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1 Introduction
1.1 Successful case and project introduction
1.1.1 Jiangsu Lianyungang BRT BRT Line 1
In December 2012, it participated in the smooth acceptance of the intelligent transportation project of Lianyungang BRT Line 1, which effectively guaranteed the “signal priority” and “right of way priority” of BRT buses from the scientific and technological means.The Gangcheng BRT Line 1 with a total length of about 34 kilometers is the longest BRT line in China so far. Combined with the company’s active RFID radio frequency products and technology, it provides a technological guarantee for “signal priority” and “right of way priority”. The advanced solution has achieved the expected effect of the design from the perspective of operation and usage, and has been well received by users
1.1.2 Zhejiang Hangzhou BRT Line 2
In August 2009, he participated in the design and development of BRT Line 2 of Zhejiang Hangzhou Bus Rapid Transit, and provided active RFID radio frequency products and technologies for the BRT project, ensuring the smooth implementation, acceptance and operation of the project;
1.1.3 Jiangsu Yancheng BRT Line 1
Participated in the design and development of BRT Line 1 of Jiangsu Yancheng BRT in January 2011, providing active RFID radio frequency products and technologies for the BRT project, ensuring the smooth implementation, acceptance and operation of the project;
1.1.4 Guangdong Foshan Express Bus BRT Line 1
Participated in the design and development of BRT Line 1 of Jiangsu Yancheng BRT in July 2011, providing active RFID radio frequency products and technologies for the BRT project, ensuring the smooth implementation, acceptance and operation of the project;
1.2 Explanation of terms and abbreviations
Term explanation
RFIDRadio frequency identification is a communication technology that can identify specific targets and read and write related data through radio signals without the need to establish mechanical or optical contact between the identification system and specific targets
The RFID active radio frequency card is composed of an embedded processor and its software, a transmitting and receiving antenna in the card, a transceiver circuit and a high-energy battery. The special number is pre-stored in the microcontroller, and a unique encrypted identification code radio signal is transmitted intermittently. The high-energy battery in the card provides energy for the normal operation of the active card, and the battery in the card can be replaced.
The directional reader is composed of information collection, processing, information transmission, and embedded software. Its main function is to complete the real-time collection and processing of the vehicle identification code output signal.
The intelligent traffic control system (signal control cabinet) receives the bus priority application instructions sent by the traffic signal machine, and realizes the green light delay at the intersection and the red light breaks early
2. Project background
2.1 Analysis of the status quo
As a new type of passenger transportation mode, the BRT system is considered to be one of the effective ways to solve the problem of urban traffic congestion due to its advantages of low project investment, short construction period, low environmental pollution, and high transportation efficiency. Successfully promoted and applied. Under the strong influence of the construction of rapid transit systems in many cities in the world and the strong promotion of relevant policies in my country, the domestic transportation industry and major cities have begun to push the rapid transit system to the forefront of alleviating urban traffic pressure. In the next 5 years, there will be 10 in China. The above cities have built a rapid transit system, which is expected to have a total length of 300 to 500 kilometers and a daily passenger flow of 2 to 4 million;
Public transportation is an important means to improve the efficiency of transportation resources and alleviate traffic congestion, and it is the main direction of solving traffic problems in big cities. With the expansion of the scale of the city and the development of the economic level, the needs of urban residents to improve travel conditions, especially the convenience of public transportation, are becoming more and more urgent;
In this context, the company has made great efforts to develop the Internet of Things technology to improve the level of urban public transport construction in my country and improve the quality of service. It has developed an intelligent management system for the priority control of BRT signals based on RFID technology;
2.2 Significance of system construction
1. Reduce the travel time of public lines and reduce the delay of public vehicle intersections;
2. Reduce the number of parking of public vehicles, improve the stability and accuracy of public vehicles, and improve the level of public transport services;
3. Reduce the delay of social vehicles on the main line and the length of the line of vehicles;
4. Reduce vehicle energy consumption, manpower and transportation equipment;
3. System Overview
3.1 Principles of System Design
The system development and construction follow the following principles:
Focus on overall planning
The BRT signal priority control intelligent management system consists of three parts. First, the core hardware of the BRT signal priority control system (including: 2.4G active electronic tags, directional readers). Second, the BRT signal priority control system platform (Including intersection control subsystem, signal communication subsystem, intelligent traffic control); third, hardware middleware (including signal control machines, industrial-grade switches, cabinets, PCs, servers, uninterruptible power supplies, etc.);
Based on independent research and development
The core technology of the system construction adopts the standard 2.4G active microwave frequency band commonly used in the market. All the core equipment provided by the company has completely independent intellectual property rights, 2.4G micro-power technology, automatic identification of long-distance moving vehicles and non-contact information Collection and processing, and effectively comprehensively apply advanced information technology, data communication technology, electronic control technology and computer processing technology to the ground transportation management system, thereby establishing a large-scale, all-round function, and real-time, accurate, and efficient Traffic management system. To achieve the purpose of prioritizing public transport signals;
Focus on future development
In terms of the overall system architecture, service equipment selection, active electronic label function selection, basic data collection, etc., full consideration is given to the realization of subsequent functions, taking into account the compatibility of equipment, system scalability, function scalability and application Diversity;
Strengthen system specifications
System development and resource construction conform to a unified technical specification and characterization system, pay attention to the continuity and sharing of development work, and pay attention to leaving standardized data and control interfaces for subsequent system development and promotion. Unified development of technical indicators such as application technology, data storage format, signal transmission system, and interconnection interface mode;
Utilize construction benefits
The development and construction of the system should combine the actual conditions of the traffic area, and further strengthen the management of the traffic on the basis of the existing system; follow the overall planning, construction while using, and gradually improve the construction ideas to give full play to the construction benefits;
3.2 The working principle of the system
The BRT signal priority control intelligent management system refers to the priority given by the traffic signal system to BRT vehicles in terms of “time”, which is mainly reflected in: when the BRT vehicle drives near the intersection, the traffic signal system recognizes the vehicle and judges the vehicle’s status The direction of operation provides a priority signal for the bus.
