为实现开放式机床控制器可移植性要求,提出一种可应用于交流伺服电机和步进电机的基于虚实映射的半闭环控制结构模型。在此基础上,讨论了针对步进电机的经济型机床半闭环结构的比例+积分的控制器设计方法。为降低机床传动机构所产生的螺距误差,通过激光干涉仪实际测量正反向定位值,将测量结果作为一个非线性环节引入半闭环结构中实现机床的螺距误差补偿。实验结果表明,该方法可实现机床伺服轴定位累积误差由220μm缩小到11μm。
To reach the replant demands of open architecture CNC machine tools, a semi-closed control structural model which can be applied for AC servo motor and stepping motor was presented based on false or true mapping. Then the design of proportional plus integal controller for stepping motor used in economic machine tool semi-closed control structure was discussed. To reduce the screw errors produced by the machine tool driving train, the forward and backword positioning values were measured by laser interferometer and the results were used as a nonlinear unit in the semi-closed loop structure to fulfill the screw compensation. The experimental results show that it can reduce accumulate positioning errors of the machine tool servo system from 220μm to 11/μm.