Data Organization And Mangement Of 3D Moving Objects

With the development of wireless communication, positioning and photogrametry, people are able to expand the information management of spatial objects from static to dynamic, and the moving objects in 3D real world are drawing more and more attentions. Many applications, such as ITS (Intelligent Transport System), digital battle field, logistics management, mobile e-commerce, traveler service and other LBS (Location Based Service) systems, need efficient MOIM (Moving Objects Information Management). And MOIM is expanding from 1D or 2D to 3D with the application of 3D GIS (Geographical Information System) and VR (Virtual Reality). The information process of moving objects is complicated as it deals with spatial attributes as well as temporal attributes. However, conventional DBMS (Database Management System) can not meet the needs of MOIM. It is designed for static data management, thus any data change will lead to explicit update in database. This is not fit for continuous spatial state change of moving objects. And SQL (Structural Query Language) is not designed and optimized for processing of spatio-temporal data. It is not good enough for moving objects data query. On the other hand, the current study of temporal database is focused on data which change slowly and to which statistic process is one of the important processes. It is not effective enough for real time process and it does not deal with spatial attributes. Therefore, it is necessary to study novel data organization and management algorithms to process the spatio-temporal data of moving objects. This paper is focused on the data organization and management of 3D moving objects, including representation of moving objects and index technique of motion data.The current study of MOIM is to regard the moving objects as the points in space, to pay no attention to the shape, size and appearance of the objects, and to study the objects' spatial states and their changes, to collect, transfer, store, index, query and process the spatial state data by different means. In this way, the representation of moving objects is simplified as the representation of objects' moving or objects' motion. There are various motion models developed. They can be classified into four categories, point model, time interval model, polyline model and function model. Each kind of model has its own advantage and fits for certain application. But most of the models are for ID or 2D moving objects, and need further improvement before they can deal with 3D moving objects. And none of the existing models takes the orientation of objects into consideration, which is very important in spatial state of 3D objects. After analyzing the temporal attributes, spatial attributes and motion attributes, this paper improves function model, especially MOST (Moving Object Spatio-Temporal) model, eliminates the implicit requirement for explicity, increment and separation of elements to motion function, and proposes GMM (General Motion Model). It also introduces LOD (Level of Details) to motion data and satisfies different application requirements by different accuracies and complexities for motion data and their processing. GMM encapsulates motion data and their processing according to object oriented method. It allows different processing methods and data with different types existing in same object, and is suitable for both function method and sampling method of motion model. In compliance with data collecting and types in most application systems, this paper proposes SSM (State Sequence Model) based on the position, orientation, moving direction, moving speed, moving acceleration, rotating speed, rotating acceleration and their relations of the moving objects. SSM restores objects' motion using discrete sample data with interpolation and extrapolation, and also encapsulates data and their process. It is a concise model for representing moving objects, which isgood for 3D objects as well as ID and 2D objects. This paper also discusses the representation for different kinds of object using S...