Research On Terrain Matching Algorithm Based On ICCP For Underwater Vehicles

Most underwater vehicles navigation systems are based on low drift Inertial Navigation system designed to sustain submerged operation for long period of time.In order to achieve the position accuracy,most underwater vehicles use Terrain-aided navigation(TAN).Terrain Elevation Matching(TEM) strategy is one of the key techniques in TAN.Many solutions to TEM have been successfully applied to underwater vehicles navigation systems.However,these solutions only work well for some special types of terrains,because they need excessive time to prepare a flight course and demand high for terrain,which limit applications of TEM systems.Therefore,studying high performance TEM algorithms with high applicability has become an important research topic in TAN area.Through researching the behavior of the underwater vehicles and the concepts of image processing technology,this dissertation introduces a new TEM algorithms-ICCP and studies its applicability in the context of TEM used in underwater vehicles navigation systems.The main work is as following:Firstly,it researches the method of gaining the contour digital map,and discusses the advantages for contour digital map as matching primitives.Two ways of contour extraction are introduced.Secondly,to analyze and evaluate the performance of algorithms,a concept of Terrain Environment Adaptability is introduced and then the dissertation introduces some usual scalars used to weight terrain information and presents the concept of terrain entropy.Through simulation results,it proves that terrain entropy can be applied to measure terrain information effectively.Where after,this dissertation researches the terrain-matching algorithm based on ICCP algorithm and its Terrain Environment Adaptability which are the key content in this paper and studied from two parts:Firstly,the basic theory of ICCP algorithm and the key technologies of ICCP algorithm are presented.The simulation results show that the algorithm is reasonable and effective;Secondly, the paper focuses on some scalars such as terrain entropy to pick some matching areas and ICCP algorithm has been applied in these areas.And then tries to analyze the possible result caused by terrain environment.At last,in the same matching area,it uses two kinds of navigation methods:ICCP and traditional method-TERCOM.Through simulation test,the paper proves that ICCP does better than traditional method-TERCOM in position accuracy.