Shanghai Zhongling Radio Frequency BRT Bus Rapid Transit Priority System
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With the rapid development of the national economy and the acceleration of urbanization and motorization, the scale of cities has continued to expand, and the number of motor vehicles and road traffic flow has increased sharply. Especially in large cities, the increase in public transport vehicles, the extension of lines, and the increase in the number of vehicles, traffic operation Not smooth. Despite the construction of a large number of transportation facilities, traffic congestion is still very serious.
Many years of practical experience at home and abroad have shown that an important way to solve urban traffic problems is to develop public transportation, establish an advanced public transportation system APTS (Advanced Public Traffic System), and improve road capacity and bus operation management. The urban public passenger transport system has not yet introduced (or is in the process of) introducing advanced high-tech, and basically still adopts the manual dispatching method of “fixed departures and stuck points at both ends”, which causes the speed of public transportation vehicles to drop, and the driving interval is not balanced, which often occurs.” The phenomenon of “crossing of cars” and “large gaps” has seriously affected the service quality of public transport passenger transport. In particular, due to the lack of modern communication means, dispatchers cannot understand the conditions of operating vehicles in real time, and it is difficult to take dispatching measures in a timely and effective manner. Bus dispatching is in a backward status of “invisible and inaudible”, with greater blindness and lag.
With the continuous development and advancement of various science and technology and application technologies, urban transportation has also begun to gradually move towards an intelligent and humanized road, which has producedsmart transportationSystem (Intelligent Traffic System, ITS) concept, it is the advanced information technology, data communication transmission technology, electronic control technology, sensor technology and computer processing technology and other technologies are effectively integrated in the transportation system, so as to achieve the The transportation system is more accurate, real-time, and comprehensively managed and controlled efficiently to maximize the harmony and unity among people, vehicles, and roads. Among them, an important direction of the development of intelligent transportation is the accurate positioning and navigation of vehicles in urban traffic, which has become an inevitable demand for the development of many industries (such as public transportation, fire fighting, emergency rescue, traffic accident handling, etc.).
1. System significance
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 queue of vehicles;
4) Reduce vehicle energy consumption, manpower and transportation equipment;
2. System architecture and program description
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;
2.1 System architecture
System network architecture
2.2 Program description
Installation location
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 until the signal state is restored, and the signal priority dispatching process is completed; the BRT signal priority control intelligent management system refers to the priority given by the traffic signal system to BRT vehicles in “time”, which is mainly reflected in: When BRT vehicles are running When approaching the intersection, the traffic signal system recognizes the vehicle and judges the direction of the vehicle, providing 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 light signal cycle and switch to the green light phase of the BRT vehicle driving 8 seconds earlier, thereby reducing the delay time of the BRT vehicle at the intersection.
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