Design And Implementation Of Navigation System In Building

Due to the great convenience of location-based services in outdoor environments,the demand for user-based location services in the building such as shopping malls,train stations,school buildings,and exhibition centers is growing.The positioning navigation system in the building can be used for path navigation in unfamiliar environments,valuable asset tracking,public safety rescue and precise advertising,etc.It has extremely broad application prospects and social value.The navigation system in the building mainly includes three aspects: positioning in building,path planning and navigation in building.For the positioning in building,positioning based on Wi-Fi signal can get out of the limitations of portability,cost and application range,but Wi-Fi signals are extremely vulnerable so that the positioning result can be affected.In order to solve the problem of instability of Wi-Fi signals,a Wi-Fi positioning scheme using template matching is designed to locate the current position.It combines deterministic matching and probability matching.When the number of Wi-Fi signals is insufficient to locate or the apparent positioning deviation occurs,QR code is used to be an assisted positioning scheme.For the path planning,a path planning strategy based on hierarchical path network is designed in consideration of multi-floor building structure.According to the floor information of the starting point and the ending point,the path planning is divided into three schemes: single floor,cross floor and multi floor.The optimized path search algorithm under the single floor is taken as the core,and the global optimal path is taken as the result;based on result of the Wi-Fi positioning and path planning result,the scheme of dynamic adjustment for acceleration is designed to detect the walking steps of the pedestrian,and the relative position of the pedestrian is determined by the estimation of heading direction and walking distance to realize the navigation.Using the above scheme of positioning and navigation,an office building of university is used as an experimental building,and an indoor navigation system is implemented on the Android platform with the idea of a module.Users can view their own positioning,set destinations,plan walking routes and realize navigation in the system.The experimental results show that the system is feasible and universal.