Have you ever found yourself stuck at a crossroads where the green light turns red just as you approach, forcing you to wait in line? Or perhaps during your commute, you're forced to crawl along due to heavy traffic congestion? Well, those days may soon be over thanks to the upcoming intelligent traffic management system. This system gathers traffic data through detection equipment and, after comprehensive calculations, creates a "green wave" along driving routes, enabling smoother journeys and enhancing both speed and driving excitement.
The heart of this intelligent traffic management system lies in the traffic command center, which oversees several subsystems. Each subsystem operates independently yet collaboratively. These subsystems are built upon hardware devices, including six controllers and various detection devices. The overall architecture of the intelligent traffic management system is illustrated in Figure 2 below.
**1.1 Traffic Information Collection System**
The traffic information collection system gathers and processes data such as traffic flow, vehicle speed, vehicle length (for vehicle classification), vehicle spacing, and congestion status using sensors and cameras installed on roads and vehicles. This data serves as the foundation for the intelligent traffic management system.
**1.1.1 Traffic Information Detector**
The primary function of the traffic information detector is to receive data from sensors (such as geomagnetic and cameras), process the received information, and then send the processed data to other subsystems and the traffic command center. Equipped with a display screen, the device allows users to view collected data and communication details. Additionally, users can configure communication parameters and detector settings via the display.
Guangzhou Zhiyuan Electronics has developed a traffic information detector using the M6G2C series core board of the Freescale i.MX6UL series Cortex-A7 processor. The detector boasts rich interface resources and processing capabilities, with large-capacity industrial-grade eMMC memory and TF cards for data storage. Firmware updates can be done remotely via the network port, reducing future maintenance efforts. The product block diagram is shown in Figure 3, and the physical image of the core board is provided in Figure 4.
**1.1.2 Geomagnetic Detection Module**
For traffic flow detection, geomagnetic sensors are the most commonly used technology. Inside the geomagnetic detection module is a controller that processes the detected data and sends it to the traffic information detector via a wireless module. The 24/7 power supply system and stable wireless transmission requirements make Zigbee and LoRa’s low-power, high-stability networking mode particularly advantageous. Guangzhou Zhiyuan Electronics provides users with Zigbee and LoRa modules, solving the wireless transmission issues of the geomagnetic detection module while offering various antenna layout assistance services, ensuring shorter R&D cycles and improved product competitiveness.
1. **Zigbee Module**
The ZM516X series ZigBee wireless module is a low-power, high-performance ZigBee module developed by Guangzhou Zhiyuan Electronics based on NXP's JN5168 chip. It provides a complete application integration solution based on the IEEE802.15.4 standard ISM (2.4-2.5GHz) frequency band. Supporting protocols include FastZigBee, ZNET, JenNet-IP, ZigBee-PRO, RF4CE, and more, making it suitable for industrial control, data acquisition, and intelligent remote control applications. A picture of the product is shown in Figure 5.
2. **LoRa Module**
The ZM470S series products are industrial-grade wireless RF communication modules developed by Guangzhou Zhiyuan Electronics based on SI4432, communicating externally through the SPI interface. The maximum communication distance exceeds 1000 meters, with the product image shown in Figure 6.
**1.1.3 Environmental Information Detector**
With the rapid growth of the automotive industry, the likelihood of traffic safety accidents is increasing. Besides human and vehicle factors, environmental and road conditions also significantly impact traffic accidents. Adverse weather conditions such as rain, snow, and smog can severely reduce road visibility, creating hidden dangers for road traffic. Additionally, icy or wet roads can lead to vehicle drift, brake failure, and skidding, potentially causing accidents. Thus, an environmental information monitoring module is needed to detect road conditions and upload the data to the management center to provide valuable insights for traffic management.
IOT-3960L is an industrial-grade industrial control board introduced by Guangzhou Zhiyuan Electronics, suitable for environmental testing. The board uses Freescale's ARM9-based i.MX28x processor for data acquisition or higher levels of user interaction. The product features 485, CAN, and other wired communication interfaces, allowing wired connections with environmental detection sensor modules. The miniPCIE wireless communication interface (supporting WIFI, GPRS, ZigBee, RFID, 3G, and other modules) enables wireless networking with the environmental detection sensor module. The product uploads detection information to the environmental monitoring center via Ethernet and transmits road conditions to user terminals via base station wireless transmission. The product can be remotely upgraded through the network port to reduce maintenance workload. A picture of the product is shown in Figure 7.
