基于改进LuGre摩擦模型的数控机床进给系统摩擦补偿与参数优化

Enhanced LuGre friction model-based friction compensation and dynamic parameter optimization for CNC feed drive systems

  • 摘要: 针对数控机床进给伺服系统中摩擦力对加工精度和动态性能的影响,聚焦伺服系统摩擦补偿与参数优化问题。首先,通过构建直线电机伺服系统机电耦合模型,建立其控制系统基本框架。其次,为精准估计动态特性及与位置相关的摩擦效应,对LuGre(Lundt-Grenoble)摩擦模型进行优化,并运用改进粒子群算法进行参数辨识。最后,采用LuGre前馈补偿与伪微分反馈与前馈(pseudo-derivative feedback with feedforward,PDFF)混合控制方法,对系统非线性摩擦进行补偿,并开展进给伺服系统性能评估及控制器参数优化工作。实验结果显示,实际位置输出超调量较优化前减少10.7%,时间滞后量缩短0.05 s,跟随误差减少0.06 mm。

     

    Abstract: Impact of friction on machining accuracy and dynamic performance in CNC machine tool feed servo systems is addressed through friction compensation and parameter optimization. Firstly, an electromechanical coupling model of the linear motor servo system was established to construct the fundamental framework of its control system. Secondly, to accurately estimate dynamic characteristics and position-dependent friction effects, the Lundt-Grenoble (LuGre) friction model was optimized, and an improved particle swarm optimization algorithm was employed for parameter identification. Finally, a hybrid control method combining LuGre feedforward compensation with pseudo-derivative feedback with feedforward (PDFF) was adopted to compensate for system nonlinear friction, followed by performance evaluation of the feed servo system and controller parameter optimization. Experimental results demonstrate that the actual position output overshoot is reduced by 10.7% compared with pre-optimization values, the time lag shorten by 0.05 s, and tracking error reduces by 0.06 mm.

     

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