vda ekb 3011 - part data exchange format...the illustration in the following figures gives an...

VDA Recommendation 308 February 2016 __

VDA EKB 3011 - Part Data Exchange Format

308

This non-binding recommendation by the German Association of the Automotive Industry (VDA) has the following objectives:

• Description of a data format for transferring component-based measuring data.

• The parameters to be exchanged can be chosen as desired. The concentration is on the transfer of measured data based on eigenvalues and some other values like compress.

• Naming for the parameters and the general structure of the guideline are based on the VDA 305 resp. EKB 3008.

EKB – Expertenkreis Bremsgeräusche (Expert Group Brake Noise)

Publisher: Verband der Automobilindustrie Copyright

Behrenstrasse 35 Reprints and any other form 10117 Berlin of duplication is only permissible Phone +49(0)30/897842-0 when the source is cited.

Telefax +49(0)30/897842-606 Internet: www.vda.de


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Disclaimer VDA recommendations are freely available for general use. The user is responsible for ensuring correct application for the specific case. They represent the latest technology available at the time of issue. Application of VDA recommendations does not relieve the user from responsibility for his own actions. In this regard, all users act at their own risk. VDA and those involved with VDA recommendations do not accept any liability. Anyone applying VDA recommendations who identifies inaccuracies or possible incorrect interpretations is invited to inform VDA immediately and any errors can thus be rectified.


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Table of Contents

0 Introduction ................................................................................................................... 4

1 Overview of file formats ................................................................................................ 7

2 File names used ........................................................................................................... 9

2.1 File names of the EEP file ................................................................................... 11

2.2 File names of the modal measurement data files ................................................ 11

2.2.1 FRF DATA FILES ........................................................................................... 11

2.2.2 ASR data files ................................................................................................. 12

2.2.3 ASE data files ................................................................................................. 12

2.2.4 XSP data files ................................................................................................. 12

2.2.5 TMR data files ................................................................................................. 12

2.2.6 TME data files ................................................................................................. 13

2.2.7 COH data files ................................................................................................ 13

2.3 File names of packed measurement archives ..................................................... 13

3 Basic EEP file format conventions .............................................................................. 14

3.1 General specifications ......................................................................................... 14

3.2 Header lines ........................................................................................................ 15

3.3 Types used .......................................................................................................... 16

3.4 Units used ........................................................................................................... 17

4 Detailed description of the EEP file format ................................................................. 18

4.1 EEP file ID ........................................................................................................... 18

4.2 Unit system definition .......................................................................................... 18

4.3 EEP file header ................................................................................................... 19

4.3.1 Description of the Measurement ..................................................................... 19

4.3.2 Description of the Part .................................................................................... 21

4.3.3 Other Header Entries ...................................................................................... 24

4.4 Comment block ................................................................................................... 24

4.5 Table with result data .......................................................................................... 25

5 Example of an EEP file ............................................................................................... 30


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0 Introduction The vehicle braking system consists of various brake components, such as the brake caliper, brake disk, brake pads and damping plates. In the process, each component is developed and produced by an independent manufacturer. For some brake components, e.g. the brake caliper, several companies are in turn involved in development and production, further increasing the complexity. The measuring technology for developing the parts is based on measuring systems of various manufacturers, and in some cases self-developed measuring technology (in-house measuring technology) is also used. In general, each measuring system saves the measuring data it generates in its own data format. These data formats are generally not compatible with each other. The conditions outlined above make a simple, parts-based data transfer between the respective development partners impossible. This makes close coordination as the basis for a well-developed product difficult. Due to increasingly short development times, growing complexity and more demanding quality requirements, the focus is increasingly on simple data transfer. The EKB 3011 format described here defines the data transfer of component-related measuring data. For example, eigenvibration and eigendamping or compress-values can be transferred as measured data. The data file is generated by the acquiring measuring system and, for example, is read in by an analysis software with which the data can be processed further. The data structure is designed so that reading is easily possible with a standard editor. The illustration in the following figures gives an example how the VDA 308 (EKB 3011) works in daily development work. Fig. 0.1 describes a situation without using VDA 308 (EKB 3011) resp. before VDA 308 becomes activ. A car maker is planning a road test with the vehicles 1-3 during development time. For a well-founded NVH-work it’s necessary to know the eigenfrequencies of the brake components like discs, calipers or pads. The brake parts are produced from the different suppliers 1-5. In normal cases the parts are measured regarding their eigenfrequencies on suppliers side with different measurement equipment and therefore with the different data exchange formats 1-5. The data formats 1-5 are not compatible with each other – so the data can’t used on OEM-side although they are available. Therefore the OEM is forced to measure the brake parts again. This is connected with additional costs and effort.


