1 Introduction
LED is widely used in landscape lighting of large and medium-sized cities in China because of its energy saving, long life, high reliability, rich color, easy control (fast response, easy non-standard design and long span control). In the Beijing Olympic Park, the “Water Cube†(National Aquatics Center) at night is exquisite and exudes a fascinating blue glow. The “Water Cube†landscape lighting project uses LED lighting. It is estimated that it can save 74.50 million kWh and save energy by more than 70% compared with traditional fluorescent lighting.
LEDs are rich in color. In theory, only the LED light source can completely cover all the saturated colors in the CIE chromaticity curve. That is, the LED can produce almost any color by organic combination with phosphorus. The LED can be powered by low voltage DC, and the dimming is convenient. The field of landscape lighting has advantages that other light sources cannot match [1].
At present, management and control integration is a key technology for lighting energy conservation. With appropriate control strategies, the LEDs can be programmed and controlled according to the overall requirements of the environment. Through the coordination of LED light colors, the overall artistic landscape effect can be produced. The application of the integrated control technology in LED landscape lighting is introduced below based on practical applications.
2 LED landscape lighting control integrated intelligent control system
LED landscape lighting control integrated intelligent control system includes two parts of equipment supervision and intelligent control. The monitoring of field equipment mainly realizes intelligent control of lighting circuit, lamps, anti-theft, online fault diagnosis and alarm. The intelligent control of LED landscape lighting is a key part of the integration of other management and control systems. The intelligent control strategy can fully reflect the advantages of LED application in landscape lighting. It is an effective means to realize the design ideas of landscape lighting designers.
2.1 Equipment Monitoring
2.1.1 Smart Controller / Drive Installation Location
The integrated control system of the control system is equipped with an intelligent controller at the line terminal. The intelligent controller/driver is installed at different locations depending on the actual needs:
a. An intelligent controller/driver is responsible for the management of one/multiple loops, monitoring of multiple lighting devices, theft prevention and data transmission. This solution is suitable for places with a large number of lighting devices and relatively concentrated.
b. Install an intelligent controller/driver for each fixture. It can automatically detect sudden events such as protection trip, line fault, voltage fluctuation, abnormal switch control, etc., and upload the alarm data to the monitoring center in time through the communication module inside the controller, so that the on-duty personnel can understand the situation and deal with it in time. This solution is suitable for places where the number of lighting devices is small and relatively dispersed.
2.1.2 Anti-theft problem
Anti-theft is a major problem facing the current landscape lighting project. Most of the landscape lighting facilities are outdoors, and the surrounding people flow greatly, which brings great difficulties to the anti-theft work. The intelligent controller of the line terminal of the integrated control system can easily play the role of anti-theft:
a. Design a tamper switch for the luminaire and distribution box, monitor and detect the electrical signal through the intelligent controller, and link with the alarm.
b. Design the glass breakage vibration switch inside the lamp, monitor and detect the electric signal through the intelligent controller, and link with the alarm. In addition, it can be monitored by a remote video surveillance system to establish a system that combines remote monitoring with personnel patrol.
2.2 Intelligent Control
The energy-saving control of LED landscape lighting is mainly reflected in the intelligent control, and the following functions are realized through communication between the intelligent controller and the monitoring center server.
2.2.1 Automatic switch light
a. According to the location of the latitude and longitude and the season of the switch light schedule, the landscape lighting intelligent control system strictly switches the landscape lighting according to the schedule. The defect of this control method is that the control method is relatively dull and the power waste is more serious.
b. Intelligent monitoring, according to the illuminance value detected by the photoelectric sensor to control the switch light, the control method is more flexible, in real time to create a gorgeous night scene without manual intervention, and also save energy.
2.2.2 Dynamic automatic dimming
After the light is turned on, the video surveillance image of the scene is processed by the video image processing technology, the human flow is calculated by the computer of the monitoring center, and the dimming control of the landscape illumination is performed according to the human flow.
2.2.3 Dynamic scene change
Set different landscape lighting scenes, automatically switch the corresponding scene according to different dates and times, set a variety of holiday scenes for holidays, and change the timing. The dynamic scene change is automatically completed by the scene control unit. The monitoring personnel only need to monitor the video through the monitoring center, or switch to the manual operation mode, and switch the landscape lighting scene by manual operation.