2d advanced surface texture module for mountainsmap · matlab. tm compatibility and more. advanced...

Advanced 2D filtering techniques

2D Fourier analysis & direct filtering of FFT plot

Statistical analysis of series of 2D profiles

Advanced data preparation.

Fractal analysis

MATLABTM compatibility and more

Advanced 2D profile filtering and analysis

2D Advanced Surface Texture Module for MountainsMap®+

The 2D Advanced Surface Texture optional module for MountainsMap® includes numerous operators for advanced datapreparation. Missing data points can be filled in automatically, anomalies can be removed by thresholding, profileresolution can be improved by resampling, profile points affected by random contamination can be retouched, andinstrument limitations can be overcome by joining together multiple measured profiles.

Advanced data preparation

remove anomalies, fill in missing data points, overcome instrument limitations

Advanced 2D filtering techniques

the latest ISO 16610 filters for surface texture analysis and more

The 2D Advanced Surface Texture optional module includes all of the filtering techniques needed to carry out advancedroughness/waviness analysis. They include form removal (required before roughness/waviness analysis), FFT-basedfilters from Gaussian to ISO 16610, and morphological filters.

Primary profile

Form Roughness + Waviness

Form Removal

Roughness/waviness filters (FFT-based)

FFT-based roughness-waviness filtering techniques go all the way from the ISO 11562 Gaussian filter to the latest ISO 16610 Cubic Splineand Robust Gaussian filters.

The cut-off is pre-selected or defined by the user and end effects can be managed automatically.

2D Advanced Surface Texture Module for MountainsMap+

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Compared to the Gaussian filter(upper right) the ISO 16610 robustGaussian filter (lower right)improves the separation betweenwaviness and roughness, reducesneighbouring peak and valley errorsand, in particular, makesevaluations based upon the bearingratio much more reliable.

The robust Gaussian filter uses aniterative method based uponGaussian regression and is alreadyused in the automotive industry,notably in Germany. Gaussian filter (ISO 11562) with cut-off 0.08 mm

Texture Isotropy study: dominant surface direction and parameters.

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Primary profile (blue)Waviness profile (red)

Roughness profile

Primary profile (blue)Waviness profile (red)

Roughness profile

Robust Gaussian filter (ISO 16610) with cut-off 0.08 mm

Morphological filters and envelopes

Profile before morphological filtering

Dilation (structuring element: 0.05 mm horizontal line segment).

Erosion (structuring element: 0.05 mm horizontal line segment).

Dilation and erosion. InMorphological Filtering astructuring element (horizontal linesegment or circular disk) is appliedto an input profile. Thefundamental operations are dilationand erosion. During dilation thestructuring element is applied to theupper side of the profile. Duringerosion the structuring element isapplied to the lower side of theprofile.

Top right: Input profile.Middle right: Dilated profile.Bottom right: Eroded profile.

Input profile (blue)Dilated profile (red)

Input profile (blue)Eroded profile (red)

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2D Advanced Surface Texture Module for MountainsMap


Closing filter. A closing filter is adilation followed by an erosion.

When a closing filter is applied,valleys are closed (filled) but peaksare unchanged.

The result is called the upperenvelope of the input profile.

Opening filter. An opening filter isan erosion followed by a dilation.

When an opening filter is applied,valleys are opened and peaks arereduced.

The result is called the lowerenvelope of the input profile.

Morphological envelopes. TheMorphological Envelopes studyshows the upper envelope (result ofthe closing filter) and the lowerenvelope (result of the openingfilter) on the input profile.

Alternating sequence filters. Inaddition a closing filter can beapplied followed by an opening filteror an opening filter can be appliedfollowed by a closing filter. Thesealternating sequence filterseliminate tall and thin peaks andvalleys.

Closing filter (structuring element: 0.05 mm horizontal line segment).

Opening filter (structuring element: 0.05 mm horizontal line segment).

Morphological envelopes based upon the application of closing and opening filters (structuring element: 0.05 mm horizontal line segment).

Alternating closing then opening filters (structuring element: 0.05 mm horizontal line segment).

Alternating opening then closing filters (structuring element: 0.05 mm horizontal line segment).

Primary profile (blue)Closing filter result (red)

Primary profile (blue)Opening filter result (red)

Primary profile (blue)Closing then opening result (red)

Primary profile (blue)Opening then closing result (red)

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MATLABTM compatibility

Design your own custom filters and apply them

MATLABTM scripts can be executedby loading an m file or writing yourown script. This makes it possiblefor users to develop and apply theirown operators to studiables(measurement data sets).

Note: Mountains 6 and MATLABTMmust be installed on the samecomputer.

2D Fourier analysis and direct filtering

understanding tool/process – profile interaction

The 2D Advanced Surface Texture optional module contains analytical studies that facilitate the study of tool/process –surface interactions. They include a frequency spectrum plot, PSD (Power Spectrum Density) plot, and autocorrelationand intercorrelation plots. The module also comes with an FFT plot editor that makes it possible to exclude specifiedwavelengths from an input profile, for example for denoising.

Frequency spectrum plot

The Frequency Spectrum plot,based on the FFT, shows themagnitude and phase of each ofthe wavelengths in a profile,facilitating the analysis ofperiodic surfaces.

Profile of a microlens array.

Frequency spectrum.

