直驱磨削过程推力-转矩波动耦合机理与抑制方法研究

It is widely used in the high efficiency and precision grinding of variety of complex rotating parts such as camshaft, crankshaft and rotor engine cavity that linear motor drives wheelhead while torque motor rotates workpiece. For canceling the transmission mechanism, the ripples of linear motor and torque motor act on the workpiece directly with delivering and coupling. That will influence the grinding process stability. Therefore, this project studies the ripple coupling mechanism of thrust-torque during direct drive grinding.Considering the combined effects of itself structure effect and grinding force, speed,loading changing of processing, revealing the relationship between following error and the output ripple of direct drive motor, thrust and torque ripple nonlinear fitting dynamics model is built. Combining the theory of multi-body dynamics and motor vector control theory, thrust-torque ripple electromechanical coupling model is founded based on contour error, stuying the law of ineraction among linear motor thrust, torque motor torque and grinding force. On this basis, suppresion method of direct drive grinding thrust-torque coupling ripple is proposed from the aspects of offline fluctuation compensation, processing parameters optimization, and online control. Provide the theory and technology basis for achieving the stable control of high efficiency direct drive grinding, and improve the design and manufacturing standards of advanced numerical control machine tools.

直线电机驱动砂轮架进给、力矩电机带动工件旋转的加工方式，广泛应用于凸轮轴、曲轴、转子发动机内腔等多种复杂回转类零件的高效精密磨削。由于取消了中间传动机构，直线电机的推力波动、力矩电机的转矩波动将直接作用于工件，且相互传递、相互耦合，影响磨削过程稳定。因此，项目对高效直驱磨削过程中的推力-转矩波动耦合机理进行研究，充分考虑直驱电机本体因素及负载力、承重、速度变化等加工条件的综合作用，揭示跟踪误差与直驱电机输出波动之间的关系，建立推力、转矩波动非线性拟合动力学模型；结合多体系统动力学与电机矢量控制理论，建立基于廓形误差的直驱磨削机电耦合模型，探索直线电机推力、力矩电机转矩波动与磨削力相互耦合规律；在此基础之上，从波动离线补偿、加工参数优化及在线控制三个方面提出直驱磨削过程推力-转矩耦合波动的综合抑制方法。为实现高效直驱磨削过程稳定控制、提高高端数控机床设计制造水平提供理论和技术基础。

凸轮轴、曲轴、偏心轴等复杂精密零件普遍采用X-C直接驱动联动磨削，其加工精度直接影响装备整机性能。然而加工过程中直线电机的推力波动、力矩电机的转矩波动将直接作用于工件，已成为影响直驱高效磨削加工精度的重要因素。项目建立了直线电机推力波动、力矩电机转矩波动的数学及仿真模型；提出了有限元方法辨识频率、递推最小二乘法辨识幅值的推力、转矩波动拟合方法；搭建了实验台，进行了推力波动与转矩波动采集与控制的仿真与实验验证；分析了X-C直驱磨削过程中误差耦合机理，建立了基于X-C直驱磨削机电耦合仿真模型；提出了过渡廓形规划加工路径优化的离线控制方法与交叉耦合非线性控制的在线控制方法，并进行了仿真与部分实验验证。上述方法一定程度上实现了直驱磨削过程推力-转矩波动有效抑制。