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Fig. 0.1: Example of assembling brake component frequency data related to a vehicle road test - without using VDA 308 (EKB 3011)

Fig. 0.2 describes a situation with using VDA 308 (EKB 3011) resp. after VDA 308 becomes activ. The car maker plans the road test and the suppliers measure the eigenfrequency data with the same equipment and in the same manner as done in Fig. 0.1. But all eigenfrequency data are stored or exported in EKB 3011 format. So there’s one format available and the data can used on OEM-side in a simple manner. So with VDA 308 (EKB 3011) there’s a much shorter and faster way.

Without

VDA 308: Disc front – Suppl. 1 Disc rear – Suppl. 1 Format 1

Most

data are

available !

Caliper rear – Suppl. 3 Format 3

OEM: Measuring the single parts

1 2

3

Pad rear – Suppl. 5 Format 5

Needs Time

Much work

Caliper front – Suppl. 2 Format 2

Pad front – Suppl. 4 Format 4


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Fig. 0.2: Example of assembling brake component frequency data related to a vehicle road test - after using VDA 308 (EKB 3011)

The benefit which is illustrated on OEM-side in the example of Fig. 0.1 and 0.2 exists also for every development partner during data exchange.

With

VDA 308: Disc front – Suppl. 1 Disc rear – Suppl. 1 EKB 3011

1 2

3

Pad rear – Suppl. 5 EKB 3011

Much faster

and easier (OEM-)Software

ready for EKB 3011

Software: Statistical

data from

overall production EKB 3011

Caliper front – Suppl. 2 EKB 3011 Caliper rear – Suppl. 3 EKB 3011

Pad front – Suppl. 4 EKB 3011


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1 Overview of file formats To take the different requirements and data transmission volumes into account, different file formats are defined. It is thus possible e.g. to transfer the results of part measurements with only a single (text) file that can be viewed using standard software (e.g. Notepad, Excel). The EEP file is the data transmission core and is therefore always required. It can already provide sufficient information for many purposes of the measurement documentation. The data scope can usually be sent via e-mail. If more extensive information is required, additional files can be added, which enable more detailed analyses. For example, measurement data files (e.g. frequency response functions, coherence data etc.) contain additional and more detailed information required for the daily development process. If a set of measurements consists of several files (i.e. not only of the EEP file), the complete set can also be transferred in the form of a packed archive file (zip format). EEP file The EEP file is the “anchor” for all other files; it is therefore the only indispensable component and needs to be evaluated before other files are processed. The EEP file includes information on the existing file format version, the language version and the unit system used. In addition, it includes header data (“header information”) of the measurement or of the measured objects; the individual header information is identified clearly with defined header identifiers. The scope and type of the header information can be chosen as desired to a large extent and depends on the corresponding data exchange purpose. Measurement results can be stored in a data table in an EEP file. How these contents are to be identified clearly is also only defined here, not the data volume to be stored. The data table defined for EEP files includes one single value line per measurement. The EEP file can be used to exchange data using only a single file if the header information included and the data table are sufficient for the intended exchange purpose. Measurement data files More detailed information can be provided by adding more files to the EEP file. Measurement data files are created for each individual measurement. A set of modal measurement data files may be used for each single measurement listed in the EEP file. For example, modal measurement data files are created during


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the measurement of resonant frequencies and damping values for brake parts. These data are provided by using specific data sets of “Universal File Format”: Universal File Data Set 58 Universal File Data Set 58 Binary A detailed description of these files formats ist available under http://www.sdrl.uc.edu/universal-file-formats-for-modal-analysis-testing-1


