CN101697237A - Cortex_M3 and GPRS based route identification RFID read-write equipment of highway toll collection system - Google Patents

Abstract

A line identification RFID read-write device for a highway non-stop toll collection system based on Cortex_M3 and GPRS, including a casing, a computer interface slot, a power input interface and a circuit board, the computer interface slot and the power input interface are arranged on the surface of the case, and the circuit board is located on the Inside the casing, it also includes a GPRS module for wireless communication between expressway vehicles and the control center and a radio frequency RFID module for obtaining information on expressway vehicles. The GPRS module is connected to the GPRS antenna. The card information is stored and transmitted to the control center through GPRS, and the corresponding station information and instant information are transmitted to the reading and writing device so that the reading and writing device can write it into the microprocessor of the card. The invention can effectively identify the vehicle route, cancel various toll stations in the middle section of the expressway, save a lot of human resources and management costs, and improve driving efficiency.

Description

Line identification RFID reading and writing equipment for highway non-stop toll collection system based on Cortex_M3 and GPRS

technical field

The invention relates to a high-speed, long-distance reading and writing device based on a Cortex_M3 microprocessor and integrating GPRS networking technology and RFID technology, which is suitable for line identification equipment in a non-stop toll collection system on expressways.

Background technique

At present, the construction of expressways in China is developing rapidly, especially in the coastal development areas. It is convenient for the masses. At present, the tolls of the expressway are calculated according to the nearest route by the computer according to the starting point and the destination of the driving. At the same time, the right of way unit cannot carry out the correct distribution of benefits because it cannot confirm the route of the vehicle, which is a problem. The national problem of expressway operation and management for many years - the problem of ambiguous route tolls and splitting.

For example, the Shanghai-Hangzhou Expressway has set up a toll station at the junction of Jiaxing and Shanghai, and the Sujia Expressway has also set up a toll station at the junction of Jiaxing, Zhejiang and Jiangsu. Judging whether it is coming from Shanghai or Suzhou, because the same high-speed vehicles in Kunshan can take both the Shanghai route and the Sujia Expressway, so it is necessary to set up the above two four toll stations, not only Wasted manpower and material resources, and reduced driving efficiency.

The toll mode of domestic expressways, whether it is cash payment or credit card deduction, currently adopts the parking toll method, which leads to long-distance queues at toll intersections and weakens the fast and convenient transportation brought by expressways. As a result, it violates the construction purpose of the expressway to be unimpeded.

Contents of the invention

In order to overcome the shortcomings of the existing highway non-stop toll collection system that the reading and writing equipment cannot effectively identify the car lines, increase various toll stations in the middle section, waste a lot of human resources and management costs, and drive low efficiency, the present invention provides a A line identification RFID reading and writing device based on Cortex_M3 and GPRS for the non-stop toll collection system of expressways that can effectively identify car routes, cancel various toll stations in the middle section of expressways, save a lot of human resources and management costs, and improve driving efficiency .

The technical solution adopted by the present invention to solve its technical problems is:

A kind of line identification RFID reading and writing equipment of the freeway non-stop charging system based on Cortex_M3 and GPRS, comprises shell, computer interface slot, power supply input interface and circuit main board, and described computer interface slot and power supply input interface are arranged on shell surface, so The circuit board is located in the housing, the computer interface slot is connected to the microcomputer interface circuit of the circuit board, the power input interface is electrically connected to the power supply end of the circuit board, and the RFID read-write device also includes a The GPRS module of central wireless communication and the radio frequency RFID module that is used to obtain the information of expressway vehicle, described GPRS module is connected with the GPRS interface circuit of described circuit board, described GPRS module connects GPRS antenna, and described radio frequency RFID module connects The radio frequency RFID interface circuit of the circuit board, the circuit board includes the card information that is responsible for receiving the read-write device, stores the card information and transmits it to the control center through GPRS, and sends the corresponding site information and instant information Passed to the read-write device so that the read-write device can write it to the card's microprocessor.

Further: the microprocessor is a Cortex_M3 processor based on the ARMv7_M architecture.

Still further, the working frequency band of the radio frequency RFID module is 2.45GHz.

