基于PDFF双直线电机二阶滑模交叉耦合控制

Second Order Sliding Mode Cross Coupling Control for Dual Linear Motors Based on PDFF

针对龙门移动式镗铣床双直线电机同步进给控制问题,采用具有前馈的伪微分反馈(PDFF)控制框架来设计各轴子系统速度控制器,以提高系统的抗干扰能力和响应速度。同时,设计一个二阶滑模交叉耦合控制器,以解决双位置环系统输出端机械耦合、电机参数变化和外部扰动等不确定性因素对同步精度的影响。二阶滑模控制律采用超螺旋算法,它可以消除相对阶为1的变结构系统的抖振现象。仿真结果表明该控制方案具有很强的鲁棒性,在不对称负载的条件下能实现位移同步。

For the control problem of the synchronized feed of dual linear motors in gantry-moving type milling machine tool, a Pseudo-Derivative Control with Feedforward Gain （PDFF） control was applied to the speed controller design of subsystem, which greatly improved the capability of the anti-jamming and the speed of response. At the same time, a second order sliding mode across-coupling synchronized controller, which can reduce the influence on the synchronization precision that was caused by the uncertainties, such as the machine coupling on the fan-out of the double velocity loops, the parametric variations of linear motor and the external disturbances, was presented to implement the synchronized feed of dual linear motors in gantry-mov- ing type milling machine tool. The super-twisting algorithm, which can remove the twitter phenomenon of the variable structure whose relative degree is one, was adopted by the control of the second order sliding mode variable structure. The simulation results show that the proposed control scheme is robust greatly and may achieve the position dynamic synchronization under the condition of asymmetry load.