超声波测距仪的制作

设计一种基于AT89S51单片机的超声波测距电路,实现超声波点对点的测量,并采用DS18B20测温,减小温度对超声波传播速度的影响。     

基于单片机STC89C51设计的超声波测距仪

介绍了一种基于单片机STC89C51的超声波测距系统,重点阐述该系统的硬件电路设计和软件设计,并利用温度检测电路有效消除了环境温度变化对传播速度的影响;在数据处理方面,利用最小二乘法得出实际值与测量值之间的补偿公式,从而使系统的测量误差进一步减小;在盲区消隐方面,通过在软件上采用延迟接收技术,有效消除了串绕信号,进一步提高了检测的精度及灵敏度。     

基于μC/OS实时系统的超声波测距系统的设计

本设计是以ATmega16单片机为核心,以UC/OS实时操作系统为软件平台的的低成本、高精度、微型化数字显示的超声波测距系统,实现对前方物体距离的测量。利用超声波传感器对前方物体进行感应,实现无接触式测量,单片机对超声波传感器发射和接收的超声波信号进行分析和处理,并采用DS18B20对系统进行温度补偿,最后将结果显示出来。此系统具有抗干扰能力强、实时性好,经过系统扩展和升级后有很好的应用前景。     

基于单片机的移动空调系统设计

本文给出了一种基于8位单片机设计实现的低功耗移动空调,可根据用户需求实现局部温湿度调节.本系统硬件部分主要包括单片机最小系统、按键操作显示面板、音乐蜂鸣器电路、温度采集电路、开关电源供电电路5个模块.数码管可显示当前温湿度信息,用户可根据需求自定义设置温湿度,实现对环境温湿度的调节及监测.     

超声波油位测量计的设计

介绍了超声波油位测量的原理、电路及测控程序。油位测量计以集成锁相环解码器LM567作为超声波检测元件,以89C2051单片机作为主控元件,可用干电池供电。用超声波测量油位具有非接触、可测低温介质、无机械运动部件、寿命长等优点;以LM567作为超声波检测元件降低了系统的价格,提高超声波捕捉能力;采用单片机控制超声发射与接收,并经温度补偿后计算出油位,使检测具有高智能性。对由于超声声速变化及LM567输出延时引起测量误差的原因作了详细的分析,并提出了提高调整波速精度及调整输出延时的措施。     

基于小波变换的高精度测距系统设计及DSP实现

目的为了解决传统物流行业机器人避障系统中存在的测距精度低、抗干扰性差等问题。方法提出一种基于DSP的温补与小波阈值滤噪的高精度超声测距系统,包括DSP最小系统、超声波传感器、LCD显示模块、温度补偿电路和报警电路等。超声波测距系统通过实时采集环境温度来修正声速值,采用小波阈值变换算法对回波信号进行处理,以提升回波信号的信噪比和起始点锐度。结果应用CCS4.2软件与DSP芯片进行调试、实验,实验表明在距离0～1200 mm内,系统的测量误差为±4 mm。结论采用小波阈值变换算法和温补电路,提高了传统物流机器人避障系统的测距精度。     

一种超声波测距装置的设计与实现

超声波测距技术应用广泛,可应用于汽车倒车、建筑施工工地以及一些工业现场的位置监控等。重点介绍了一种基于单片机的超声波测距装置的设计与实现。包括电路的基本组成及设计原理,超声波测量模块的接口特性及基本功能,软件设计原理以及测量精度的控制等。     

一种高精度卷简纸印刷机振动测试系统的设计

目的为了解决卷筒纸印刷机高速运转时带来的纸带横向振动问题,设计一种高精度卷筒纸印刷机振动测试系统。方法把纸带的横向振动转化为距离测量,采用超声波测距的方法对纸带横向振动量进行测量,利用MSP430单片机自带的AD进行模数转换,把超声波探头输出距离的模拟量转化成数据量输出,显示在液晶屏上,并在PC端设计上位机软件,通过串口通信把测量的数据进行实时显示。结果通过对测试系统的实验,得到了实时的振动数据,经测试,该系统对振动纸张进行检测的精度达到了0.1 mm。结论通过超声波测距方法设计出一套卷筒纸印刷机纸带横向振动测试系统,减小了测量误差,提高了测量精度。     

