Research On Indoor Floor Plan Construction Method Based On PDR&WIFI

The development of indoor location and navigation technology provides technical support for indoor location-based service,however,the implementation of location-based service applications needs to rely on an important support tool — indoor maps.Most of the existing indoor maps appear in the form of traditional paper,which cannot achieve real-time interaction with location navigation applications,and the usability is not high.Therefore,it is very necessary to build an indoor electronic map with high availability.Different from simultaneous localization and mapping(SLAM)technology,this paper proposes a method for build indoor floor plan based on smart phones.The method includes pedestrian dead reckoning(PDR)positioning technology and WIFI-based indoor positioning technology,the method is divided into three steps: indoor floor plan data acquisition,indoor floor plan construction method,and indoor floor plan visualization.The indoor floor plan data is the PDR positioning trajectory obtained by using the pedestrian dead reckoning algorithm,the plan construction adopts the method of superposition PDR trajectories,but in indoor pedestrian inertial positioning,obstacle avoidance made the positioning reckoning trajectory distort from actual path,and causes the floor plan distort from actual layout.the visualization of indoor floor plan which is no concrete feasible method.Aiming at the above problems,this paper mainly carries out the following two studies:(1)In order to improve the mapping accuracy between the positioning trajectory and the actual path,a trajectory correction method of decision tree motion classification is proposed.The method analyzes the pedestrian motion characteristics and builds a decision tree to classify the positioning trajectories,and then,different trajectory correction methods are adopted based on the deviation of each trajectory type from the current main direction in the indoor building structure.The experimental results on the pedestrian autonomous positioning trajectory in a complex indoor environment show that,the proposed method obviously improves the trajectory mapping accuracy and the constructed floor plan has a high similarity with the actual layout.(2)In order to achieve the indoor floor plan visualization,a method of using indoor light intensity and WIFI positioning is proposed.Firstly,regional classification is implemented by using the light intensity distribution characteristics of different areas in the indoor area.Second,the indoor room is located by used the WIFI-based approximate positioning method,and the location room information is identified by using the WIFI device.The experimental results show that the proposed method can complete the classification of the floor plan and the identification of the room information,effectively realize the visualization of indoor floor plan.