排序方式: 共有19条查询结果,搜索用时 15 毫秒
11.
12.
Characteristics analyzing and parametric modeling of the arc sound in CO2 GMAW for on-line quality monitoring 总被引:1,自引:0,他引:1
For on-line monitoring of welding quality, the characteristics of the arc sound signals in short circuit CO2 GMAW were analyzed in the time and frequency domains. The arc sound presents a series of ringing-like oscillations that occur at the end of short circuit i. e. the moment of arc re-ignition, and distributes mainly in the frequency band below 10 kHz. A concept of the arc tone channel and its equivalent electrical model were suggested, which is considered a time-dependent distributed parametric system of which the transmission properties depend upon the geometric and physical characteristics of the arc and surroundings, and is excited by the sound source results from the change of arc energy so that results in arc sound. The linear prediction coding ( LPC ) model is an estimation of the tone channel. The radial basis function ( RBF ) neural networks were built for on-line pattern recognition of the gas-lack in welding, in which the input vectors were formed with the LPC coefficients. The test results proved that the LPC model of arc sound and the RBF networks are feasible in on-line quality monitoring. 相似文献
13.
14.
下一代网络业务提供是一个分布式系统,在支持通信类增值业务时要求一定的QoS保证。实时CORBA采用面向对象的方法,提高了分布式应用软件的可重用性利可扩展性,大大简化了分布式应用系统的开发和维护,便于异构环境下的系统集成;而日.为分布实时应用提供端到端的可预测性。结合实时CORBA规范及其产品中的实现技术,讨论了实时CORBA的资源控制策略及其实现的协议框架,并用试验分析验证它的实时性能。实时CORBA改善了通用CORBA的实时性能,能够为下一代网络业务提供一定的实时保证。 相似文献
15.
本文设计了以VB6.0为软件开发平台,AC6115型A/D卡为硬件核心的CO2焊接信号采集系统,实现焊接同步信号高采样率下的连续采集及波形显示等功能。并利用VB与MATLAB混合编程,对数据进行频域分析。实际应用表明该系统稳定可靠,操作简便,具有实际应用价值。 相似文献
16.
围绕环境风险评价的基本概念、在国内外的发展,结合化工行业的风险特点,阐述了在化工行业进行环境风险评价的重要意义。在《建设项目环境风险评价技术导则》基础上,提出了化工行业环境风险评价的方法。通过对某化工集团合成氨项目的实例分析,运用事故树方法分析事故发生最可能的原因,并估算事故发生产生的危害,对该项目环境风险做了一个初步的评价,对某化工集团的环境风险管理提出了建议。 相似文献
17.
18.
19.