Research And Design Of Ultrasonic Positioning System

Nowadays many positioning systems locate the target by means of GPS satelite,although this method is very convenient,the position accuracy is relatively low,most of location areas are in the outdoor areas,sometimes we need to locate the target to achieve high-precision positioning,which GPS can not achieve.The common indoor positioning systems such as:WiFi positioning,Bluetooth positioning,RFID positioning and so on are widely used,but the accuracy is not very acurte.In some places cannot be applied.Many systems arrange the nodes on the ceiling,which brings inconvenience to the arrangement of nodes.At the same time,due to the limitation of the transmitter angle,too many nodes need to be arranged in the small area and also causes a rise in costs.In view of the problem of nodes placement in traditional ultrasonic positioning system,if we can increase the radiation of the ultrasonic transmitter,then we can effectively reduce the number of receiving nodes,so as to achieve the purpose of reducing costs.The paper proposes an ultrasonic positioning system based on reflection cone,which can effectively expands the range of ultrasonic radiation emitted by ultrasonic transmitter to realize the omnidirectional transmitting and receiving of the ultrasonic wave at the transmitter and receiver.In the aspect of localization algorithm,firstly,the TOF data are reconstructed by the triangle geometry,Then the initial position estimation is obtained by combining Chan algorithm,Then use the Taylor algorithm to estimate this estimate,and finally get the final location information of the target nodes.After comparing with Chan algorithm and Taylor algorithm,the algorithm has higher positioning accuracy and smaller dispersion.The experimental results show that the system has stable performance,and the positioning accuracy can reach within 4 cm.