Gustavo W. Denardin

An intelligent system for street lighting monitoring and control

One of the major challenges at the moment is the improvement of the present street lighting system. These systems are considered outdated due the lack of communication capabilities, not allowing system feedback. This work aims to add communication capabilities to the systems already in use, through the integration of an IEEE 802.15.4 compatible transceiver to the photoelectric relay used to turn the HPS lamps on/off. This change will turn each device into a node of a large wireless network across the city.

An Intelligent System for Street Lighting Control and Measurement

One of the major challenges at the moment is the improvement of the present street lighting system. These systems are considered outdated due the lack of communication capabilities, not allowing system feedback. This work aims to add communication capabilities to the systems already in use, through the integration of a ZigBee™ compatible transceiver to the photoelectric relay used to turn the HPS lamps on/off. This change will turn each device into a node of a large wireless network across the city.

A geographic routing hybrid approach for void resolution in wireless sensor networks

Abstract: Geographic routing is one of the most suitable routing strategies for large scale wireless sensor networks due to its low overhead and high scalability features. A geographic routing scheme usually combines a geographic greedy forwarding with a recovery mechanism to solve the local minima problem. Solutions proposed in the literature commonly combine greedy forwarding with the well known face routing for achieving this goal. However, the average path length in number of hops produced by face routing could be much worse than the optimal topological path in most realistic scenarios. In this paper, we propose a new intermediate procedure between the geographic greedy mode and the recovery mode in order to improve routing efficiency in number of hops, without network overhead. It exploits the optimal topological route to base stations, obtained by beacon messages, as a resource to find better routes than the ones created by face routing. We show by simulations that the proposed hybrid approach leads to a significant improvement of routing performance when applied to combined greedy-face routing algorithms.

Control network for modern street lighting systems

This paper proposes a control network for a LED street lighting system. The use of LEDs is being considered a promising solution to modern street lighting systems, due to their longer lifetime, higher luminous efficiency and higher CRI. The proposed control network enables disconnection of the street lighting system from the mains during peak load time, reducing its impact in the distributed power system automatically at overload conditions. It also allows to reduce the power consumption, decrease the management cost and monitor the status information of each street lighting unit. In order to meet the system requirements, a wireless sensor network based on IEEE 802.15.4™ standard is employed. Its network layer is implemented using geographic routing strategy, which provides low overhead and high scalability features. However, due to well known drawbacks of the existing techniques, a novel routing algorithm is proposed. Simulations show that this algorithm leads to a significant improvement of routing performance when applied to sparse large scale scenarios, which is the case of a street lighting system. Field tests have been performed on IEEE 802.15.4-compliant wireless control units. The obtained experimental results show that the proposed control network is able to meet the requirements of a LED street lighting system.

Design procedure for a compact lamp using high-intensity LEDs

This paper proposes a circuit to a compact lamp based on light emitting diodes (LEDs). It aims energy savings, high luminous efficiency and high useful life with the replacement of incandescent or compact fluorescent lamps by LEDs without any change in the electrical system installation. In order to supply the LEDs by mains with a constant current, the Buck converter has been used because it provides an output voltage lower than the input one. The circuit has been designed to supply 36 to 52 high-brightness LEDs connected in series, resulting in a converter output voltage between 90 V and 187 V. The load can also be composed of power LEDs. The main disadvantage of series connection is that the damage of one LED can results in an open-circuit, disconnecting the entire group. The proposed idea to solve this problem is the introduction of Diacs connected in parallel with groups of LEDs. So, if one LED burns, the Diac in parallel with this group keeps the current path, guaranteeing the operation of the others groups. To verify the proposed idea, prototypes of the lamp have been implemented and tested.

Game theoretic channel assignment for wireless sensor networks with geographic routing

Multi-channel wireless sensor networks exploit the capability of sensor nodes to tune its radio over different channels to communicate. The main goal of multi-channel communication is to achieve improved throughput, delivery ratio and cause/suffer less interference in the network. However, optimally assigning channels has been shown to be a hard problem. Thus, recently game theory has been used to design a protocol, termed GBCA (Game-Based Channel Allocation), that is able to exploit topology and routing information (TIRI) for assigning sub-optimally the channels to the nodes in a distributed way. However, GBCA only works with static routing. On the other hand, geographic routing, which is a popular well-studied routing technique in wireless sensor networks, is a dynamic routing algorithm. It uses the positions of nodes to find on demand the next hop for the packet. Therefore, GBCA can not be readily applied in networks that employ geographic routing. To address this issue, we propose a modification to GBCA, which we termed GBCA-G, that is suitable for wireless sensor networks that make use of geographic routing algorithms.

Specifications for a power management fieldbus

One of the major challenges at the moment is the improvement of the present power system. The traditional power industry is outdated, but the responsibility is not just in the utility side. The consumer is being forced to perform a high quality load and ration the power consumption. A way to improve the power system is turn it intelligent, through a network. In this study, we analyze the features of a set of control fieldbuses and summarize the main features of a specific fieldbus for power management.

Impact of lower layers for the development of routing protocols for large-scale wireless sensor networks

This paper presents an analysis of relevant aspects of the physical and media access control protocol layers for large scale wireless sensor networks compliant with the IEEE 802.15.4 standard. Based on this analysis we propose methodologies to be adopted for the development of routing protocols in these scenarios. It is verified through simulations that the proposed methods improve the performance of well known packet forwarding techniques, such as geographic and hierarchical routing protocols.

Dimmable Lighting System Strategy Based on Integral Compact Fluorescent Lamps with Digital Compensation

Compact fluorescent lamps are one of the important energy efficient lighting applications. The dimming technology for compact fluorescent systems is available to make this product a more direct replacement for dimmable incandescent applications. This work presents a dimming strategy using Single Ended Primary Inductance Converter (SEPIC) for power factor correction and to dim an integral compact fluorescent lamp (CFL) group. The integral CFL group presents variable loads, which determinates the use of digital compensation in order to attend the load variation, and the output voltage control, since the dimming feature is obtained through the output SEPIC voltage variation using a microcontroller.

LED Lamp with a Compact Emergency Lighting System

This paper presents an efficient and compact emergency lighting system using high intensity light emitting diodes (LEDs). The proposal aims energy saving, high luminous efficacy and high useful life when replacing traditional emergency lighting systems and incandescent or compact fluorescent lamps by LEDs without any change in electrical system installation. A Buck converter is used to supply the LEDs and charge the battery by mains, with universal input voltage (90 VAC - 240 VAC), and a Boost converter is used to supply the LEDs by battery. The converters operate at high frequency and control the LEDs current independently. A Li-Ion battery was chosen because it has higher voltage and density of energy than Ni-MH one. The design attends the Brazilian standard (NBR 10898) and IEEE standard (IEEE Std 446-1995) for emergency lighting systems. The complete circuit was implemented and the experimental results show a satisfactory behavior of the lamp.