  Existing galvanometer-based laser scanning systems are challenging to apply
in multi-scale 3D reconstruction because of the difficulty in achieving a
balance between high reconstruction accuracy and a wide reconstruction range.
This paper presents a novel method that synchronizes laser scanning by
switching the field-of-view (FOV) of a camera using multi-galvanometers. In
addition to the advanced hardware setup, we establish a comprehensive
mathematical model of the system by modeling dynamic camera, dynamic laser, and
their combined interaction. We then propose a high-precision and flexible
calibration method by constructing an error model and minimizing the objective
function. Finally, we evaluate the performance of the proposed system by
scanning standard components. The evaluation results demonstrate that the
accuracy of the proposed 3D reconstruction system achieves 0.3 mm when the
measurement range is extended to 1100 mm $\times$ 1300 mm $\times$ 650 mm. With
the same reconstruction accuracy, the reconstruction range is expanded by a
factor of 25, indicating that the proposed method simultaneously allows for
high-precision and wide-range 3D reconstruction in industrial applications.
