基于球杆仪的三坐标并联动力头运动学标定方法

Kinematic Calibration of 3-DOF Spindle Head Using Double-ball Bar

以一种新型3自由度并联动力头——A3头为对象,研究基于球杆仪检测信息的运动学标定方法。通过将误差闭环方程向支链驱动与约束方向投影,建立球杆仪检测信息与支链几何误差源的线性映射模型,所建模型可有效地分离出影响动平台可补偿和不可补偿精度的几何误差源。在此基础上,提出一种具有分层递阶格式的运动学标定方法,即首先识别出初始位形的支链零点误差,其次利用球杆仪识别其他几何误差源。计算机仿真和试验结果表明,所提出的运动学标定方法是有效的。

A double-ball bar（DBB） based approach for kinematic calibration of a novel 3 DOF spindle head named A3 head is presented.The error model is formulated by projecting the loop closure equations onto in the directions of actuation and constraints of each limb,allowing the geometric source errors affecting the compensatable and uncompensatable pose accuracy to be separated.A two-step kinematic calibration algorithm is then carried out,i.e.firstly to identify the relative and absolute home errors of each limb by using a diameter and cylindrical gauge,and then to identify the rest source errors by using a DBB.The effectiveness of this approach is verified by both computational and experimental results.