부산대학교 도서관

The growing interest towards green and efficient use of electrical energy has recently pushed the industry of street light control systems. In the past, very simple on/off switching mechanism based on daylight sensing and cyclic preventive maintenance procedures were adopted. Nowadays, intelligent control systems offering remote supervision have strongly contributed to a change in perspective in maintenance engineering form a traditional “Fail and Fix” view to a “Predict and Prevent” approach. However, most of the infrastructure is already in place and replace street light with improved units has to be economical feasible. Traditional solutions exploit Power Line Communications (PLCs). In this paper we propose a wireless retrofitting of lamps, which has some advantages due to the independence from power line faults. In addition, the service provider usually ignores the exact location of the lamp poles and the integration with Geographic Information System (GIS) databases requires a preliminary on-site survey. The novelty of our proposal relies on the exploitation of nodes self location capability. Radios based on Chirp Spread Spectrum (CSS) modulation are used in order to achieve a good spatial resolution without the adoption of expensive GPS modules. In particular, experimental results are focused on the ranging capabilities of such devices, showing the feasibility of the proposed approach. Open field trials, mimicking real world applications, have shown an overall accuracy on the order of one meter.