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PSD (power spectrum density) plot

The Power Spectrum Densityplot represents the dominantwavelengths in a profile. It canhelp to identify process andmachine-tool problems inprocesses that are periodic orrepetitive.

Profile extracted from a turned surface.

PSD plot (the wavelength is selected interactively using the slider).

Autocorrelation plot

The Autocorrelation plot canfacilitate understanding of changesin more random processes.

Profile extracted from a surface prepared by grinding.

Autocorrelation plot of the profile.

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FFT plot editor

The FFT plot editor is used toexclude wavelengths within intervalsthat can be selected graphically onthe FFT plot.

See the simple example to the left.

The input profile is shown at thetop.

Long wavelengths (red) are selectedand excluded on the FFT plot editor.(Any wavelengths can be selectedfor exclusion. The ability to zoomup to x64 on the FFT plot facilitateswavelength selection.)

The output profile is shown at thebottom.

Excluded wavelengths

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Fractal Analysis

study the fractal dimension of a surface using two standard methods

The Fractal Analysis studycalculates a number of parametersfor profiles using two methods: theenclosing boxes method and themorphological envelopes method.The number of enclosing boxes orthe enclosed area is shown as afunction of scale (the size of theboxes or structuring elements).

The following parameters arecalculated:

• Fractal dimension (between 1 and2 for a profile).

• Slope and correlation coefficient(R2) of regression line(s).

Enclosing boxes method Morphological envelopes method

Input profile for fractal analysis

Creation and analysis of series of profiles

generate statistics on parameters and step heights

The 2D Advanced Surface Texture optional module can be used to create a series of profiles for basic statisticalanalysis. (The Statistics optional module is available for more advanced statistical analysis).

Automatic conversion of a surface into a series of profiles. 3D surface measurement data can be displayed as apseudo-color image and be automatically converted into a series of profiles for analysis.

Manual definition of a series of profiles. Any set of measured profiles can be turned into a series of profiles. Theprofiles in the series can originate from a single surface or from multiple surfaces (for example in a productionenvironment).

Preprocessing of a series of profiles. Once a series of profiles has been created, new profiles can be added to theseries and existing profiles in the series can be removed from it. Profiles in a series can be aligned automatically prior toanalysis. Operators like leveling zooming, mirroring, flipping and resampling can be applied not only to individualprofiles but also to a series of profiles.

Analysis of a series of profiles. Analysis includes statistics on any set of 2D parameters and step height dimensions.

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Statistics on 2D surface texture parameters (series of profiles)

Profiles measured on a single surface or a series of surfaces.

Series of profiles.

Surface texture parameter table for the series of profiles including mean, min, max and standard deviation.

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Pseudo color topographical image of a reference standard surface which is converted into a series of 1957 profiles for statistical analysis.

Statistical analysis of 26 step heights after conversion of the surface into a series of 1957 profiles. It is possible to step through the profiles in the series one by one.

Statistical analysis of step heights (series of profiles)

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Selected features2D Advanced Surface Texture Module for MountainsMap®Extended instrument compatibility • 3D profilers

• Pseudo-color image of surface topography with vertical scale.• Extract point-to-point profiles

Data preparation • Remove anomalies (e.g. spikes) using thresholding.• Fill in missing data points.• Retouch existing profile points (e.g. to remove random contamination).• Resample to improve image resolution.• Join two profiles.

Roughness/waviness filtering • Form removal.• Roughness/waviness filters: (ISO 1152 Gaussian, ISO 13565-1 double Gaussian, ISO 16610-22 cubic spline, ISO 16610-31 robust Gaussian) with default or user-defined cut-off and optional end-effect management.

Morphological filtering •Dilation and erosion operations using a line segment or disk as a structuring element.• Closing (dilation followed by erosion), opening (erosion followed by opening) and sequential (closing followed by opening or opening followed by closing) operations.• Upper and lower morphological envelopes generated by opening and closing operations.

MATLABTM

compatibility • Execute MATLABTM

scripts by loading an m file or writing your own script.• Develop and apply custom operators (MATLAB

TM and MountainsMap must be installed on the same

computer).Fractal analysis • Carry out fractal analysis using the enclosing boxes method or the

morphological envelopes method.• Calculate fractal dimension, slope and correlation coefficient (R

2) of

regression line(s).2D Fourier analysis and filtering • Frequency spectrum plot.

• Power spectrum density plot.• Autocorrelation and intercorrelation operations.• FFT plot editor with optional thresholding for direct filtering/denoising.

Series of profiles analysis (basic statistics) • Convert a surface into a series of profiles for basic statistical analysis.• Create a series of profiles from any set of profile measurements on the same surface or on different surfaces.• Level, zoom, mirror, flip, resample a series of profiles.• Automatic lateral alignment of profiles in a series.• Display Abbott-Firestone curve and depth histogram for every profile in the series.• Generate statistics on a series of step heights: mean, min, max and total height, width.• Parameter tables for the series with mean, standard deviation, min, max, median, range, variance, quartiles, etc.

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Digital Surf Head Office & R&D Center16 rue Lavoisier,

25000 Besançon, FranceTel +33 3 81 50 48 00 [email protected] www.digitalsurf.com

Doc revision: 20160627


2d advanced surface texture module for mountainsmap · matlab. tm compatibility and more. advanced...

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