Static error prediction model of linkage deformation of self-driven articulated arm coordinate measuring machine

The driving motor, reducer and other components are added to the joints of the self-driven articulated arm coordinate measuring machine (AACMM). The action of gravity causes the elastic deformation of the linkage and the measurement error of linkage deformation cannot be ignored. In this paper, a self-driven AACMM measurement model is established based on the screw exponential product formula. The transformation matrix expressions between the articulated gravity coordinate systems are established. Because of the flexibility of the linkages, a static deformation error prediction model of the self-driving AACMM is proposed. The deformation errors of three typical postures of the self-driven AACMM were predicted. The ANSYS Workbench software was used to carry out the finite element statics simulation. An equivalent experiment prototype of the linkage deformation of self-driven AACMM was designed and developed. The linkage deformation detection experiments were carried out. Experiment results show that the deformation error is reduced by about 88% after being corrected by the linkage deformation error prediction model. Simulation and experiment results show that the study in this paper can effectively improve the measurement precision of self-driven AACCM. © 2020, Science Press. All right reserved.