Wireless network intelligent LED street lamp low-energy-consumption system for collecting road conditions

Abstract

According to the intelligent LED street lamp hardware system based on the wireless network, the networking technology that LED lighting is matched with multi-sensor feedback, wireless ZigBee-k and the 5G technology is adopted, the remote operation and maintenance capacity is provided, and the problems that an existing street lamp system is too large in light source power consumption, low in system intelligent control degree and weak in maintenance capacity are effectively solved; an overall scheme of a street lamp management center, a monitoring substation and a street lamp low-energy-consumption control terminal is designed, control background software is based on a 5G network, street lamp low-energy-consumption control terminal hardware equipment is connected with an intelligent control substation through ZigBee-k, the intelligent control substation processes and accesses a background management system through a 5G terminal at the same time, real-time interaction of data is achieved, and the street lamp low-energy-consumption control terminal is connected with the intelligent control substation. A ZigBee-k short-distance wireless communication technology is adopted between the monitoring substation and each street lamp low-energy-consumption control terminal and between the monitoring substation and each street lamp low-energy-consumption control terminal and each street lamp terminal, new broadband communication 5G is greatly improved in the aspects of data rate and delay capacity, interaction and application are enhanced, and the requirements of an intelligent street lamp system are met.

Description

Technical Field

[0001] The present application relates to a wireless network LED street lamp low energy consumption system, and more particularly to a wireless network intelligent LED street lamp low energy consumption system for collecting road conditions, belonging to the technical field of intelligent LED street lamps. Background Art

[0002] Urban development requires more and more street lighting to provide safety and convenience, which will inevitably consume more and more electric energy. The electric energy used for lighting has reached 12% of the total power generation, and road lighting accounts for 34% of the total lighting energy consumption. For sustainable development, it is necessary to improve energy utilization, start from the street lighting system, adopt advanced technology, and reduce electric energy consumption through technical improvements to achieve the purpose of protecting the environment. The reason why urban street lighting consumes too much energy is that it uses traditional inefficient light sources and there are many disadvantages in its control method. For example, most street lighting switches on and off at fixed times, such as turning on the lights at 6 pm and 7 am. This mode of operation does not require manual adjustment of the brightness of the street lights according to the ambient light around the street lights, which reduces the workload of the staff, but causes a waste of electric energy. When the ambient light suddenly dims and lighting is needed, the street lights cannot be turned on, which also brings safety hazards. In addition, if the line fails, the lights that should be turned off are not turned off, which also causes a waste of electric energy.

[0003] The three traditional lighting giants, Philips Lighting, General Electric, and Osram, have all developed their own street light control systems. For example, Philips Lighting has developed the Intelligentcity system and added Vodafone M2M SIM cards to its smart street lights. This move will allow them to connect to Philips Lighting's CityTouch management platform for remote control. Through the CityTouch lighting management platform, you only need to open the web page to log in to the control system, and you can see the details of all street lights on the city map. With a simple mouse circle, managers can turn on, dim, and turn off city lights in a variety of ways. In addition, managers can also promptly discover bulbs that need to be repaired and replaced to create a smart city street light environment.

[0004] Traditional communication equipment manufacturers have also seen the huge market for intelligent lighting control. Relying on their existing communication equipment and network construction advantages, they have entered the field of intelligent street light control. Among them, ZTE, based on the concept of "Internet of Everything, Integrated Integration", is the first in the industry to launch the "BluePillar" smart street light comprehensive solution that integrates street lights, charging piles, base stations, and smart city information collection. This solution enables traditional street light poles to be both 5G / 5G base stations and electric vehicle charging piles. At the same time, it can collect comprehensive information on meteorology, environment, transportation, and security in the city. The large-screen outdoor LED screen can also provide convenient information and be used for advertising operations. However, most of the street light control systems on the market are single-function and do not use vehicle and personnel detection sensors.

[0005] However, the street lamp system in the prior art still has problems. The difficulties and problems to be solved in this application are concentrated in the following aspects:

[0006] (1) The existing street light control system lacks joint design in terms of time control, light control, and environmental control. The network control lacks real-time parameter feedback. Key information on the monitoring terminal and the single street light node is missing. The switch status, power, and temperature status are missing. The street lights cannot be dynamically switched on and off according to the time setting. The street lights cannot be switched on and off and dimmed according to external environmental conditions. Offline control of street lights in the event of communication failure is very difficult. The control substation has only a single function except network bridging. The robustness and reliability of outdoor sensors are poor. The efficiency of street light sources is low. Most street lights have fixed switching times, or the brightness of the street lights needs to be adjusted manually according to the ambient light around the street lights. The workload of the staff is large and it is easy to cause waste of electricity. When the ambient light suddenly dims and lighting is needed, the street lights cannot be turned on, which also brings safety hazards. In addition, if the line fails, the lights that should be turned off are not turned off, which also causes waste of electricity.

[0007] (2) The street light control terminal in the prior art cannot switch on and off or dim the street lights according to the requirements of the control substation and the background when online; there is no step to detect the light intensity and send it to the control substation, and ask the control substation to determine whether to switch on and off or dim the light; it cannot detect the status of the temperature sensor, and there is no way to shut down the LED driver when it exceeds the limit and send a warning message to the intelligent control substation and the background; there is no detection of lamp power, and the user cannot configure the time interval according to needs, and there is no method to deal with lamp power exceeding the limit; there is no detection of wireless communication status, and there is no method to deal with link breakage; and it is impossible to provide location information when initializing the street light node configuration.

[0008] (2) The street lights in the existing technology are not energy-efficient enough and lack time and background detection to control the light power in real time. The real-time performance of street light management is weak, and it is impossible to ensure that the control information of the background control system and the substation controller reaches the street light node in the shortest time. The data status on the street light node cannot be displayed on the IoT terminal in the shortest time, and the network transmits data to the database slowly. The reliability is poor, the control and data status of the street light node are inconsistent with the control background, the wireless communication system is unreliable, and the link is often disconnected, and it is difficult to reconnect after disconnection. It is not advanced enough, and the ZigBee-k street light node, sensor, substation wireless communication, 5G bridge Ethernet, vehicle and personnel movement sensor, ambient illumination sensor, and temperature sensor are not added to the system. The intelligence level of the system is low, and it is impossible to use GIS map to display the current terminal position on the map, view the street light node and sensor information on the map, and the intelligence level of street light management is poor.

[0009] (4) The existing street lighting system has high energy consumption, single control method, inconvenient maintenance, lacks Doppler microwave radar detection circuit to detect pedestrians and vehicles, and cannot adjust the power output according to the real-time situation of pedestrians and vehicles. It is impossible to effectively save energy consumption while ensuring that the lighting provides urban safety. Due to the lack of control over street lights according to pedestrian and vehicle conditions at midnight, the street lights still maintain a high brightness when no one is around, the intelligent management is weak, and a large amount of electricity is wasted. Summary of the invention

[0010] The intelligent street light low-energy control system of the present application uses time control, light control, and environmental control to intelligently monitor and control key information on the terminal and a single street light node. Its technical advantages are mainly reflected in: 1) Energy saving. By setting low-power LED street lights, increasing time and background detection to control the light power in real time, energy consumption is reduced. 2) Real-time. The control information of the background control system and the substation controller reaches the street light node in the shortest time. At the same time, the data status on the street light node is displayed on the Internet of Things terminal in the shortest time. By using the 5G network to transmit the data to the database, the real-time performance is improved. 3) Reliable. The control and data status of the street light node are completely consistent with the control background. The wireless communication system is reliable and has less link loss. After the link loss is determined, it reconnects quickly. When the link is completely lost, the street light terminal controller starts the link loss mechanism to autonomously control the switching and dimming of the light. 4) Advancedness: 780MHz ZigBee-k streetlight nodes, sensors, substation wireless communication, 5G bridged Ethernet, vehicle and personnel movement sensors, ambient illumination sensors, and temperature sensors are added to the system to improve the intelligence level of the system. The current terminal position on the map is displayed using a GIS map, and the information of streetlight nodes and sensors can be viewed on the map. Various types of precise and accurate control of streetlights are carried out to achieve intelligent management of control, positioning, and monitoring, which has huge technical advantages and broad application prospects.

