NB-IoT Smart Street Lighting System

In the actual application of street lamps, there will be control, detection and safety problems, including the inability of street lamps to adjust the time and modify the switch light time according to the actual situation (weather changes, major events, festivals), and the LED lights cannot be dimmed. Realize secondary energy saving; faults are mainly based on reports from inspectors and complaints from citizens, lack of initiative, timeliness and reliability, and cannot monitor the operation status of street lights in the city in a real-time, accurate and comprehensive manner. The management department lacks the ability of unified dispatching, and can only make adjustments one by one, which is not only time-consuming and laborious, but also increases the possibility of human misoperation; equipment is easy to lose and faults cannot be located, and it is impossible to accurately detect cable theft and lamp caps. Theft and disconnection, once the above situations occur, will bring huge economic losses, and affect the normal life and travel safety of citizens at the same time.

At present, the "Guiding Opinions on Promoting the Healthy Development of Smart Cities" has been released at the national level, pointing out that a number of smart cities with distinctive features will be built in 2020 to achieve convenient public services, refined urban management, livable living environment, and infrastructure. Intelligent etc. The internal requirements of cost reduction, efficiency enhancement and refined operation also drive the construction of smart street lights to reduce the cost of manual inspections, reduce economic losses caused by safety issues, improve control accuracy, comprehensiveness, and unified scheduling. Compared with other control technologies, NB-IoT technology can well meet the above requirements, realize the intelligent control of street lights, promote the construction of smart cities, and meet the internal management needs of cost reduction, efficiency increase and refined operation.

1. The development status of street lamps

Starting from incandescent lamps, street lamps have gone through the stage of gas discharge lamps and LED lamps. The energy consumption has gradually decreased, and the degree of intelligence has continued to increase. At present, the luminous efficiency of LED street lamps can reach 160lpw, saving more than 90% of electricity than incandescent lamps, 50% to 70% of electricity than high-pressure sodium lamps, and its lifespan is as high as 50,000hrs. It can be controlled by PLC or zigbee and other technologies.

In recent years, my country's urban construction has shown a rapid growth trend. As a part of urban infrastructure, urban road lighting has also developed rapidly. According to the data of the National Bureau of Statistics, in the past ten years from 2007 to 2015, the number of urban road lighting street lights in the country increased from 13.95 million to 24.23 million. The average compound growth rate reached 7.14%. In terms of the use types of urban road lighting street lamps, according to the different sources of road lighting street lamps, they can be divided into high-pressure sodium lamps, LED street lamps, energy-saving street lamps, and new xenon street lamps.

In terms of light sources, sodium lamps account for the vast majority, followed by LED lamps, and other types of lamps account for a small proportion.

According to the statistics of Ag81 key cities including all municipalities directly under the Central Government, provincial capital cities, and cities specifically designated in the state plan, the total number of intelligent monitors is the largest, reaching 21,826 points, which are 3 times, 6.8 times, 9.2 times.

In the usage of urban road lighting monitoring system, the "three remote" system is the most commonly used, accounting for 64%; followed by the "five remote" system, accounting for 23%; "four remote" and GPRS systems accounted for 5% and 8% respectively.

2. Problems in the intelligent evolution of street lamps

The monitoring and management methods are relatively extensive. The traditional "three-remote" system can only achieve loop-level collection and control, and cannot monitor the operation of a single lamp in real time and accurately. When a lamp fails, it cannot be fed back to the monitoring center in time, and it cannot realize intelligent monitoring and refined management. In addition, it is impossible to track and analyze the fault handling situation in real time, which affects the lighting production management assessment and decision-making judgment.

Energy consumption is too high. In the absence of flexible and effective energy-saving control means, it is difficult to reconcile the contradiction between excessive lighting and insufficient lighting (that is, to operate according to the city image illumination in the first half of the night, and to adopt energy-saving illumination in the second half of the night). Reduce lighting energy consumption.

The operation and maintenance efficiency is low and the cost is high. At present, the fault detection mechanism of lighting facilities mainly adopts the manual inspection mode, which has a huge workload and may leave blind spots. The operation and maintenance efficiency is low, and it is difficult to achieve active service and guarantee service quality; in the maintenance process, the procurement of materials is also lack of science. According to the basis, inappropriate material stocking will cause capital occupation, and the materials cannot be finely managed.

