基于PIC 单片机的通用胎压监测系统的设计外文翻译完成版

毕业设计(论文)外文资料翻译系别：电子信息系专业：通信工程班级：B090310*名：**学号：B********外文出处：网络资源附件： 1. 原文；2. 译文2013年03月原文：Design of Universal TPMS Based on PIC MCU1 IntroductionWith the high speed of road network booming rise，Traffic is developed，Vehicle speed increasing, traffic hazards prevention problems imminent, if because of the tire air-leaks and explosion etc cause traffic accident, many are by tyres work to high temperature or unreasonable tire pressure cause. Research car tires tire pressure monitoring system of modern automobile driving, when the economy, safety and manipulation stability is particularly important practical significance.Hardware constitution and software design method of the universal TPMS are introduced based on PIC MCU.The Design projects of the remote monitoring module based on infineon SPI2 sensor, Microchip rfPIC12F675F with ASK/FSK transmitter and the central receiver module based on Microchip PIC16F877A are described, and hardware circuitry and related programs flowcharts, communication protocols and algorithms are given1The system can measure the tire's interior temperature, instantaneous pressure, voltage and acceleration at anytime, indicate the blooey tires and alarm the driver to avoid the danger.It's of great importance for the popularization and optimization of the TPMS in our country.As authoritative research indicates,the key to Prevent a tire blow-out is maintaining standard tire Pressure and detecting tire fault beforehand.Thus,tire Pressure monitoring becomes meaningful and important.TPMS ( Tire Pressure Monitoring System )，Mainly used in automobile driving real-time monitoring of tyre pressure automatically. Currently developed countries of the tire pressure early-warning system mainly divided into two types: one is JiaJieShi, it through car ABS (anti holding brake system) of the wheel sensor and tyre mechanical model, indirectly calculated for tyre pressure, in order to achieve the purpose; monitor tyre pressure Another kind is direct type, it USES installed in each of the tires with lithium ion battery for power supply pressure sensor to direct measurement of tyre pressure, and through wireless modulation launch to install insearch of monitor, and monitor at any time display various tyre pressure, drivers can intuitivey understanding each tire pressure condition, when the tyre pressure is too low or have leakage, the system will automatically alarm, ensure safety.TPMS as a new type automobile active safety device has been developing rapidly in recent years worldwide. Since it could monitor tire pressure and temperature in real time and alert the driver in time, most traffic accidents caused by flat tire could be avoided to ensure safe driving. The development of tire pressure monitoring systems is reviewed including wheel speed based TPMS, pressure-sensor based TPMS and the coming generation so called non-battery passive TPMS. The components and working mechanism of tire pressure monitoring system are introduced and their merits and defects analyzed and compared with the emphasis on three dominant direct TPMS systems, which are significant in its research and development. The prospect of future development trend is looked ahead. The non-battery TPMS is expected to replace the current one and become the dominant.Wireless signal transmission stability reliability insufficiency, the battery life problem, sensor life and durability problem, is the present T PMS products in the common problem. This system in addition to the sensor, all use Microchip company transceiver chip and micro control processor, low energy consumption, good compatibility and high reliability.And utilize FSK modulator mode, one-way communication mode, improving the system of signal transmission of anti-interference ability. Combined with the system USES the SP12 sensor and monitoring module microprocessor rfPIC12F675F characteristics, adopt LF low-frequency sensei technology, time-sharing send and receive different monitoring module rf signals, thus solving signal collision interference problems, and further energy saving system.2 System RequirementsCause a flat tire and blowout reasons are as follows:①tyre temperature is exorbitant, ②the tyre pressure too big, ③tyres used for a long time, ④ tire overload, ⑤automobile driving too fast.For that car to be in a safe driving condition, drivers must in driving processreal-time understand tyre overpressure, voltage, temperature, etc. Work of the state, the system has the following functions: ①real-time monitor tire pressure, temperature conditions, ②when a tire over-voltage, overheating, automatic sound and light alarm, ③when a tyre in undervoltage condition, corresponding the advantages