A status indicator hole is installed on the shell, and the status indicators for displaying power supply, communication and radio frequency transmission and reception are installed in the status indicator hole, and the status indicator is connected to the circuit board.

The status indicator hole is located on the front panel of the housing, the computer interface slot is located on the front side of the housing, the power input interface is located on the right side of the computer interface slot, and the GPRS antenna is located on the top of the housing.

The technical idea of the present invention is: based on radio frequency technology RFID technology, using electronic tags as information carriers, designing and developing high-speed, long-distance, high-reliability RFID reading and writing equipment, on the one hand, as a path identification equipment for vehicles to complete the high-speed The identification and recording of vehicle information can realize the automatic identification of vehicle travel routes, resolve ambiguous path splitting, and realize the reasonable distribution of benefits. On the other hand, the use of long-distance RFID readers can also realize non-stop charging of vehicles and solve the problem of vehicle congestion at expressway exits. RFID reading and writing equipment has very important practical significance.

The beneficial effects of the present invention are mainly manifested in: 1. The main control part of the present invention adopts the Cortex_M3 based on the ARMv7_M architecture as a processor, and the central Cortex-M3 kernel uses a 3-stage pipeline Harvard architecture, which is realized by using branch prediction, single-cycle multiplication and hardware division functions An excellent efficiency of 1.25DMIPS/MHz. The Thumb-2 instruction set combines features such as unaligned data storage and atomic bit processing to easily achieve 32-bit performance with the storage space required by 8-bit and 16-bit devices. 2. The Cortex-M3 processor is specially designed for those applications that are very sensitive to cost and power consumption but also have high performance requirements. It creates a myth of $1 price and provides unparalleled competitiveness. The reader-writer developed on this basis not only greatly improves the performance, but also effectively reduces the cost. 3. The radio frequency RFID part of the system works in the 2.45GHz microwave band. Taking advantage of its high energy wave, low loss, more concentrated wave, stronger directionality, and high communication rate (1Mbps), it can achieve a farther transmission distance of 50m, reaching High-speed transmission speed. 4. The design of GPRS function not only provides convenience for wireless data transmission, but also saves costs for system expansion instead of network wiring. 5. After being put into practical application, various toll stations in the middle section of the expressway line will be cancelled. As a result, not only the driving efficiency will be greatly improved, but also the toll distribution will be carried out on the basis of the actual driving route, thus saving a lot of human resources and resources. management costs. 6. Increase the charging method of RFID vehicle tickets, so that these vehicles can realize non-stop at the toll entrance and exit, reduce congestion and the exit toll station with people.

Description of drawings

Fig. 1 is a schematic diagram of the appearance and structure of the RFID reading and writing device of the present invention.

Fig. 2 is a circuit block diagram of the RFID reading and writing device of the present invention.

Fig. 3 is a functional block diagram of storage and time in the circuit schematic diagram of the RFID read-write device of the present invention.

Fig. 4 is a diagram of RFID functional modules in the schematic circuit diagram of the RFID reading and writing device of the present invention.

Fig. 5 is a GSM functional block diagram in the circuit schematic diagram of the RFID reading and writing device of the present invention.

Fig. 6 is a diagram of an indicator light module in the schematic circuit diagram of the RFID reading and writing device of the present invention.

Fig. 7 is a schematic diagram of the power supply function module in the circuit schematic diagram of the RFID reading and writing device of the present invention.

Fig. 8 is a program block diagram of the workflow of the RFID reading and writing device of the present invention.

Fig. 9 is a program block diagram of the process of reading and writing electronic tags by the radio frequency part.