[0011] In order to realize the above technical features, the technical solutions adopted in this application are as follows:

[0012] The wireless network intelligent LED street light low-energy consumption system for collecting road conditions has the following features: first, the overall system architecture, which is divided into four parts: street light low-energy consumption control terminal, sensor multi-mode unit, intelligent control substation, and background server real-time computing system; second, street light low-energy consumption control terminal, including: KEC bus switch dimming circuit, temperature sensor, street light power acquisition circuit; third, sensor multi-mode unit, including: image sensor multi-mode module, Doppler radar link passive infrared sensor; fourth, intelligent control substation, including: power module and power-on timing, ZigBee-k communication, and ZigBee-k communication link indicator calculation;

[0013] This application integrates digital LED light sources, various sensors, intelligent control, and background services to propose a new type of LED intelligent street light low-energy control system solution, using digital LED light sources that are easy to switch and dim as the lighting solution, based on the intelligent street light low-energy control system communication method that combines long-distance and short-distance dual wireless networks, using 780MHz ZigBee-k as the LED street light low-energy control terminal, a wireless solution for short-distance communication between sensors and substation controllers, and 5G communication between long-distance substation controllers and background servers; the street light terminal controller integrates main control, wireless, data acquisition and analysis, and adds lightning protection design; a combination of three mobile detection sensor modules is used, including passive infrared sensors, Doppler microwave radar modules, and image sensor modules based on machine vision technology, and targeted improvements are made according to the characteristics of each module to accurately sense vehicles and pedestrians; a special networking pairing method is proposed, using positioning technology to compare the installer's handheld networking tools and the geographical address of the street light. During the networking process, searching for networking nodes is convenient and reliable.

[0014] Furthermore, the overall architecture of the system: the street lamp low-energy consumption controller terminal module includes six parts, namely: switch / dimming module, temperature sensor module, current and voltage sampling module, positioning module, ZigBee-k module and light measurement sensor module. The control terminal module communicates directly with the intelligent control substation through the 780MHz frequency band ZigBee-k. The street lamp low-energy consumption controller terminal realizes the switch and dimming control of the street lamp. These controls communicate with the LED driver through the wired digital interface KEC, and simultaneously perform current and voltage sampling, and upload this information to the intelligent control substation;

[0015] The sensor multi-mode unit provides the system with real-time status of the external environment, including: external environment illumination, vehicle and personnel flow status near the sensor. These sensors exist as separate nodes, and they are in the same position as the street light low-energy control unit in the ZigBee-k network. When in normal state, the status is regularly queried by the intelligent control substation and the background. When the sensor detects data changes, it actively sends information to the intelligent control substation and the background. After the intelligent control substation and the background analyze and process these data, they control and manage the street light nodes accordingly. The sensors include image presence sensors, light measurement sensors, and Doppler radar linked passive infrared presence sensors;

[0016] The intelligent control substation module is installed in the cabinet under the lamp post: 1) Switch and dim the street lights in the corresponding street light group uniformly; 2) Detect the status of various sensors and analyze them; 3) Download configurations according to the low-energy control requirements of street lights; 4) Communicate with street light nodes as the coordinator of the ZigBee-k network and upload street light information to the background control platform. At the same time, it serves as a transfer platform between the background control platform and the street light nodes, and connects to the background control platform through the underlying data link of 5G; 5) Detect the wireless communication status, and perform heartbeat detection with the street light nodes and the control background at the application layer; 6) Power on and off other devices in the cabinet through programming; 7) Detect the opening and closing of the cabinet door, and send alarm information to the control background if the door is found to be open; 8) Detect the power consumption of the entire group of street lights as needed; 9) Control the group street light nodes according to the configuration information when there is no background control or disconnection;

[0017] The intelligent control substation includes ZigBee-k module and 5G module, current and voltage sampling, and wired control and data acquisition in addition to wireless control. The intelligent control substation communicates with image sensors, light measurement sensors, Doppler radar sensors and passive infrared sensors through ZigBee-k. At the same time, the intelligent control substation also has USB storage, SDcard data storage, and 10 / 100M Ethernet port configuration for the substation controller;

[0018] The backend module is a real-time computing system of the backend server. The backend module facilitates remote operation and maintenance. When introducing backend control, the backend server and intelligent control substation are connected to the backend server system through the 5G network. The backend control provides the corresponding location information and operation status information of each street light node, sensor node and substation controller. These operation status information include: communication status, lighting status, power status of street light nodes, communication status of sensors, and information collection status.

[0019] Furthermore, the street lamp low energy consumption control terminal is composed of an SPD module, a street lamp terminal controller module, and a lighting driver module;

[0020] The SPD module is a lightning protection module that suppresses surges caused by inductive lightning on power lines;

[0021] Lighting driver module: Power the LED lamp particles and the street lamp terminal controller respectively. The street lamp terminal controller controls the LED driver through the KEC interface. It uses the Xitanium 150W 0.35-0.7AGL ProgsXt outdoor LED driver. At the same time, it cooperates with Luxeon high-power LED particles. The LED driver outputs constant DC current to work with high-power LEDs and uses the KEC interface.

[0022] Street lamp terminal controller: including: SAM3S4A main controller, EEPROM module, positioning circuit module, ZigBee-k module, lamp power detection circuit, temperature sensor module, ambient illumination sensor module and KEC bus switch dimming circuit;

[0023] The EEPROM module is a chip that stores configuration information, including the address of the node controller in the ZigBee-k network, the control strategy of the local street light, and the configuration information is saved after power failure. The EEPROM is connected to the main controller through the I2C bus;

[0024] The positioning module MAX7C extracts the geographical location information of the current street light node, which is sent to the intelligent control substation and finally to the background map system. The geographical address of each light can be seen in the background to enhance the maintenance information of the system.

[0025] The lamp power detection circuit detects the power of a single lamp node; the temperature sensor detects the working temperature inside the street lamp. When the temperature exceeds the limit, the system issues a light-off command to protect the street lamp.

[0026] The ambient illumination sensor detects the background light illumination;

[0027] The KEC bus sends these switching and dimming commands when the node controller switches and dims the digital rectifier and the digital LED driver.

[0028] Further, the KEC bus switch dimming circuit: The switch dimming circuit adopts the KEC bus: It is built with discrete devices and defines 4 types of commands according to professional lighting management, namely: 1) Switch: Digital rectifier or digital LED driver with independent address in the switch system; 2) Dimming: 125-level dimming control of digital LED driver with dimming function; 3) Lighting scene: In a KEC group, up to 16 lighting scenes can be set; 4) Status display: Display the working status of the digital LED driver;

[0029] The two optocouplers on the left side of the KEC bus circuit physically isolate the KEC signal on the high-voltage side to ensure the safety of the low-voltage part. The right side is connected to the microcontroller, and the KEC protocol inside the microcontroller uses these ports for communication.

[0030] Furthermore, the temperature sensor detects the temperature inside the lamp. When the temperature is higher than 100 degrees Celsius, the lamp controller turns off the lamp output for protection and sends the temperature over-limit information to the intelligent control substation. The temperature change causes the resistance value of thermistor R1702 to change, thereby changing the voltage divider. The voltage is sent to the ADC of the microcontroller, and the temperature value is obtained through analog-to-digital conversion.

[0031] In the terminal system software, the main CPU chip ATSAM3S4A regularly reads the voltage value of the temperature sensor through the ADC pin. When the read AD value exceeds the maximum limit, the LED driver is turned off through the KEC bus, and an error code is generated and transmitted to the intelligent control substation through the ZigBee-k wireless protocol.

[0032] Furthermore, the street lamp power collection circuit: a voltage sampling circuit is used in the circuit, the live wire voltage is gradually divided and then sampled through the ADC port of the STM8 microcontroller. The ADC processing circuit is placed on the high-voltage side, and the collected voltage is sent to the main controller through optocoupler isolation. The current sampling is measured by the current transformer connected to the live wire. Finally, these signals are analyzed and calculated by the main controller to obtain the real-time power of the LED light source. The left side is the live wire voltage input end, and the right side is the signal optocoupler output end. The collection end is obtained through resistance division. The purpose of adding a TVS tube at the end is to suppress the damage caused by surges on the line to the I / 0 port of the microcontroller.

