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毕业设计(论文)基于超声波的汽车防撞系统设计 本科学生毕业基于超声波的汽车防撞系统设计系部名称 汽车 专业班级 B06-7班 学生姓名 指导教师 职 称 黑 龙 江 工 程 学 院 二年月The Graduation Design for Bachelors DegreeThe Design of The AutomotiveAnti-collision Systen Based on The UltrasonicDepartmentAutomotive ngineering SpecialtyVehicle ngineeringClassB06-7 The Students Name Qi GuodongSupervisorLv DegangTitlesLecturerHeilongjiang Institute of Technology2010-06Harbin摘 要近年来我国高速公路追尾碰撞事故频繁发生而车载追尾碰撞预警系统在解决高速公路行车安全中具有良好的前景因此引起了研究人员的广泛关注根据超声波测量距离系统给出了汽车测距防撞报警系统的设计该系统能在汽车行驶以及倒车过程中自动检测出汽车与最近障碍物之间的距离 或行车中的车距 并通过L E D 显示出来 当到达极限距离时 系统能发出声光报警 进而提醒司机雌防撞车 在公路街道停车场车库等拥挤狭窄的地方倒车时驾驶员既要前瞻又要后顾稍微不小心就会发生追尾事故据相关调查统计15的汽车碰撞事故是因倒车时汽车的后视能力不良造成的因此增加汽车的后视能力研制汽车后部探测障碍物的倒车雷达便成为近些年来的研究热点安全避免障碍物的前提是快速准确地测量障碍物与汽车之间的距离为此设计了以单片机为核心利用超声波实现无接触测距的倒车雷达系统 超声波一般指频率在20 kHz以上的机械波具有穿透性强衰减小反射能力强等特点工作时超声波发射器不断发射出一系列连续脉冲给测量逻辑电路提供一个短脉冲最后由信号处理装置对接收的信号依据时间差进行处理自动计算出车与障碍物之间的距离超声波测距原理简单成本低制作方便但其传输速度受天气影响较大不能精确测距另外超声波能量与距离的平方成正比衰减因此距离越远灵敏度越低从而使超声波测距方式只适用于较短距离目前国内外一般的超声波测距仪其理想的测量距离为45 m因此大都用于汽车倒车雷达等近距离测距中本文根据声波在空气中传播反射原理以超声波换能器为接口部件介绍了基于TC89C52单片机的超声波测距器该设计由超声波发射模块信号接收模块单片机处理模块数码显示以及声光告警显示模块等部分组成文中详细介绍了测距器的硬件组成检测原理方法以及软件结构超声波发射模块中采用555定时器构成的时基电路接收电路使用SONY公司的CX20106A红外检测专用芯片该芯片常用于38kHz的检波电路文中通过对芯片内部电路的仔细分析设计出能够成功对40kHz超声波检波的硬件电路并且增益可调与传统超声波检波电路相比电路变得精简调试变得相对容易测距器使用数码管显示目标物的距离关键词 汽车防撞报警系统 单片机TC89C52超声波测距ABSTRACTThe accident of automobile rear-end collision has taken place frequently in recent yearsand rear-end collision warning system has good use in improving expressway traffic safetyso the warning system has been paid more attention in the worldThe vehicle collision avoidance alarm apparatus system was introdued according to the ultrasonic measurement distances system The system can automaticanlly xeamine the distance between the back and the nearest obstacle or the distance among cars whicwould be demonstarted through LED that when it arrives the limit distance the systemb can send out the warning and reminds the driver for preventing the vehicle colliding The experimental results showed that the system illustrates a good prospect of application and xetensionHighways streets parking garage and other crowded places narrow reverse the driver should not only forward but also looking back a little rear-end careless accidents can occur According to related statistics 15 of motor vehicle collisions when the vehicle is reversing as the capacity of the latter caused by badSo after the increase of motor vehicles as the ability to detect obstacles on the development of the rear of the car reversing radar has become the research hotspot in recent years Security to avoid obstacles on the premise that the rapid and accurate measurement of obstructions and the distance between motor vehicles To this end the design of a single-chip microcomputer as the core the use of ultrasonic ranging to achieve non-contact reversing radar system Generally refers to ultrasonic frequencies above 20 kHz mechanical waves with penetrating and attenuation of small reflecting the ability and so on Work the ultrasonic transmitter continuously emits a series of consecutive pulses to the measurement of logic circuits to provide a short pulse Finally signal processing devices based on the received signal for processing the time difference automatic calculation of turnout and the distance between obstacles Ultrasonic Ranging simple low cost easy production but the transmission speed by a larger weather can not be precise range In addition the ultrasonic energy and the attenuation is directly proportional to the square of the distance the farther the distance the lower sensitivity and thus Ultrasonic Ranging way so that only apply to a shorter distance At present ultrasonic range finder at home and abroad in general the ideal distance of the measurement 4 5 m thus reversing radar are used in cars such as close range in this paper according to the spread of sound waves in air reflection to ultrasonic transducer interface components based on MCU STC89C52 ultrasonic range-finder Designed by the ultrasonic transmitter module receiver module single-chip processing module a digital display and alarm sound and light display module such as parts the text in detail the range of hardware devices detection theory methods and software architecture The use of ultrasonic transmitter module consisting of 555 time-base timer circuit receiving circuit using the SONY company dedicated CX20106A infrared detecting chip the chip used in the detector circuit 38kHz the text of the chip through the careful analysis of the internal circuit design can successfully 40kHz ultrasonic detection of hardware circuitry and adjustable gain and compared to conventional ultrasonic detection circuit the circuit has become streamlined and easier to debug The use of digital rangefinder display the distance between objectsKey wordsAutomotive anti-co
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