indicator emit light.3 Hardware DesignThe system was divided into two Parts functionally:tire Pressure measuring block and central monitoring block.The haudware composition was introduced respectively;hardware circuits ofeach block were also presented in this paper.Performance and function of main chips were introduced in detail,such as the sensor SP12,rfPIC12F675(MCU with embedded UHF translmiter),receiver rfRXD0420,PIC16F877,and some other important components like LCM(with a T6963Ccontroller embeded)and ete.To enhance the anti-interference performance and realize low powerConsumption management,an active Low Frequency(LF)wake-up technology was adopted.As for software design,a dynamic time cycle measuring and transmitting method was proposed,and corresponding software arithmetic were given,Combining LF wake-up technology with low power management thought.Taking into consideration severe electromagnetic interference environment of cars,a CRC(Cyelic Redundancy Cheek)arithmetic was added into the communication protocol frames,compositive software filtering methods were also used to enhance the Reliability and preside of the system.This system consists of 5 modules, as shown in figure 1 shows, 4 for tyre within the surveillance modules, a used car, receiving modules. Monitoring module includes sensor and launch module. The sensor to measure the pressure and temperature signals are converted to electric signals through wireless transmitting devices will signal launched. The pressure of the temperature sensor launched by the receiving module can receive and process information,after driving on the display shows that in the course of driving real-time monitor. Showing the way such as LED, LCD or voiceprompt, etc. Can be in accordance with the actualrequirements to design. The tyres monitoring module by central mainframe control module low-frequency LF signal control, settle into work patterns interval time-sharing, rest time dormant.3.1 Hardware design of the master control moduleCar tires unique working environment conditions determines the tire pressure real-time monitoring of the high pressure sensor objectives: wide temperature area, wide voltage range of high accuracy and reliability, Low power requirements; Bad environment wireless signal transmission stability requirement. This system USES Infineon (Infineon) company SP12 tyre pressure temperature acceleration special detection sensor.Because electricity saving and super small-scale demand, so adopted SP12 sensor. SP12 is a kind of piezoelectric resistor sensor, besides can measure pressure and temperature besides,still integrated add speed sensor and voltage preach implement, pressure measurement range 100 ~ 450kPa, temperature measurement range for - 40 ~ + 125. The average power consumption for standby mode only 13 muon A. Has the SPI serial communication mouth, more convenient and controller can be composed SCM system.RfPIC12F675F Microchip company is launched monolithic integrated embedded rf wireless data transmitters 8-bit CMOS micro controller. 1024 x 14 programmable an EPROM, 64 x 8 bytes data storage, 128 x 8 bytes EEPROM data storage, 16 special function of hardware registers, The watchdog timer, low power consumption, sleep patterns, six general I/O functions; Working voltage, low power consumption 55V 25 ~ sleep patterns for 500 mu A current. Embedded UHF add/FSK emitter, rf frequency range for 230 ~ 930MH z,adjustable output power + 6 ~ - 15dBm, add data emission rate 0 ~ 40Kbps, FSK data launch rate 0 ~ 20Kbps; PLL phase-locked VCO, integrated oscillators, and that the circuit only a few external components. Comply with US and European EN300220 'ts 15231 FCC rules.The tyres monitoring module circuit structure as figure shows, by micro controller rfPIC12F675F, pressure and temperature acceleration sensor SP12, antenna network and LF low-frequency awakening of circuit composed of four. Peripheralcomponents and simple circuit, and high reliability. Using the SPI serial data interface SP12 SDO, SCLK and SDI respectively with micro-controller rfPIC12F675F on GP4, GP1 and GP2 connection, because rfPIC12F675F without hardware SPI function, but it is easier for software simulation and SP12 between serial communication. The built-in launch chips contain transmit power amplifier PA, the crystal oscillator, phase-locked VCO is PLL, VCO and pattern logic control blocks circuits, etc. This application system by working frequency for 433M Hz, XTAL pins and FSKOUT pins between join external crystal oscillator clamps its X1 capacitor C1, C2,realize FSK modulation. When DATAFSK=1, FSKOUT for high impedance condition,transmit frequency fMAX; for, When DATAFSK=0, FSKOUT and VSSRF grounding,capacitance C1, C2 