共查询到20条相似文献,搜索用时 15 毫秒
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介绍了一种基于PIC单片机的避障机器人超声波测距系统,该系统通过测量输出脉冲宽度(即发射与接收超声波的时间间隔)来测量障碍物与避障机器人之间的距离,从而控制机器人电机的停、转,达到对机器人的自动控制。并对实验结果进行了分析,基本可以达到实际应用的目的。该系统包括门控电路、放大电路及信号筛选、整形电路,具有硬件简单、工作可靠、测距误差小等特点。 相似文献
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介绍了基于脉冲超声波聚焦技术的压电陶瓷激波发生器结构和工作原理。建立了以微型计算机为核心的试验测试系统。对激波能量的基本影响因素和控制规律进行了试验研究。研究了声阻抗匹配、电阻抗匹配、前过渡匹配层、电激励波形等影响单元换能器发射脉冲超声波的各项技术。为今后的研究工作提供了理论依据和试验基础。 相似文献
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针对声波测井压电陶瓷换能器容性大的负载特性,采用单片机和CPLD相结合的方式设计了一种输出幅度高、驱动电流大、脉冲宽度可调的双通道高压脉冲信号源。系统利用C8051F350单片机及PWM控制芯片MM33060A,并结合自耦变压器反激式升压电路将12 V直流供电电压抬升至300 V。采用CPLD产生精确的频率可控的300 V脉冲电压,利用脉冲变压器进一步提升电压,得到了上千伏的高压激励脉冲。实验结果标明,设计的信号源在激励压电陶瓷换能器时,负载上得到了比较理想的波形,波形上升沿陡峭,无拖尾及振荡现象,满足实际应用需求。 相似文献
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介绍了一种基于CAN总线的嵌入式超声波测距仪设计,在该系统中主要采用微处理器作为控制核心,运用超声波传感器及相应的放大电路组成超声波的发射与接收电路.在发送与接收超声波信号时,通过微处理器和程序计算出发送与接收超声波的时间差,再由已知的超声波传播速度,求出障碍物与超声波传感器之间的距离.同时,微处理器可以对测量的数据结果进行处理后送到LED显示器进行显示,也可以通过CAN总线将数据传送给上位机,实现远程监视和网络控制的智能化仪表功能. 相似文献
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低频高能超声收发电路系统是为解决粗晶材料中含有空隙时,声波能量高衰减造成无法检测与达不到规定检测深度而设计的。该电路系统主要由发射电路、接收电路和发射接收转换电路三部分组成。通过可编程器件STC89C52可改变激励脉冲频率、相位和数目,以根据需要产生kHz级低频超声,结合双极性脉冲变压电路可产生高激发能量。实践表明:该电路系统可用于声衰减高的接触式无损检测场合,同时电路具有高Q值和高灵敏度,抗干扰能力强等特点。 相似文献
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通过对海洋环鸣法声速仪的深入分析,阐述环鸣法声速仪的工作原理,设计了1种的超声波发射/接收电路。重点研究了高压窄带脉冲产生电路、MOS管驱动电路以及匹配网络。对研制的电路进行了性能分析,所有的电子器件均无过热现象,获得了较为理想的超声波。整个电路结构简单,成本相对低廉,操作安全,易于模块化实现,符合待定检测的要求。 相似文献
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In this paper, a picosecond impulse generator using step recovery diodes (SRDs) is presented. In order to reduce the pulse width of an impulse generator, we employed a cascaded SRD pulse-shaping circuit. A short impulse generation is confirmed in numerical simulation of a time-transient circuit simulator. Measurements show that the measured pulse width of the cascaded SRD impulse generator is 250 ps at 10% of the peak amplitude, which is improved by 85 ps compared with a conventional SRD impulse generator. 相似文献
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提出一种利用SOPC (System on a Programmable Chip)技术及DDS技术开发信号发生器的方法,只需用一片FPGA芯片加必要的外围电路就可以实现函数信号发生器的功能.所设计的信号发生器可以输出正弦波、三角波、矩形波3种波形,且矩形波的占空比可调.每种输出波形的频率最小值为1 Hz,最小步进值为1 Hz. 相似文献
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A. V. Ponomarev A. S. Pudikov A. I. Gusev M. S. Pedos 《Instruments and Experimental Techniques》2014,57(2):135-139
A solid-state high-frequency damping oscillation pulse generator based on a pulsed excitation circuit is designed. The frequency of high-frequency oscillations reaches units of megahertz with a pulse repetition rate in the continuous mode of up to 1 kHz. The frequency of output pulses determines the power consumption from the supply mains that does not exceed 700 W. In this case, the peak power of output pulses reaches hundreds of kilowatts with a generator efficiency of up to 65%, if the optimal resistive load is used. The main area of the generator application is the generation of low-temperature atmospheric-pressure plasma. 相似文献
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Huang YP Wang JS Huang KN Ho CT Huang JD Young MS 《The Review of scientific instruments》2007,78(6):065103
A novel microcomputer-based ultrasonic distance measurement system is presented. This study proposes an efficient algorithm which combines both the amplitude modulation (AM) and the phase modulation (PM) of the pulse-echo technique. The proposed system can reduce error caused by inertia delay and amplitude attenuation effect when using the AM and PM envelope square wave form (APESW). The APESW ultrasonic driving wave form causes a phase inversion phenomenon in the relative wave form of the receiver. The phase inversion phenomenon sufficiently identifies the "measurement pulse" in