射频电流对桥丝式电雷管安全性与可靠性影响数值计算

为了研究射频电流对桥丝式电雷管在贮存与使用过程中可能出现的意外发火、迟发火与瞎火现象,选取了一种桥丝式电雷管进行热分析数值计算.首先建立了热分析的数理模型,然后根据所建立的模型对电雷管接受射频电流作用后药剂的性能变化进行了计算.确定了所研究的电雷管在受到0.09A以上电流作用时,出现意外发火现象,影响其贮存安全性;在受到0.08A以下电流作用时,出现迟发火与瞎火现象,影响其使用可靠性.     

基于Labview的OBDⅡ故障发生器开发

2005年中国政府对OBDⅡ提出了系统的要求,OBDⅡ对减少大气污染,提高整车系统安全作用明显。笔者对氧传感器老化和失火诊断策略进行了分析,研究了用于燃气汽车OBDⅡ开发的氧传感器老化和失火诊断故障信号发生器,通过采用NI公司的板卡、Labview和Matlab／Simulink等开发工具产生了故障信号,经测试故障信号满足要求,能够用于OBDⅡ系统的测试开发。     

坑道掘进爆破毫秒导爆管雷管拒爆现象分析

针对抗道掘进爆破中所遇到的毫秒导爆管雷管发生拒爆现象进行了分析,当传毫秒导爆管雷起爆作业断面上导爆管雷管时,所产生的“延期时间”会影响网络设计效果,从而导致拒爆现象发生。     

导爆管雷管瞎火原因探讨

从消爆气室的大小、药剂、压药压力和环境等７个方面分析了导爆管雷管瞎火的原因,并探讨了相应的解决方法。     

电控柴油机的在线失火诊断策略研究

为了满足日益严格的排放法规，电控发动机均要求装备OBD(在线诊断)系统。而在线的失火诊断则是电控柴油机故障诊断项目中的一个重要内容。为此采用曲轴的瞬时角加速度对发动机的失火故障进行监测，并制定了相应的诊断策略。实机试验表明，该失火诊断策略能实时有效地诊断出失火故障。     

Residual generation and statistical pattern recognition for engine misfire diagnostics

Methods for diagnosing misfire in internal combustion engines are presented in this paper. Crank-angle domain digital filters are used to extract features from the measured engine speed signal that are characteristic of misfire. Features for intermittent and continuous misfires are developed separately, since the engine speed responses for intermittent and continuous misfires are distinctly different. Also, the influence of crankshaft torsional vibration and repeatable measurement errors must be addressed differently in each case. The outputs from the digital filters serve as inputs to a pattern recognition network based on linear parametric classifiers. Experimental results from implementation on a Ford 4.6L V-8 engine are provided.     

Experimental study on axial stratification process and its effects (I)-Stratification in Engine-

This paper is the first of several companion papers, which investigate axial stratification process and its effects in an SI engine. The axial stratification is very sophisticate phenomenon, which results from combination of fuel injection, port and in-cylinder flow and mixing. Because of the inherent unsteady condition in the reciprocating engine, it is impossible to understand the mechanism through the analytical method. In this paper, the ports were characterized by swirl and tumble number in steady flow bench test. After this, lean misfire limit of the engines, which had different port characteristic, were investigated as a function of swirl ratio and injection timing for confirming the existence of stratification. In addition, gas fuel was used for verifying whether this phenomenon depends on bulk air motion of cylinder or on evaporation of fuel. High-speed gas sampling and analysis was also performed to estimate stratification charging effect. The results show that the AFR at the spark plug and LML are very closely related and the AFR is the results of bulk air motion.     

电爆网路联接方式对准爆可靠性的影响

煤矿采掘和地面爆破施工中,爆破可靠性是个重要环节。发生在串联网路或串并朕网路中部的成组拒爆,或者只有一端爆炸的情况,往往令爆破作业者费解。该研究一改往常定性方法描述不良爆破的征兆,通过试验、理论推导、定量分析,评价电爆网路中出现的成组拒爆现象。     

瞬态电磁耦合法检测与识别硐室爆破盲炮的可行性探讨

为探明硐室爆破中的盲炮,在瞬变电磁法的基础上进行改进形成瞬态电磁耦合法,进行盲炮检测与识别的可行性理论分析与实验论证。在硐室内预置电磁灵敏感应器,在地表布置瞬态电磁耦合检测系统,检测炸药爆炸前后电磁场异常状况来实现硐室爆破盲炮检测与识别。结果表明,电磁灵敏感应器在感应耦合的作用下产生规则化涡流,在复杂的地形地质条件下,可以检测与识别出埋深不超过55m的单个盲炮;药室内的电雷管可能产生的感应电流远小于安全电流,可确保检测过程中电雷管的安全;但对于存在多个盲炮瞬态电磁耦合法难以精确的检测与识别。     

频分多址法用于硐室盲炮检测与识别的试验

为探明硐室爆破中的盲炮,在高精度磁法、瞬变电磁法和瞬态电磁耦合法的研究基础上研究开发了频分多址法。该法是利用电磁波在大地中的传播规律,在不同装药硐室中预置发射不同频率的电磁信号发生器,在地面安装无线检测接收系统,通过接收到的不同频率信号来实现硐室盲炮检测与识别。试验结果表明,电场信号信噪比低、反应微弱,磁场信号的信噪比高,采用频率在1000Hz左右的磁场信号作为检测的信号源的实用性更好;频分多址法可以检测与识别出地下225m的盲炮,能满足地下硐室盲炮检测的距离要求;检测精度可达到2Hz,能同时有效地检测与识别地下单个及多个盲炮的存在。