Real-Time Display Method On Multi-Point Three-dimensional Information Of Underwater Target Laser Scanning

Human beings have entered the new era of exploiting ocean since 2000. Development of ocean science and technology, especially the ocean hi-tech has become important content of new technological revolution in the world.In deepwater target detection and underwater work, the underwater equipments are mostly running under the state of remote control. In order to achieve real-time precision control for underwater equipment, such as ROV, deep-sea oil and gas exploration equipment, and effective detection and surveillance for seabed target, it is necessary to do research on Underwater three-dimensional visual technology (including two-dimensional underwater visual technology). It is one of the key technologies of deep-sea exploration and operating. So at home and abroad it is spent on a lot of manpower and resources to carry out the research of the technology. Especially since the invention of the laser in 1960, it has conducted 40 years of underwater laser two-dimensional and three-dimensional visual technology research. The underwater laser-scanning Seatex three-dimensional image system developed by American needs three seconds to scan a three-dimensional image, while the underwater laser difference-frequency three-dimensional vision system developed by our country can transduce the information of a three-dimensional image in one second, and can display the three-dimensional information on the two-dimensional picture, which could achieve the goal of real-time control.This article first analyzes the principle and the methods of traditional submarine target three-dimensional image survey, and then introduces the key technologies and development of underwater three-dimensional image survey technique. We propose the high-speed access technologies for laser difference-frequency scanning three-dimensional image information, and man-machine interaction method of real-time display for multi-point depth information, and tested the system resolution. We verified this method through the experiments that were carried out underwater. The result of experiments indicates that the laser difference-frequency scanning three-dimensional visual technology can get the multi–point three-dimensional image information of the target in a high speed, and in the two-dimensional image, the depth information can be real-time displayed. So it is suitable for the underwater practical application. The last part of this article discusses these aspects that need to be improved and expresses the expectations of future research.