温度测控系统在全自动包装机中的应用

温度测量与控制系统是全自动包装机不可缺少的温度测控部件,研究要求较高的控制精度和成本较低的测控模块,采用单片机作为数字控制器,并将温度仪表的分散控制转换为集中管理,即双路温度测量和控制于一体,实现真正意义上温度测量及控制的综合管理.克服了传统温度测控系统体积大、测控精度低、电路较复杂及测试困难、价格较高等问题.     

一种实用铂热电阻测温电路

针对铂热电阻传感器测量温度,采用普通稳压源桥式电路而产生非线性误差的问题,运用集成运算放大器工作在线性区域的特性,将恒流源原理应用到测温桥式电路中,并采用集成A/D转换技术的单片机Mega16,通过运算消除了非线性误差,实现了对温度的精确测量.试验结果表明,应用此种测温电路,缩短了单片机计算时同,一定程度上缓解了变送滞后对测量精度的影响,同时降低了误差.     

Compact and high-precision range finder with wide dynamic range andits application

Described is a new range finder using a self-mixing laser diode (SM-LD). The range finder has a high accuracy of ±0.15% and a wide dynamic range of 0.2-1 m using only one sensor head. Compared to ultrasonic range finders, the light beam of this laser range finder can be focused and scanned. The feasibility study shows a possible application of the range finder to a visual sensor of a robot. The proposed range finder has been successfully applied as an infrared (IR) active type range finder of a single-lens reflex camera     

基于手持式激光测距仪的大尺寸测量应用研究

提出了一种基于手持式激光测距仪的大尺寸测量系统及方法.分别通过以手持式激光测距仪和增最式光电编码器为核心的测距及测角单元获得目标测量点的极坐标;再南运动控制器、驱动器、执行电机等构成的伺服控制系统,带动测距仪完成工件的扫描测量;然后在极坐标系下利用最小二乘拟合法进行数据处理,并对一钢质圆环内径进行了测量,测量半径标准差为0.2mm.最后,研究了多站组合测量模式及坐标配准方法.     

基于实时温控系统的鼓式制动器设计

针对货车制动器失效问题设计了一套自动降温双核控制系统制动器,主要是对制动器的温度控制系统、主副双单片机之间通信的软硬件进行了设计,通过温度传感器测试刹车片实时温度,经过信号转换传给单片机进行分析处理,控制继电器淋水阀喷水降低制动器温度,系统加设双单片机进行控制,以提高鼓式制动器的可靠性,保证行车制动安全。     

Use of the maximum probability method for increasing the accuracy of measuring distance by a range finder with frequency modulation of the sounding signal

Analysis of the error for a range finder using the maximum probability method for estimating the range is provided. The effect of noise interference, nonlinearity of the modulation characteristic of the range finder transmitter, parasitic amplitude and phase modulations are evaluated by means of computer simulation. Comparative analysis is given for algorithms of frequency measurement whose use makes it possible to exclude anomalous errors in using the maximum probability method. __________ Translated from Izmeritel’naya Tekhnika, No. 10, pp. 22–26, October, 2006.     

