该文以一台5轴混联机床为对象,对运动学标定中的测量轨迹评价和误差补偿进行实验研究。根据矢量闭环方程和一阶摄动法,分别建立了混联机床的运动学模型和误差模型。基于向量非正交度的描述方法,提出了一种用于评价测量轨迹的指标。利用该指标设计两个不同测量轨迹,并分别进行了标定实验研究,验证了指标的有效性。分析和比较了基于运动学正解和逆解的误差补偿方案,并通过标定实验验证了基于运动学逆解的误差补偿方案更能有效提高该机床的精度。"S"形试件切削实验结果显示94%的测点合格,验证了该指标和误差补偿方案的有效性。
This paper described the kinematic calibration of the measurement trajectory and error compensation of a 5-axis hybrid machine tool. The kinematics model was based on the closed loop vector kinematic equations while the error model was based on the linear perturbation method. An index to evaluate the measurement trajectory was developed from a non-orthogonal index of the trajectory vectors. Two calibration tests were performed using different trajectories. Two error compensation schemes were based on the forward and inverse kinematics. The calibration tests show that the error compensation scheme based on the inverse kinematics has higher compensation accuracy. Finally, a test of machining an "S"-shape test specimen shows that 94% of the detected points are acceptable. The results verify the effectiveness of the index and the error compensation scheme.