采用间接测量法对平面3-RPR机构进行运动学标定的仿真

Simulation on the Kinematic Calibration of Planar 3-RPR Mechanism Through Indirect Measurement

采用间接测量对平面机构进行标定时 ,需要引进标准测量参照物 ,但参照物本身仍可能存在一定的尺寸误差 ;另外间接测量时要不断变换标准测量参照物的位置 ,又会引进位置误差。为便于解决实际问题 ,使研究更具可操作性 ,将上述误差和待标定的机构结构误差一起考虑对机构进行了标定仿真 ,同时在仿真过程中采用矩阵重构的方法来解决测量误差扰动的问题 ,避免了大规模的空间寻优。仿真结果表明 。

During the indirect measuring process of a mechanism, some standard objects are needed such as standard cubic box or bar. Consequently,the dimension errors and position errors where the objects are placed during the measurement are considered. All these errors together with mechanism structure errors are unknown in the kinematic calibration simulation of the planar mechanism in order to make it more practical; meanwhile Jacobean matrix regrouping method is used in stead of arduous optimization. It is effective to avoid the noise magnification of the measurement. Simulation results show that both structure errors of planar mechanism and the errors accompanied with experiment can be identified accurately by means of indirect measurement if the moving platform pass through different tracks such as lines and circle. If this method can be successfully applied for spatial mechanism, the problem of kinematic calibration of virtual axis machine tool will be resolved subsequently.