甲基丙烯酸酯类共聚物的超声衰减与声速

用脉冲回波法测定了甲基丙烯酸酯类共聚物的超声衰减与声速。在2.5和5MHz 两种频率下,考察了共聚物超声衰减的温度关系。所得结果与 DSC 法作了比较,共聚物的玻璃化转变温度 T_g 相近。     

3-D measurements using a video camera and a range finder

The geometric modeling of the environment can be carried out by incorporating a video camera range finder. When the quality of images is poor, the range finder, which is mounted on a site and azimuth rotation turret, brings an indispensable complement by measures of depth. The purpose of this paper is to build a geometric database of a three-dimensional (3-D) world in telerobotic applications. The calibration of the sensor system is presented by focusing on models of the range finder and methods we studied to determine them. The experimental results allow the evaluation of models and methods in terms of accuracy and stability. We show how the problem of setting up the 3-D geometric database can be solved by cooperation between human operator and sensors. Two cases are treated for database updating: determining the right position of known objects and inserting an embodying volume to model unknown objects, The experimental results concerning object modeling of cylindrical and polyhedral pattern and are given in terms of volume dimensions and position errors     

Signal Averaging for Noise Reduction in Mobile Robot 3D Measurement System

Accurate information from sensors plays an important role in precision measurement. In such measurement small component of a noise can leads to a large variation in the output of the system. For the applications like multi-sensor data integration, sequences of observations from a number of different sensors are used to integrate into a single best estimate of the state of the environment. For integration of sensory information, sensor registration is considered as an important step. This research work is focused upon reduction of a noise from the repetitive motion of the pan tilt unit. The outcome of this paper is implemented on 3D feature extraction of the mobile robot’s environment using a laser range finder. In the proposed work averaging technique is implemented on the Pan Tilt Unit (PTU) of the system where laser range finder is fixed upon the PTU to extract the 3D feature of the target objects. Registration of the angular displacement of PTU and laser range finder is an essential element of the 3D feature extraction. An experimental result of sensor registration shows a substantial improvement in signal to noise (S/N) ratio and quality of 3D feature extraction is also found improved.     

聚合物多层微流控芯片超声波键合界面温度研究

针对聚合物多层微流控芯片键合,采用热辅助超声波键合方法实现了4层微流控芯片的键合,搭建了多界面温度测试装置,采用埋置热电偶的方法测试了三个被封接界面的温度场,研究了单独超声波作用和热辅助超声波键合法中各界面的温度并进行了比对.温度测试实验结果表明,在顶层热辅助温度70℃、6μm振幅、30kHz频率、100N超声波焊接压力和25s超声波作用时间下,基于热辅助的多层超声波键合方法可以使各键合界面的温度基本一致,从而实现多层微流控器件的多个界面键合质量一致.本文的研究为聚合物微流控器件的超声波多层键合机理研究提供了有益借鉴.     

Influence of Processing Parameters on the Mechanical Properties of a Plasma Radical Nitrided SCM440 Steel

Plasma radical nitriding was performed to harden the surface of SCM440 steel for 1-10 h at temperature range of 450-550℃. This process involved the use of NH3 gas instead of N2 gas employed for the well-established plasma nitriding method. No compound layer was formed during this process except the experiment carried out at 500℃ for 10 h. The main phase produced in the diffusion zone was identified to be γ＇-Fe4（N, C）. A diffusion depth increased with increasing treatment temperature and time （up to about 250 μm）. The surface hardness of radical nitrided layer was about two times higher than that of the untreated surface. The tensile test was carried out to estimate the mechanical properties of surface-hardened SCM440 steel prepared at various plasma radical nitriding treatment time and temperature. The influence of radical nitriding treatment on the tensile strength of the specimen was found to be insignificant. The highest value of the ultimate tensile strength was obtained in the experiment carried out at 500℃ for 1 h. However, the elongation was greatly affected by the radical nitriding processing parameters. The maximum value of elongation, which is equal to about 18.1%, was also obtained under the condition of 500℃ for 1 h.     

Short-range ultrasonic communications in air using quadrature modulation

A study has been undertaken of ultrasonic communications methods in air, using a quadrature modulation method. Simulations were first performed to establish the likely performance of quadrature phase shift keying over the limited bandwidth available in an ultrasonic system. Quadrature phase shift keying modulation was then implemented within an experimental communication system, using capacitive ultrasonic sources and receivers. The results show that such a system is feasible in principle for communications over distances of several meters, using frequencies in the 200 to 400 kHz range.