Study On Spatial Data Model For Blind Navigation In Indoor Space Based On Aisle-Functional Unit

There are about 550 million blind people in China,which has the largest number of the blind in the world and the number is increasing with an annual rate of 450,000.The blind cannot get the surrounding environment information through the visual channel,this has brought their daily lives great inconvenience.In recent years,with the continuous development of modern spatial information technology,using it to replenish the lack of spatial visual information of the blind has become the Research hotspot to solve the Blind travel problems.This paper analysised the psychological characteristics and demand characteristics to spatial information of the blind walking in indoor space,for the target of blind indoor navigation,researched the indoor spatial data modeling,the data conversion method from Shapefile to the data model established in this paper and the path planning algorithm for the blind.?This paper analysis the demand characteristics to spatial information of the blind walking in indoor space and data model for indoor navigation,divide the spatial information of blind walking in indoor space into macro environment,Microscopic spatial objects and spatial attribute information,etc.Summarize the special spatial information need,point out that modeling also need to consider more specific information,topological relationships and semantic description.?Based on object-oriented data organization,the basic idea of “Aisle-Functional Unit”,design the spatial data model service for blind indoor navigation.The characteristics of the data model are illustrated as follow:(1)the whole indoor space are represented by a series of spatial objects,they are divided into path and generic objects;(2)in addition to the obstacles and surface irregular objects,other generic object can be equipped with functions than meet the specific needs of the blind,and they can connect with path by entrance;(3)design the semantics to describing the indoor space objects,which provides more detail information for blind navigation;(4)through the connection of paths and the entrance of the functional objects,it preserves the topological information of the indoor spatial objects.?Based on above data models,design data generation methods of indoor spatial object form Shapefile,convert the Shapefile to data model for blind indoor navigation,store the data model into the database.?Based on the level information,topological information and risk calculation rules,design path optimization algorithm of global path and local path to guarantee a safe travel for the blind.