Design of a handheld bus fare collection and information statistics device

    Abstract: A handheld bus fare collection and information statistics device is proposed. It charges passengers according to the distance they travel, rather than the traditional segmented charging method. It can also count the number of people getting on the bus at each station, the number of people getting off the bus at each station, and the number of people currently in the bus. Then, the wireless data transmission module can also send the information on the bus to the platform for the reference of passengers waiting for the bus. This device can also read and write existing bus cards, providing convenience for citizens' green travel. This device can store and summarize passenger flow information on the bus, and by analyzing the information on vehicle and passenger flow, it can also facilitate bus companies to dispatch and count.

    At present, the traffic congestion in cities is quite serious. According to relevant news reports: In China, the traffic congestion has expanded from megacities such as Beijing, Shanghai, and Guangzhou to some large and medium-sized cities: from local "point" congestion within the city to local "surface" congestion. During the morning and evening peak hours when residents travel, the congestion phenomenon is more obvious, and urban roads are in a state of obvious saturation. According to statistics from relevant departments, the economic losses caused by the inconvenience of urban transportation in China can reach hundreds of billions of yuan every year. Countries around the world attach great importance to the role of the development of public transportation in solving the problem of urban traffic congestion, and the principle of public transportation priority has become a consensus among various urban management departments in China.
    However, under the same service level, the per capita dynamic occupied road area of ​​public transportation is relatively small, which can greatly save road resources. The per capita dynamic occupied road area ratio of buses, bicycles, and non-public transportation motor vehicles is 1:4:12. At present, in China's urban public transportation system, buses and trams carry more than 80% of the city's passenger volume. For travel within the city, the cost of taking a bus is much lower than that of non-buses. Therefore, for long-distance travel within the city, the total cost of public transportation is the lowest. The flow of people, logistics and motor vehicles in China's cities are increasing rapidly, which exposes the problems of urban traffic.
    The bus charging and information statistics device proposed in this paper can charge different fees to passengers taking different distances, and can also count, store and send the information inside the vehicle.

1 System Function Description
    This paper mainly provides a handheld bus charging and information statistics device to design a new charging device to address the defects of the existing technology. The functions of the device are as follows: 1) Use Zigbee technology to transmit the number of people and location information in the car to the platform for display. 2) Use voice technology to announce the station and the LCD interface digital display to remind the number of people arriving at each station. 3) Use arrays to store information on passenger flow statistics, which is conducive to analyzing passenger flow characteristics and facilitating bus scheduling and route planning. 4) Automatically count the ticket sales amount to facilitate account management after bus operation.
This handheld bus charging and information statistics device mainly includes a wireless transceiver module, a voice broadcast module, a liquid crystal display module, a contactless IC card reader and writer module, a microprocessor and a keyboard input module. Its structural block diagram is shown in Figure 1.

    
    The functions of each structure are as follows:
    1) Wireless module The wireless module mainly sends the information inside the car to the passengers on the platform, so that passengers can know the information inside the car in advance and choose the travel route better; thus avoiding inconvenience caused by excessive crowding of some cars.
    2) The voice module is mainly used to remind passengers and crew members of the arrival information, so that passengers can prepare to get off the car.
    3) The LCD module reminds that the station is about to arrive, displays passenger and car information, and provides a good human-computer exchange interface.
    4) The contactless IC card reader and writer module integrates the functions of the original bus card, and can read and write bus cards, which is convenient for passengers holding cards to board the bus.
    5) The core module of the single-chip microcomputer module device is used to process various data, process various types of information, connect the various modules of the device, and make the entire device work well.
    6) The input module enters passenger information and provides a channel for human-computer exchange.

2 System Hardware Design
    This handheld bus fare collection and information statistics device is mainly used in long-distance buses with ticket sellers. It includes a contactless IC card reader/writer module, a wireless transceiver module, a liquid crystal display module, a keyboard input, a voice broadcast and a microprocessor . The modules of this device use serial port connection communication. The hardware module connection circuit diagram of this device is shown in Figure 2.

