Digital filtering of surface topography: Part II. Applications of robust and valley suppression filters

Wavelet transform becomes a more and more common method of processing 3D signals. It is widely used to analyze data in various branches of science and technology (medicine, seismology, engineering, etc.). In the field of mechanical engineering wavelet transform is usually used to investigate surface micro-and nanotopography. Wavelet transform is commonly regarded as a very good tool to analyze non-stationary signals. However, to analyze periodical signals, most researchers prefer to use well-known methods such as Fourier analysis. In this paper authors make an attempt to prove that wavelet transform can be a useful method to analyze 3D signals that are approximately periodical. As an example of such signal, measurement data of cylindrical workpieces are investigated. The calculations were performed in the MATLAB environment using the Wavelet Toolbox.

Section: Discussionmentioning

confidence: 99%

An Analysis of Deviations of Cylindrical Surfaces with the Use of Wavelet Transform

Stępień¹,

Makiela²

2013

“…It was found that even robust filters caused distortion of profiles having a wider valley than 100 µm [12,13]. These valleys can exist on cylinder surfaces (for example in the circumferential direction).…”

Section: Filtering Of 2d Profilesmentioning

confidence: 99%

“…Short computation time is its advantage. Median absolute deviation MAD is a more robust scale parameter than median absolute MED [12,13]. However, even robust filters with a cut-off of 0.8 mm caused distortion of profiles with valleys wider than 100 µm.…”

Section: Introductionmentioning

confidence: 99%

Modification of Robust Filtering of Stratified Surface Topography

Dobrzański¹,

Pawlus²

2013

Various components of surface texture are identified, namely form, waviness and roughness. Separation of these components is done by digital filtering. Several problems exist during analysis of two-process surfaces. Therefore the Gaussian robust profile filtering technique was established and has been studied here. The computer generated 2D profiles and 3D surface topographies having triangular scratches as well as measured stratified surfaces were subjected to filtration. However even robust filter applications cause distortion of profiles having valleys wider than 100 µm. In order to minimize the distortion associated with wide and deep valleys, the robust filter should be modified. A special procedure was elaborated for minimizing distortion of roughness profiles caused by filtration. Application of this method to analyses of several profiles was presented. The difference between 1-D and 2-D filtering of surface topography using the same kind of filter was discussed. As a result we found that modification of a 2-D surface topography filter was not necessary.

“…In the latest navigation systems in the process of the route and position adjustment the probabilistic methods are used. These methods are successfully used to analyse the measurement signals [5,6,13] and they have been quickly implemented in mobile robotics [11,16].…”

Section: Introductionmentioning

confidence: 99%

Application Of Kalman Filter In Navigation Process Of Automated Guided Vehicles

Śmieszek

Dobrzańska

2015

In the paper an example of application of the Kalman filtering in the navigation process of automatically guided vehicles was presented. The basis for determining the position of automatically guided vehicles is odometry -the navigation calculation. This method of determining the position of a vehicle is affected by many errors. In order to eliminate these errors, in modern vehicles additional systems to increase accuracy in determining the position of a vehicle are used. In the latest navigation systems during route and position adjustments the probabilistic methods are used. The most frequently applied are Kalman filters.