在对θFXZ型测量机Z轴伺服系统的机械结构和控制系统进行分析的基础上,建立了伺服系统的动力学模型.根据受力分析,对系统的干扰力进行建模.利用对PID参数的自适应调节和干扰力的前馈补偿,实现对系统的误差补偿.实验结果表明,补偿后的跟踪误差约为补偿前的1/4,系统静差也由原来的2μm减小到0.4μm以内.该伺服系统的动力学建模和干扰力建模能直观、有效地描述Z轴系统的运动特性,补偿方案能很好地改善系统的动态跟踪误差和控制定位精度.
A dynamic model was built on the basis of mechanical structure and the control system of Z-axis servo sys-tem of θFXZ-type coordinate measuring machine.Then the disturbing force model was built by force analysis.Finally,through the PID parameters′ adaptive adjustment and feed-forward compensation for disturbing force,the error compensation of the system was carried out.The experimental results show that the following error after com-pensation is four times less than that before compensation,and the static error of the system after compensation de-creases from 2.0 μm to 0.4 μm.In a word,the servo system dynamic model and disturbing force model can intuitively and effectively describe the movement characteristics of Z-axis system.Furthermore,the compensation method can improve the following error of the system and the positioning accuracy.