Abstract: Street lights are everywhere in people’s daily lives. But street lights can sometimes cause problems for people. First of all, long-term power-on will cause a lot of cost and energy consumption; secondly, the lighting requirements of each time period are different, and simple traditional street lamps cannot solve this problem. From this, it is thought that the radar can be applied to the street lamp intelligent control system, which opens a new chapter of urban lighting “management energy conservation”. This solution can help LED street lights meet energy saving requirements and meet lighting needs in many different situations. Radar detection technology is used to detect objects and increase street lamp power to meet lighting requirements. When the target object exceeds the radar detection range, the power of the street light decreases. This not only ensures the energy saving of the street lamps, but also makes the street lamps meet the needs of different time and conditions.
A radar is a detection system that uses radio waves to determine the range, angle or speed of an object. It can be used to detect aircraft, ships, spacecraft, missiles, motor vehicles, weather formation and terrain. Radar systems include transmitters that generate electromagnetic waves in the radio or microwave domain, transmit antennas, receive antennas (usually for transmitting and receiving the same antenna), and receivers and processors for determining the properties of objects. . Radio waves from the transmitter (pulse or continuous) reflect the object and return to the receiver, providing information about the position and velocity of the object. The modern use of radar is highly diverse, including air and ground traffic control, radar astronomy, air defense systems, anti-missile systems, marine radars for locating landmarks and other ships, aircraft collision avoidance systems, marine surveillance systems, outer space surveillance and rendezvous systems. , meteorological precipitation monitoring, altimetry and flight control systems, missile target location systems, ground penetrating radars for geological observations, and distance control radars for public health surveillance. High-tech radar systems are associated with digital signal processing, machine learning, and the ability to extract useful information from very high noise levels.
As far as the radar signal is concerned, the radar system has a transmitter that emits a radio wave called a radar signal in a predetermined direction. When they are in contact with an object, they are usually reflected or scattered in many directions. But some of them will absorb and penetrate into the target to some extent. Radar signals are particularly well reflected by materials with considerable electrical conductivity - especially most metals, sea water and wetlands. Some of them make the use of radar altimeters possible. The radar signal that is reflected back to the transmitter is ideal for radar operation. If the object moves toward or away from the transmitter, the frequency of the radio wave caused by the Doppler effect changes slightly.
The radar receiver is usually (but not always) co-located with the transmitter. Although the reflected radar signals captured by the receiving antennas are usually very weak, they can be enhanced by electronic amplifiers. More sophisticated signal processing methods are also used to recover useful radar signals. The weak absorption of radio waves by the medium it passes allows the radar group to detect objects over a relatively long range, in which other electromagnetic wavelengths (such as visible light, infrared light and ultraviolet light) are attenuated too strongly. Weather phenomena such as fog, clouds, rain, falling snow, and sleet that blocks visible light are usually transparent to radio waves. When designing a radar, certain radio frequencies that are absorbed or scattered by water vapor, raindrops or atmospheric gases (especially oxygen) can be avoided, unless they are being tested.
This radar intelligent system also needs to be realized based on IoT ideas and technologies.The Internet of things (IoT) is the network of devices, vehicles, and home appliances that contain electronics, software, actuators, and connectivity which allows these things to connect, interact and exchange data.IoT involves extending Internet connectivity beyond standard devices, such as desktops, laptops, smartphones and tablets, to any range of traditionally dumb or non-internet-enabled physical devices and everyday objects. Embedded with technology, these devices can communicate and interact over the Internet, and they can be remotely monitored and controlled.
The main components of the radar intelligent street light system are: millimeter wave radar sensor, single lamp controller and centralized controller. The millimeter wave radar sensor can effectively recognize the moving speed and direction of the moving target by using the Doppler effect of the millimeter wave sensor. The radar sensor can provide target distance and speed information for 3~5 street lamps and transmit test data. Give a light controller. A single lamp controller is placed in the lamp head of each street lamp, and 3-5 single lamp controllers are grouped together to determine the brightness of the street lamp based on the target information provided by the radar. At the same time, it can also detect street lamp failure and the aging of LED lights. Detect and troubleshoot the fault and report the information to the centralized controller. The centralized controller installs a centralized controller every 30 to 50 lights as a bridge between the local and monitoring centers, receives report information for each street light, and distributes control information for the monitoring center. It features power detection, line fault and anti-theft detection, and is self-tested and reported. The internal storage time can be automatically run when the monitoring center fails and loses control of each street light.
The system should have the following five characteristics: First, automatic detection of street lights: automatic detection of street lights, view faults and automatically generate maintenance orders. Second, street light control: turn the street light on or off, adjust the brightness or preset. Third, equipment management: light poles, lights, lines, electricity meters, switches, monitors, etc. to achieve computer information management. Fourth, environmental sensing: automatic perception of road traffic, weather, light intensity and other information. Fifth, the network information release module: smoothly communicate with the working website for remote management.
The above is the thinking of radar to solve the problem of street lighting. It can be seen from various news that the intelligent street lamp system is gradually being implemented. The radar system can fully meet the energy-saving needs, and can also better control the rise and fall of the street lamp power to provide better lighting conditions for passers-by. Future road lighting systems are likely to evolve gradually into radar intelligent control systems.