基于压脚位移补偿的机器人制孔锪窝深度控制

为了解决机器人自动制孔过程中由于飞机壁板变形和振动引起的锪窝深度控制问题,提出将终端执行器压脚位移作为实时补偿信号的制孔进给轴全闭环控制系统设计方法;根据制孔过程中压脚振动的实际频率特性,引入低通滤波器,考虑飞机壁板锪窝深度精度要求确定截止频率,有效抑制压脚高频振荡对进给轴位置精度的影响,保证锪窝深度以及加工孔的表面质量.在材料为铝合金的圆弧工件和平面工件上,分别加工直径为5.8和9.8mm的孔.实验结果表明,该系统可将加工孔的锪窝深度误差控制在0.02mm以内,表面粗糙度达到0.8μm.

Countersink depth control of robot drilling based on pressure foot displacement compensation

A method of full closed loop control system design for end effector’s feed shaft was presented in order to ensure the countersink depth of robot drilling caused by the deformation and vibration of the aircraft’s panels.The displacement of end effector’s pressure foot was added to countersink depth as real-time compensation.A low-pass filter was introduced to restrain the interference of high frequency vibration to feed shaft’s positioning accuracy according to the vibration frequency characteristics of the pressure foot during the drilling process.Its cutoff frequency was determined by the countersink depth accuracy of the aircraft’s panels,and thereby the countersink depth was ensured and the high hole quality was achieved.Drilling with hole diameter 5.8 mm and 9.8 mm on arc and flat aluminum alloy workpiece respectively,the hole quality turned out to be very accurate,with the countersink depth variation at 0.02 mm in the worst case and the surface roughness reaching 0.8 μm.