Research On The Wireless Monitoring System Of Urban Lighting Based On ZigBee Technology

As an essential public infrastructure in urban lighting, street lamp is inextricably linked to traffic safety and people’s daily life. The level of street lighting control and management is a city symbol of modern civilization. More and more malpractice of switch and inspection mode has been gradually appeared in traditional street lights, not only the energy utilization is low, but also bring a lot of manual inspection and maintenance trouble, resulting in excessive waste of energy and human resources.Because of the weakness of streetlight control and management level, in the developing trend of wireless communication technology, this paper design a kind of lamp wireless monitoring system. This system is mainly divided into three levels, the first one is lamps management center with man-machine interface function. The second one is streetlight monitoring sub-station with sending control commands and collecting street node information. The last one is streetlight controling terminal with gathering node status information, more important, there are two communicate network, GPRS communication and ZigBee communication respectively. Actually, GPRS is responsible for communication between lamps management center and streetlight monitoring sub-station, which is provided with broad coverage and high speed transmission, furthermore, it achieve remote monitoring. Meanwhile, ZigBee is responsible for commuinication between streetlight monitoring sub-station and streetlight controling terminal.This paper will focus on ZigBee technology, and design the whole syetem from ZigBee protocol stack, ZigBee node type and ZigBee network topology in detail, researching on ZigBee MAC layer and Network layer, recommending ZigBee routing protocol and RS485communication protocol. Routing protocols is one kind of transmission reliablity mechanism in the communication between streetlight and streetlight, routing is a transmission path loaded effective information. This paper based on the disadvantage of commonly used ZigBee routing algorithm, provided an improved routing algorithm named ZBR algorithm, whice increase the network’s stability and reliability. RS485protocol is used in the communication between the MCU of streetlight controling terminal and LED driver control panel, replacing the traditional RS232communication, it has the advantage of far transmission distance and high speed transmission rate. Finally, this paper describes the design of hardware, including the selection of each unit module and analysis of schematic. Making use of three serial port of MCU to achieve communication with GPRS module, RF module and LED driving control module. Meanwhile, in the design of software, transplanting μCOS-Ⅱ operating system, which prioritizes the tasks of data transmission, makes use of CPU resources in reason and solves the signal transmission conflict. Using LED lights with solar panels to achieve brightness adjustment according to the PWM wave output by the software design. Taking use of sub-time control mechanism can save energy. The streetlight management center login server using C/S architectures, through GPRS technology, can achieve remote control operation on the streetlight.