Study Of A Instrument For Prominence On Surface Of Semiconducting Polymer Measurement

The semi-conductive shielding material is a necessary matching material for middle-high voltage power cables, which is generally considered to play an important role in uniforming electric field. The experience of long-running shows that semi-conductive shielding layer has a closer relation of the cable service life. The prominence of semi-conductive layer cause partial discharge which have potential impact on cables.Taking semi-conductive polymer as object, detection technology of surface prominence is researched. Principle of line structured light and processing method of morphologic are use to extract size information of prominence effectively and complete detection for prominence on surface of semi-conductive polymer basically.Related experiments are carried out using line structured light principle. Array CCD as the core device, measurement system was established based on line structured light and laser stripe image is analyzed and processed. First, according to the image histogram characteristics prominence stripes are cut, laser stripes are obtained. Second, several methods of laser stripe center extraction is designed, by comparing and analysis, gray weighted centroid algorithm and curve fitting method are fitting for extraction strip center. However, because of existing technical specifications of lasers, the limit of lens resolution cannot meet the requirements of measurement; this method is verified not to achieve the goal. Finally, by analyzing the shape features of protrusion, a fuzzy detection method by using morphology is proposed. Line laser is replaced by spotlight. Using low-angle to irradiate the surface of semi-conducting polymer, prominence image information which is obtained by CCD is processed by pre-processing, segmentation, corrosion and expansion to get circular spot. Prominence size is estimated according to the circular spot. Finally, using Visual C++ 6.0 development environment, upper computer software based on dialog box is compiled to realize the control of acquisition system, the display of dimension information of prominence, statistics, print etc.Through the experiment analysis, tiny prominence detection by use of morphological principle is proved. Based on morphological process method intended purpose is achieved. The feasibility of the program is verified.