**1.2 Traffic Signal Control System**
The traffic signal control system is a real-time networked control system integrating modern computer, communication, and control technologies. Its primary function is to control motorized traffic lights, countdown timers, and pedestrian signals, adjusting the corresponding traffic and prohibited times dynamically based on traffic volumes. This system plays a crucial role in maintaining traffic order, improving intersection efficiency, and preventing accidents.
**1.2.1 Traffic Signal Control Machine**
The main function of the traffic signal control machine is to manage traffic lights and countdown timers, integrate GPS timing modules, 4G communication modules, wireless modules, Ethernet, and more. It can receive signals from pedestrian buttons and infrared remote controllers.
Guangzhou Zhiyuan Electronics designed the traffic signal controller using the M6G2C series core board of the Freescale i.MX6UL series Cortex-A7 processor. The controller design scheme is shown in Figure 8.
**1.2.2 Traffic Light Fault Monitor**
Traffic lights installed above poles are exposed to harsh outdoor conditions, such as rain, lightning, and high temperatures, making them prone to damage. Such failures can lead to traffic jams and even accidents. Therefore, it is essential to implement fault detection for traffic lights. The signal light fault monitor can directly detect the light using a light sensor or indirectly by monitoring the voltage and current of the signal light. Test results are uploaded to the traffic management center via Ethernet or directly reported to the traffic light maintenance management center via GPRS.
Zhiyuan Electronics utilized the M28A-T series core board of the Freescale i.MX28 series ARM9 processor to design the traffic light fault monitor program. Although the ARM9 processor has fewer resources compared to the A7 processor, it is more affordable and sufficient for this application. The device can remotely upgrade the firmware through the network port and GPRS to reduce future maintenance workload. The block diagram of the scheme is shown in Figure 9, and the physical image of the core board is shown in Figure 10.
The GPRS module on the traffic light fault monitor is a communication module for reporting fault information. PCIE-SIM800G is an industrial-grade GPRS module introduced by Guangzhou Zhiyuan Electronics. Designed by SIMCOM SIM800G, the module is compact and suitable for IoT data acquisition, consumer electronics, and industrial control applications. The product is shown in Figure 11.
**1.2.3 Detection Module**
In addition to the monitor, fault detection of traffic lights requires a detection module. The detection module acts as the front line of signal light failure detection, constantly monitoring the actions of the signal lights and reporting the results to the monitor. In today's era of advanced wireless communication, wireless data transmission eliminates cable constraints while reducing installation and maintenance costs. The detection module consists of two parts: acquisition processing and communication. A microprocessor coordinates the completion of these tasks.
The AW824P2EF wireless development module is a low-power, high-performance ZigBee secondary development module developed by Guangzhou Zhiyuan Electronics based on NXP's JN5161 and LPC824 chips. This module fully meets the resource requirements of the detection module. The LPC824 is a 32-bit low-power processor with an ARM@CortexTM M0+ core, clocked at up to 30Mhz, featuring 32KB of on-chip flash memory and 8KB of on-chip SRAM memory. It integrates flexible peripheral modules and supports I2C, UART, SPI, ADC, and TIMER functions. The JN5161 is NXP's ZigBee chip, providing a complete application integration solution based on the IEEE802.15.4 standard ISM (2.4-2.5GHz) band and supporting the FastZigBee protocol. The product image is shown in Figure 12.
**1.2.4 Peripheral Module**
In addition to the traffic signal control system, the traffic signal control system includes several peripheral modules, such as countdown timers, signal lights, remote controls, and pedestrian buttons. Countdown timers display the duration of traffic lights; remote controls allow traffic personnel to issue commands under special circumstances; pedestrian buttons are typically installed in areas with minimal impact on motor vehicles, long traffic lines, single directions, and fewer pedestrians, such as school gates, to ensure student safety when crossing streets.
