基于均值属性测度聚类分析的推土机故障诊断

提出了一种基于均值属性测度聚类分析的推土机柴油发动机故障诊断模型。模型以训练样本中各分类样本平均值表示其分类中心,建立各判别因子的未确知测度函数,然后计算单指标未确知测度和样本的均值属性测度,以样本均值属性测度进行等级判别;模型回判的正确率为100％。研究表明,该方法是一种用于推土机发动机工作状态分类和故障诊断识别的有效方法。     

国V柴油对车用柴油机排放影响的试验研究

采用AVL全流采样(CVS)系统,在3台国Ⅳ重型柴油机上进行了国Ⅳ、国Ⅴ柴油油品对排放影响的对比试验,试验使用ESC,ETC以及ELR测试循环。3台发动机均采用增压中冷+SCR技术路线,供油系统包括高压共轨和电控单体泵系统,排量范围为3.8～11.9 L。研究发现,无论是ESC循环还是ETC循环,国Ⅴ柴油相对于国Ⅳ柴油,均可以降低重型柴油机的PM和CO排放,但对NO_x,THC和ELR烟度没有明显影响。     

发动机排气热量测量方法比较研究

介绍了目前常用的排气热量测量方法,即直接测量法和间接测量法;通过测量WD615柴油机排气热量,对两种方法进行比较研究。试验结果表明,在试验条件有限时,采用直接测量法可以得到相对更好的结果。     

Fault-tolerant control of heavy-haul trains

The fault-tolerant control (FTC) of heavy-haul trains is discussed on the basis of the speed regulation proposed in previous works. The fault modes of trains are assumed and the corresponding fault detection and isolation (FDI) are studied. The FDI of sensor faults is based on a geometric approach for residual generators. The FDI of a braking system is based on the observation of the steady-state speed. From the difference of the steady-state speeds between the fault system and the faultless system, one can get fault information. Simulation tests were conducted on the suitability of the FDIs and the redesigned speed regulators. It is shown that the proposed FTC does not explicitly worsen the performance of the speed regulator in the case of a faultless system, while it obviously improves the performance of the speed regulator in the case of a faulty system.     

An ABS control logic based on wheel force measurement

The paper presents an anti-lock braking system (ABS) control logic based on the measurement of the longitudinal forces at the hub bearings. The availability of force information allows to design a logic that does not rely on the estimation of the tyre–road friction coefficient, since it continuously tries to exploit the maximum longitudinal tyre force.

The logic is designed by means of computer simulation and then tested on a specific hardware in the loop test bench: the experimental results confirm that measured wheel force can lead to a significant improvement of the ABS performances in terms of stopping distance also in the presence of road with variable friction coefficient.     

大跨度系杆拱桥柔性吊杆张力监测和参数识别研究

研究了基于弦振动理论应用频率法进行大跨度系杆拱桥柔性吊杆张力测试的基本方法,尤其是对影响频率法测定吊杆张力精度的若干参数,如吊杆的边界条件、减振阻尼器及有效计算长度等进行了较理想的识别。文中推导了张力测试的实用公式,并通过现场张力标定,对上述若干参数进行有效识别,提高了张力测试精度并减少了识别工作量。实测结果表明,根据文中提供的参数识别方法进行参数识别后所得到的吊杆张力计算值大部分具有较高的监测精度,可以满足施工和运营期间监测吊杆张力的需要。     

汽车接近角,离去角和纵向通过角的测量

介绍了日本汽车标准化协会（JASO）对汽车接近角、离去角和纵向通过角的定义。按照该定义，可以用简单的测量工具测得若干个长度尺寸，然后代入按几何关系推导出的公式中求得上述三个角度的精确值，既提高了测量精度，又便于各车型之间这些参数的比较。     

汽车外部凸出物检测系统及测试方法研究

对ＧＢ１５６６－８９《汽车外部凸出物》的规定进行了探讨，并研制开发了汽车外部凸出物检测系统。     

车用催化器流动阻力的试验与理论研究

在稳流试验台上利用U型管测量了不同结构催化器的压力损失 ,并进行了理论分析。研究表明 ,在小角度范围内 ,扩张角越大 ,压力损失也越大 ;但当锥角超过一定值之后 ,锥角越大 ,压力损失反而略有下降 ;在相同的扩张管长度下 ,斜扩张管催化器的压力损失大于直扩张管催化器的压力损失 ;载体位于催化器中部较顶部和底部压力损失大。