The sand table is presented in a sand table mode, consisting of a sand table model, intelligent vehicle management system, vehicle tracking system, AI intelligent parking lot system, ETC control system, smart community system, urban environment monitoring system, urban lighting control system, dangerous road warning system, traffic light indication system, traffic flow detection system, central control system, VR virtual reality experience system, mobile terminal control system, intelligent gateway system, and IoT cloud server. The scene mainly includes intelligent bus control, traffic indicator lights, ETC control system, intelligent parking lot, dangerous road monitoring, environmental monitoring, IoT applications, intelligent street lights, traffic flow monitoring, license plate recognition, vehicle positioning, etc. Corresponding sensors and actuators are arranged in the scene. The sand table comprehensively embodies and realizes the following functions: smart community, intelligent transportation, intelligent parking lot, environmental monitoring, physical network application, path planning, and VR virtual reality application. Intelligent transportation is mainly reflected in the road network, buses, and parking lots on the sand table, with other functions corresponding to specific areas on the sand table. Through comprehensive learning of the system, students are guided to gradually understand the application and development of IoT technology in the field of smart cities from scratch. At the same time, it also provides technical solutions for solving modern urban traffic congestion, road accidents, parking difficulties, urban fire protection, public transportation management, community safety, urban lighting management, hit and run traffic, ETC toll collection, etc.

Figure 1 Product Physical Picture

The intelligent car on the sand table operates using AGV magnetic navigation. The magnetic strip provided for the car's magnetic navigation in the sand table is buried below the sand table road surface, and the magnetic strip cannot be seen from the sand table, which does not damage the overall appearance of the sand table.

The networking adopts ZigBee technology for interconnection, where the ZigBee part uses CC2530 processor and provides independent CC2530 module nodes. CC2530 nodes are installed using clip connectors, which can be disassembled without any tools, without the need for glue or screws to fix, making it convenient for students to disassemble and reconstruct.

VR virtual reality has increased the experience of the sandbox, allowing users to experience the motion path of the intelligent car on the sandbox model from its first perspective, making the sandbox more realistic.

Figure 2 VR Smart City System Interface

1. Intelligent Vehicle Management System

The system prepares a complete bus route and configures a set of intelligent bus stop signs. The intelligent bus stop signs display the bus location and route in real time, providing users with the latest bus location and facilitating the selection of suitable buses; Simultaneously displaying real-time environmental information from IoT application systems, providing users with the latest weather information.

Equipment involved: smart car, serial display screen, M3 node control board, ZigBee communication core board and other components.

2. Vehicle tracking system

This system uses image processing technology to enable computers to automatically recognize and track vehicles in the sandbox, and send location information to the central control system. The main functions of this system include specific marking and positioning functions, as well as tracking of moving objects.

Related devices: USB signal amplification extension cable, image positioning camera and other components.

3. ETC control system

The sand table is equipped with an ETC entrance and exit, which intelligently charges passing vehicles without the need for manual intervention. Charges will be based on the model of the vehicle and the required services. After the vehicle enters the range of the UHF (simulated actual ETC reader) card reader, the UHF card reader automatically reads the vehicle information and provides real-time feedback to the IoT application system for scheduling. The ETC system automatically controls the electronic barrier gate. When the vehicle passes, the barrier gate railing automatically lifts, simulating automatic toll collection. After the vehicle passes, the railing automatically drops, achieving non-stop toll collection.

Equipment involved: 915M ultra-high frequency read-write module, ZigBee communication core board, barrier gate control module, infrared diffuse reflection sensor and other components

4. Smart Community System

The sand table is equipped with a smart community system, which realizes the first warning of fire hazards through the interconnection of home fire sensing points, home warning, community investigation, automatic fire dispatch, optimal route dispatch, and fire priority passage. The future fire protection will be based on intelligent fire protection built on the Internet of Things interconnection. The system arranges relevant sensors for IoT application detection in appropriate locations, mainly including smoke, combustible gas, flame, human infrared and other sensors. The sensor data is collected and uploaded in real-time to the intelligent gateway system through ZigBee wireless. The intelligent gateway system summarizes the corresponding data and uploads it to the server for IoT application systems to obtain and schedule information.

Equipment involved: smoke sensors, gas sensors, flame alarms, human infrared sensors and other components.

5. Urban environmental monitoring system

This system collects real-time environmental data through sensors and can promptly alert in case of special environmental conditions. The sensor communicates with the node control board through 485 and uses Modbus bus protocol. Upload the data to the smart gateway through ZigBee, and the smart gateway will summarize and send the data to the server.

Equipment involved: components such as lighting sensors, air temperature and humidity sensors, PM2.5 sensors, wind speed sensors, etc.

6. Urban lighting control system

The sand table is equipped with street lights on both sides of the road section to simulate real street light control. The intelligent street light control system provides two types of control modes: intelligent control mode and time period control mode.

Intelligent control mode: The system controls the overall streetlights based on real-time lighting data.