the received wave forms, which can be used for accurate time-of-flight (TOF) measurement. In addition, combining a countertechnique to compute the phase shifts of the last cycle for TOF, the presented system can obtain distance resolution of 0.1% of the wavelength corresponding to the 40 kHz frequency of the ultrasonic wave. The standard uncertainty of the proposed distance measurement system is found to be 0.2 mm at a range of 50-500 mm. The APESW signal generator and phase detector of this measuring system are designed on a complex programmable logic device, which is used to govern the TOF measurement and send the data to a personal computer for distance calibration and examination. The main advantages of this APESW system are high resolution, low cost, narrow bandwidth requirement, and ease of implementation. 相似文献
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为满足海底沉积物声学特性的实验室测量,该文基于DDS专用芯片AD9850,设计了一种高精度可编程的超声波信号发生器。介绍了AD9850的基本原理和工作特点,给出了单片机与AD9850的硬件接口模块、功率放大电路模块。运用此信号发生器产生的超声波对海底沉积物柱状样品的声特性进行实验测量,并对实验结果进行分析。 相似文献
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以单片机为核心,设计了一个超低频任意函数信号发生器.该信号发生器采用数字波形合成技术,通过硬件电路和软件程序相结合,可输出自定义波形,如正弦波、三角波、方波和锯齿波及其他任意波形,且超低频的功能突出.详细介绍了任意波形的生成原理、硬件电路设计以及软件系统部分的设计原理.波形的频率和幅值在一定范围内可任意改变.与传统信号发生器只有固定的几种输出波形相比,具有输出波形的任意化和低频精度高的特点. 相似文献
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Beziuk G 《The Review of scientific instruments》2011,82(7):074705
A subnanosecond pulse generator based on two Blumlein pulse-forming lines (PFL) is investigated. The width of an output pulse of the generator does not depend on its load resistance in contrast to the basic structure of a Blumlein PFL. Therefore, the generator does not need to be matched to load in order to avoid the reflections. The circuit design was simulated by PSPICE simulation software. The reported subnanosecond pulser was made using a microstrip technique. A comparison between measured and simulated results shows good agreement. 相似文献
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张步超 《仪器仪表标准化与计量》2005,(6):35-36
介绍一种高精度的超声波厚度测量仪系统。论述系统的测量原理、系统构成,给出脉冲发生器、同步电路、计数器等电路的设计。总结系统的实验结果和系统特点。 相似文献
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小试件材料弹性常数超声测量系统的研制 总被引:2,自引:0,他引:2
本文针对小试件块体纳米材料力学性能测试的特殊需求,设计开发了一套小试件材料弹性常数超声精密测量系统。系统由线聚焦PVDF探头、四轴精密运动平台、NI PXI总线嵌入式控制器、超声脉冲产生/接收仪以及数字记忆示波器组成。系统基于声学显微镜技术,利用同时测定纵波和漏表面波波速来表征材料的弹性常数等,既适用于各向同性材料,又适用于各向异性材料。试验结果表明本测量系统工作良好,能够满足试验要求,为进一步评价小试件纳米材料制备工艺和表征纳米材料的力学性能奠定了基础。 相似文献
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A self-integrating Rogowski coil with magnetic core is investigated for accurate measurement of high-impulse current in this paper. Usually, the distributed parameters of Rogowski coil generate deleterious high-frequency resonant signal parasitizing in the useful signal of the coil circuit. Damping resistors can be used to eliminate the parasitic resonant component of the signal. In this paper, damping effects of the damping resistors on the output signal of Rogowski coil are studied in detail. According to circuit theory, approximate circuit equations of Rogowski coil with lumped parameters in simplification are put forward. Response signal of coil is analyzed and a reasonable method for choosing damping resistance is also presented. When the 50 Ω damping resistance is used, the amplitude of parasitic resonant signal has been damped by 5.7 times in contrast to the situation without any damping resistance. Result of Pspice circuit simulation corresponds to the theoretical calculation result. A standard 10 ns square pulse has been used to calibrate the coil signal before and after the damping resistors soldering on the coil, respectively. Experimental results show that the response time of the coil with magnetic core is 1.1 ns and the parasitic resonance in the coil signal is almost eliminated. The coil can accurately detect high-pulse current at kA range. 相似文献