Field distortion correction in galvanometric scanning system by interpolation with symmetric polynomials

Due to its high precision and flexibility, laser process system is widely used in laser marking, drilling, cutting and projection. Laser scanning machines are usually equipped with high-speed galvanometric scanning systems, which are inevitably accompanied by field distortion. The error compensation method can help improve the marking quality that minimizes inherent and random errors. This paper introduces a facile software compensation method for this purpose. Based on symmetry of field distortion, the length of four characteristic lines is required to determine the polynomial compensation function. The experimental results verified that the technique could effectively reduce the field-distortion errors in the galvanometer laser-machining system, which verifies the feasibility and effectiveness of the compensation method. Within the processing range of the experiment (100 x 100 mm), the average relative position accuracy is 0.00068 (<1 parts per thousand). In the light of these results, high-quality laser processing is promising for achieving by the compensation method.