Design of Underwater Laser Triangulation Ranging System and Monte Carlo Simulation Optimization

The laser triangulation ranging system has the effect of refraction at air-glass-water interfaces when underwater applications are underway, as well as the reduction of the active distance and the deterioration of the image quality of the target reflection point due to the scattering and absorption by the aqueous medium. In order to solve these problems, we started with the principle of laser triangulation and then used the Monte Carlo method to establish a random model of underwater laser transmission based on the theory of radiative transfer. TracePro software was used for ray tracing simulation, thereby to obtain the contrast of the reflection point image. The influences of system parameters such as target distance, laser intensity, baseline distance and objective lens aperture on the contrast were discussed and then the parameters were optimized. Finally, starting from the actual situation and needs of the system, determine the laser light intensity 1W, baseline distance 200mm, imaging objective lens 50mm/F2, to ensure a good target contrast within 6m, thus ensuring the implementation of laser triangulation.