焊缝跟踪中的非接触式超声波传感器的研究

介绍了超声波的物理基础,研制了焊接缝跟踪中的非接触超声波传感器。利用声阻抗匹配技术减小了超声波的传输损耗。设计了聚焦透镜,使声束焦点直径达到了０．５ｍｍ。     

线阵CCD视觉智能焊缝自动跟踪系统的研究

叙述了一种基于线阵ＣＣＤ摄像机为传感器的焊缝自动跟踪系统。对电弧的光学特性进行了研究，得出了正向干扰的结论。并通过传感器的结构设计、滤光、模拟滤波及计算机数字滤波等，解决了弧光干扰问题。系统跟踪精度约为±０．３ｍｍ     

设定轨迹焊缝的高精度CCD跟踪系统

文中介绍了一种以双线阵ＣＣＤ为传感器,激光二极管为光源的主动式的设定轨迹焊缝的高精度ＣＣＤ跟踪系统。此跟踪系统是一种智能形的成像控制器。它对焊缝的识别精度为３５ｕｍ／１０ｍｍ;对设定轨迹焊缝的识别精度高于３．５ｕｍ／１０ｍｍ,此跟踪系统具有对其金属板坯表面的光学性能、角度变化包容性强和抗强光的特点。     

新型非晶态合金位移传感器的研制

介绍了一种新型非接触式位移传感器。该传感器的电路由呈星状分布的１２对以非晶态合金圆丝为芯的线圈组和多谐振荡桥路两个部分所组成,探测一块永久磁铁的位移量。具体介绍了零磁致伸缩系数非晶丝的磁特性、传感器的测量原理及制作技术。该传感器可检测０．３μｍ－１．５ｍｍ的位移量,频响为０－４ｋＨｚ。     

金刚石配比对复合基锯片切割特性的影响

通过生产试验研究了不同金刚石配比复合基圆锯片的切割特性。提出应根据花岗石种类选择金刚石浓度、强度和大小及其相对量。对三刃结构复合基刀头，最佳的金刚石分布密度ＮＡ＝３．０～３．５粒／ｍｍ２，平均间距λ＝１．１～１．３ｍｍ，金刚石浓度４４％～４８％。设计刀头时，应着重考虑通过调整金刚石配比，获得最大切屑厚度和切削力间的合理平衡。     

基于机器视觉的焊接跟踪技术的应用研究

在传统接触式埋弧焊焊缝跟踪系统的基础上,通过摄像机进行焊接坡口复合跟踪。焊接前,对焊接坡口进行数据采集,运用计算机进行图像处理,生成虚拟焊缝识别系统。焊接时,虚拟焊缝识别系统控制焊枪,实现焊缝自动跟踪,从而达到实时和精确．保证了焊接质量。     

超声传感埋弧焊焊缝跟踪的研究

本文提出了一种非接触超声传感埋弧焊焊缝跟踪系统。介绍了超声波传感器及其焊缝跟踪工作原理。在焊缝跟踪中既可以采取检测焊缝坡口的跟踪方法,也可以采取检测磁性胶条的跟踪方法。埋弧焊焊缝跟踪实验表明,该系统具有良好的动态性能和控制精度。该焊缝跟踪方法能够满足压力容器焊接工程的需要。     

自动定心铣槽夹具的研制

自动定心铣槽夹具的研制沈阳冶金专科学校叶旭明，贾向义，曲贞江一、问题的提出在纺织器材中，有一种纺针，其结构如图１所示。从图中可知，纺针截面尺寸为０．５×３ｍｍ，需在０．５ｍｍ宽的纵向面上铣出一宽为０．２６ｍｍ的槽，该槽要求对称度允差０．０１ｍｍ．目前...     

