Sensor Placement in the Ultrasonic Positioning System

Indoor positioning systems have attracted intensive research in recent years, especially the ultrasonic positioning systems which have the properties of high accuracy and low cost. However, little research has been conducted to address the ultrasonic sensor placement which significantly influences the performance of the localization system. Basing on the position estimation techniques of trilateration and Nonlinear Least Square (NLS), the coverage of three different sensor placement schemes (triangle, square grid and hexagon) are maximized under the constraints of angle limitation and particular application requirements of positioning accuracy, precision and reliability in three dimension case. The performances of different configurations are compared to cover the different scale of region. Finally the optimal sensor placement scheme is presented.