**1.3 Video Surveillance System**
The video surveillance system includes the traffic video surveillance system, security bayonet system, and electronic police system. The system primarily collects information through cameras and then analyzes and processes the collected data.
**1.3.1 Traffic Video Surveillance System**
The front end of the traffic video surveillance system uses IP high-definition cameras or high-speed dome cameras to connect video signals to the command center through a video transmission private network for storage, retrieval, and playback. All high-definition video images are aggregated to the command center through the fiber-optic network and uniformly stored in the command center. The storage management strategy is uniformly managed through the central management platform, greatly enhancing the flexibility of the storage system.
**1.3.2 Security Bayonet System**
The security bayonet system can automatically collect and process vehicle information on monitored road surfaces, providing data and evidence for criminal and public security cases involving vehicles, tracking and detecting deck and black cars; bayonet data can be used for vehicle traffic analysis and basic information for discriminant analysis of sub-services such as traffic guidance guidance and traffic command systems.
**1.3.3 Electronic Police System**
The electronic police system refers to a system that can be installed at signal-controlled intersections and sections to automatically detect and record motor vehicle red-light violations in designated lanes. After technological extension, it can also be used for automatic detection and recording of traffic violations such as逆行 (illegal lane changes), illegal lane changes, and non-lane driving.
**1.4 Traffic Guidance System**
The traffic guidance system is based on modern technologies such as electronics, computers, networks, and communications. It provides optimal route guidance instructions to road users based on their starting points or helps road users find a point from the starting point to the destination by obtaining real-time traffic information. The characteristic of this system is that it considers people, vehicles, and roads together, improving the road traffic system by inducing the travel behavior of road users and reducing the occurrence of blockages. It decreases the time vehicles spend on the road, achieving a rational distribution of traffic flow across various road sections.
The traffic guidance system mainly consists of a traffic information control center, a communication system, and a traffic guidance information release system. The Traffic Information Control Center is responsible for collecting various real-time traffic information from the traffic network and processing the information; the communication system is responsible for data exchange between the information control center and the vehicles on the road; the traffic guidance information release system primarily releases induction information through various terminals. Guangzhou Zhiyuan Electronics used the M6G2C series core board of the Freescale i.MX6UL series Cortex-A7 processor as the controller to design a traffic guidance controller scheme. The controller serves as the terminal equipment of the induction system and receives the induction information issued by the traffic command center, controlling the display terminal. The device can remotely upgrade the firmware through the network port and GPRS to reduce the workload in the later period. The controller design scheme is shown in Figure 16.
**1.5 Environmental Adaptability**
The intelligent traffic management system controller and its optional equipment will be rigorously tested through actual simulations of harsh application conditions by Zhiyuan Electronics' EMC Laboratory, Safety Laboratory, and Environmental Laboratory. Each discrete device can meet at least the EMC Industrial Class III standards, exhibiting excellent static resistance, lightning surge resistance, electrical transient group pulse resistance, and extremely low EMI conduction disturbance; it can operate within an industrial grade temperature range of -40°C to +85°C. This provides a solid guarantee for the reliability and stability of the entire system.
**1.6 Product Failure Analysis and Fault Detection Methods**
**1.6.1 Geomagnetic Module**
The primary issue with the geomagnetic module is the lifespan of the battery. Installed underground, the module is difficult to install and maintain, and battery replacement costs are high. The module is also prone to water and dust erosion, especially after repeated pressure from heavy traffic and vehicles. The accuracy of the product is another concern. Current batteries on the market can last over five years, which meets usage needs. Sealing with silicone gel offers better waterproofing and dustproofing. Besides physical protection, software testing is equally important. The product undergoes periodic automatic calibration to ensure measurement accuracy. Self-testing is performed regularly, and the verification function is normal, with the test results uploaded to the upper-level processor for product maintenance.
