Research On Multi-node Self-organized Network Cooperative Positioning Technique Based On UWB

The Global Positioning System(GPS)can achieve excellent positioning performance in outdoor environment,however,it is difficult to realize high-accuracy positioning for the GPS-denied indoor environment,due to its complex environment,serious multipath and non-line of sight.To solve this problem,a large number of indoor positioning techniques emerged,such as infrared ray,Bluetooth,Zigbee,Wifi and ultrasonic.However,these techniques have a negative performance on accuracy.With the development of wireless communication,Cooperative Positioning(CP)arises,which can effectively improve the positioning accuracy through the exchange of measurement information between nodes.Considering the advantages of Ultra-Wide Bandwidth technology(UWB),such as strong penetrating power,low power consumption and high anti-multipath capability,and has outstanding advantages in distance measurement and location,UWB and Cooperative Positioning(CP)techniques are applied to indoor positioning in this paper,an indoor cooperative positioning method based on UWB is proposed firstly.In the proposed method,target nodes can communicate their measurements,which make the nodes that are not within the reference node's transmission distance can also be located,The experimental results show that the positioning performance of this method is obviously better than that of the traditional indoor positioning method.Secondly,in order to solve the problem that the UWB signal is affected by the obstruction of tables,chairs,doors,windows and other obstacles in the process of propagation,the least squares residuals(LSR)method is introduced to exclude the node with large ranging error and a cooperative positioning method based on UWB and LSR is proposed.The experimental results show that the method can effectively remove the fault node and improve the positioning accuracy of the system.Thirdly,an improved total least squares residuals(ITLSR)algorithm is proposed to solve the problem that the traditional least squares residuals method can only exclude the single fault,and its rejection ability of multi-node fault is verified by simulation.Finally,the ITLSR algorithm is applied to the indoor cooperative positioning,a cooperative positioning algorithm based on UWB and ITLSR is proposed and implemented on the embedded platform.The experimental results show that the algorithm can effectively improve the positioning accuracy of the system.