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2 File names used The storage location of a file is described in the operating system by the path, the file name and the file extension. The path should be identical for all files that belong to a set of measurements, i.e. all files are stored into one subfolder. The name of the subfolder can be chosen as desired. However, it is advisable to use the measurement name described below for the subfolder. The file names themselves are self-explanatory to a large extent: every file name begins with the (freely selectable) measurement name (<measname>), which documents the assignment of the corresponding file to a specific set of measurements. Since such a set may apply to different parts, an identifier for the corresponding part type (<parttypeID>) is attached to the measurement name. If a separate file exists for every single measurement, an identifier for the corresponding measurement (<measID>) is also added. Every file name is always completed at the end by an identifier for the file type (<fileID>) (possible file types: EEP, FRF, ASR, ASE, XSP, TMR, TME, COH). Whereas <measID> is only used in the file name if the corresponding files may deviate in terms of this property, every file name always begins with <measname> (assignment to a specific set of measurements) and always ends with <fileID> (identification of the file type). By contrast, the file extension should always be selected according to the standard file type, since that facilitates work with the operating system and standard software significantly. For the text-based file type (EEP) this is the extension “.csv” (“Comma Separated Values” Format), and for the modal measurement file types (FRF, ASR, ASE, XSP, TMR, TME, and COH) this is the extension “.uff” or “.unv” (Universal File Format). The elements of the file names (<measname>, <parttypeID>, <measID>, and <fileID>) are separated by underscores (“_”). The file names are therefore given the following basic structure: <measname>_<parttypeID>_<measID>_<fileID>.<fileExt> <measname>: identifier for a set of measurements As mentioned above, the <measname> identifier can be chosen as desired for each set of measurements and is then to be used at the start of every file name belonging to the set. Basically, there are no size restrictions. However, for a good overview, only a limited number of characters should be used, which are sufficient to clearly assign a test. Examples of test names would be e.g. “W221-A000111222-T4711” or “MYTEST001” etc. To avoid any confusion, always make sure, if possible, that the measurement names themselves do not include the identifiers defined in the following for the part (<parttypeID>), the individual measurement (<measID>), or the


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file type (<fileID>). Also, it is advisable not to use blanks or underscores within the <measname>. <parttypeID>: identifier for the part type Since a file only applies to one part, an identifier for the part type needs to be added to the file name. The corresponding part type is indicated by the <parttypeID> of the file name. Possible values for <parttypeID> are: di disc e.g. one-part disc, friction ring, pot or two-part-disc dr drum drum of a brake pa pad brake pad assemblied or not br brake one-part caliper, e.g. fixed monoblock caliper sh shim shim without brake pad pi piston piston for fixed or floating caliper kn knuckle knuckle ap any any part (dummy name for any other brake component) Abbreviations for additional detailed descriptions of part types (more than one possible) -in -inside inner part of two-part caliper, e.g. splitted fixed caliper -ou -outside outer part of two-part caliper, e.g. splitted fixed caliper -ho -housing housing of caliper -ca -carrier carrier of caliper -po -pot pot of disc -ri -ring friction ring of disc -rw -raw raw casted parts, not machined -fn -finished finished, machined parts Note: The <parttypeID> used for the file name is identical to the identifer called “part_type” in the header area of the file (see chapter 4.3.2). The short abbreviations are used to form the <parttypeID> of the file name. For the header identifier “part_type” short or long abbreviations may be used - the long versions are preferred for more (human) readability. <measID>: identification of a single measurement If a file applies to a specific measurement, an identifier needs to be added to the file name. The corresponding measurement is indicated by the <measID>. The <measID> has the following structure: nr<nnnnn> whereas <nnnnn> is the five-digit id-number of a measurement listed in the EEP file (“00001”, “00026” etc.).


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<fileID>: identification of the file type Every file name ends with the <fileID> for the file type. The following values are possible for the <fileID>: _eep EEP file (main file, contains header data and overview of results) _frf FRF file (contains data of a Frequency Response Function measurement) _asr Spectrum file (contains the Auto Spectrum of Response data) _ase Spectrum file (contains the Auto Spectrum of Excitation data) _xsp Spectrum file (contains Cross Spectrum data) _tmr Time Record file (contains the Time record of Response) _tme Time Record file (contains the Time record of Excitation) _coh Coherence file (contains Coherence data of a measurement) <fileExt>: standard file extension The file extension always corresponds to the standard file type. <fileExt> should therefore be selected as follows: .csv for the text-based file type EEP .uff or .unv for all measurement files in Universal File Format

2.1 File names of the EEP file

The EEP file is always required for data exchange. It applies to the entire set of measurements for one part. The file name consists of the measurement name, the <parttypeID> for the corresponding part and the “_eep” (<fileID>) for the EEP file. “.csv” is used as the file extension: <measname>_<parttypeID>_eep.csv Examples for EEP file names: 120730-frequency-disc-A000111222_di_eep.csv Set of measurements (e.g. eigenfrequencies) called “120730-frequency-disc-A000111222” of discs. sattel-gruen_br-ca_eep.csv Set of measurements called „sattel-gruen“ of brake carriers.