Fig. 10 is a block diagram of the program flow of the active RFID card applicable to the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

With reference to Fig. 1～Fig. 10, a kind of line identification RFID read-write equipment of the expressway non-stop charging system based on Cortex_M3 and GPRS, comprises shell 1, computer interface slot 3, power supply input interface 4 and circuit board 8, and described computer interface Groove 3 and power input interface 4 are arranged on shell 1 surface, and described circuit main board 8 is positioned at described shell 1, and described computer interface slot 3 is connected with the microcomputer interface circuit of circuit main board 8, and power input interface 4 is connected with circuit main board 8. The power supply end is electrically connected, and the RFID read-write device also includes a GPRS module 6 for wireless communication between the highway vehicle and the control center and a radio frequency RFID module 7 for obtaining information on the highway vehicle, the GPRS module 6 and the The GPRS interface circuit of the circuit board is connected, the GPRS module 6 is connected to the GPRS antenna, and the radio frequency RFID module 7 is connected to the radio frequency RFID interface circuit of the circuit board 8, and the circuit board 8 includes a device for receiving and reading and writing. The card information is stored and transmitted to the control center through GPRS, and the corresponding site information and instant information are transmitted to the read-write device so that the read-write device can write it into the microprocessor of the card.

The schematic diagram of the appearance and structure of the RFID reading and writing device of this embodiment is shown on the left in Figure 1, the physical diagram of the mainboard circuit is shown on the right in Figure 1, and its circuit block diagram is shown in Figure 2, and the schematic circuit diagram of one of its embodiments is shown in Figure 1 3 to 7, its work flow chart is shown in Figure 8, and its radio frequency part reads and writes the electronic tag flow program block diagram as shown in Figure 9, and the program flow block diagram applicable to the active RFID card of the present invention is shown in Figure 9. 10 shown. The reader-writer of the present invention is made of shell 1, status indicator hole 2, computer interface slot 3, power input interface 4, GPRS antenna hole 5, GPRS module 6, radio frequency RFID module 7, circuit mainboard 8 and is jointly installed and connected, and its mutually The position and connection relationship are as follows: the status indicator hole 2 is located on the front panel of the shell 1, corresponding to the power supply, 485 communication, and radio frequency transceiver indicator lights of the circuit board; the computer interface slot 3 is located on the front side of the shell 1, and the computer interface slot 3 is installed There are pin-type parallel connectors and are electrically connected to the corresponding points on the circuit board through their respective signal lines. The power input interface 4 is located on the right side of the computer interface slot 3 on the front side of the shell, and is electrically connected to the power terminal on the circuit board. The GPRS antenna hole is located at the top of the shell 1, and the antenna connected to the GPRS module 6 can extend to the outside of the shell through the antenna hole; the GPRS module 6 is inserted on the circuit main board 8 through the pin row; the radio frequency RFID module 7 is inserted into the circuit through the pin row On the main board 8; its circuit main board 8 is made of common electric connection of microprocessor circuit, microcomputer interface circuit, memory circuit, real-time clock circuit, GPRS interface circuit, radio frequency RFID interface circuit, and its interconnection relation is: microprocessor circuit passes through respectively Microcomputer interface signal lines, memory signal lines, real-time clock signal lines, GPRS signal lines, and radio frequency RFID interface signal lines are electrically connected; wherein: the microprocessor circuit is composed of the smallest system unit composed of a Cortex_M3 microprocessor with an ARMv7_M architecture; the microcomputer interface The circuit is composed of 485 communication chip MAX3082A; the memory circuit is composed of flash memory W25X16A and the common electrical connection of the flash memory in the microprocessor; the real-time clock circuit is composed of real-time clock chip PDF8563; the GPRS interface circuit is composed of GPRS module connection cable TC35B, The SIM card slot chip SIM1 is jointly connected; the radio frequency RFID interface circuit is composed of a radio frequency RFID module slot and a microcontroller electrical connection.

The working process of the reader in this embodiment can be divided into three parts: the working process of the microprocessor LM3S6911, the reading and writing process of the radio frequency RFID module, and the working process of the active RFID card. Combined with their corresponding program flow charts, they are described as follows:

As shown in Figure 8, it is the working program flow chart of the microprocessor LM3S6911. The microprocessor is mainly responsible for receiving the card information read by the read-write device, storing the information, passing it to the control center through GPRS, and passing the corresponding site information and instant information to the read-write device so that the read-write device can write it into the card . The detailed working process is as follows: After the system initialization is completed, enter the card data waiting to be received, if the waiting for receiving timeout, return to continue waiting for receiving; if the uploaded card data is received, the received data will be stored in the flash memory, and Send it to the control center through GPRS, and at the same time, LM3S6911 transmits the corresponding site information and the current time information to write it into the card, and the corresponding LED flashes.