Time control mode: The overall control of the street lights is achieved through preset time parameters.

Equipment involved: M3 node control board, ZigBee communication core board, street lamp module and other components.

7. Warning system for dangerous road sections

Set up dangerous section monitoring on highway sections, which will trigger local sound and light alarms when abnormalities occur. At the same time, the alarm information of the section will be uploaded to the intelligent gateway, which will implement emergency shutdown processing for the section.

Equipment involved: sound and light alarm, single beam infrared detector, rain and snow sensor, wireless network camera and other components.

8. Traffic light command system

Provide two modes: fixed duration and dynamic adjustment. In dynamic adjustment mode, the system can dynamically adjust the time interval of traffic lights according to the size of traffic flow. The system can also cooperate with the central control system to achieve functions such as priority passage for specific vehicles.

Equipment involved: M3 node control board, ZigBee communication core board, traffic indicator lights and other components.

9. Traffic flow detection system

Bury infrared diffuse reflection sensors at intersections to count passing vehicles, achieve real-time monitoring of traffic flow on main roads, and promptly report and warn traffic information through traffic information boards.

Equipment involved: M3 node control board, ZigBee communication core board, infrared diffuse reflection sensor and other components.

10. Central control system

Provide a graphical interface for operators to intuitively manage devices. Implement functions such as parameter setting and real-time monitoring of intelligent parking lot systems, parameter setting and real-time monitoring of traffic indicator systems, parameter setting and real-time monitoring of ETC subsystems, real-time monitoring of environmental monitoring station systems, monitoring of dangerous road sections systems, monitoring of IoT application systems, and joint scheduling of various systems.

Equipment involved: components such as vertical touch all-in-one machines.

11. Mobile terminal control system

Users can access the system through mobile terminals, PADs, or other Android devices to achieve real-time status queries of training system environment information, bus information, highway section information, etc.

Related devices: open source mobile terminals and other components.

12. Intelligent gateway system

Based on the Internet of Things cloud service system, realize data aggregation, data analysis, data uploading and interaction functions. The gateway aggregates and uploads real-time data from systems such as intelligent buses, traffic lights, ETC control, intelligent parking lots, dangerous road monitoring, environmental monitoring, IoT applications, intelligent street lights, and traffic flow monitoring to the server. At the same time, it forwards instructions from the central control system and distributes them to various systems.

Related devices: IoT gateway, wireless coordinator, wireless router and other components.

Project Background:

In modern society, with the continuous development of computer technology and the continuous improvement of information application level, traditional urban models have been greatly impacted. The demand for intelligence in areas such as people's livelihood, environmental protection, public safety, transportation, and urban services is increasing day by day. How to use advanced information technology to achieve intelligent management and operation of cities, and create a better life for people in cities, promote the harmonious and sustainable growth of cities, has become a new direction of thinking for various countries and major enterprises. In this context, the construction of smart cities has emerged. This not only promotes the evolution of traditional cities towards new smart cities, but also puts forward higher requirements for the cultivation of high-quality technical talents corresponding to the construction and development of smart cities. It is urgent to build a curriculum system centered on abilities, strengthen the connection between theoretical courses and practical applications, cultivate students' practical hands-on abilities, and establish comprehensive training bases.

Project 1: ETC non-stop toll collection system scenario

Scenario introduction: Simulate a scenario where a vehicle uses ETC to pass through a highway toll station. The sand table is equipped with an ETC entrance and exit, which intelligently charges passing vehicles without the need for manual intervention. Charges will be based on the model of the vehicle and the required services. After the vehicle enters the range of the UHF (simulated actual ETC reader) card reader, the UHF card reader automatically reads the vehicle information and provides real-time feedback to the IoT application system for scheduling. The ETC system automatically controls the electronic barrier gate. When the vehicle passes, the barrier gate railing automatically lifts, simulating automatic toll collection. After the vehicle passes, the railing automatically drops, achieving non-stop toll collection.

Equipment involved: serial display screen, 915M ultra-high frequency read-write module, M3 node control board, ZigBee communication core board, barrier gate control module, infrared diffuse reflection sensor and other components.

Project 2: Scene where the ambulance is trapped in traffic

Scenario introduction: Simulate a scene where an ambulance carrying a patient is stuck in traffic at an intersection, and the system automatically adjusts to make it pass smoothly and arrive at the hospital. Firstly, the central control system combines image processing technology to enable the computer to automatically identify and track vehicles in the sandbox, and send location information to the central control system. Then the central control system arranges the fastest route for the ambulance to reach the hospital based on the real-time feedback of the intersection vehicle condition from the infrared diffuse reflection sensor buried at the intersection. Finally, the central control system can dynamically adjust the time interval of traffic lights based on the volume of traffic, allowing ambulances to pass first.

Related systems: vehicle tracking system, traffic light indication system, traffic flow detection system, central control system

Equipment involved: USB signal amplification extension cable, drive free camera, M3 node control board, ZigBee communication core board, traffic indicator light, infrared diffuse reflection sensor and other components.