机床横梁悬浮系统的反演自适应动态滑模变结构控制研究

Study on Machine Tool Crossbeam Magnetic Levitation SystemBased on Backstepping Self-adaptive Dynamic Sliding Mode Control

在龙门数控加工中心移动横梁磁悬浮系统中,刀具切削工件过程中磁悬浮系统所受到扰动和系统自身参数的时变性对悬浮高度有影响。为了实现悬浮高度的精确控制,设计了控制悬浮高度的反演自适应动态滑模控制器,该控制器可有效削弱系统抖振并保持悬浮高度的稳定性;引入自适应控制策略,大大改进了滑模控制对不确定性系统参数的控制能力。仿真结果表明:该控制器具有很强的抗扰性,并使系统具有较高刚度,实现了稳定悬浮。

Disturbance and the system parameters time variation have effects on magnetic levitation system when the tool was cutting.In order to achieve levitation gaps precision control,a backstepping self-adaptive dynamic sliding mode controller was designed at the moving crossbeam levitation system of the gantry NC machining center.Using this method,chatting of the system could be effectively decreased and the stability of levitation system could be kept.Due to the introduction of self-adaptive control strategy,the control ability restraining parameters uncertainty was greatly improved.The simulated result shows that this controller has powerful anti-disturbance ability and makes the system has high rigidity.It can achieve steady levitation.