SELECTION OF REFERENCE PLANE BY THE LEAST SQUARES FITTING METHODS
 
More details
Hide details
1
Rzeszow University of Technology, Powstańców Warszawy 12, 35-959 Rzeszów, Poland
CORRESPONDING AUTHOR
Przemysław Podulka   

Rzeszow University of Technology, al. Powstańców Warszawy 12, 35-959 Rzeszów, Poland
Publication date: 2016-06-01
 
Adv. Sci. Technol. Res. J. 2016; 10(30):164–175
 
KEYWORDS
TOPICS
ABSTRACT
There are many disadvantages affecting the accuracy of surface topography measurement and analysis. One of them are the errors obtained during data processing. Usually surface topographies of car engine parts are studied after form removal. Many algorithms and procedures were developed and suggested. However, the selection of reference plane with accordance to surface topography measurements of cylindrical elements was not fully recognized. In this paper least squares fitting methods (cylinder, polynomial) and commercial filters (Gaussian filter, Gaussian regression filter and robust Gaussian regression filter) for areal form removal were compared and proposed. Three types of surfaces: cylinder liners after plateau-honing, plateau-honed cylinder liners with oil pockets created by burnishing techniques and turned piston skirts were analyzed. Distortion of surface topography parameters (from ISO 25178 standard) according to improper selection of reference plane was also taken into consideration. It was assumed that least squares fitted cylinder plane gave better results for both of type cylinder liners according to commonly used algorithm. However, for piston skirt surfaces the obtained results were very similar. For least squares polynomial fittings it was found that applied method for cylinder liners gave usually better robustness for scratches, valleys and dimples occurrence. For piston skirt surfaces better edge-filtering results were obtained. It was also recommended to analyse the Sk parameters for proper selection of reference plane in surface topography measurements.