2.2 File names of the modal measurement data files

2.2.1 FRF DATA FILES

The FRF file contains the measured Frequency Response Function. The file name consists of the measurement name <measname>, the <parttypeID> for the


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corresponding part, the <measID> for the corresponding measurement and the “_frf” (<fileID>) for the FRF file. “.uff” or “.unv” is used as the file extension: <measname>_<parttypeID>_<measID>_frf.uff

2.2.2 ASR data files

The ASR file contains the measured Auto Spectrum of the response signal. The file name consists of the measurement name <measname>, the <parttypeID> for the corresponding part, the <measID> for the corresponding measurement and the “_asr” (<fileID>) for the ASR file. “.uff” or “.unv” is used as the file extension: <measname>_<parttypeID>_<measID>_asr.uff

2.2.3 ASE data files

The ASE file contains the measured Auto Spectrum of the excitation signal. The file name consists of the measurement name <measname>, the <parttypeID> for the corresponding part, the <measID> for the corresponding measurement and the “_ase” (<fileID>) for the ASE file. “.uff” or “.unv” is used as the file extension: <measname>_<parttypeID>_<measID>_ase.uff

2.2.4 XSP data files

The XSP file contains the measured Cross Spectrum of response and excitation signal. The file name consists of the measurement name <measname>, the <parttypeID> for the corresponding part, the <measID> for the corresponding measurement and the “_xsp” (<fileID>) for the XSP file. “.uff” or “.unv” is used as the file extension: <measname>_<parttypeID>_<measID>_xsp.uff

2.2.5 TMR data files

The TMR file contains the measured response signal time record. The file name consists of the measurement name <measname>, the <parttypeID> for the corresponding part, the <measID> for the corresponding measurement and the “_tmr” (<fileID>) for the TMR file. “.uff” or “.unv” is used as the file extension: <measname>_<parttypeID>_<measID>_tmr.uff


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2.2.6 TME data files

The TME file contains the measured excitation signal time record. The file name consists of the measurement name <measname>, the <parttypeID> for the corresponding part, the <measID> for the corresponding measurement and the “_tme” (<fileID>) for the TME file. “.uff” or “.unv” is used as the file extension: <measname>_<parttypeID>_<measID>_tme.uff

2.2.7 COH data files

The COH file contains the coherence obtained during frequency response function measurement. The file name consists of the measurement name <measname>, the <parttypeID> for the corresponding part, the <measID> for the corresponding measurement and the “_coh” (<fileID>) for the COH file. “.uff” or “.unv” is used as the file extension: <measname>_<parttypeID>_<measID>_coh.uff

2.3 File names of packed measurement archives

All files created in the context of a set of measurements are to be saved to one directory. Depending on the selected scope of information, a large number of files may be created. To transfer a complete test (e.g. via CD-ROM or e-mail attachment), all files of a measurement or part may be “packed” into a single file. For this, the ZIP format and the DEFLATE compression method are to be used. Since most files are in text format, a high compression rate is thus achieved. In additional, transmission errors are detected reliably, due to the ZIP checksums. However, “.eep” should be used as <fileExt>, not “.zip”; the file is thus identified directly as a set of measurements for parts in the packed EKB 3011 format: <measname>_<parttypeID>.eep


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3 Basic EEP file format conventions EEP files are text files whose structure corresponds to Microsoft’s CSV (“Comma Separated Values”) format. Data fields (text information or numerical values) are stored here in text format.

3.1 General specifications

• The files have a line-by-line structure. Every line ends with the character sequence <CR><LF> (Carriage Return, Line Feed).

• A line may have several fields (“columns”). Within a line with several fields, the individual fields are separated by field or column separators (<colSep>). Additional field separators at the end of a line (before the end of line sequence <CR><LF>) are permitted, but normally not necessary.

• Every data element (identifier, numerical value or text) is assigned to a field. Leading or trailing blanks (which enable e.g. better text formatting) are permitted. However, they will be removed by the reading program or not evaluated.

• Data in floating point notation is given a decimal separator (in the English language version the decimal point). In addition, the scientific notation may be used (e.g. “4.0858E-02” instead of “0.040858”). Other separators (e.g. thousands separator, in the English language version a comma) are not permitted for displaying numbers.

• Texts that contain field and/or decimal separators shall be set in quotation marks (example: “this text contains ; a semicolon”). If the text itself has a quotation mark, it needs to be duplicated (example: “here, “”brake”” is in quotes” or “one inch is 1””). It is advisable to always set all texts in quotation marks.

• The first line of a file must include the file identifier, which defines the file type, the file version and the language version (e.g. “eep_100_us” means: EEP file, version 1.00, US English language version). No other entries are permitted in the first line. Files with an unknown file identifier are discarded.

