The demand for indoor navigation is increasingly urgent in many applications such as safe management of underground spaces or location services in complex indoor environment, e.g. shopping centres, airports, museums, underground parking lot and hospitals. Indoor navigation is still a challenging research field, as currently applied indoor navigation algorithms commonly ignore important environmental and human factors and therefore do not provide precise navigation. Flexible and detailed networks representing the connectivity of spaces and considering indoor objects such as furniture are very important to a precise navigation. In this paper we concentrate on indoor navigation considering obstacles represented as polygons. We introduce a specific space subdivision based on a simplified floor plan to build the indoor navigation network. The experiments demonstrate that we are able to navigate around the obstacles using the proposed network. Considering to well-known path-finding approaches based on Medial Axis Transform (MAT) or Visibility Graph (VG), the approach in this paper provides a quick subdivision of space and routes, which are compatible with the results of VG. With the increased urbanization, public buildings such as shopping centres, airports, museums and music halls have become larger and more complex. Therefore it becomes difficult for people to arrive at a specific room or place even if they are familiar with the environment . Indoor navigation is still a challenging research field for several reasons: positioning is not very accurate, users can move freely inside, path network construction process may not be easy and straightforward due to the indoor space complex configurations  The information of common 2D floor plan drawings cannot be directly used for navigation, neither the information available as a digital plan or stored in databases (Wu, 2015) . Therefore, available indoor spatial information has to be processed to create indoor network that can be used for path computation. After the initial 2D floor plan is redrawn and all the obstacles are correctly presented, the question is how to extract the network that will be used for path computation. Therefore, it's necessary to deal effectively with the remaining free space, which needs to be subdivided. In this paper, we use Delaunay triangulation to create a mesh (Du et al., 2015; Yu, 2013) . The
Xu et al. REF used a simplification of 2D floor plan to subdivide the free space inside buildings by applied Delaunay triangulation.
AN INDOOR NAVIGATION APPROACH CONSIDERING OBSTACLES AND SPACE SUBDIVISION OF 2D PLAN