    
    The IC card reader/writer module uses a radio frequency card reader/writer module, model wm_17tc, which can read and write 8k and 32k mifare cards. It uses an ARM processor, has fast reading and writing speed, good reading and writing stability, and can upload the card number without polling. It is simple to program, has complete development materials, online technical support, and has a large usage volume. It is the best choice for single-chip microcomputer development.
    The wireless transceiver module uses the CC2430 chip to achieve the required functions. The CC2430/CC2431 chip is produced using a 0.18μm CMOS process. In the receiving and transmitting modes, the current consumption is less than 27 mA or 25 mA respectively. The sleep mode of CC2430/CC2431 and the ultra-short time to switch to the active mode are particularly suitable for applications that require very long battery life.
    The model of the LCD display module is HG1286419. This chip displays monochrome color. The screen size of the LCM LCD module is 3 inches. The contrast of the STN yellow-green mode is adjustable. The resolution is 128x64, the dot pitch is 0.40x0.40 (mm), the response time is 500 ms, the viewing angle is 50°, and the display size is 60.0x32.6 mm2. The dot size: single 5 V/single 3.3 V can be used.
    The voice broadcast uses the ISD4004 chip; the working voltage of this chip is 3 V, and the single-chip recording and playback time is 8 to 16 minutes. The chip uses CMOS technology, which contains an oscillator, an anti-aliasing filter, automatic squelch, and a high-density multi-level flash storage display. The sampling frequency can be 4.0, 5.3, 6.4, and 8.0 kHz. The lower the frequency, the longer the recording and playback time, and the sound quality is reduced. The information on the chip is stored in the flash memory, which can be saved for 100 years in the case of power failure and recorded repeatedly 100,000 times.
    The microprocessor uses ATMEL's AT89S52 single-chip microcomputer, which is a low-power, high-performance CMOS 8-bit microcontroller. It has 8 k in-system programmable Flash memory. It is manufactured using ATMEL's non-volatile memory technology and is fully compatible with the instructions and pins of industrial 80C51 products. The on-chip Flash allows the memory to be programmable in the system and is also suitable for conventional programmers. AT89S52 has the following standard functions: 8 k bytes of Flash, 256 bytes of RAM, 32-bit I/O port lines, timers, 2 data pointers, 3 16-bit timers/counters, 1 6-vector 2-level interrupt structure, full-duplex serial port, on-chip crystal oscillator and clock circuit.
    The keyboard of this device is set as a 4x4 matrix keyboard, which includes numeric keys 0 to 9, correction, confirmation, multiplication, card swipe, broadcast and send. The function settings of each key are as follows: numeric keys 0 to 9 are used as station input and number input, and the clear key is used to clear the record of the last key input. The confirmation key is used to confirm after entering the platform number and the number of people. After pressing the confirmation key, the specific amount can be displayed on the LCD. The multiplication key is an identification key between the input platform and the input number of people. After pressing the platform number, press the multiplication key again, and then press the number of people, which indicates how many people will get off the bus at the platform with the above platform number. The function of the card swipe key is to use the contactless IC card reader and writer module of the device to deduct the specific amount from the IC card after obtaining the amount, so as to realize the reading and writing of the bus card. The function of the announcement is to announce the platform and the number of people who need to get off the bus. Pressing "number + send" indicates the number of people getting on the bus at the platform, and this number is the number of people that the conductor needs to charge. At the same time, when the "send" key is pressed, the wireless data transceiver module is also triggered to send data to the platform.

    3 System Software Design

    The software program of the system mainly includes keyboard input software system, single-chip processing system, and wireless transceiver software system. The keyboard input system collects information and transmits it to the single-chip processing system. The single-chip processes the data and reflects the required information on the LCD display module and the voice broadcast module. At the same time, the information input by the keyboard is also processed, and the useful information is sent to the platform through wireless transmission. The platform can send the received information to the next platform. In this way, the information of the entire bus operation process can be counted so that the bus company can reasonably dispatch the buses.

    The whole program is written in C language, and the main program process is shown in Figure 3.

    
    This device also has the function of counting the passenger flow in the interval for a long time. According to the number of stations the passengers get on and off each time, the information of the interval each time the passengers travel will be accumulated and recorded in the device.
    This device mainly relies on the keyboard module to input information. The software program of the keyboard module is as follows:
    

    The following is the data statistics of a bus trip as shown in Figure 4 and Table 1.

    
    Table 1 clearly shows the situation inside the bus during driving. The bus has the largest passenger flow at the middle stations, and the middle stations also have the largest number of people getting on and off. The information is output to the computer through the interface for analysis. Long-term passenger riding interval statistics are helpful for bus scheduling and bus route planning. At the same time, data on the number of bus travelers and conditions can be collected to analyze the number of people getting on at each station and understand the needs of each station. Using the records and statistics of these data, through nonlinear algorithm analysis, it is even possible to analyze the road conditions, congestion level and whether there are traffic accidents on a certain day and at a certain time.

4 Conclusion
    This handheld bus fare collection device has largely optimized the unreasonableness of the current one-size-fits-all fare collection method, and has provided great convenience for various passengers, especially those traveling close to the bus. At the same time, the statistics and feedback of the information inside the bus have a good reminder and forecasting effect on passengers at the bus station, and the bus company can also reasonably analyze and process the data.