Facility security is difficult to guarantee. Lack of real-time supervision measures, lighting cables and other facilities are frequently stolen or damaged, causing direct economic losses to the lighting management department, seriously affecting the normal operation of urban lighting, and bringing security risks. Lack of effective management of facility resources. The resource management of urban lighting facilities basically stays in the era of manual ledgers, lacking informatization means, and the quantity and status of facility resources are unclear, which is not conducive to operation and maintenance.

The benefits brought by the smart street lamp scheme to street lamps are obvious. However, the traditional non-intelligent sodium lamps are still the main street lamps in cities in my country, and the resistance to intelligent transformation is very large: 1: The cost of LED street lamps is relatively high. l2 To replace sodium lamps with LED lamps and upgrade them intelligently, it will take several months to transform the entire city. 3. Replacing sodium lamps with LED lamps saves energy but not money, and increases the workload. Usually, street lamp maintenance requires three people, one for driving, one for maintenance, and one for on-site maintenance. Although great progress has been made, LED lamps for street lamps still have defects, such as insufficient penetration, difficult to illuminate in foggy weather; poorer scattering ability than sodium lamps, and smaller irradiation range.

3. Comparative analysis of technical selection of NB-IoT technology in intelligent street lamp control

At present, the group control method is mainly used. With the continuous improvement of street lamps' requirements for fine control and the continuous acceleration of the construction process of smart cities, some cities have begun to adopt single control. The single control of intelligent street lights mainly adopts two-hop and one-hop systems. The two hops are connected to the platform after computing and aggregation through the FAN network, and the one-hop directly communicates with the platform through the WAN.

Two jumps: Municipal street lighting management is based on road sections, and each road section is equipped with a power distribution cabinet for power supply. The road segment electrical parameter collector and gateway are usually integrated and deployed in the power distribution cabinet. Expand applications that require edge computing on street light poles, such as W, security monitoring, advertising screens, etc. FAN network mainly adopts PLC, ZigBee/RF technology at present.

One hop: single-lamp fault location, single-lamp switch, and dimming do not require local centralized calculation and control. Discrete extended applications are directly connected to the network, without the need for local centralized computing and control. The one-hop network makes the entire street light network simpler. The business side only needs to pay attention to the application layer standards, and can quickly access devices from different manufacturers.

The two-hop solution is divided into two types: PLC and Zigbee/RF technology, and at the same time, it is equipped with GPRS technology to realize street light control. The one-hop solution mainly includes LoRa and NB-IoT. After comparative analysis, it is found that the whole street light network is simple in one hop, and the business side only needs to pay attention to the application layer standard, and can quickly access devices from different manufacturers. At the same time, NB-IoT in one hop IoT technology is even better.

At present, in the field of intelligent monitoring of single lamps in urban public lighting, cable carrier communication is the mainstream direction of the underlying communication technology, accounting for about 90% of the actual application; ZigBee technology also has certain applications, accounting for about 10% of the market share; others Technology is used less. In the field of remote transmission, GPRS technology is mostly used at present, and technologies such as NB-IoT will gradually increase in the future.

From the perspective of cost, NB-IoT has the lowest technical cost, including construction cost, operating cost and average annual cost. From a technical point of view, NB-IoT is more suitable for street lamp control because of its wider coverage, larger capacity, and guaranteed communication quality.

4. NB-IoT expansion strategy for smart street lights

4.1 Aggregation

Establish a model pilot effect. Joint street lamp institutes, street lamp manufacturers, terminal system solution providers, and operators provide terminal subsidies to promote smart street lamp manufacturers to carry out terminal transformation and create NB-IoT demonstration application projects.

Promote the aggregation of street lamp industry. Through the aggregation of module suppliers, street lamp manufacturers, platform providers, system integrators, street lamp management, etc., build industry alliances, form industry standards, reduce the cost of smart street lamp manufacturing, smart chip modules, etc., and focus on promoting the maturity of the street lamp industry. Low tariffs attract users and quickly expand the use of street lights in a short period of time.

4.2 Fight for the initiative

Based on the pipeline, vigorously promote the content of the platform layer, so that street lights can become carriers of smart cities and smart transportation on the basis of intelligence. Operators should take advantage of resource advantages to promote and publicize demonstration results, seize the opportunity, and compete for the right to speak on the smart street lamp platform.