[0033] Furthermore, the image sensor multi-mode module is installed separately on the light pole to detect pedestrians and vehicles on the road. At night, when there are few vehicles and pedestrians, the system adjusts the light brightness to 20% of the full power output. This is the default value, and the user can set it according to actual needs. When pedestrians or vehicles move, the image sensor detects these movements and then sends the information to the intelligent control substation. The intelligent control substation dims the corresponding street lights according to the results, increasing the light power to 100%, and then delaying for 1 minute. After one minute, if pedestrians are detected again, continue to maintain 100%. If no movement is detected after another minute, the system will reduce the corresponding light power to 20%;

[0034] The image sensor CB is the control board, which realizes the physical layer communication of ZigBee-k. The main control microcontroller, power module, and DB are the digital board, which are the integration of the camera module. At the same time, the DSP processes and analyzes the image to obtain the information of the movement of people or vehicles. After analysis and processing, the control board main control microcontroller is directly notified through the serial port whether there is movement. The image sensor analyzes the image captured by the camera and then outputs the required personnel and vehicle movement information. The DB board has 3 LED indicator lights, which respectively indicate the power working status, whether there is movement, and the communication status.

[0035] Furthermore, the Doppler radar is linked to the passive infrared sensor: the Doppler microwave radar detection circuit detects pedestrians and vehicles, and is turned on when there are fewer vehicles on the road late at night. When no one or no vehicle passes by, the street lamp is automatically controlled to dim and reduce the lamp power. When someone or a vehicle passes by, the street lamp is automatically controlled to restore full power output, saving energy consumption while ensuring that lighting provides urban safety.

[0036] The oscillator circuit sends out a 5.8GHz continuous wave signal through the transmitting antenna. The signal reaches the detection object and is reflected back and received by the receiving antenna. The signal enters the mixer and mixes with the local oscillator signal to obtain an intermediate frequency of several to tens of Hz, which corresponds to the moving speed of the vehicle or person.

[0037] The input interface is set up with 3 wires, power supply, ground wire and signal wire. The input power voltage range is 15-45V, and the working current is about 20mA. When there is no movement detection, the signal line outputs a TTL 5V low level, and when movement is detected, it outputs a TTL5V high level signal.

[0038] Timing: When no vehicle movement is detected late at night, the system adjusts the background light to 20% of the full power. When a car is detected, within 0.8 seconds, the system adjusts the approaching light to 100% power output. When the car leaves, the system keeps the corresponding light output at 100% for one minute. If no vehicle movement is detected within one minute, the system will reduce the corresponding light output power to 20% again.

[0039] Passive infrared determines the person by detecting the infrared wavelength of this band. The passive infrared detector is equipped with two important devices. One is the pyroelectric infrared sensor, which is set just below the white transparent Fresnel prism. It converts the infrared signal change between the wavelength of 8-12um into an electrical signal. Four separate sensing units are set. Within the sensing range of the passive infrared detector, when there is no vehicle or person moving, the pyroelectric infrared sensor only senses the background temperature. When the human body enters the sensing range, through the projection of the Fresnel lens, the pyroelectric infrared sensor senses the difference signal between the human body temperature and the background temperature. At the same time, due to the role of multiple units, the electrical signal of the detection unit pulses successively to determine the movement of the person; the other device is the Fresnel refractive lens, which focuses and refracts the pyroelectric infrared signal on the PIR sensing element, divides the sensing range into several sensing areas, and makes the moving object entering the sensing range generate a changing pyroelectric infrared signal on the PIR in the form of temperature change. By detecting these changing electrical signals, the heat of the person and the car is indirectly detected, that is, the movement of the person and the car is detected;

[0040] The processing circuit Q1 of the infrared unit is a multi-mode unit of the PIR sensor. After being amplified by U2, it enters the ADC of the microcontroller for sampling and analog-to-digital conversion. The SW1 signal adjusts the gain of the infrared processing circuit.

[0041] Furthermore, the intelligent control substation includes: 1) the communication link between the control background and the substation controller, and the communication link between the street lamp and the sensor node and the substation controller; 2) controlling the street lamp node according to the background or its own configuration information; 3) detecting various sensor information to realize intelligent control of the street lamp;

[0042] The substation controller includes a power module, a ZigBee-k module, which is used to communicate with the street light nodes, and a 5G module, which is used to communicate with the background system. The substation controller is designed with several expansion interfaces to control the street lights. In addition, the peripheral interfaces are as follows:

[0043] 1) KEC digital lighting interface module and A-BUS; 2) 7 current sampling units to process various wired sensor information; 3) 1 RS485, 1 RS232, external communication interface; 4) 2 relay switches to directly open and cut off the wired street lights that need to be controlled; 5) 1 analog input interface, 1 digital input interface to expand analog and quantitative data collection; 6) 2 USB host interfaces to access USB storage; 7) 1 RJ45 10 / 10OM Ethernet interface to download configuration to the substation controller;

[0044] The main processing chip STM32F103 of the substation controller serves as a wide area network communication and data concentrator module. On one side, it realizes the function of ZigBee-k network coordinator through SPI bus and AT86RF212B to communicate with the low-energy control node of the street lamp. On the other side, it uses serial port UART to communicate with 5G module ME909S-821 to configure the working mode of 5G module and communicate with normal 5G data traffic, SMS or background server.

[0045] Furthermore, the ZigBee-k communication link indicator is calculated as follows: the number of jumps in this application is less than 3, that is, the number of jumps from the substation controller to the edge street lamp terminal controller farthest from it does not exceed 3 times,

[0046] The wireless communication system link consists of several parameters, including the actual transmission power of the transmitter AT86RF212B, matching circuit loss, transmission antenna gain, transmission path loss, receiving antenna gain, receiving matching circuit loss, and chip receiving sensitivity. The chip transmission power is 10dBm, the matching loss is actually tested to be 2Db, and the antenna gain is -3.8dBi. The path loss corresponds to a transmission distance of 300 meters.

[0047] The path loss includes the vector superposition of direct transmission loss and ground reflection loss. R1 is the direct transmission path and R2 is the ground reflection path. There is a relationship in equation 1:

[0048]

[0049] HRX is the height of the streetlight pole of the receiving terminal controller, HTX is the height of the streetlight pole of the transmitting substation controller or terminal controller, d is the distance between the streetlight poles of the corresponding communication nodes, and the direct transmission power path is R1, which is calculated using Formula 2:

[0050]

[0051] P TX is the transmission power, G TX1 is the antenna gain, G RX1 is the receiving antenna gain, λ is the wavelength coefficient;

[0052] The reflected transmission power path is R2:

[0053]

[0054] Γ is the reflection coefficient, G TX1 =G TX2 =G RX1 =G RX2 Assuming the matching loss of the transmitting system and the receiving system and the gain of the antenna and the vertical polarization of the antenna, the total received power on the receiving side is:

[0055] E tot =E dir +E refl ×cos(kΔR) Equation 4

[0056] k is the electromagnetic wave propagation constant, ΔR = R2-R1, and the path loss formula 5 is calculated:

[0057]

[0058] In the above formula, λ is the wavelength of 780Mhz, which is 0.384 meters. The installation height is 7.2 meters. The link margin at a communication distance of 300 meters is calculated to be 10.9dB, and the limit distance reaches 2600 meters. Based on the relationship between the link budget margin and the communication distance in free space and with ground reflection, the communication distance has reached 2600 meters, far exceeding the communication distance requirement of 300 meters. The wireless system provides sufficient margin.

[0059] A forest with a width of 10 meters has a 2dB attenuation on electromagnetic waves with a frequency of 1GHz, which means that to ensure a communication distance of 300 meters, a maximum length of 50 meters of forest is allowed on the transmission path.

[0060] Compared with the prior art, the innovations and advantages of this application are:

[0061] (1) This application analyzes the current street lamp system based on the characteristics of the urban lighting system and proposes an intelligent LED street lamp hardware system based on a wireless network. The system adopts LED lighting, multi-sensor feedback, wireless ZigBee-k and 5G technology networking technology to realize the intelligence of LED street lamps and provide remote operation and maintenance capabilities, effectively solving the problems of excessive power consumption of light sources in the current street lamp system, low system intelligent control level and weak maintenance capabilities. The overall plan of the street lamp management center, monitoring substation and street lamp low-energy control terminal is designed. The control background software is based on the 5G network. The street lamp low-energy control terminal hardware equipment is connected to the intelligent control substation through ZigBee-k. The intelligent control substation processes and accesses the background management system through the 5G terminal at the same time to realize real-time data interaction. The monitoring substation and each street lamp low-energy control terminal and the street lamp terminal use ZigBee-k short-range wireless communication technology. The new broadband communication 5G has made great improvements in data rate and delay capacity, and has been strengthened in interaction and application, meeting the needs of the intelligent street lamp system.

