基于静压轴承的非圆轨迹成型及控制

Non-circular Trajectory Forming and Control Technology Based on Hydrostatic Bearing

为了实现机床的非圆曲面加工,采用了基于主动控制型静压轴承系统的非圆轨迹成型技术。系统由静压轴承和压电薄膜节流器组成,主要原理是通过节流器对静压轴承进油量的主动调节实现主轴的非圆轨迹运动。同时对系统进行动力学建模和参数辨识进而得到了系统模型。通过实验中主轴非圆轨迹的运动,验证了系统模型的有效性。此外,对于该系统在加工中存在的外部扰动进行了分析,从而得到在外部扰动下主轴轨迹的变化情况,最后通过PID控制器对主轴的运动进行调节。仿真结果显示,PID控制器能够较好地对误差进行调节。

In order to realize the machining of non-circular surface,a non-circular trajectory forming technology based on active control hydrostatic bearing system is adopted.The system is composed of hydrostatic bearing and piezoelectric membrane restrictors.The basic principle of the system is to realize the non-circular trajectory of the spindle through the active adjustment of the oil intake of hydrostatic bearing by the restrictors.The dynamic modelling and parameters identification of the system are carried out,and then the system model is obtained.The validity of the system model is verified by the non-circular trajectory of the spindle in the experiment.In addition,the external disturbance of the system in the processing was analyzed,so as to get the spindle trajectory under the external disturbance.Finally,the motion of the spindle is adjusted by PID controller.The simulation results show that the PID controller can adjust the motion error.