白车身柔性测量机器人本体补偿方法

Main Body Compensation Method of Flexible Measuring Robot for Car BIW

为了提高柔性坐标测量系统的精度,提出了测量机器人本体的补偿方法。利用距离误差模型构造出机器人本体的约束方程,并求解出机器人的实际几何参数,进而将该参数应用于修正系统的运动学模型。通过运用修正后的运动学模型对车身点实施测量,并与跟踪仪的实测距离数据进行比较。实验表明,补偿前后测量系统的重复性精度基本没有发生改变,误差低于0.1mm,但补偿后测量点间的距离误差由0.6mm降到0.3mm以下,精度大为提高。

In order to improve the accuracy of the whole flexible measurement system, a compensation method based on robot was put forward. Constraint equations were constructed by using distance error model, and the actual geometric parameters of the robot were solved, and then these parameters were used in the modified kinematics model. Car body points were measured by using the modified kinematics model and compared with the distance data of laser tracker. Experiments prove that, the repeatability error of the measurement system is stable and less than 0.1 mm before and after compensation, but the absolute error of the measurement system declines from 0.6 mm to 0.3 mm and the accuracy is improved greatly.