[0062] (2) This system can effectively solve the problems existing in the current street light system and improve the utilization rate of electric energy. Based on the application of digital LED lighting, this system integrates 5G communication and ZigBee-k methods, and combines various sensors to form a set of low-energy consumption control network for street lights. It can collect data from street lights and various sensors in real time, analyze them, monitor the road background conditions and street light status, and give corresponding control plans. When the ambient light changes, when the number of vehicles and pedestrians on the road changes, the lighting status can be flexibly adjusted. When the system line fails, it can also provide timely feedback to the main control system so that the main control system can respond in time and handle the fault. The new street light low-energy consumption control system greatly reduces the waste of electric energy, saves the expenses of the street light management department, and reduces maintenance costs by intelligently adjusting the switch and dimming status of the street lights. The intelligent street light low-energy consumption control system achieves low energy consumption and intelligent information management on the basis of ensuring the safety of lighting, and is easy to maintain, which is worthy of vigorous promotion.

[0063] (3) The intelligent street light low-energy control system of the present application uses time control, light control, and environmental control to intelligently monitor and control key information on the terminal and a single street light node. Its technical advantages are mainly reflected in: 1) Energy saving. By setting low-power LED street lights, increasing time and background detection to control the light power in real time, energy consumption is reduced. 2) Real-time. The control information of the background control system and the substation controller reaches the street light node in the shortest time. At the same time, the data status on the street light node is displayed on the Internet of Things terminal in the shortest time. By using the 5G network to transmit data to the database, the real-time performance is improved. 3) Reliability. The control and data status of the street light node are completely consistent with the control background. The wireless communication system is reliable and rarely drops. After the drop is determined, it reconnects quickly. When the drop is completely, the street light terminal controller starts the drop mechanism to autonomously control the switching and dimming of the light. 4) Advancedness: 780MHz ZigBee-k streetlight nodes, sensors, substation wireless communication, 5G bridged Ethernet, vehicle and personnel movement sensors, ambient illumination sensors, and temperature sensors are added to the system to improve the intelligence level of the system. The current terminal position on the map is displayed using a GIS map, and the information of streetlight nodes and sensors can be viewed on the map. Various types of precise and accurate control of streetlights are carried out to achieve intelligent management of control, positioning, and monitoring, which has huge technical advantages and broad application prospects.

[0064] (4) This application uses LED light sources, which have high light efficiency, long life, and are easy to digitally control. At the same time, wireless methods are used for communication between street lamps, between street lamps and control background, and between sensors and control background. This method does not require the laying of a large number of copper cables, saves manpower and material resources, increases the collection of environmental, pedestrian, and vehicle information by various sensors, optimizes the control of the system, and can promptly feedback to the control center when a street lamp in the system fails, improves the maintenance efficiency of the faulty street lamp, makes the street lamp system safer and more reliable, and reduces maintenance costs. By combining digital LED lighting technology, sensor technology, ZigBee-k short-range wireless network and long-range 5G technology, a smart LED street lamp system solution based on wireless network is proposed. The system has data acquisition, terminal control, self-organizing network, intelligent judgment and processing, and real-time monitoring of the working status of street lamps. Once a street lamp in the line fails, the system will promptly alarm, and the maintenance personnel will promptly handle the fault according to the information provided by the alarm system. The lighting system also realizes the self-collection of road condition information and makes corresponding control of street lamp lighting based on the information. The intelligent lighting control system improves the management level of the urban lighting system. Under the premise of ensuring scientific and reasonable lighting, it effectively saves resources and has high economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is the overall structure diagram of the wireless network intelligent LED street light low energy consumption system that collects road conditions.

[0066] Figure 2 It is a structural diagram of a low-energy consumption control terminal for street lamps.

[0067] Figure 3 This is the internal block diagram of the street light terminal controller.

[0068] Figure 4 This is the schematic diagram of the KEC bus switch dimming circuit.

[0069] Figure 5 It is a schematic diagram of the Doppler radar link structure.

[0070] Figure 6 This is a timing diagram of Doppler radar linked to passive infrared sensor.

[0071] Figure 7 It is the structural block diagram and specific design drawing of the intelligent control substation.

[0072] Figure 8 This is a schematic diagram of the actual street light installation of the intelligent control substation.

[0073] Fig. 9 It is a link structure diagram of the wireless communication system of the present application.

[0074] Fig.10This is a schematic diagram of the node path of the ZigBee-k communication link.

[0075] Fig.11 The following are link budget plots for free space and with ground reflection. DETAILED DESCRIPTION

[0076] The following, in conjunction with the accompanying drawings, further describes the technical solution of the wireless network intelligent LED street lamp low-energy consumption system for collecting road conditions provided by the present application, so that technicians in this field can better understand the present application and implement it.

[0077] This application designs the hardware circuits related to the monitoring substation and the low-energy consumption control terminal of the street lamp: the ambient light illumination detection module enables the street lamp to automatically control the dimming state of the street lamp according to the changes in the external ambient light intensity; the KEC dimming circuit enables the street lamp to adopt different lighting scenes according to the actual environment; the voltage and current detection circuit detects the working voltage and current of the LED driver to obtain the input power, and judges whether the street lamp is faulty according to the change of the power; the Doppler microwave radar detection circuit detects pedestrians and vehicles, adjusts the power output according to the real-time situation of pedestrians and vehicles, and effectively saves the consumption of electricity while ensuring that the lighting provides urban safety. In addition, the hardware design of the monitoring substation is also realized.

[0078] System tests show that each module can work well as required. The street light system has achieved good lighting and energy-saving effects through the combination of multiple new technologies including LED lighting, sensors, wireless, and intelligent control, while improving the efficiency of system management.

[0079] 1. System overall architecture

[0080] The overall structure of the intelligent street light low-energy consumption control system based on the Internet of Things is divided into four parts: street light low-energy consumption control terminal, sensor multi-mode unit, intelligent control substation, and background server real-time computing system. Figure 1 shown.

[0081] Functions realized by street light low energy consumption control terminal:

[0082] 1) When online, switch and dim street lights according to the requirements of the intelligent control substation and background;

[0083] 2) Detect the light intensity and send it to the intelligent control substation, asking the intelligent control substation to determine whether to switch on and off or dim the light.

[0084] 3) Detect the status of the temperature sensor. If it exceeds the limit, turn off the LED driver and send a warning message to the intelligent control substation and the background;

[0085] 4) Check the lamp power. The default timer is 5 minutes. Users can also configure the time interval as needed. Send the status to the intelligent control substation and the background. If the lamp power exceeds the limit, the LED driver will be turned off and a warning message will be sent to the intelligent control substation and the background.

[0086] 5) Detect the wireless communication status. If the link is broken, reconnect. If the link is still broken, enter the offline working state and control the switch and dimming of the street lamp according to the initial timing and light intensity detection;

[0087] 6)) Provide location information when initializing the configuration of street light nodes.

[0088] The street light low-energy controller terminal module consists of six parts: switch / dimming module, temperature sensor module, current and voltage sampling module, positioning module, ZigBee-k module and light measurement sensor module. The control terminal module communicates directly with the intelligent control substation through the 780MHz frequency band ZigBee-k. The street light low-energy controller terminal realizes the switch and dimming control of the street light. These controls communicate with the LED driver through the wired digital interface KEC, and perform current and voltage sampling at the same time, and upload this information to the intelligent control substation.

[0089] The sensor multi-mode unit provides the system with real-time status of the external environment, including: external environment illumination, vehicle and personnel flow status near the sensor. These sensors exist as separate nodes, and they are in the same position as the street light low-energy control unit in the ZigBee-k network. When in normal state, they are regularly queried by the intelligent control substation and background. When the sensor detects data changes, it actively sends information to the intelligent control substation and background. After the intelligent control substation and background analyze and process these data, they control and manage the street light nodes accordingly. The sensors include image presence sensors, light measurement sensors, and Doppler radar linked passive infrared presence sensors.

[0090] The intelligent control substation module is installed in the cabinet under the lamp post. 1) It switches and dims the streetlights in the corresponding streetlight group uniformly; 2) It detects the status of various sensors and analyzes them; 3) It downloads configurations according to the low-energy consumption control requirements of streetlights; 4) It communicates with the streetlight nodes as the coordinator of the ZigBee-k network and uploads streetlight information to the background control platform. At the same time, it serves as a switching platform between the background control platform and the streetlight nodes, and connects to the background control platform through the underlying data link of 5G; 5) It detects the wireless communication status and performs heartbeat detection with the streetlight nodes and the control background at the application layer; 6) It controls the power on and off of other devices in the cabinet through programming; 7) It detects the opening and closing of the cabinet door, and if the door is found to be open, it sends an alarm message to the control background; 8) It detects the power consumption of the entire group of streetlights as needed; 9) In the absence of background control or disconnection, it controls the group streetlight nodes according to the configuration information.