跳线成型机

本文介绍了跳线成型机的结构、原理、技术要求、制造技术、装校及故障处理。线型长度可在５－４２ｍｍ范围内调节，线脚长度为５－８ｍｍ，根据需要选定，适用线径为０．５－０．７ｍｍ。     

基于视觉传感的焊缝跟踪控制系统

介绍了传感器在焊接生产中的应用和视觉传感原理。分析了视觉传感焊缝跟踪系统的原理和特点。提出焊缝图像特征提取方法和流程，以及实施焊缝跟踪控制的方法。系统采用条形光传感方法，选用CCD等光学器件组成焊缝图像传感系统，然后将获取的焊缝图形信息进行识别处理，获得焊接电弧与焊缝中心是否偏离、偏离方向和偏离程度的处理结果。根据这一结果，调整电孤与焊缝中心的相对位置，消除电弧与焊缝的偏离，达到焊接电弧准确跟踪焊缝的目的。     

焊缝跟踪FUZZY—P控制规则的研究

介绍了一种非接触超声传感焊缝跟踪系统。该焊缝跟踪系统采用了Fuzzy—P控制理论,即在大偏差时采用比例控制,在小偏差时采用自调整模糊控制。研究了Fuzzy—P控制的阈值和比例控制的规则。介绍了自调整模糊控制的原理,提出了焊缝跟踪中的双因数自调整模糊控制方法。在试验的基础上确定了双因数的数值。应用公式法生成了模糊控制规则表。同时分析了自调整模糊控制中的比例系数对系统动态特性的影响。通过试验确定了该系统中的比例系数的数值。试验证明,该跟踪系统具有快速、准确、稳定的特点,完全能够满足实际工程应用的需要。     

In situ Measurement of Journal Bearing Lubricant Viscosity by Means of a Novel Ultrasonic Measurement Technique Using Matching Layer

An ultrasonic viscometer was used to measure the circumferential viscosity variation in a journal bearing noninvasively. This sensing technique is based on the reflection of a shear wave at a solid–liquid boundary that depends on the viscosity of the liquid and the acoustic properties of the solid. Very little ultrasonic energy can propagate into the oil at a metal–oil interface because the acoustic mismatch is significant. Interleaving a matching layer between the metal and the lubricant enables accurate ultrasonic viscosity measurements (M. Schirru, et al., Tribology Leters, Vol. 60, No. 3, 2015). This technique has been used to build a miniaturized ultrasonic viscometer that is accommodated inside a journal to obtain the circumferential viscosity profile. Four viscosity regions are identified due to the variations in the localized temperatures and loads. The results are compared with the isothermal solution of the Reynolds equations for hydrodynamic lubricated bearings. The ultrasonic viscometer locates the angle at which the maximum load occurs and the length of the loaded contact with good accuracy. Finally, the viscosity results are used to estimate the frictional power losses. It is shown that over 70% of the total losses in the journal bearing occur in the region where the load is maximum.     

Assessment of combined V/Z clamp-on ultrasonic flow metering

Clamp-on ultrasonic flow metering can provide a non-invasive and portable means for flow measurement. However, it indicates flow rates with low measurement accuracy at low flow velocity in pipe flows. Typical accuracy of the clamp-on ultrasonic flow metering amounts as low as ±1% if the flow velocity in a pipe is greater than 0.5 m/s. The accuracy can be increased greater than ±2% if the flow velocity is lowered smaller than 0.5 m/s. Inner pipe diameter can be also an influential factor in flow metering when the exact value of the inner diameter is not known. The inner pipe diameter cannot be found if the pipe is too large to measure or if there are erosions or adhesions on the inner pipe surface due to small particles in the flow. These shortcomings of the clamp-on ultrasonic flow metering can be overcome by combining two transit times along a Z-shaped and a V-shaped ultrasonic path. This technique is termed combined V/Z clamp-on ultrasonic flow metering. With the water flow standard system in KRISS, this combined technique exhibited intermediate performance between the two flow metering techniques along the Z-shaped and the V-shaped ultrasonic paths. Notably, the combined technique showed better performance (expanded uncertainty less than 0.76%, k = 2) than the two flow metering techniques (1.61% and 1.17%, k = 2) in the flow range of (100–400) m³/h with pipe diameter of 250 mm.     

