数控机床专用永磁同步电机分数阶滑模控制

Fractional Order Sliding Mode Control System for Permanent Magnet Synchronous Motor Using in NC Machine Tool

数控机床专用伺服电机要求很高的精度,尤其是在负载扰动和外部干扰情况下,也不能影响电机的精度。滑模控制方法无疑是一种比较适合伺服电机的控制算法,但存在抖震问题。针对传统整数阶滑模控制系统中存在的抖震问题,提出分数阶滑模控制策略。采用滑模分数阶导数面代替传统整数阶切换流形面,不但能增加系统调节自由度,而且利用分数阶算子随时间的衰减特性分散系统的能量,有效地削减抖震。并采用模糊逻辑推理算法,实现软开关切换增益的自整定。仿真结果证明:提出的基于参数模糊自整定的分数阶滑模控制系统不但能有效地削减抖震,而且能保持滑模控制器对系统参数变化的强鲁棒特性。

A scheme of designing fractional order sliding mode controller based on fuzzy inference algorithm was proposed for dealing with the chattering existing in conventional integral order sliding mode controller.Fractional calculus was introduced to design the control law of sliding mode controller.The soft-switching will not act on the integral order derivative of sliding mode surface but on its fractional order derivative.Based on the property of fractional calculus,this action will decrease chattering.Moreover,in order to deal with the upper bound of uncertainties,fuzzy logic inference algorithm was used to obtain the gain of soft-switching.Simulation results demonstrate that the proposed fractional order sliding mode controller based on fuzzy logic inference system not only can achieve better control performance than the conventional integral sliding mode control system,but also is robust with regard to system parameter variations.