CTS机构几何误差分析及补偿

Geometric Error Analysis and Compensation of CTS Mechanism

分析了风洞现有分离体模型6自由度机构(简称CTS机构)的几何误差,研究了误差产生的原因,包括机构总体坐标系与风洞固定坐标系不重合的零位误差、直线运动导轨与机构总体坐标系轴线不平行产生的误差,以及偏航俯仰轴线与理想设计轴线不重合引起的分离体模型位姿误差。建立了误差模型,并将分析得到的各项误差通过最小二乘法拟合得到误差函数补偿到运动学正解方程中,再通过牛顿迭代法求取补偿后的运动学逆解,实现对CTS机构的误差补偿,提高机构的运动精度。通过标定试验,对三轴联动的误差补偿效果进行验证,得出了补偿后比补偿前定位精度提高88.21%的结论,证明了补偿方法的有效性。

The essay analyzes the geometric error of the separation mechanism with 6-DOF（ referred as CTS Mechanism） that has been existed,including that the zero error of the global coordinate system of mechanism and wind tunnel fixed coordinate system do not coincide,the position error of the linear motion guide rail and the global coordinate system of mechanism do not parallel,and that the position and attitude error of the separation model caused by the yaw and pitch axis do not coincide with the ideal design axis. The compensated forward kinematics solution is obtained by introduced the error terms into the kinematics equations. The modified inverse kinematics of the CTS mechanism is solved by Newton iterative method in order to realize the compensation of the mechanism and improve the accuracy of the mechanism. Through the test in wind tunnel,the error compensation effect of three axis linkage is verified,and the validity of the compensation method is also proved. And the accuracy after the error compensation improved by 88. 21% than no compensation.