3PRS并联机构的运动学和误差分析

Kinematics and error analysis of 3PRS parallel mechanism

为了提高机床的加工性能,研究机床的精度是关键,建立了一种用于大型复杂曲面零件高效铣削加工的3PRS并联摆角头的运动学模型,并进行了误差分析。该机构具有3个自由度,通过修正的K-G公式对其自由度进行了验证;进一步分析了该机构的位置正逆解;在此基础上给定结构参数误差,利用开发的程序植入Ansys计算刀尖点位姿,通过两组位姿误差的比较,为后续运动学标定和误差补偿试验做准备。

In order to improve the machining performance of the machine tool,it is crucial to study the accuracy of the machine tool,so a kinematic model of a 3PRS parallel pendulum angular head for high-efficiency milling and machining of large and complex curved surface parts is established,and then error analysis is carried out.The mechanism,with 3 degrees of freedom,is validated by the modified K-G formula.The position-inverse solution of the mechanism is further analyzed.On this basis,structural parameter errors are considered,and a program embedded in Ansys is utilized to calculate the tool point pose.By comparing the pose errors of two groups,preparation for subsequent kinematic calibration and error compensation experiments is facilitated.