The BRT signal priority control intelligent management system mainly includes active electronic tags and base station type directional readers. Its basic working principle and characteristics are that when the RFID base station type directional reader detects that the BRT vehicle is approaching an intersection, it sends a request signal to the intersection signal, and the RFID base station type directional reader recognizes the detected BRT vehicle. , And transmit the information to the traffic signal control system in real time through the dedicated communication optical fiber, and the traffic control system center will issue instructions to the intersection signal machine for timing adjustment. The traffic control system of BRT vehicles adopts two solutions: (1) When the BRT vehicle approaches the intersection and encounters a green light, the current green light phase time is appropriately extended by 8 seconds to ensure that the BRT vehicle passes through the intersection smoothly; (2) When the BRT vehicle approaches the intersection When the intersection encounters a red light, shorten the red signal cycle and switch to the green light phase of the BRT vehicle driving 8 seconds in advance, thereby reducing the delay time of the BRT vehicle at the intersection;
3.3 Schematic diagram of overall system design
3.4 System function introduction
When the vehicle arrives at the intersection, the RFID reader reads the tag and obtains vehicle information; obtains the real-time scheduling status of the vehicle by interacting with the intelligent scheduling system, including whether it is late, whether it is express scheduling, and the full load rate, etc., and generates a request according to the real-time status of the vehicle; After that, the signal priority system submits a priority application to the traffic management department. The traffic management department system processes the request based on the original plan information and real-time scheduling information, and finally gives priority results; after the vehicle leaves the positioning area, the signal control system enters The signal state is restored to the state, until the signal state is restored, the signal priority scheduling process is completed;
3.5 System middleware software
Traffic signal control system
The traffic signal control system is an important subsystem of the intelligent traffic management system, and it plays a role of the nerve center in constructing the intelligent management system for the priority control of the BRT signal. When the RFID base station type directional reader detects the identity of the BRT vehicle, and transmits the information to the traffic signal control system in real time through the dedicated communication optical fiber, the traffic control system center then issues instructions to the intersection signal machine for timing adjustment;
3.6 Overall system construction plan
The design of the intelligent management system for the BRT signal priority control includes the intelligent bus dispatching system and the BRT vehicle signal priority control system. The two parts are independent and closely related to each other, and jointly form the intelligent and information management of the transportation field;
Below we explain in detail the two components of the intelligent management system for the priority control of the BRT signal. 3.6.1 BRT vehicle signal priority control system
The RFID base station type directional reader is installed at 100-200 meters away from the intersection. When the bus approaches the intersection, the 2.4G active electronic tag on the front of the car echoes the RFID base station type directional reader installed on the roadside, reading and writing When the signal is connected with the traffic signal control system of the traffic command center, the traffic signal lights at the intersection will change: extend the green light in the direction of the dedicated lane for BRT vehicles, or shorten the red light;
3.6.2 Hardware composition
1) RFID base station type directional reader, 80-100 meters away from the intersection, installed RFID base station type directional reader, used to read the active electronic tag information on BRT vehicles, and output through the serial port 485 or RJ45, relay, Connect with the traffic command center and the traffic signal control system for signal transmission and communication;
2) RFID active radio frequency card, installed in each controlled BRT vehicle, for vehicle information identification;
3) The traffic signal control machine adjusts the timing of the traffic signal so that the green light is delayed and the red light is advanced;
3.6.2 Precautions for hardware installation
1) RFID base station type directional reader, please pay attention to the installation position, height, waterproof connector (power connector, network connector), and the installation angle of the antenna panel;
2) The installation position of the RFID active radio frequency card on the BRT vehicle can be bundled or hung, and pasted on the front windshield of the vehicle or the rearview mirror of the vehicle;
3) The installation of optical fiber communication system mainly pay attention to the waterproof of the connector;
4. Introduction of hardware equipment
4.1 RW-R902 base station type directional reader
4.2 RW-T908 ultra-thin electronic label
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