Figure 9 shows the flow chart of the reading and writing work program of the radio frequency RFID part. The system intermittently sends the agreed broadcast signal. When a certain card responds, the reader will lock the card and establish a channel for data interaction with it. The detailed process is: after the system initialization is completed, enter the state of sending broadcast packets, and send out the agreed broadcast packets; then transfer to the receiving state, waiting to receive the corresponding card information; if the waiting time for receiving is overtime, return to resend broadcast packets; If the data information of the card is received, the corresponding LED will blink, and at the same time, the received data information will be sent to the upper computer LM3S6911, and the station information and time information transmitted by the LM3S6911 will be sent to store in the card , and the corresponding send LED blinks.

Figure 10 shows the program flow chart of the active RFID card applicable to this system. The card is usually in standby or sleep mode. When it enters the corresponding reading and writing area, if it receives the agreed broadcast signal, it will wake up and start working, and exchange data with the reader. The detailed working process is as follows: after the system initialization is completed, enter the standby mode, wait for the agreed broadcast signal to be received, and return to continue receiving if the received broadcast signal is timed out; This system mainly sends out the ID number; then it turns to the waiting state to receive the site information and instant information sent by the reading and writing equipment. If the waiting time for receiving is overtime, it will return to resend the data in the card; otherwise, if it receives the corresponding site information and instant information, it will store these site information and instant information in the card, and the system will switch to standby or sleep mode.

As shown on the left side of Figure 1, aluminum alloy or plastic materials can be selected, and the casing of the reader is manufactured by stamping and other machining methods, and the front panel of the casing 1 is set and punched to correspond to the size of the LED on the circuit board. The round hole 2 is reserved on the front side of the casing 1 and punched to install the interface groove 3 and the power input interface hole 4 of the computer interface. Among them, the computer interface can choose pin-type parallel interface, and the power input interface can choose ordinary plug-in DC input interface.

Draw the circuit board as shown in Figure 2, Figure 3-7, and then screen the components for installation and connection, for example: the processor selects the Cortex_M3_LM3S6911 microprocessor chip of TI's ARMv7_M architecture, and the central Cortex-M3 core uses a 3-stage pipeline Harvard architecture , using branch prediction, single-cycle multiply, and hardware divide to achieve an outstanding efficiency of 1.25DMIPS/MHz. The Thumb-2 instruction set combines features such as unaligned data storage and atomic bit processing to easily achieve 32-bit performance with the storage space required by 8-bit and 16-bit devices. The chip integrates 256K bytes of flash memory, and the program can be directly written to the chip repeatedly. The 485 communication chip in the microcomputer interface circuit chooses the MAX3082A chip. The memory chip in the memory circuit selects the flash memory W25X16A, which is a high-capacity, low-power, high-efficiency flash memory of 16M words, which is used to store the control program specially customized for this system and store a large amount of data information; The software on the memory is executed by the LM3S6911 controller. The real-time clock chip chooses PCF8563. PCF8563 is a low-power CMOS real-time clock calendar chip. It provides a programmable clock output, an interrupt output and a power-down detector. All addresses and data are serially transmitted through the I2C bus interface. The maximum bus speed is 400Kbits/s, and the embedded word address register will automatically increase after each read and write data. The GPRS module chooses the Siemens TC35i module. The new version of the Siemens industrial GSM module of the TC35i is an industrial-grade GSM module that supports Chinese short messages. It works in EGSM900 and GSM1800 dual-bands. The power supply range is DC 3.3-4.8V. mA, idle state is 25mA, transmit state is 300mA (average), 2.5A peak; can transmit voice and data signals, power consumption is 2W and 1W in EGSM900 (category 4) and GSM1800 (category 1), respectively, through the interface connector and antenna connector to connect SIM card reader and antenna respectively. The SIM voltage is 3V/1.8V, and the data interface (CMOS level) of TC35i can transmit instructions and data bidirectionally through AT commands. The optional baud rate is 300b/s～115kb/s, and the automatic baud rate is 1.2kb/s ~115kb/s. It supports SMS (Short Message Service, short message) in Text and PDU formats, and can realize restart and fault recovery through AT commands or shutdown signals. TC35i consists of 6 parts including power supply module (ASIC), flash memory, ZIF connector and antenna interface. As the core baseband processor of TC35i, it mainly deals with voice and data signals in GSM terminals, and covers all analog and digital functions in cellular radio frequency equipment. The core chip of the radio frequency RFID module chooses nRF24LE1 from Nordic, a Nordic integrated circuit company. For long-distance interconnection applications, it works in the ISM industrial, scientific and medical frequency bands. The device has 125 frequency points, which can realize point-to-point and point-to-multipoint wireless communication. At the same time, frequency changing and frequency hopping can be used to avoid interference. It is small in size, low in power consumption, and requires few peripheral components for design, so it has a great price advantage.

