离计算、结果的输出等工作。5、结论 对所要求测量范围 30cm200cm 内的平面物体做了多次测量发现，其最大误差为0.5cm，且重复性好。可见基于单片机设计的超声波测距系统具有硬件结构简单、工作可靠、测量误差小等特点。因此，它不仅可用于移动机器人，还可用在其它检测系统中。思考：至于为什么接收不用晶体管做放大电路呢，因为放大倍数搞不好，集成放大电路，还带自动电平增益控制，放大倍数为 76dB，中心频率是 38k 到 40k，刚好是超声波传感器的谐振频率 。 ‐5‐ 毕业设计（论文）英文翻译 参考文献1. Fox J.D. Khuri-Yakub B.T. and Kino G.S. quotHigh Frequency Acoustic WaveMeasurement in Airquot in Proceedings of IEEE 1983 Ultrasonic Symposium October 31-2November 1983 Atlanta GA pp. 581-4.2. Martin Abreu J.M. Ceres R. and Freire T. quotUltrasonic Ranging: Envelope AnalysisGives Improved Accuracyquot Sensor Review Vol. 12 No. 1 1992 pp. 17-21.3. Parrilla M. Anaya J.J. and Fritsch C. quotDigital Signal Processing Techniques for HighAccuracy Ultrasonic Range Measurementsquot IEEE Transactions: Instrumentation andMeasurement Vol. 40 No. 4 August 1991 pp. 759-63.4. Canali C. Cicco G.D. Mortem B. Prudenziati M. and Taron A. quotA TemperatureCompensated Ultrasonic Sensor Operating in Air for Distance and ProximityMeasurementquot IEEE Transaction on Industry Electronics Vol. IE-29 No. 4 1982 pp.336-41. ‐6‐ 毕业设
计（论文）英文翻译 Ultrasonic ranging system design Publicationtitle: Sensor Review. Bradford: 1993. Vol. 13ABSTRACT：Ultrasonic ranging technology has wide using worth in many fields，such as the industriallocale，vehicle navigation and sonar engineering．Now it has been used in level measurement，self-guided autonomous vehicles fieldwork robots automotive navigation，air and underwater targetdetection，identification，location and so on．So there is an important practicing meaning to learn theranging theory and ways deeply. To improve the precision of the ultrasonic ranging system in hand，satisfy the request of the engineering personnel for the ranging precision，the bound and the usage，aportable ultrasonic ranging system based on the single chip processor was developed．Keywords：Ultrasound r，Ranging System，Single Chip
Processor1.Introductive With the development of science and technology the improvement of peoplesstandard of living speeding up the development and construction of the city. urbandrainage system have greatly developed their situation is constantly improving. Howeverdue to historical reasons many unpredictable factors in the synthesis of her time the citydrainage system. In particular drainage system often lags behind urban construction.Therefore there are often
good building excavation has been building facilities to upgradethe drainage system phenomenon. It brought to the city sewage and it is clear to the citysewage and drainage culvert in the sewage treatment system. comfort is very important topeoples lives. Mobile robots designed to clear the drainage culvert and the automaticcontrol system Free sewage culvert clear guarantee robot the robot is designed to clear theculvert sewage to the core. Control System is the core component of the development ofultrasonic range finder. Therefore it is very important to design a good ultrasonic rangefinder.2. A principle of ultrasonic distance measurement ‐7‐ 毕业设计（论文）英文翻译2.1 The principle of piezoelectric ultrasonic generator Piezoelectric ultrasonic generator is the use of piezoelectric crystal resonators to work.Ultrasonic generator the internal structure as shown it has two piezoelectric chip and aresonance plate. When its two plus pulse signal the frequency equal to the
intrinsicpiezoelectric oscillation frequency chip the chip will happen piezoelectric resonance andpromote the development of plate vibration resonance ultrasound is generated. Converselyif the two are not inter-electrode voltage when the board received ultrasonic resonance itwill
be for vibration suppression of piezoelectric chip the mechanical energy is convertedto electrical signals then it becomes the ultrasonic receiver. The traditional way to determine the moment of the echos arrival is based onthresholding the received signal with a fixed reference. The threshold is chosen well abovethe noise level whereas the moment of arrival of an echo is defined as the first moment theecho signal surpasses that threshold. The intensity of an echo reflecting from an objectstrongly depends on the objects nature size and distance from the sensor. Further the timeinterval from the echos starting point to the moment when it surpasses the thresholdchanges with the intensity of the echo. As a consequence a considerable error may occurEven two echoes with different intensities arriving exactly at the same time will surpass thethreshold at different moments. The stronger one will surpass the threshold earlier than theweaker so it will be considered as belonging to a nearer object.2.2The principle of ultrasonic distance measurement Ultrasonic transmitter in a direction to launch ultrasound in the moment to launch thebeginning of time at the same time the spread of ultrasound in the air obstacles on his wayto return immediately the ultrasonic reflected wave received by the
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