in parallel, the transmit frequency for f MIN. This system transmission power for + 2dB, standby current consumption only 10 mu A. During liftoff, VCO output signal is directly into the VCO output to PA, the frequency of crystal oscillator frequency 32 times, taking landuse-dat AFSK the input of digital signal (GP0 for signal input control terminals, and taking landuse-dat AFSK connected) was FSK after power amplifier output,PA to direct drive antenna.The low-frequency sensei module by L and C form a parallel LC resonant circuit used to receive from the host a LF sensei signal. Output terminal with rfPIC12F675FIO port GP3 connected, as the result of a relatively high voltage, comparator output interrupts. Sensei rfPIC12F675F, the sensitivity of 5mV.3.2 Host control module hardware designThe main engine control module by low frequency signals sent circuit and MCU, rf receive circuit and human-computer interface 4 parts. One chooses MICROCHIP companies producing the MCU midrange micro controller PIC16F877A, it has low price, high performance, chip rich resources and high reliability etc. Low frequency signal transmission circuit adopts high-power CMOS chip drive serial driver resonant circuit, sending low frequency signal. Rf receive circuit used MICROCHIP rf receiver chips r fRXD0420, it has small, receiving high sensitivity, strong anti-jamming capability advantages. The man-machine interface circuit using mature module design, use the buttons as input interface, 128 * 64-bit bitmap graphics LCD as output interface.When the circuit in-tune, tandem resonance frequency by formula: f = 1 / (2 L C). As to reduce cost, tandem resonant circuit driver PIC16F877A PWM signal used by its issued function, driven signal incentive series circuit.4 Software designTPMS system is strictly for power requirements, so they need good algorithms for complete system requirements.You should minimize the number of required for TPMS because of power-transmission system.The sensors need little of power consumption in sleep mode.4.1 Tire Monitoring ModuleThe system goes into sleep mode after initialization, waiting for the host module LF low frequency signals emitted wake. Resolved and the LF signal based on the received command, configure the sensor SP12, real-time pressure and temperature data collection, taking the average 100 (false alarm), formed by the data frame transmitted encoded data. Start UHF RF transmitter circuit for data transmission.4.2 Host display moduleHost PIC16F877A after initialization (including the completion of its surrounding RF module and display module initialization), by scanning interval to four tire rotation frequency of 125kHz module sends an LF low frequency signals, in turn will activate and turn the tire module RF receiver interrupt waiting to receive each module sends back the tire temperature data in real time for the decoded analysis, the standard set safety pressure and temperature range, and determines whether the alarm, and transmit data to the liquid crystal screen display. Set reasonable time delay, the loop above flow timeshare acquisition and monitoring the pressure of the tire module temperature conditions. Thus the fundamental solution to the problem of collisions with the frequency signal interference, but also to save power provides an effective control methods. Fully into account the energy and real-time monitoring of these two factors, the system initiates a set interval 200ms LF wakeup operations.4.3 Communication ProtocolIn order to achieve four tire module and the central host to receive module for wireless communication, a communication protocol must be developed. Manchester encoding used here, FSK Modulation and 9600BP / S transfer rate. Tire module sends data in the form of data frames, when the tire module rfPIC12F675F determine when to send data, the leading bit of the data frame by sending a wake up the host receiver module then sends ID, pressure, temperature, status, parity, and stop bits.5 SummaryThis paper proposes a new method of calculating target distance.This method does not need to obtain accurate focusing of the image, you only need a normal CCD camera to get the distance information, so the system structure is simple, easy to operate .While using a single camer a from selecting and feature points for image registration, in favour of real-time system implementation;And the algorithm to take full advantage of all color information for the image, avoid using grayscale image information loss-free .Experiments show that its effect is better than using a grayscale image to obtain depth information.译文：基于PIC 单片机的通用胎压监测系统的设计1 引言随着高速公路网的蓬勃兴起，交通的日趋发达，车辆行驶速度的不断攀升，交通隐患的防范问题迫在眉睫，如因车胎漏气和爆炸等原因造成的交通事故，很多是由轮胎的工作温度过高或者不合理胎压引起的。