4.3 Broaden thinking and enrich service content

Utilize the unique advantages of street lights and combine the technical characteristics of NB-IoT to expand street light services. For example, turn street lamps into environmental weather stations, add PM2.5, temperature and humidity sensors to smart gateways, and broadcast comprehensive urban information such as local weather and environment on street lamp carriers.

5. NB-IoT technology monitoring system for smart street lights

Road lighting is an indispensable road traffic safety facility in people's lives. Traditional road lighting adopts a fixed management mode of centralized power supply (lighting at night and turning off during the day), which has many disadvantages:

(1) The brightness of street lights cannot be adjusted according to the surrounding traffic flow and weather changes;

(2) It is not possible to remotely set the lighting mode and modify parameters;

(3) Cannot automatically report the fault and locate the specific location of the fault. In order to save electric energy and facilitate people to travel, it is necessary to upgrade the traditional street lamp control system. Narrowband Internet of Things (NB-IoT for short) technology has become an important branch of the Internet of Everything. It is based on the cellular network and is a communication technology developed by the 3GPP organization. It uses the authorized GSM and LTE frequency bands and uses existing 4G base stations. And related equipment, without rebuilding the network.

NB-IoT technology has the following advantages:

(1) Wide coverage. Relying on the networks of the three major operators to achieve nationwide coverage.

(2) Deep coverage.

(3) Low power consumption. Based on these advantages, NB-IoT technology can be applied to the street lamp monitoring system to monitor the running status of street lamps and related equipment to achieve efficient, intelligent and scientific management. The NB-IoT technology is applied to the intelligent street lamp monitoring system, so that each street lamp is connected to the network and has a unique ID identification code. In this way, the system can monitor and manage street lights in real time, effectively improve the efficiency of system operation, save power, and meet the requirements of smart town development and construction.

5.1 Network Architecture of Intelligent Street Light Monitoring System

The intelligent street lamp monitoring system based on NB-IoT technology includes perception layer, network layer and application layer. The perception layer consists of a separate street lamp control module and NB-IoT terminal. Each street lamp on the road is equipped with a street lamp control module. The street lamp control module manages the switch of the street lamp, is responsible for the collection of data information and monitors the operating status of the street lamp. It communicates wirelessly with the NB-IoT terminal through the NB-IoT network; NB - The IoT terminal uploads the data information collected by the street lamp control module to the NB-IoT base station, and sends the management commands from the mobile phone or monitoring center in the application layer to the street lamp control module to manage and monitor the street lamps in the perception layer. The network layer is composed of NB-IoT base station and Internet network. The Internet network mainly uses the 4G LTE platform to transmit the data information of the perception layer to the application layer in real time, and at the same time transmit the control commands of the application layer to the perception layer.

5.2 System hardware design

(1) Street lamp control module: The structural block diagram of the street lamp control module is shown in Figure 2. The street lamp control module is the core component of the perception layer. It monitors and manages the street lamp site. It is mainly composed of a microcontroller, NB-IoT module, GPS positioning unit, information collection module, detection circuit and drive circuit. Each street lamp control module is provided with a unique ID code, which is convenient for identifying different street lamps. The GPS positioning unit can locate the specific location of the street lamp, and provide a detailed address for the monitoring and maintenance of the street lamp. The NB-IoT module realizes the communication between the street lamp control module and the NB-IoT terminal. The street lamp control module sends the street lamp field data information collected by the information collection module to the NB-IoT terminal through the NB-IoT module, and at the same time receives various control commands transmitted by the application layer through the NB-IoT terminal. The information collection module is mainly composed of temperature and humidity sensors, light sensors, traffic flow sensors and pyroelectric infrared sensors. The temperature and humidity sensor collects the temperature and humidity of the surrounding environment, the light sensor collects the intensity of light, the traffic flow sensor collects the traffic flow on the road, and the pyroelectric infrared sensor collects the pedestrian flow on the road. The detection circuit detects the power quality of the power supply of the system, the voltage and current of the street lamp and the running state of the street lamp, and the driving circuit is used to control the switch and brightness adjustment of the street lamp.

