天然气汽车改装中CNG喷射器喷嘴孔径的确定

在压缩天然气汽车(CNGV)的改装过程中，CNG喷射器喷嘴孔径这个工艺参数，极为关键却又难以把握。为了提高安装作业的效率及精度，探究出一种能辅助安装者更快更准地确定所需孔径的方法，提出了以模糊模式识别原理的算法，根据待改装车辆的发动机功率、行驶总里程和当前火花塞使用中的行驶里程这3个指标，对喷嘴孔径的尺寸进行识别，以实现在CNG系统安装前对孔径进行确定。在MATLAB中对该算法进行验证时，发现采用随机性更好的分组抽样且对算法的数据运算过程进一步匹配修正后，孔径的识别精准性显著提高。经过与此前的实际安装记录数据的核对，最终证实了该算法的可行性及准确性。

Determination of the nozzle aperture of a compressed natural gas injector in the conversion of a comressed natural gas vehicle

In the reifit process of a compressed natural gas (CNG) vehicle, the nozzle aperture of a CNG injector is an important process parameter and is difficult to determine. To improve the efficiency and accuracy of installation work, it is imperative to find a method for installers to quickly and accurately determine the required aperture. For this purpose, we analyzed a large volume of data obtained in actual refitting practices, and proposed a fuzzy pattern-recognition algorithm for determining the size of a nozzle aperture based on the engine power, the total mileage and the current mileage of spark plugs being used of the vehicle to be refitted. Verification of the algorithm in MATLAB finds that by using more random sampling and grouping and modifying the computing process of the algorithm, the accuracy of aperture recognition is improved significantly. The feasibility and accuracy of the algorithm are confirmed by comparison of the computed results with previous installation records.