[0091] The intelligent control substation includes ZigBee-k module and 5G module, current and voltage sampling, and in addition to wireless control, it uses wired (4-20mA, RS485, RS232, KEC, digital I / O, relay, ABUS, positioning) control and data acquisition. The intelligent control substation communicates with image sensors, light measurement sensors, Doppler radar sensors and passive infrared sensors through ZigBee-k. At the same time, the intelligent control substation also has USB storage, SDcard data storage, and 10 / 100M Ethernet port to configure the substation controller.

[0092] The backend module is a real-time computing system of the backend server. The backend module facilitates remote operation and maintenance. When introducing backend control, the backend server and intelligent control substation are connected to the backend server system through the 5G network. The backend control provides the corresponding location information and operation status information of each street light node, sensor node and substation controller. These operation status information include: communication status, lighting status, power status of street light nodes, communication status of sensors, and information collection status.

[0093] 2. Street Light Low Energy Consumption Control Terminal

[0094] The street light low energy consumption control terminal consists of SPD module, street light terminal controller module and lighting driver module. Figure 2 This is a schematic diagram of the structure of the low-energy consumption control terminal for street lamps.

[0095] The SPD module is a lightning protection module that suppresses surges caused by inductive lightning on power lines.

[0096] Lighting driver module: Power is supplied to LED lamp particles and street lamp terminal controller respectively. The street lamp terminal controller controls the LED driver through the KEC interface. It adopts Xitanium 150W 0.35-0.7AGL ProgsXt outdoor LED driver. At the same time, it cooperates with Luxeon high-power LED particles. The LED driver outputs high-power LED with constant DC current and adopts KEC interface.

[0097] Street light terminal controller: The internal block diagram of the street light terminal controller is as follows Figure 3 As shown, it includes: SAM3S4A main controller, EEPROM module, positioning circuit module, ZigBee-k module, lamp power detection circuit, temperature sensor module, ambient illumination sensor module and KEC bus switch dimming circuit.

[0098] The EEPROM module is a chip that stores configuration information. The information includes the address of the node controller in the ZigBee-k network and the control strategy of the local street light. The configuration information is saved after power failure and is not lost. The EEPROM is connected to the main controller through the I2C bus.

[0099] The positioning module MAX7C extracts the geographical location information of the current street light node, which is sent to the intelligent control substation and finally to the background map system. The geographical address of each lamp can be seen in the background to enhance the maintenance information of the system.

[0100] The lamp power detection circuit detects the power of a single lamp node; the temperature sensor detects the working temperature inside the street lamp. When the temperature exceeds the limit, the system issues a light-off command to protect the street lamp.

[0101] The ambient illumination sensor detects the background light illumination to achieve the purpose of automatically turning the light on and off.

[0102] The KEC bus sends these switching and dimming commands when the node controller switches and dims the digital rectifier and the digital LED driver.

[0103] (I) KEC bus switch dimming circuit

[0104] The switch dimming circuit adopts KEC bus: it is built with discrete devices and defines 4 types of commands according to professional lighting management, namely: 1) Switch: a digital rectifier or digital LED driver with an independent address in the switch system; 2) Dimming: 125-level dimming control of the digital LED driver with dimming function; 3) Lighting scene: in a KEC group, up to 16 lighting scenes can be set; 4) Status display: display the working status of the digital LED driver.

[0105] like Figure 4It is the circuit implementation of the KEC bus. The two optocouplers on the left physically isolate the KEC signal on the high-voltage side to ensure the safety of the low-voltage part. The right side is connected to the microcontroller, and the KEC protocol inside the microcontroller uses these ports for communication.

[0106] (2) Temperature sensor

[0107] The temperature sensor detects the temperature inside the lamp. When it detects that the temperature is higher than 100 degrees Celsius, the lamp controller turns off the output of the lamp for protection and sends the temperature limit information to the intelligent control substation. The temperature change causes the resistance value of thermistor R1702 to change, thereby changing the voltage divider. The voltage is sent to the ADC of the microcontroller and the temperature value is obtained through analog-to-digital conversion.

[0108] In the terminal system software, the main CPU chip ATSAM3S4A regularly reads the voltage value of the temperature sensor through the ADC pin. When the read AD value exceeds the maximum limit, the LED driver is turned off through the KEC bus, and an error code is generated and transmitted to the intelligent control substation through the ZigBee-k wireless protocol.

[0109] (III) Street light power collection circuit

[0110] The circuit uses a voltage sampling circuit to gradually divide the live wire voltage and then sample it through the ADC port of the STM8 microcontroller. The ADC processing circuit is placed on the high-voltage side, and the collected voltage is sent to the main controller through optocoupler isolation. The current sampling is measured by the current transformer connected to the live wire. Finally, these signals are analyzed and calculated by the main controller to obtain the real-time power of the LED light source. The left side of the voltage sampling is the live wire voltage input terminal, and the right side is the signal optocoupler output terminal. The collection terminal is obtained by resistor voltage division. The purpose of adding a TVS tube at the end is to suppress the damage caused by surges on the line to the I / O port of the microcontroller.

[0111] 3. Sensor Multi-mode Unit

[0112] (I) Image sensor multi-mode module

[0113] It is installed separately on the light pole to detect pedestrians and vehicles on the road. At night when there are few vehicles and pedestrians, the system adjusts the light brightness to 20% of the full power output. This is the default value and the user can set it according to actual needs. When pedestrians or vehicles move, the image sensor detects these movements and then sends the information to the intelligent control substation. The intelligent control substation dims the corresponding street lights according to the results, increasing the light power to 100% and then delaying for 1 minute. After one minute, if pedestrians are detected again, the light power will continue to be 100%. If no movement is detected after another minute, the system will reduce the corresponding light power to 20%.

[0114] The image sensor CB is the control board, which realizes the physical layer communication of ZigBee-k. The main control microcontroller, power module, and DB are the digital board, which are the integration of the camera module. At the same time, the DSP processes and analyzes the image to obtain the information of the movement of people or vehicles. After analysis and processing, the control board main control microcontroller is directly notified through the serial port whether there is movement. The image sensor analyzes the image captured by the camera and then outputs the required personnel and vehicle movement information. The DB board has 3 LED indicator lights, which respectively indicate the power working status, whether there is movement, and the communication status.

[0115] (ii) Doppler radar linked to passive infrared sensor

[0116] The Doppler microwave radar detection circuit detects pedestrians and vehicles. It is turned on when there are fewer vehicles on the road late at night. When no one or no vehicles pass by, the street lamps are automatically dimmed to reduce the lamp power. When people or vehicles pass by, the street lamps are automatically controlled to restore full power output, effectively saving energy consumption while ensuring that lighting provides urban safety.

[0117] The Doppler microwave and passive infrared unit sensors are a complement to the image sensor multi-mode unit. Users can choose both at the same time or just one.

[0118] The basic structure of the module is as follows Figure 5 As shown, the oscillator circuit sends out a 5.8GHz continuous wave signal through the transmitting antenna. The signal reaches the detection object and is reflected back and received by the receiving antenna. The signal enters the mixer and mixes with the local oscillator signal to obtain an intermediate frequency of several to tens of Hz, which corresponds to the moving speed of the vehicle or person.

[0119] The input interface is set up with 3 wires, power supply, ground line and signal line. The input power supply voltage range is 15-45V, and the working current is about 20mA. When there is no movement detection, the signal line outputs a TTL 5V low level. When movement is detected, it outputs a TTL5V high level signal.

[0120] The actual adoption sequence is as follows Figure 6 As shown: When no vehicle movement is detected late at night, the system adjusts the background light to 20% of the full power. When a car is detected, within 0.8 seconds, the system adjusts the approaching light to 100% power output. When the car leaves, the system keeps the corresponding light output at 100% for one minute. If no vehicle movement is detected within one minute, the system reduces the corresponding light output power back to 20%.

