High-precision practical calibration method with virtual point constraint for line-structured light sensor

In engineering measurement scenarios, factors such as wide fields of view, large depth of field can significantly degrade the accuracy of line-structured light sensors. Existing calibration methods struggle to overcome these adverse effects. This paper proposed a high-precision calibration method through calibration object design, virtual calibration points extraction method, continuous linear displacement calibration platform development. The detailed collection and description of the laser surface helps to achieve high-precision calibration. Within a working range of 260 mm to 540 mm, the proposed method achieved RMSE values of 0.007 mm and 0.032 mm in gauge block and rail profile measurement experiments, respectively. These results represented improvements of 77.4% and 86.9% compared to the light plane method, with RMSE values of 0.031 mm and 0.246 mm. The proposed method demonstrated the ability to maintain high accuracy across entire measurement range and realize automated calibration process, highlighting its significant practical value in engineering applications.