英语翻译摘要传统的机械式车速表是由轮子输出动力,经驱动蜗轮轴带动软轴头端同步转动,使与软轴另一端固定的永久磁铁跟着同步转

　　Abstract
　　Traditional mechanical speedometer output power from the wheels,worm gear drive shaft driven by the flexible shaft tip synchronous rotation,so that the other side of the fixed and flexible shaft of the permanent magnet synchronous rotation followed,resulting in rotating magnetic field of the magnetic field in the rotating disk,it disk rotation speed so that,together with the table pointer to the occurrence of the deflection.When the electromagnetic torque and resistance torque generated by the spring balance,the indicators remain at a deflection point of view.Pointer deflection is proportional to angle and speed,so that its speed can be used.
　　Mechanical defects in the speed table is obvious.As the dial indicator shaft deflection is proportional to the degree of rotation of the magnetic force generated,when a lower speed,the magnetic force smaller,with larger fluctuations in speed changes.Therefore,the low-speed table pointer when the swing's intense,measurement and display accuracy is not high.The rear engine vehicle,the speedometer pointer to the deflection by the transmission power transmitted by flexible shaft,such as driver's cab,a long flexible shaft arrangement is bound to,how long will such a rotating shaft from the structural arrangement of properly,is certainly a very difficult task.In addition,the traditional mechanical speedometer all the defects,the instrument has gradually been eliminated
　　This article describes the design of the speed and odometer to the smallest single-chip microcomputer system and the Hall sensor at the core.Different speed sensor into the different frequency pulse signal input to the control and calculation of single-chip,and then show that the use of LED modules,making the speed of electric bicycle mileage data and visual display to the user.
　　The system by the Hall sensor,RC filter circuit,microcontroller AT89S8252,systematic LED display module,data storage circuit.Hall sensor which includes signal amplification and waveform shaping.Treatment of test signals to enlarge the purpose of treatment is to reduce the magnitude of the signal measurement requirements; wave transformation and wave shaping circuit is used to convert the amplified signal can be connected with the single-chip TTL signal; through the MCU can set up internal Timer T1 input pin T0 pulse control,this can be calculated accurately pin T0 added to the unit time detected pulses; design speed display using LED modules,obtained through the conversion rate of mileage using I2C bus and through E2PROM to store not only save the required mouth-line single-chip microcomputer and peripheral devices,as well as simplifying the display part of the software programming
　　In this paper,among the first to design the necessary equipment odometer detail of the design problems are described; the latter part of the hardware and software design and the realization of made a serious analysis; and then gives the system modeling process and the corresponding system model,on the basis of a control simulation,and simulation results are compared.
　　The odometer of the design is simple in structure,low costs,and show the clear advantages of stable and reliable.And can be expanded to include the function of table speed,and more convenient to understand the situation you are now.
　　Key words:single-chip,LED digital tube,Hall sensor,EEPROM memory.

　　Abstract
　　Traditional mechanical speedometer output power from the wheels, worm gear drive shaft driven by the flexible shaft tip synchronous rotation, so that the other side of the fixed and f...