毕业论文--超声波测距系统硬件设计.docVIP

目录 摘要 I Abstract II 1. 绪论 1 2. 方案论证与整体设计思想 5 2.1方案论证 5 2.1.1测距方法的方案论证 5 2.1.2超声波发送的方案论证 6 2.1.3主要控制器件的方案论证 6 2.1.4测温电路的方案论证 7 2.2主要元件的选择 8 2.2.1主控芯片的选择； 8 2.2.2超声波传感器的选择 9 2.2.3温度传感器的选择。 9 2.3 整体设计思想 10 3. 发射部分 12 3.1发射部分的整体框图 12 3.2脉冲调制信号产生电路. 12 3.3发射驱动电路 14 4. 接收部分 16 4.1 接收部分的整体框图 16 4.2 前置放大电路 16 4.3带通滤波电路 17 4.4中间级放大电路 18 4.5 中断信号产生电路 20 5. 智能温度传感器DS18B20 23 5.1 DS18B20的内部结构 23 5.2 DS18B20的测温原理 26 5.3DS18B20与单片机的典型接口设计 28 6. 单片机外围电路 29 6.1单片机整体电路 29 6.2单片机外围电路介绍 30 结论 31 参考文献 33 附录A 34 附录B 35 致谢 36 超声波测距系统硬件设计 摘要 文介绍了一种以单片机AT89S52为核心控制器件，用LED直接显示测量距离的超声波测距仪的设计方法。在设计中采用单片机AT89S52控制555定时器产生脉冲调制信号，进行超声波信号的发送。通过检测超声波信号从发送到接收的时间间隔，计算出测量距离。由于超声波传播速度受温度的影响很大，所以系统中还采用了温度传感器DS18B20来检测环境温度，对超声波的传播速度进行温度补偿，提高测量精度。 在设计中为了达到测量误差小于测量量程5%的精度要求，在硬件设计过程中采用了带通滤波，仪表放大等电路来消除干扰信号对测量精度的影响。同时采用RS触发器来消除盲区引起的测量误差，提高了测量精度。通过实际测量证明该系统工作稳定，性能良好，测量精度较高。可适用于工业测距，距离开关，汽车安全，智能机器人等，有非常广阔的应用前景。 Abstract In this article, it was introduced that one design method of ultrasonic range finder that distance was demonstrated directly with LED and one-chip microcomputer is the core component. The one-chip computer AT89S52 was used to transmit ultrasonic wave signal by controlling 555 timers to produce the impulse modulation signal in this design. The distance was worked out when time-gap that ultrasonic wave was transmitted from transmission to receiving was gained .Because the speed that ultrasonic wave was propagated was influenced seriously by temperature, therefore temperature sensor of DS18B20 was also used to correct the error value of finding range under various kinds of environment temperature by examine the ambient temperature in this system. So the measuring accuracy was improved. In order to achieve the precision request that measuring error is smaller than the survey measuring range’s 5%, has used the band-pass filter and circuit of appliance enlargement in the hardware design to reduce influence of interference signal in this design. At the same time, the measuring accuracy was im