采用微型排水罩的药H焊丝水下焊接焊缝自动跟踪系统

针对水下焊接图像噪声大、清晰度差的特殊情况,设计并研制成功一套药芯焊丝水下焊接的视觉传感焊缝自动跟踪系统.该系统由视觉传感、图像预处理及偏差识别系统,控制系统和执行机构等组成.采用小波多尺度变换进行水下焊缝图像边缘提取,结果保留大多数的细节,得到有利于焊缝位置特征提取的预处理图像,在一种基于二值图像的焊缝中心位置识别算法计算后,得出焊缝偏差.在理论分析视觉传感焊缝自动跟踪系统模型的基础上,设计满足跟踪精度要求的规则自调整模糊算法.对影响跟踪系统精度的因素进行分析,并采用相应的措施以提高系统的精度.通过药芯焊丝湿法水下焊接焊缝自动跟踪试验表明,采用规则自调整模糊控制能够达到较高的焊缝跟踪精度.在斜线、折线和曲线三种不同形状待焊焊缝的跟踪试验中,系统都能满足药芯焊丝水下自动焊接的要求.经过改进微型排水罩,进行微型排水罩局部干法药芯焊丝水下焊接焊缝跟踪试验,采用规则自调整模糊控制,不仅得到满意的焊缝跟踪效果,还改善焊缝成形质量.     

Ultrasonic fingerprint sensor in underglass prototype using impedance mismatching

Fingerprint imaging is a powerful tool in biometric identification systems. There are several methods for measuring fingerprints, such as optics, capacitive, and ultrasonic methods. The previous ultrasonic imaging techniques have been available in immersion systems which require the hands to be put into water. Also, pulse-echo system in dry condition has coupling layer which is similar acoustic impedance to human tissue or high impedance materials based on waveguide. For fingerprint imaging in the dry state, we propose an ultrasonic imaging technique in underglass by using the impedance mismatch between the fingertip and the solid plate. We present the image results according to the plate material such as acrylic, glass and PDMS. In addition, simulation results based on small 2-D array transducers in a near field suggest the feasibility of compact and fast fingerprint scanning system. Therefore, this work presents feasibility of ultrasonic pulse-echo fingerprint sensing method for dry hand.     

焊缝特征值提取与分析

在主动式视觉传感器的焊缝跟踪系统中，提出了新的接缝图像处理和特征值提取的算法，详述了直线段的调整、线段拟合算法以及接缝特征值的获取。经过误差分析，焊枪与接缝的实际偏差为0.2mm。     

Simulation and experimental study of the sensor emitting frequency for ultrasonic tomography system in a conducting pipe

Ultrasonic tomography techniques provide flow visualization capability, non-invasively and non-intrusively, to enhance the understanding of complex flow processes. There is limited ultrasonic research in tomography imaging systems in the tomogram analysis of fluid flow in a conducting pipe because of a high acoustic impedance mismatch, which means that very little ultrasonic energy can be transmitted through the interface. The majority of industrial pipelines are constructed from metallic composites. Therefore, the development and improvement of ultrasonic measurement methods to accommodate a stainless steel pipe are proposed in this paper. Experimental and simulation distribution studies of the ultrasonic emitting frequency in acrylic versus stainless steel pipes were studied, measured and analyzed. During the simulation, ultrasonic transducers were placed on the surface of the investigated pipe to inspect the ultrasonic sensing field. The distribution of the sound wave acoustic pressure was simulated based on the physical dimensions and parameters of the actual experimental hardware set-up. We developed ultrasonic acoustic models using the finite element method with COMSOL software, and experiments were carried out to validate the simulation results. Finally, by performing the static phantoms tests, a feasibility study of ultrasonic tomography system was presented to investigate the void fraction of liquid column inside a stainless steel pipe.     

自调整比例因子Fuzzy-P控制在焊缝跟踪中的应用

介绍了自调整比例因子Ｆｕｚｚｙ—Ｐ控制理论及其在非接触超声传感焊缝跟踪系统中的应用。试验表明,该系统具有良好的控制特性,能满足焊接工程应用的要求。     

焊缝自动跟踪的发展现状与展望

焊缝自动跟踪在焊接工业中占有极其重要的地位,焊缝自动跟踪的精度和实时性对保证焊接质量有着不可估量的作用。研究如何提高焊缝自动跟踪的精度和降低焊缝自动跟踪系统的成本很有意义。从焊缝跟踪系统的硬件组成和控制方法角度分析了焊缝自动跟踪系统的发展历程,并对该技术的发展趋势进行了分析和展望。