Research On Underwater Pipeline Detecting And Tracking By AUVs

In recent years, with the substantial consume of energy sources and increase of population, ocean research and exploitation gradually become the new development space of people surviving. So AUV (autonomous underwater vehicle) has been widely applied as an important component of ocean high-tech. The intelligent AUV technique is also a pop research area of AUV system, and vision based recognition and track is one of key technologies of AUV patroling and working in the complexities and uncertainties of underwater environments.The main prupose of this paper is to carry out with a real-time underwater pipeline detecion and track system for AUV. Taking monocular CCD (charge coupled device) camera as a vision sensor, the navigation information of underwater pipelines can be acquired by vision-measuring method. On this basis, an underwater pipeline detection and track system for AUV is constructed. The detailed content as follows:1. Give a brief overview to the development, applications and research status of the vision based underwater pipeline detection and track system for AUV in and out side of the country. Point out the difficites and new research directions in current underwater pipeline detection and track system for AUV research area.2. According to the abstract degree of data structure, the data information transferred in this system can be divided into six hierarchies from low to high. Information in each hierarchy is described. The general content of vision system is proposed and the system architecture of underwater pipeline detection and track system for AUV is designed, also a monocular vision hardware and software system is developed.3. In the layer of image processing, the underwater image-forming are briefly analyzed. According to the analysis of underwater imaging and improve the accuracy and real-time performace of this system, then some simpe and high efficient improved image processing methods are put forward.4. In the layer of explation, according to the underwater imaging, the affine invariants based on region moments are constructed. Based on neural network theory, then two new methods of underwater objects recognition with global searching ability are proposed. Structure and modeling of the immune genetic neural network (IGNN) applied to target recognition. In order to improve the accuracy and real-time performace of this system, the detection method based on dynamic window technology and kalman filter for pipeline datas association are applied.5. In the layer of environmental insight, the methods and foundation of camera calibration are introduced and analyzed. The model of a vision sensor based on structured light is constructed with perspective imaging and coordinatie transform principle.The projective relation between pipelines’image plane coordinate system and submarine plane coordinatie system are constructed.6. In the layer of AUV decision plan and motion control, coordinates the behavior of motion controller and the decision plan are solved. According to the nacigational information of underwater pipeline from layer of environmental insight and motion information of AUV, some motion sequences of AUV are generated. The thrust force of ever degree executing unit also could be computed by intelligent motion controller algorithms to fulfil the task of underwater pipeline detection and track.Finally, the proposed algorithm is validated by the AUV trail simulation and pool experiment. The experimental results showe that the procedure based on the above algorithm can perform the real-time track system, and these methods proposed are feasible and effective for the task of pipeline detection and track.