城市公交车无线自动报站系统外文文献原稿和译文(共6页).doc

精选优质文档-----倾情为你奉上The bus stops system automatically 1、The bus is automatically stops the background and significance The people of car out for provides convenient service, while the bus stops directly affect the quality of the service. Traditional stops by the crew artificially, and in this way because of its poor and working intensity effect is too great, in many big cities have been eliminated. In recent years, with the development of science and technology progress and microcomputer technology in many fields has been widely used. In the acoustic field, with various pronunciation chip microcomputer technology, can complete combined speech synthesis technology, makes the car stops controller is realized for citizens becomes possible, and thus provide a more personalized service. In view of the traditional bus stops system deficiency, combined with the use of public transport vehicle characteristics and practical operating environment, the design of a single-chip microcomputer control bus stops system automatically. The bus stops the design of automatic device is mainly to compensate for changing the traditional voice stops device must have driver control can work backward way, pitted, automatic station broadcasts six-foot-tall service term for the public and provide more humanized more perfect service. 2. The system design of each component This system is designed hardware circuit design part: use AT89C51 as controller, through ISD4004 pronunciation chip establish speech, forming a variety of information and use the voice messages broadcast speech information and tips amplifier, and using speech, LED digital display for standing count. When the bus arrived at one site, use the keyboard control the system work, through the yukon voice circuits output speech information and tips, stood in several information LED digital tube display. The whole system hardware design including keyboard circuit and reset circuit, display driver circuit, display circuit, memory expansion circuit module. In order to realize the bus stops, namely in speech automatic six-foot-tall; and when voice prompt information and automatic reporting service term, while utilizing of LED dot matrix circuit Chinese displaying. This design is required to exploit the AT89C51 as the master control circuit design of chips, auxiliary circuit requirements including voice circuits, Chinese dot matrix display circuit, the power supply circuit, etc. The CPU control and control signals, pronunciation chip, output indicator light component. The bus station is automatically stops the car wheel design, to count the pulse Angle, will count value compared with preset value, can determine moments, attain the precise automatically stops the purpose. USES AT89C51 as main control chip, combining to foreign pulse count ISD4004 output voice pronunciation chip. System consists of pulse detection, pulse count, CPU control and control signals, pronunciation chip, output indicator light component. About AT89C51 chip: AT89C51 it mainly consists of for the following parts: 1 eight central processing unit (CPU), piece you in memory, the pieces (Flash RAM, 4 of 8 bits two-way addressable I/O port, 1 full-duplex UART (general asynchronous receiver transmitter) serial interface, 2 16 timer/counters, multiple priority nested interrupt structure, and a piece inside oscillator and clock circuit. In AT89C51 structure, the most striking characteristics of internal contains Flash memory is, while in other aspects of the structure of the Intel corporation, the and the structure of the 8051 no much difference. Main performance: 1. With MCS - 51 compatible 2. 4K bytes programmable flashing memory Life expectancy: 1000 times to write/wipe cycle Data retention time: 10 years 3. All the static job: 0Hz - 24Hz 4. Tertiary program memory lock5. 128 * 8 bits inside 6. 32 programmable I/O lines 7. Two 16 timers, counter 8. Five interrupt source 9. Programmable serial channels 10. Slice clock circuit oscillator and withinThe design of pulse detection circuit: The design of the key is that the rotor turn lap count, considering the vehicles will be running in a complex environment, and the hall componets are resistant to vibrate, afraid of dust, grease, water vapor and salt fog the advantages of the pollution or corrosion, so adopt reliable hall element DN6848 as signal acquisition device, again by photoelectric couplers 4N25 input to microcontroller. Photoelectric coupler current transmission 10% ~ 25%, than for less than 10us response time. About speech output circuit design This series of chip required by the microprocessor or micro controller series through serial peripheral interfaces and serial interface addressing and control. The recording data is stored method of multistage storage is through ISD patent technology implementation, with sound and audio signals directly in the natural form of solid state memory, thus providing high quality replay。