基于模态解耦-状态反馈控制的磁悬浮铣削系统稳定性研究

铣削加工效率和加工精度的提高,必然要求铣床加工速度的提高。随着磁悬浮技术的发展,高速磁悬浮电主轴已成为铣床的关键部件。然而磁悬浮电主轴转子系统在高速运行时存在较强的陀螺耦合效应,其过强的耦合效应使得高速铣削的稳定性区域变窄,甚至使铣削系统失稳。为此,提出基于PD控制器的模态解耦-状态反馈的控制方法。通过该方法对转子系统的平动模态和转动模态之间的耦合以及2个方向上转动模态之间的耦合进行解耦,独立调节各个模态控制器的比例和阻尼系数来降低陀螺耦合效应对磁悬浮铣削系统稳定性区域的影响,从而增大铣削的稳定性区域。通过仿真研究基于PD控制器的模态解耦-状态反馈控制前后陀螺耦合效应对铣削稳定性区域的影响。结果表明:通过基于PD控制器的模态解耦-状态反馈控制技术,不仅能够降低陀螺效应对铣削稳定型的影响,也能够改善铣削的稳定性区域。

Stability of Magnetic Levitation Milling System Based on Modal Decoupling-State Feedback Control

The improvement of milling processing efficiency and machining accuracy will require the improvement of milling machine processing speed. With the development of magnetic levitation technology, high speed magnetic levitation electric spindle has become a key component of milling machine. The magnetic levitating motorized spindle rotor system has strong gyro coupling effect at high speed operation, and its excessive coupling effect makes the stability region of high speed milling narrow and even makes the milling system unstable. So, a control method based on PD controller for modal decoupling-state feedback was proposed. By using the method, the coupling between the translational mode and the rotational mode of the rotor system and the coupling between the rotational modes in the two directions were decoupled,the proportional and damping coefficients of the controller were independently adjusted to reduce the influence of the gyro coupling effect on the stability region of the magnetic levitation milling system, and the stability region of milling was improved. The effects of modal decoupling-state feedback control gyro coupling effects on the stability of the milling region based on PD controller were studied by simulation. The results show that by using the modal decoupling-state feedback control technology based on PD controller, not only the effect of gyro effect on milling stability type can be reduced, but also the stability area of milling can be improved.