共查询到18条相似文献,搜索用时 62 毫秒
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焊接电弧声信号降噪技术 总被引:3,自引:1,他引:2
焊接电弧声作为焊接过程质量监控潜在的源信号之一,在传感、转换以及传输等过程极易受到设备、环境噪声的污染,从硬件、软件两个方面分别对其进行降噪处理.硬件方面包括低噪声传声器、接地装置、消除直流偏移的交流耦合、采用仪器放大器、抗混叠滤波以及屏蔽电缆等措施;软件方面运用基于多尺度分析理论的 Mallat 算法,实现了基于 LabVIEW 的电弧声小波分解重构降噪处理.结果表明,电弧声信号经硬件、软件降噪后,不仅"毛刺"得到有效滤除,而且波形突变部分更加清晰,信噪比大幅度提高,为后续电弧声信号特征分析提取以及利用电弧声来监控焊接质量提供技术基础.Abstract: Arc sound is well known as one of the potential source signals for controlling of welding process quality, which is vulnerable to noise pollution by equipment and environment in sensing, conversing and transmission. Therefore, it is necessary to reduce arc sound noise by hardware and software. Hardware measures include low-noise microphone, grounding devices, eliminating the DC offset exchange coupling, equipment amplifiers, anti-alias filtering and shielding cables, etc. In terms of software, by using Mallat algorithm based on principle of multi-resolution, the noise of arc sound signal is reduced via wavelet decomposition and reconstruction based on LabVIEW. The results show that the burr of arc sound is effectively filtered out, the mutations of waveform are clearer and the noise ratio is obviously increased. The reducing noise means provide technical basis for extracting characteristics of arc signal and monitoring welding quality via arc signal. 相似文献
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压力管道声发射泄漏检测 总被引:10,自引:2,他引:8
工艺设备及管道泄漏的声发射检测是声发射技术应用的一个重要方面。经调查,金陵石化某厂盛装毒气HF的带压管线由于腐蚀泄漏而引起的停产、事故处理等损失每天达40万元。多年来,科学工作者不断进行声发射泄漏检测的原理、机理、仪器设计等方面的研究。 相似文献
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对管道MIG焊双通道信号采集和特征分析做了初步研究.因管道其内部是一个相对狭小密闭的空间,回声的干扰相对较大,经过对采集的双通道电弧声信号进行ICA信号分离,对分离后的信号做小波降噪处理,信噪比得到明显提高.对降噪后的信号从时域、频域和时频域角度,综合分析管内和管外电弧声信号与焊缝熔透状态之间的内在相关性,发现电弧声信号能量及其频谱特性与熔透状态高度相关,焊接过程中信号能量幅值随熔透增大而增大,为后续利用电弧声信号来控制焊接质量提供了基础. 相似文献
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开发了一套适用于铁碳合金材料焊接裂纹监测分析的声发射监测系统,并对不同材质和不同焊接工艺条件下的焊接接头AE信号进行了采集和分析,发现及证实了一些对深入研究焊接裂纹AE的形成机理有重要意义的现象和规律. 相似文献
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采用脉冲YAG激光焊、微束等离子弧焊和激光-微束等离子弧复合焊对304不锈钢进行焊接试验,实时采集焊接过程中的结构负载声发射信号,研究声发射信号对焊接过程的表征. 结果表明,激光离焦量为-2 mm的激光-微束等离子弧复合焊接,热源复合效果更好,焊缝表现出更显著的复合热源焊接特征. 焊缝获得了更好的表面成形和熔深、熔宽. 热源复合效果更好的焊接过程,其声发射信号波形表现出更大振幅,且更为均匀,并与激光热源的周期性相符,呈现出明显的复合热源焊接周期性. 因此可以利用焊接过程检测到的结构负载声发射信号表征激光和微束等离子弧两种热源复合效果特征. 相似文献
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Bused on chaos time series and fiactal theory, acoustic emission signals were studied in the process of spot welding. According to calculating 8 welding parameters using phase space reconstruction method, the largest Lyapunov exponents were positive values and chaos characteristics were firstly discovered from acoustic emission signals in spot welding. In order to evaluate acoustic emission signal, Hausdorff dimension is put forward to analyze and estimate chaos characteristics. The experiment and calculation results indicate that the Hausdorff dimension of acoustic emission signal is significantly distinguishable in the nuggets with different welding parameters. This research provides a new method for measuring the resistance spot welding quality. 相似文献
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In laser non-penetration deep penetration welding process, welding material will vaporize, metal vapor and ambient gas will produce a higher degree ionization, which forms plasma of high concentration. In the case of forming a small hole, plasma will eject .from the hole, and form acoustic emission ( AE ) signals. Because AE information has many advantages such as non-contact measuring, fast response, and high ratio of signal to noise, it can be used as a monitor variable for in-process control. By studying AE information, information of welding pool and small hole can be obtained. According to characteristic of AE information, this paper reveals the correlation between welding parameters and AE signals, and provides a good base for further quality control. 相似文献
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以结构负载压电传感的方式,研究借助声发射信号表征电阻点焊铝合金过程的熔核形核信息,包括焊接过程的声发射信号表征和熔核质量信息的声发射信号表征.结果表明,电阻点焊不论是稳定形核还是非稳定形核均可以用声发射信号来表征熔核形核的不同物理阶段.熔核形核的飞溅、开裂等特征事件也可以利用电阻点焊过程声发射信号的形核声发射特征参数来予以界定.声发射特征参数与熔核形核尺寸、焊点拉剪载荷具有较好的相关性.可以使用焊接过程中的声发射特征参数作为检测或预测熔核形核尺寸和焊点拉剪载荷的依据之一. 相似文献
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核环境中的管道焊接修复,需要采用遥控方式来完成.根据核环境下管道修复的特点,在自主开发的小口径管道全位置焊接机头的基础上,对遥操作控制系统进行了研究.系统由工控机上插接PC—6501D板卡组成,通过VC++6.0编程提供驱动器的信号,实现整个系统的运动.加入闭环弧压反馈调节机构,以保证全位置焊接过程中电弧长度稳定,提高焊缝成形质量.结果表明,控制系统可以实现全位置焊接的速度和方向可调,并且在闭环弧压反馈调节的控制下,电弧电压的偏差不超过±0.2V,焊缝成形好. 相似文献