Beacon Placement Research Articles

Effect of beacon orientation on beacon placement strategies in the ultrasonic positioning system

Ultrasonic positioning system (UPS) is useful in warehouse and underwater applications to track automated objects. One of the key factors determining the performance of the UPS is the beacon placement. Existing literatures are restricted to placing beacons perpendicularly downward to the target moving plane. In this study, considering three common placement patterns: triangle, square and hexagon, by relaxing beacon orientation, our analysis shows that hexagon placement is the best option, and the improvement in terms of qualified coverage per beacon has a negative relationship with the beacon height. Even conditioning on a height of 20% of the sensing range, a factor of 8 and 7 can be achieved in the non-regular placement and regular placement, respectively. Furthermore, critical heights which differentiate the non-perpendicular placement (NPP) and perpendicular placement (PP) for all patterns are identified. In general, regular NPP with the hexagon pattern is advised. In addition, our analysis investigates the advantage of increasing the cone angle by clustering which groups transducers by relaxing transducer orientation, and result shows that continuous clustering of seven transducers has the largest marginal contribution of 24% and 41% to improve the qualified coverage in the non-regular NPP with hexagon placement and regular PP, respectively. Finally, considering the beacon clustering cost and the beacon station cost, the economic beacon placement strategies are identified for applications with different clustering cost and beacon height.