(2) NB-IoT terminal: NB-IoT terminal uses industrial-grade 32-bit ARM9 series chips, supported by an embedded real-time operating system, which can be connected to the street lamp control module in a large capacity, and communicate with the street lamp control module wirelessly. Information and Communication. At the same time, it is equipped with wired RS485 and RS232 serial port communication to receive the data information collected by the street lamp control module and the status parameters of the street lamp operation, and transmit the control commands issued by the monitoring center. According to the number of street lamps and the actual control requirements of the system, through calculation and analysis, the number and location of NB-IoT terminals are reasonably planned, so that each NB-IoT terminal can communicate with the street lamp control module connected to it.

(3) NB-IoT base station: Since there are many base stations in the 4G communication network and the signal coverage is wide, using the existing 4G communication base station to plan and erect the NB-IoT network base station can make the signal coverage wider and the transmission capability stronger. The NB-IoT base station is deployed on the existing base station, and the on-site data information of the street lights is transmitted to the monitoring center through the 4G network of the three major operators to achieve wired long-distance transmission. The order is issued to the street light control module.

5.3 Monitoring Center Software Design

The application layer of the monitoring system is mainly composed of mobile phones, monitoring centers and alarm devices. The monitoring center is the core of the application layer and a human-computer interaction platform for the perception layer to process data, manage status, handle faults and manage energy consumption. Through the monitoring APP on the mobile phone, the staff can monitor and manage the operation of street lights anytime and anywhere.

The monitoring center is the human-computer interaction window for the staff and the remote monitoring system, which can directly reflect the data collection of the entire system and the operation status of the street lights. Therefore, its design must meet the requirements of control, and also take into account the real-time performance and operability of the entire system. sex and stability. The functional module block diagram of the monitoring center software is shown in Figure 3. Data processing realizes data collection, storage, query and report output printing. Data collection mainly collects parameters such as temperature and humidity, light intensity, traffic flow, and people flow, as well as voltage, current, and power of street lamps; data storage mainly stores on-site data information; data query can quickly query historical data. State management realizes the setting of system parameters, the setting of street lamp control mode, the setting of street lamp mode, the setting of street lamp dimming mode and the query of running status. The street light control mode can adopt automatic control mode, latitude and longitude mode, holiday mode and temporary mode, etc.; Traffic and people flow automatically turn on relevant street lights, and you can also set different percentages of PWM switch street lights according to the time period, or realize full-on, half-on or full-off street lights according to the collected natural environment information. Fault handling realizes automatic monitoring of faults, locking of fault location information and automatic alarm, and notifies the staff in the form of short messages. Energy consumption management realizes remote meter reading, energy consumption statistics of each road section and system, and energy consumption can generate curve reports according to time for staff analysis.

Summarize

A set of intelligent street lamp monitoring system based on NB-IoT technology is designed. The system uses the street lamp control module to collect field data information, and then uses the NB-IoT terminal to transmit the field data to the network layer through the wireless network. The network layer utilizes the NB-IoT base station and 4G network to realize the uploading of data information and the issuing of control commands. The intelligent street lamp monitoring system based on NB-IoT technology realizes four major functions of data processing, status management, fault handling and energy consumption management, which meets the real-time, automation and Internet of things requirements of the street lamp control system of the Internet of Things, and improves the street lamp monitoring system. The intelligence of the lighting monitoring system has improved the management level and technical service level of the system, and can play a role in building an energy-saving and environment-friendly green town.

The above are the details of the smart street lamp solution introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. for you. If you have the development and design needs of the intelligent street lamp monitoring system, you can rest assured to entrust it to us. We have rich experience in customizing and developing electronic products. We can evaluate the development cycle and IC price as soon as possible, and can also calculate the PCBA quotation. We are a number of chip agents at home and abroad: Songhan, Yingguang, Jieli, Ankai, Quanzhi, realtek, with MCU, voice IC, Bluetooth IC and module, wifi module. Our development capabilities cover PCB design, single-chip microcomputer development, Bluetooth technology development, software customization development, APP customization development, WeChat official account development and other hardware and software design. It can also undertake the research and development of smart electronic products, the design of household appliances, the development of beauty equipment, the development of Internet of Things applications, the design of smart home solutions, the development of TWS earphones, the development of Bluetooth earphone speakers, the development of children's toys, and the development of electronic education products.