工业机器人由于其高柔性和低成本而被越来越多地应用到飞机自动钻铆系统中,使用精度补偿有效地提高机器人的绝对定位精度是保证产品质量的关键,为进一步提高机器人末端定位精度,提出了基于误差相似度的残差补偿方法。首先使用基于运动学参数标定的方法辨识出机器人的几何参数误差,再利用基于误差相似度的方法对残余误差进行估计,实现对机器人的误差和残差的补偿。以工业机器人KUKA KR-30 HA为对象所进行的试验验证表明,机器人的绝对定位精度平均值由补偿前的0.879mm经过定位误差补偿后提高到0.194mm,经过残差补偿后进一步提高到0.141mm,经过定位误差和残差补偿后的机器人最大误差由1.492mm降低为0.296mm,最大绝对定位精度误差降低了80.16%。该方法能有效地补偿参数辨识后遗留的残差,进一步提高机器人的定位精度。
Nowadays,industrial robots have been increasingly applied to aircraft automatic drilling and riveting system due to their high flexibility and low cost.The key to product quality assurance is compensating the absolute positional errors of the robot effectively.In order to further improve end location accuracy of the robot,a method of compensation for residual error based on error similarity is proposed.The geometric parameters of the robot are first identified based on kinematics parameter calibration.The residual error is then compensated based on error similarity.An experiment on the KUKA KR-30 HA industrial robot is conducted to demonstrate the effectiveness of the compensation.The result shows that the average absolute positioning accuracy of the robot can be improved from 0.879 mm to 0.194 mm after compensation of the positioning error.The average absolute positioning accuracy is further increased to 0.141 mm after a residual compensation.The maximum absolute positioning error is reduced by 80.16%from 1.492 mm to 0.296 mm.This method can compensate the residual errors left over after parameter identification effectively.