**1.6.2 Traffic Management Control Cabinet**
The traffic management control cabinet is located beside the road or suspended on poles, exposed to a harsh working environment. Over time, it suffers damage from dust, rain, lightning, and more, and in special circumstances, salt spray. To counteract these natural damages, the cabinet structure is designed with water resistance in mind, offering some dust protection. The metal surfaces inside and outside the cabinet are painted. While this design can withstand most damage, some dust, moisture, and salt spray can still enter the cabinet. Therefore, the PCB board of the internal controller is coated with three anti-paint to resist corrosion. Additionally, the signal power supply originates from the local power grid, which may have voltage fluctuations, high harmonics, and pulse interference. This requires the equipment inside the cabinet to have a wide voltage input function and good EMI protection. Lightning surge protection is necessary for communication and power cables.
**Traffic Signal Control Machine**
The traffic signal control machine is the direct control part of the traffic signal. Any malfunction could cause traffic chaos and even accidents. The driving part of the signal machine is a power-amplifying circuit, which is easily damaged. A matching detection circuit is necessary to feedback the working state of the driving circuit to the signal control machine. The detection of the signal control machine is primarily completed by the traffic light fault monitor, with redundant drive circuits and signal lights designed. When an anomaly occurs in a specific signal light, the redundant circuit can be activated immediately, ensuring the normal operation of the traffic system. Fault information is reported simultaneously. Besides physical protection, the product undergoes periodic self-tests to confirm functionality and uploads the test information to the superior management system.
**Remaining Controllers**
The remaining controllers in the traffic management control cabinet apply the same physical protection methods. Each controller has a self-test program that periodically performs self-tests and uploads the results to the superior management center.
**1.6.3 Environmental Monitoring Sensors**
There are numerous environmental sensors in the traffic management system, sharing the same working environment and requiring similar physical protection. The fault detection method of the sensor compares the collected data with the average data of the larger environment. If the difference between the detected data and the average data of the larger environment is significant, it is necessary to check whether the environmental factor is faulty or if the device itself is faulty.
**1.7 Network Storm**
**1.7.1 Definition of Network Storm**
Due to design and connection issues in the network topology or other reasons, large-scale broadcasts are copied in the network segment, leading to the propagation of data frames, which degrade network performance and even cause network failure. This is known as a network storm.
**1.7.2 Contents of Network Storm**
Each node on a data frame or packet transmitted to the local network segment (defined by the broadcast domain) is broadcast. Due to design and connection issues in the network topology or other reasons, the broadcast is heavily replicated in the network segment, causing the propagation of data frames. This leads to degraded network performance and even network failure. The broadcast storm phenomenon is one of the most common data flooding. It is a typical snowball effect. When broadcast storms occur, they spread endlessly in the network, breeding without limit in the network. Excessive broadcast packets consume a lot of network bandwidth, taking up many network resources. Normal packets cannot be transmitted on the network. At this point, the network device processor is running at high load. Not only does it affect network devices, but all hosts must receive broadcast packets at the link layer, and thus tens of thousands of packets per second often make the network card work extremely busy, exceeding the load of the processor. The operating system of the device responds slowly, and network communication is severely blocked. This seriously endangers the normal operation of the network, greatly reducing the communication performance of the entire Ethernet. It can even cause an overall flaw in the network.
**1.7.3 Prevention of Network Storm**
From practical experience, more than 90% of network broadcast storms are caused by viruses. Therefore, anti-virus systems, IDS intrusion detection systems, and network traffic detection tools should be installed in the LAN to strengthen the prevention and control of network viruses. Monitoring the operation status of the network line, timely discovering and handling abnormal traffic and virus attacks on the network, and formulating a computer security management system to ensure the normal operation of the network line.
Remember not to use a hub to set up a shared network. Instead, use a switch to form a switched network. Use proper VLANs, narrow broadcast domains to isolate broadcast storms, and enable broadcast storm control on Gigabit Ethernet ports on the switch. Limit the network to avoid being paralyzed again.
**1.7.4 Troubleshooting Network Storms**
Use traffic viewing software such as MRGT to check the ports that are short-circuited. If the switch is network-managed, you can also search and find out by blocking the ports one by one, then find the faulty device, and then check whether it is caused by a virus or hardware damage. The right medicine can be administered accordingly.
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