Through the screening and installation of the above key components and other electronic components, the actual rendering of the mainboard circuit is finally shown in Figure 1 on the right.

Write each part of the software program as shown in Figure 8 to Figure 10, and burn the edited software program into the corresponding chip of each part; after the system is powered on, the power indicator LED is on, and the hardware is reset automatically first, and then , the software initializes the relevant memory, and then enters the execution of the main program. When the reader sends a data signal, that is: when sending a broadcast signal or writing a card, the corresponding sending indicator LED flashes, which means that the radio frequency RFID sends data normally; when the reader receives data information (ie: reading the card), the corresponding receiving indicator light The LED flashes, which means that the radio frequency RFID is receiving data normally; when the reader transmits the data to the background control system through GPRS, the corresponding GPRS indicator LED flashes, which means that the GPRS transmission data is normal; if the data is exchanged with the reader through the computer interface software , the corresponding computer interface indicator light, that is, the 485 communication indicator LED flashes, which means that the communication and data interaction are normal. The whole system has the characteristics of intelligent identification and easy to use. The user only needs to place it on the appropriate reading and writing point and power it on, and the system can automatically run and work.

Claims (5)

1. identification of lines RFID read-write equipment based on the highway toll collection system of Cortex_M3 and GPRS, comprise shell, the computer interface groove, power input interface and circuit main board, described computer interface groove and power input interface are located at case surface, described circuit main board is positioned at described shell, described computer interface groove is connected with the microcomputer interface circuit of circuit main board, the power end of power input interface and circuit main board is electrically connected, it is characterized in that: described RFID read-write equipment also comprises the GPRS module that is used for vehicle on highway and control center's radio communication and is used to obtain the radio frequency ID module of the information of vehicle on highway, described GPRS module is connected with the GPRS interface circuit of described circuit main board, described GPRS module connects the GPRS antenna, described radio frequency ID module connects the radio frequency ID interface circuit of described circuit main board, described circuit main board comprises and is used for be responsible for receiving the card image that read-write equipment reads, pass to control center with described card image storage and by GPRS, and the site information and the instant messages of correspondence passed to read-write equipment so that read-write equipment writes the microprocessor of card with it.

2. the identification of lines RFID read-write equipment of the highway toll collection system based on Cortex_M3 and GPRS as claimed in claim 1 is characterized in that: described microprocessor is the processor based on the Cortex_M3 of ARMv7_M framework.

3. the identification of lines RFID read-write equipment of the highway toll collection system based on Cortex_M3 and GPRS as claimed in claim 1 or 2, it is characterized in that: the working frequency range of described radio frequency ID module is 2.45GHz.

4. the identification of lines RFID read-write equipment of the highway toll collection system based on Cortex_M3 and GPRS as claimed in claim 3, it is characterized in that: installment state indicator lamp hole on the described shell, the status indicator lamp that is used for display power supply, communication and radio-frequency receiving-transmitting is installed in the described status indicator lamp hole, and described status indicator lamp is connected with described circuit main board.

5. the identification of lines RFID read-write equipment of the highway toll collection system based on Cortex_M3 and GPRS as claimed in claim 4, it is characterized in that: described status indicator lamp hole is positioned on the front panel of described shell, described computer interface groove is positioned at the positive side of shell, described power input interface is positioned at the right-hand of computer interface groove, and described GPRS antenna is positioned at the top of shell.

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