INTRODUCTION isprsarchives XL 4 W5 7 2015

AUTOMATIC TOPOLOGY DERIVATION FROM IFC BUILDING MODEL FOR IN-DOOR INTELLIGENT NAVIGATION S. J. Tang b , Q. Zhu bc , W. W. WANG a , Y.T. ZHANG b a Shenzhen research center of digital city engineering, Shenzhen, P.R. China-measurer163.com b State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing, Wuhan University, Wuhan, P.R. China-shengjun.tangwhu.edu.cn c Faculty of Geosciences and Environmental Engineering of Southwest Jiaotong University, Chengdu, P.R. China- zhuq66263.net CommissionWG KEY WORDS: IFC, Geometry-Semantics-based, Topology Derivation, Navigation ABSTRACT: With the goal to achieve an accuracy navigation within the building environment, it is critical to explore a feasible way for building the connectivity relationships among 3D geographical features called in-building topology network. Traditional topology construction approaches for indoor space always based on 2D maps or pure geometry model, which remained information insufficient problem. Especially, an intelligent navigation for different applications depends mainly on the precise geometry and semantics of the navigation network. The trouble caused by existed topology construction approaches can be smoothed by employing IFC building model which contains detailed semantic and geometric information. In this paper, we present a method which combined a straight media axis transformation algorithm S-MAT with IFC building model to reconstruct indoor geometric topology network. This derived topology aimed at facilitating the decision making for different in-building navigation. In this work, we describe a multi-step deviation process including semantic cleaning, walkable features extraction, Multi-Storey 2D Mapping and S-MAT implementation to automatically generate topography information from existing indoor building model data given in IFC.

1. INTRODUCTION

As the growing complexity of Indoor environment and an increasing number of disasters compartment fires, terrorist attack, etc., there has been a practical requirements on indoor navigation approach, which is still one of the most challenging topics for research. A successful navigation depends mainly on the accuracy geometry and semantics of network Li and He, 2008 . As these complex geometry information can be easily obtained in outside by different 3D data capturing technologies Shi et al., 2004 , most researchers focus on the outdoor navigation environment. On the contrary, the information related to indoor still remains limited Isikdag et al., 2013 . Many cases of the indoor navigation process based on 2D maps or pure geometry information, which are inadequate for 3D topology deviation Lee and Kwan, 2005 . A successful navigation depends on correct semantic and structural information about building elements. Many researches imply that Building Information Model BIMs can serve as a valuable information source for facilitating indoor navigation Chen and Huang; Isikdag et al., 2013; Li, 2012; Rueppel and Stuebbe, 2008 . A BIM model is a digital representation of all the physical and functional characteristics of a building through its entire life cycle Isikdag and Zlatanova, 2009; Isikdag and Zlatanova, 2009; van Nederveen et al., 2014 . The trouble, lack of indoor geometry and semantic information can be smoothed by employing IFC building model which contains detailed semantic and geometric information. Clear definition of building elements like storeys, door, windows, spaces in IFC model can provide pivotal information for topology derivation and detailed physical, functional characteristics contained in each element is enable intelligent routing and other indoor applications. Integrated spatial relationship between building elements in IFC such as a stair can link two floors together and wall can be a container of openings can also facilitate the derivation of the topology network. Semantically rich 3D models can provide critical information for navigation. In this paper, we present a method which combined a straight media axis transformation algorithm S-MAT with IFC building model to reconstruct indoor geometric topology network. This derived topology network aimed at facilitating the decision making for different in-building navigation. The remainder of this paper is organized as follows. Next section depicts the research background about IFC Building Model and topology deviation methods. Section 3 elaborates on a multi- step deviation process including semantic cleaning, walkable features extraction, Multi-Storey 2D Mapping and S-MAT implementation for generating topography information from existing indoor building model data given in IFC. Section 4 illustrates the applicability of the approach involving a typical IFC model. Sections 6 concludes by outlining the advantages of using the approach for topology derivations and overviews the future developments.

2. RESEARCH BACKGROUND