Precision compensation method for visual measurement based on nonuniform refractive index field reconstruction

Visual measurement is widely used in industrial manufacturing and assembly fields. Due to the fact that the refractive index field of the measurement environment is inhomogeneous, the transmitted light for visual measurements will produce errors. To compensate for these errors, we introduce a binocular camera for visual measurement based on the reconstruction of a nonuniform refractive index field using the schlieren method, followed by the reduction of the inverse ray path by the Runge–Kutta method to compensate for the measurement error introduced by the nonuniform refractive index field. Finally, the effectiveness of the method is experimentally verified, with a reduction in measurement error of about 60% in the built measurement environment.