[0121] Passive infrared is a supplement to microwave sensors. Microwave sensors may be falsely triggered by swaying trees outdoors, but passive infrared does not have this problem. The infrared light waves radiated by the human body have a wavelength of 3 to 50u. m range, passive infrared determines personnel by detecting the infrared wavelength of this band. The passive infrared detector is equipped with two important devices. One is the pyroelectric infrared sensor, which is set just below the white transparent Fresnel prism. It converts the infrared signal changes between 8-12um wavelength into electrical signals. Four separate sensing units are set. Within the sensing range of the passive infrared detector, when there is no vehicle or person moving, the pyroelectric infrared sensor senses only the background temperature. When the human body enters the sensing range, through the Fresnel lens projection, the pyroelectric infrared sensor senses the difference signal between the human body temperature and the background temperature. At the same time, due to the role of multiple units, the electrical signal of the detection unit pulses successively to determine the movement of the person; the other device is the Fresnel refractive lens, which focuses and refracts the pyroelectric infrared signal on the PIR sensing element, divides the sensing range into several sensing areas, and makes the moving objects entering the sensing range generate changing pyroelectric infrared signals on the PIR in the form of temperature changes. By detecting these changing electrical signals, the heat of people and cars is indirectly detected, that is, the movement of people and cars is detected.

[0122] In the design of the infrared unit processing circuit, Q1 is a multi-mode unit of the PIR sensor. After being amplified by U2, it enters the ADC of the microcontroller for sampling and analog-to-digital conversion. The purpose of the SW1 signal is to adjust the gain of the infrared processing circuit.

[0123] 4. Intelligent Control Substation

[0124] The structure diagram and specific design of the intelligent control substation are as follows: Figure 7 As shown:

[0125] The intelligent control substation includes: 1) the communication link between the control background and the substation controller, and the communication link between the street lamp and sensor node and the substation controller; 2) controlling the street lamp node according to the background or its own configuration information; 3) detecting various sensor information to realize intelligent control of street lamps.

[0126] The substation controller includes a power module, a ZigBee-k module, which is used to communicate with the street light nodes, and a 5G module, which is used to communicate with the background system. The substation controller is designed with several expansion interfaces to control the street lights. In addition, the peripheral interfaces are as follows:

[0127] 1) KEC digital lighting interface module and A-BUS; 2) 7 current sampling units to process various wired sensor information; 3) 1 RS485, 1 RS232, external communication interface; 4) 2 relay switches to directly open and cut off the wired street lights that need to be controlled; 5) 1 analog input interface, 1 digital input interface to expand analog and quantitative data collection; 6) 2 USB host interfaces to access USB storage; 7) 1 RJ45 10 / 10OM Ethernet interface to download configuration to the substation controller.

[0128] The main processing chip STM32F103 of the substation controller serves as a wide area network communication and data concentrator module. On one side, it realizes the function of ZigBee-k network coordinator through SPI bus and AT86RF212B to communicate with the low-energy control node of the street lamp. On the other side, it uses serial port UART to communicate with 5G module ME909S-821 to configure the working mode of 5G module and communicate with normal 5G data traffic, SMS or background server.

[0129] The left side of the intelligent control substation circuit is the power input part, and the right side is the signal processing, interface and RF part.

[0130] (I) Power module and power-on sequence

[0131] After the system is powered on, the DC / DC converts power from 12V to 5V, and then converts 5V to 3.3V through LDO. A diode is used to isolate the battery and the 3.3V circuit to power the onboard RTC battery. The actual operating voltage of the STM32F103 is 3.1V. The STM32F103 is powered on first. When the STM32F103 is stable after powering on, the LDO that powers the 5G module is started, and then the 5G module is powered and initialized. After a certain delay, ensure that the 5G module is initialized and enters a stable state, and then the STM32F103 starts the 5G module by pulling down the POWER_ON port of the 5G module for about one second, and the rest of the circuits are powered separately by a DC / DC circuit.

[0132] (2) ZigBee-k communication

[0133] The ZigBee-k terminal is installed at the street light terminal and is responsible for collecting data and converting the collected data information into wireless data information for transmission, and converting the received wireless data into control information to realize street light status control; the ZigBee-k coordinator is installed at the substation. When receiving the control command from the street light management center, the substation sends the command to the target street light terminal through the ZigBee-k network.

[0134] Based on the ZigBee-k communication characteristics of the intelligent street light system and the arrangement of urban street lights, the coordinator is set at the geographical center to achieve the most efficient arrival at each street light terminal with the least number of routes. When the coordinator finds that a new street light node has joined the network of the system, after handshake, it assigns a network address to the node and adds it to the list. A monitoring substation is equipped with 50 street light terminal nodes, such as Figure 8 shown.

[0135] Sensors are arranged at intervals of every 5 street lamps. At the same time, sensors are arranged at the entrances and exits of the road. When the sensors at the entrances and exits detect pedestrians and vehicles, the 5 street lamps behind their walking paths switch from 20% output power mode to 100% output mode. When the next sensor detects pedestrians and vehicles, the corresponding next 5 street lamps also switch from low output mode to high output mode. The system detects the status of the previous sensor. When no movement is detected, it enters a 1-minute timing. If no movement is detected within this time, the corresponding street lamp switches from high output mode to low output mode, and the control process is similar.

[0136] If a route or terminal is found to be disconnected and after multiple reconnection attempts fail, the system will delete the node from the routing table and update a new routing table to achieve system self-healing.

[0137] (III) ZigBee-k communication link indicator calculation

[0138] Whether the low-energy controllers of street lights can communicate reliably and whether the low-energy controllers of street lights can communicate with the intelligent control substation reliably is the key to the success of the design of wireless street light systems. The corresponding communication distance is the key indicator of the hardware design of the low-energy control system of street lights. In principle, ZigBee-k is a mesh network architecture. As long as any node in the system can be connected to a neighboring node, the non-neighboring nodes in the system can achieve the goal of wireless communication through countless routes and jumps. However, in actual applications, the overhead of the wireless network system must be as small as possible, and more jumps will bring more overhead to the system, which may cause delays in the control instructions reaching the controlled objects. In some cases, long delays make the system unable to meet the basic design requirements. In this case, in order to achieve the basic performance of the system, some solutions need to be provided, such as increasing the number of substation controllers and reducing the scale of the system. Although these solutions can solve the problem of communication distance, they will increase the hardware cost of the system, which is a solution that engineering design needs to avoid. Therefore, as a hardware system, if the terminal controller can be guaranteed to have sufficient communication distance, the number of jumps will be reduced.

[0139] The number of jumps in this application is less than 3, that is, the number of jumps from the substation controller to the edge street lamp terminal controller farthest from it does not exceed 3 times.

[0140] The wireless communication system link structure of the present application is as follows Fig. 9 As shown, there are several parameters including the actual transmitting power of the transmitting end AT86RF212B, matching circuit loss (Balun insertion loss, low-pass filter loss), transmitting antenna gain, transmission path loss, receiving antenna gain, receiving matching circuit loss, and chip receiving sensitivity. The chip transmitting power is 10dBm, and the actual receiving sensitivity is -99dBm under the standard test condition of 2% packet loss rate. The matching loss is actually tested to be 2Db, while the antenna gain is -3.8dBi, and the path loss corresponds to a transmission distance of 300 meters.

[0141] Path loss includes the vector superposition of direct transmission loss and ground reflection loss, such as Fig.10 As shown. R1 is the direct transmission path, R2 is the ground reflection path, and there is a relationship in formula 1:

[0142]

[0143] HRX is the height of the lamp post of the receiving terminal controller (from the ground to the antenna), HTX is the height of the lamp post of the transmitting substation controller or terminal controller, d is the distance between the lamp posts of the corresponding communication nodes, and the direct transmission power path is R1, which is calculated using Formula 2:

[0144]

[0145] P TX is the transmission power, G TX1 is the antenna gain, G RX1 is the receiving antenna gain, λ is the wavelength coefficient;

[0146] The reflected transmission power path is R2:

[0147]

[0148] Γ is the reflection coefficient, G TX1 =G TX2 =G RX1 =G RX2 Assuming the matching loss of the transmitting system and the receiving system and the gain of the antenna and the vertical polarization of the antenna, the total received power on the receiving side is:

[0149] E tot =E dir +E refl ×cos(kΔR) Equation 4

[0150] k is the electromagnetic wave propagation constant, ΔR = R2-R1, and the path loss formula 5 is calculated:

[0151]

[0152] In the above formula, λ is the wavelength of 780Mhz, which is 0.384 meters. The installation height is 7.2 meters. The link margin at a communication distance of 300 meters is calculated to be 10.9dB, and the maximum distance reaches 2600 meters. Fig.11 It is the relationship between the link budget margin and the communication distance in free space and with ground reflection. From the calculation results, the communication distance has reached 2600 meters, far exceeding the communication distance requirement of 300 meters. The wireless system provides sufficient margin. Since the wireless intelligent street light system is in a complex external environment, vehicles and buildings form multipath reflections, and trees, rain and snow weather and dust have a certain attenuation on the transmission of electromagnetic waves, so a certain budget margin must be maintained;

[0153] A 10-meter-wide forest has a 2dB attenuation on 1GHz electromagnetic waves, which means that to ensure a communication distance of 300 meters, a maximum of 50 meters of forest is allowed on the transmission path. By comparing the actual test results with the theoretical calculation results, this design fully meets the expected design requirements.