Field and decimal separators deviate according to the language version of the operating system. To ensure the unproblematic handling of the files, the language version used must be specified in the first line. So far, the language versions “US English” and “German” are defined: “_us” identifier: US English version: decimal separator dot (.), field separator comma (,) “_de” identifier: German version:

decimal separator comma (,), field separator semicolon (;)


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• The second line of the EEP file must contain the “unit system” entry made with the header identifier “unit_system”:

unit_system , ekb_eu In the first stage, there is one unit system defined with the units normally used in Europe (“ekb_eu”). Other unit systems may be subsequently added.

• All identifiers are not “case sensitive”, i.e. upper case or lower case may be used or a combination of both (e.g. “part_type”, “Part_Type” and “PART_TYPE” are identical identifiers).

• A line with leading “{” character is interpreted as a comment line and therefore ignored completely. A field that starts with the “{” character is interpreted as a comment line and ignored. Note: Such comments may only be used in the corresponding header areas. In the area of the file ID (i.e. the first and second lines of the file) and in the data sectors (i.e. between the identifiers “part_data_begin” and “part_data_end”), these comments are not permitted.

• An identifier beginning with the “@” character is interpreted as a user-specific identifier and is ignored (however, it can be evaluated by user-specific software).

3.2 Header lines

A header line shall start with a valid identifier; that means that the first field of a header line shall contain an identifier. Leading and trailing blanks are permitted. In general, header lines have the following structure: <headerID><colSep><value><CR><LF> <headerID> is the placeholder for the desired header identifier, <colSep> is the field separator and <value> is the placeholder for the desired value. There are also header identifiers, to which several values need to be assigned. For example, if three values are necessary, a header line has the following structure: <headerID><colSep><value1><colSep><value2><colSep><value3><CR><LF> Example: The header identifier “part_eigenfrequency_values” requires a certain number of values (the number is specified by the identifier “part_eigenfrequency_no” or by the number of entries). For example, the header entry part_eigenfrequency_values, 810, 1725, 2376 specifies that there are three eigenfrequency values (frequency reference values).


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Typical examples of header lines: <headerID> <colSep> <value> eep_100_de unit_system , ekb_eu meas_program , SAE J3001 meas_start_date , 09/21/2008 15:49:15 meas_end_date , 09/22/2008 18:35:07 meas_total_quantity , 100 meas_actual_quantity , 96 { - this is a comment - } part_type , shim part_eigenfrequency_values , 810,1725,2376

3.3 Types used

Only the following data types are used to display the values in all language versions in the header and data sector of the EEP files: <text> Any text; if there is no entry: empty string or string filled with blanks <num> Number. With or without sign, with or without decimal separator, with or

without exponent; if there is no entry: “novalue” or “n/a” <enum> List type, e.g. “left, right” or “front, rear” etc…; if there is no entry:

“novalue” or “n/a” <bool> Boolean expression, values are “yes” or “no”, “On” or “Off”, “1” or “0”,

“true” or “false” (always equivalent); if there is no entry: “novalue” or “n/a”

<time> Specification of a time difference in the form “(h)hh:mm:ss” <date> Specification of the date and time in the form: “dd.mm.yyyy hh:mm:ss”

(German language version) or “mm/dd/yyyy hh:mm:ss” (US English language version).

Note: Normally, value fields without values can simply be omitted, instead of using “novalue” or “n/a” (empty string or string filled with blanks). However, bear in mind that some programs (e.g. MS Excel) use the numerical value 0 without a message for such empty strings, whereas “novalue” or “n/a” will possibly result in a desired error message if there really are no measured values.


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3.4 Units used

For calculations or conversions with the data provided it is essential to transfer the data in defined units. The unit system used is specified in the header under “unit_system”. So far, only the “ekb_eu” unit system is defined; further definitions (e.g. a system with Anglo-Saxon units etc.) may still follow. (Non-SI units are displayed in bold) Unit system “ekb_eu” Value Unit Displacement (structures) [m] Length (distance driven by the vehicle) [m] Length (total driving distance of a test) [km] Length (diameter, piston/lever travel, thickness) [mm] Length (compression values) [µm] Area (piston area) [mm²] Velocity (vehicle) [km/h] Velocity (cooling air, structures) [m/s] Flow rate (cooling air) [m³/h] Volume (brake fluid) [mm³] Acceleration (vehicle, structures)(1) [m/s²] Force [N] Torque [Nm] