机动子直接和驱动部件相连，伺服驱动系统与机械系统之间存在着复杂的多参数多回路耦合作用。尤其在切削加工过程中，多频的切削力扰动以及复杂的机械动态特性，会加剧直线电机进给系统中的多物理场耦合现象，恶化进给系统的运动性能以及零件的加工精度。本项目针对应用于数控机床的直线电机直驱进给系统，综合考虑各类非线性扰动，系统表征了切削加工过程中的多源扰动（电机推力、电机法向吸力、切削力、摩擦力等）的频谱特征以及参数演变规律；综合考虑结合部柔性以及电机动子和定子配套机械部件动态特性建立了机械系统动力学模型，分析了机械系统的主要振动形式和模态分布，解析表征了机械系统在多源扰动作用下的输出响应；针对直驱进给系统的机电磁力多物理场耦合问题，将数据驱动技术与频谱特征理论建模相融合，以各物理场非线性扰动谱特征建模为基础，以数据挖掘与特征融合为手段，提出了一种机电磁力多物理场耦合分析方法，系统分析了加工过程中的气隙波动、编码器误差、反馈控制等不同层级间不同参数间的多场耦合现象，为各类直驱运动装备多场耦合问题的研究提供了新思路。建立了多场耦合方程，提出了耦合强度定量评价方法，阐明了以应力场为媒介的直驱进给系统磁场、电场、结构场之间的非线性转换的力学机理和本构关系，从本质上揭示多源非线性扰动作用下的机电磁力多场耦合机理；建立多场耦合作用下的系统集成模型，揭示了运动误差的生成-传递-耦合-演化机制，解析表征了多源扰动作用下的系统运动精度，为直驱运动装备的性能分析以及运动误差的预测与溯源提供理论依据。基于以上研究，根据不同耦合回路的发生条件、耦合机制以及造成的运动误差形式，提出了多物理场耦合特征检测与耦合模式精确识别方法；构建了一种基于耦合模式识别的直驱进给系统模型参考自适应控制方法，为实现直驱运动装备的智能控制提供了理论和技术基础。