Claims

1. The wireless network intelligent LED street light low energy consumption system for collecting road conditions is characterized by: The first is the overall system architecture, which is divided into four parts: street lamp low-energy control terminal, sensor multi-mode unit, intelligent control substation, and background server real-time computing system; The second is the street lamp low-energy consumption control terminal, including: KEC bus switch dimming circuit, temperature sensor, street lamp power collection circuit; the third is the sensor multi-mode unit, including: image sensor multi-mode module, Doppler radar link passive infrared sensor; the fourth is the intelligent control substation, including: power module and power-on timing, ZigBee-k communication, ZigBee-k communication link indicator calculation; This application integrates digital LED light sources, various sensors, intelligent control, and background services to propose a new type of LED intelligent street light low-energy control system solution, adopts a digital LED light source that is easy to switch and dim as a lighting solution, and is based on a method that combines long-distance and short-distance dual wireless networks for communication in an intelligent street light low-energy control system. 78OMHz ZigBee-k is used as the LED street light low-energy control terminal, a wireless solution for short-distance communication between sensors and substation controllers, and 5G communication is used between long-distance substation controllers and background servers; the street light terminal controller integrates main control, wireless, data acquisition and analysis, and adds lightning protection design; a combination of three mobile detection sensor modules is used, including a passive infrared sensor, a Doppler microwave radar module, and an image sensor module based on machine vision technology, and targeted improvements are made according to the characteristics of each module to accurately sense vehicles and pedestrians; a special networking pairing method is proposed, which uses positioning technology to compare the installer's handheld networking tool and the geographical address of the street light. During the networking process, searching for networking nodes is convenient and reliable.

2. According to claim 1, the wireless network intelligent LED street lamp low energy consumption system for collecting road conditions is characterized in that: Overall system architecture: The street lamp low-energy controller terminal module consists of six parts: switch / dimming module, temperature sensor module, current and voltage sampling module, positioning module, ZigBee-k module and light measurement sensor module. The control terminal module communicates directly with the intelligent control substation through the 780MHz frequency band ZigBee-k. The street lamp low-energy controller terminal realizes the switch and dimming control of the street lamp. These controls communicate with the LED driver through the wired digital interface KEC, and perform current and voltage sampling at the same time, and upload this information to the intelligent control substation; The sensor multi-mode unit provides the system with real-time status of the external environment, including: external environment illumination, vehicle and personnel flow status near the sensor. These sensors exist as separate nodes, and they are in the same position as the street light low-energy control unit in the ZigBee-k network. When in normal state, the status is regularly queried by the intelligent control substation and the background. When the sensor detects data changes, it actively sends information to the intelligent control substation and the background. After the intelligent control substation and the background analyze and process these data, they control and manage the street light nodes accordingly. The sensors include image presence sensors, light measurement sensors, and Doppler radar linked passive infrared presence sensors; The intelligent control substation module is installed in the cabinet under the lamp post: 1) Switch and dim the street lights in the corresponding street light group uniformly; 2) Detect the status of various sensors and analyze them; 3) Download configurations according to the low-energy control requirements of street lights; 4) Communicate with street light nodes as the coordinator of the ZigBee-k network and upload street light information to the background control platform. At the same time, it serves as a transfer platform between the background control platform and the street light nodes, and connects to the background control platform through the underlying data link of 5G; 5) Detect the wireless communication status, and perform heartbeat detection with the street light nodes and the control background at the application layer; 6) Power on and off other devices in the cabinet through programming; 7) Detect the opening and closing of the cabinet door, and send alarm information to the control background if the door is found to be open; 8) Detect the power consumption of the entire group of street lights as needed; 9) Control the group street light nodes according to the configuration information when there is no background control or disconnection; The intelligent control substation includes ZigBee-k module and 5G module, current and voltage sampling, and wired control and data acquisition in addition to wireless control. The intelligent control substation communicates with image sensors, light measurement sensors, Doppler radar sensors and passive infrared sensors through ZigBee-k. At the same time, the intelligent control substation also has USB storage, SDcard data storage, and 10 / 100M Ethernet port configuration for the substation controller; The backend module is a real-time computing system of the backend server. The backend module facilitates remote operation and maintenance. When introducing backend control, the backend server and intelligent control substation are connected to the backend server system through the 5G network. The backend control provides the corresponding location information and operation status information of each street light node, sensor node and substation controller. These operation status information include: communication status, lighting status, power status of street light nodes, communication status of sensors, and information collection status.

3. According to claim 1, the wireless network intelligent LED street lamp low energy consumption system for collecting road conditions is characterized in that: Street light low energy consumption control terminal: consists of SPD module, street light terminal controller module and lighting driver module; The SPD module is a lightning protection module that suppresses surges caused by inductive lightning on power lines; Lighting driver module: Power the LED lamp particles and the street lamp terminal controller respectively. The street lamp terminal controller controls the LED driver through the KEC interface. It uses the Xitanium 150W 0.35-0.7AGL ProgsXt outdoor LED driver. At the same time, it cooperates with Luxeon high-power LED particles. The LED driver outputs constant DC current to work with high-power LEDs and uses the KEC interface. Street lamp terminal controller: including: SAM3S4A main controller, EEPROM module, positioning circuit module, ZigBee-k module, lamp power detection circuit, temperature sensor module, ambient illumination sensor module and KEC bus switch dimming circuit; The EEPROM module is a chip that stores configuration information, including the address of the node controller in the ZigBee-k network, the control strategy of the local street light, and the configuration information is saved after power failure. The EEPROM is connected to the main controller through the I2C bus; The positioning module MAX7C extracts the geographical location information of the current street light node, which is sent to the intelligent control substation and finally to the background map system. The geographical address of each light can be seen in the background to enhance the maintenance information of the system. The lamp power detection circuit detects the power of a single lamp node; the temperature sensor detects the working temperature inside the street lamp. When the temperature exceeds the limit, the system issues a light-off command to protect the street lamp. The ambient illumination sensor detects the background light illumination; The KEC bus sends these switching and dimming commands when the node controller switches and dims the digital rectifier and the digital LED driver.

4. According to claim 1, the wireless network intelligent LED street lamp low energy consumption system for collecting road conditions is characterized in that: KEC bus switch dimming circuit: The switch dimming circuit adopts KEC bus: It is built with discrete devices and defines 4 types of commands according to professional lighting management, namely: 1) Switch: Digital rectifier or digital LED driver with independent address in the switch system; 2) Dimming: 125-level dimming control of digital LED driver with dimming function; 3) Lighting scene: In a KEC group, up to 16 lighting scenes can be set; 4) Status display: displays the working status of the digital LED driver; The two optocouplers on the left side of the KEC bus circuit physically isolate the KEC signal on the high-voltage side to ensure the safety of the low-voltage part. The right side is connected to the microcontroller, and the KEC protocol inside the microcontroller uses these ports for communication.

5. According to claim 1, the wireless network intelligent LED street lamp low energy consumption system for collecting road conditions is characterized in that: Temperature sensor: detects the temperature inside the lamp. When the temperature is detected to be higher than 100 degrees Celsius, the lamp controller turns off the lamp output for protection and sends the temperature over-limit information to the intelligent control substation. The temperature change causes the resistance value of thermistor R1702 to change, thereby changing the voltage divider. The voltage is sent to the ADC of the microcontroller, and the temperature value is obtained through analog-to-digital conversion. In the terminal system software, the main CPU chip ATSAM3S4A regularly reads the voltage value of the temperature sensor through the ADC pin. When the read AD value exceeds the maximum limit, the LED driver is turned off through the KEC bus, and an error code is generated and transmitted to the intelligent control substation through the ZigBee-k wireless protocol.

