As a high-precision measuring instrument, laser tracker is widely used
in the field of geometric error detection of CNC machine tools. However,
the employment of this laser tracker will lead to high cost as well as
low measurement accuracy caused by the angle error. In order to solve
these problems, the passive 3D laser tracking ball bar based on the
principle of laser interference is introduced in this paper. The
following measurement is realized by the passive stretching of the
telescopic mechanism, and the space attitude adjustment of the laser is
ensured by two precise rotating shafts. Moreover, the deflection caused
by the telescopic guideway is an important factor affecting the accuracy
of the device. Therefore, the telescopic mechanism is designed by the
maximum deviation of the laser obtained by the experiment, and the
finite element analysis is carried out. The results showed that the
accuracy requirements are met. The main error model of the device is
established and the influence of each error is analyzed. Moreover, the
simulation results showed that the vertical axis offset angle error has
the greatest impact on the device. At last, the reason of different
influence of errors on the device is analyzed.