外文翻譯--基于at89c2051 的智能型汽車防撞報警器的設計

1、An AT89C2051 Based Intelligent Proxim ityWarning Indicator for AutomobileIt introduces the function and characteristicsofm icrocontrollerAT89C2051 Based on it. A low cost high-accuracy microm iniaturization and digital d

2、isplay proxim ity warning indicator for automobile is designed. The indicatormeasures the distance and speed of the automobile, with ultrasonicwave and integrated Hall unit and controls the system by the real-time cont

3、rol and Data-processing of the microcontroller Moreover. its circuitry principle is introduced in detail as well as its software design.Along with modern rhythm of life speeding up, the frequency which the traffic accide

4、nt occurred is increasing, for enhances the security of automobile movement. This article introduced one kind of alarm system based on monolithic integrated circuit controls the automobile guards against hitting. This eq

5、uipment the monolithic integratedcircuit real-time control and the data processing function, with the ultrasonic wave range finder technology, the sensor technologyunifies, may examine in the automobile movement rear ar

6、ea the obstacle and the automobile distance and the automobile vehicle speed, reveals the installment demonstration distance through the number, and is away from far and near the situation by the sound production elect

7、riccircuit basis to send out the warning sound. The ultrasonic ranging principle is, after unceasingly examines the ultrasonic wave launch to meet the echo which the obstacle reflects, thus determines the launch ultrason

8、ic wave and receives the echo the time difference. Then extracts is away from S=C×T/2, C is the ultrasonic wave wave velocity, under the normal temperature takes is 344 m/s. After sonic speed determination, so long

9、 as obtains the ultrasonic wave round-trip the time, then obtains the distance.The automobile vehicle speed survey is integrates the sensor through Hall to realize. Namely, is loaded with the permanent magnet the turntab

10、le input axis and the wheel revolution axis is connected, when the wheel rotates, the turntable along with it rotation, this time, on the turn table permanent magnet can integrate the sensor after Hall, thus integrates

11、the sensor in Hall the input end to obtain a magnetism signal, if the turntable does not stop the rotation, Hall integratesthe sensor then to be able to output the rotational speed signal. It can be said that, to the a

12、utomobile vehicle speed survey essence into the rotational speed signal frequency survey.AT89C2051 is a low power loss, the high performance 8 CMOS microprocessor, is compatible with the MCS-51 series instruction collec

13、tion and the pin, has following characteristic: 128 bytes internal RAM, 2 K bytes EPROM, fifteen I/O line, two sixteen-fixed time counters, five two-level of interrupt sources, one entire duplex serial port, internal p

14、recisely simulates the comparator and internal swingming, the low power loss leaves unused and falls the electricity pattern. The working voltage scope 4.25 ~ 5.5 V, the operating frequency takes12 MHz.In AT89C2051, two

15、 sixteen-fixed time/counters registers is T0 and T1, make fixed time/counters, may count the machine cycle, counts the frequency for the oscilation frequency 1/12; When makes the counter, may appears to on exterior inp

16、ut pin P3.4/T0 and P3.5/T1 from 1 to 0 changes when increase 1, counts the frequency for way, when ultrasonic wave launch starts to count, after pin P3.2 receives the echo, stops counting, T0 times namely for the ultras

17、onic wave round-trip transmission time, the monolithic integrated circuit carries on processing to this data, then determines the distance.The internal timer T1 work is counting the way, counts by P3.5 pin input pulse si

18、gnal control T1, counts the value by T1 to determine the automobile the rotational speed. The monolithic integrated circuit basis measured is away from and the vehicle speed carries on thecomparison, judges whether actu

19、ates the alarm circuit to report to thepolice, like hypothesis: When the vehicle speed is smaller or equal to 30km/s, the safe distance should be bigger than is equal to 1m; When the vehicle speed is smaller or equal t

20、o 80 km/s, the safe distance should be bigger than is equal to 2m; When the vehicle speed is bigger than 80 km/ s, the safe distance should bebigger than is equal to 5m .This installment control software must complete th

21、e system initialization, the control trigger pulse signal launch and the receive, according to fixed time the count-down obstacle distance, according to counts the frequency computation automobile vehicle speed, judges m

22、easured is away from whether in the margin for safety which the vehicle speed corresponds, and according to calculates has the BCD code and the corresponding frequency pulse signal with the judgement result, actuates th