6. According to claim 1, the wireless network intelligent LED street lamp low energy consumption system for collecting road conditions is characterized in that: Street light power acquisition circuit: A voltage sampling circuit is used in the circuit to gradually divide the live wire voltage and then sample it through the ADC port of the STM8 microcontroller. The ADC processing circuit is placed on the high-voltage side, and the collected voltage is sent to the main controller through optocoupler isolation. The current sampling is measured through the current transformer connected to the live wire. Finally, these signals are analyzed and calculated by the main controller to obtain the real-time power of the LED light source. The left side is the live wire voltage input end, and the right side is the signal optocoupler output end. The acquisition end is obtained through resistor voltage division. The purpose of adding a TVS tube at the end is to suppress the damage caused by surges on the line to the I / 0 port of the microcontroller.

7. The wireless network intelligent LED street light low energy consumption system for collecting road conditions according to claim 1 is characterized in that: Image sensor multi-mode module: installed separately on the light pole, it detects pedestrians and vehicles on the road. At night, when there are few vehicles and pedestrians, the system adjusts the light brightness to 20% of the full power output. This is the default value, and the user can set it according to actual needs. When pedestrians or vehicles move, the image sensor detects these movements and then sends the information to the intelligent control substation. The intelligent control substation dims the corresponding street lights according to the results, increasing the light power to 100% and then delaying it for 1 minute. After one minute, if pedestrians are detected again, it will continue to maintain 100%. If no movement is detected after another minute, the system will reduce the corresponding light power to 20%; The image sensor CB is the control board, which realizes the physical layer communication of ZigBee-k. The main control microcontroller, power module, and DB are the digital board, which are the integration of the camera module. At the same time, the DSP processes and analyzes the image to obtain the information of the movement of people or vehicles. After analysis and processing, the control board main control microcontroller is directly notified through the serial port whether there is movement. The image sensor analyzes the image captured by the camera and then outputs the required personnel and vehicle movement information. The DB board has 3 LED indicator lights, which respectively indicate the power working status, whether there is movement, and the communication status.

8. According to claim 1, the wireless network intelligent LED street lamp low energy consumption system for collecting road conditions is characterized in that: Doppler radar linked to passive infrared sensor: Doppler microwave radar detection circuit detects pedestrians and vehicles. It is turned on when there are few vehicles on the road late at night. When no one or no vehicle passes by, it automatically controls the street lamp to dim and reduce the lamp power. When someone or a vehicle passes by, it automatically controls the street lamp to restore full power output, saving energy consumption while ensuring that lighting provides urban safety. The oscillator circuit sends out a 5.8GHz continuous wave signal through the transmitting antenna. The signal reaches the detection object and is reflected back and received by the receiving antenna. The signal enters the mixer and mixes with the local oscillator signal to obtain an intermediate frequency of several to tens of Hz, which corresponds to the moving speed of the vehicle or person. The input interface is set up with 3 wires, power supply, ground wire and signal wire. The input power supply voltage range is 15-45V, and the working current is about 20mA. When there is no movement detection, the signal line outputs a TTL 5V low level, and when movement is detected, it outputs a TTL 5V high level signal. Timing: When no vehicle movement is detected late at night, the system adjusts the background light to 20% of the full power. When a car is detected, within 0.8 seconds, the system adjusts the approaching light to 100% power output. When the car leaves, the system keeps the corresponding light output at 100% for one minute. If no vehicle movement is detected within one minute, the system will reduce the corresponding light output power to 20% again. Passive infrared determines the person by detecting the infrared wavelength of this band. The passive infrared detector is equipped with two important devices. One is the pyroelectric infrared sensor, which is set just below the white transparent Fresnel prism. It converts the infrared signal change between the wavelength of 8-12um into an electrical signal. Four separate sensing units are set. Within the sensing range of the passive infrared detector, when there is no vehicle or person moving, the pyroelectric infrared sensor only senses the background temperature. When the human body enters the sensing range, through the projection of the Fresnel lens, the pyroelectric infrared sensor senses the difference signal between the human body temperature and the background temperature. At the same time, due to the role of multiple units, the electrical signal of the detection unit pulses successively to determine the movement of the person; the other device is the Fresnel refractive lens, which focuses and refracts the pyroelectric infrared signal on the PIR sensing element, divides the sensing range into several sensing areas, and makes the moving object entering the sensing range generate a changing pyroelectric infrared signal on the PIR in the form of temperature change. By detecting these changing electrical signals, the heat of the person and the car is indirectly detected, that is, the movement of the person and the car is detected; The processing circuit Q1 of the infrared unit is a multi-mode unit of the PIR sensor. After being amplified by U2, it enters the ADC of the microcontroller for sampling and analog-to-digital conversion. The SW1 signal adjusts the gain of the infrared processing circuit.

9. The wireless network intelligent LED street light low energy consumption system for collecting road conditions according to claim 1 is characterized in that: Intelligent control substation: including: 1) communication link between control background and substation controller, communication link between street lamp and sensor node and substation controller; 2) control street lamp node according to background or its own configuration information; 3) detect various sensor information to realize intelligent control of street lamp; The substation controller includes a power module, a ZigBee-k module, which is used to communicate with the street light nodes, and a 5G module, which is used to communicate with the background system. The substation controller is designed with several expansion interfaces to control the street lights. In addition, the peripheral interfaces are as follows: 1) KEC digital lighting interface module and A-BUS; 2) 7 current sampling units to process various wired sensor information; 3) 1 RS485, 1 RS232, external communication interface; 4) 2 relay switches to directly open and cut off the wired street lights that need to be controlled; 5) 1 analog input interface, 1 digital input interface to expand analog and quantitative data collection; 6) 2 USB host interfaces to access USB storage; 7) 1 RJ45 10 / 10OM Ethernet interface to download configuration to the substation controller; The main processing chip STM32F103 of the substation controller serves as a wide area network communication and data concentrator module. On one side, it realizes the function of ZigBee-k network coordinator through SPI bus and AT86RF212B to communicate with the low-energy control node of the street lamp. On the other side, it uses serial port UART to communicate with 5G module ME909S-821 to configure the working mode of 5G module and communicate with normal 5G data traffic, SMS or background server.

10. The wireless network intelligent LED street lamp low energy consumption system for collecting road conditions according to claim 1 is characterized in that: ZigBee-k communication link indicator calculation: The number of jumps in this application is less than 3, that is, the number of jumps from the substation controller to the edge street lamp terminal controller farthest from it does not exceed 3 times; The wireless communication system link consists of several parameters, including the actual transmission power of the transmitter AT86RF212B, matching circuit loss, transmission antenna gain, transmission path loss, receiving antenna gain, receiving matching circuit loss, and chip receiving sensitivity. The chip transmission power is 10dBm, the matching loss is actually tested to be 2Db, and the antenna gain is -3.8dBi. The path loss corresponds to a transmission distance of 300 meters. The path loss includes the vector superposition of direct transmission loss and ground reflection loss. R1 is the direct transmission path and R2 is the ground reflection path. There is a relationship in equation 1: HRX is the height of the streetlight pole of the receiving terminal controller, HTX is the height of the streetlight pole of the transmitting substation controller or terminal controller, d is the distance between the streetlight poles of the corresponding communication nodes, and the direct transmission power path is R1, which is calculated using Formula 2: P TX is the transmission power, G TX1 is the antenna gain, G RX1 is the receiving antenna gain, λ is the wavelength coefficient; The reflected transmission power path is R2: Γ is the reflection coefficient, G TX1 =G TX2 =G RX1 =G RX2 Assuming the matching loss of the transmitting system and the receiving system and the gain of the antenna and the vertical polarization of the antenna, the total received power on the receiving side is: E tot = E dir + E refl × cos(kΔR) Equation 4 k is the electromagnetic wave propagation constant, ΔR = R2-R1, and the path loss formula 5 is calculated: In the above formula, λ is the wavelength of 780Mhz, which is 0.384 meters. The installation height is 7.2 meters. The link margin at a communication distance of 300 meters is calculated to be 10.9dB, and the limit distance reaches 2600 meters. Based on the relationship between the link budget margin and the communication distance in free space and with ground reflection, the communication distance has reached 2600 meters, far exceeding the communication distance requirement of 300 meters. The wireless system provides sufficient margin. A forest with a width of 10 meters has a 2dB attenuation on electromagnetic waves with a frequency of 1GHz, which means that to ensure a communication distance of 300 meters, a maximum length of 50 meters of forest is allowed on the transmission path.

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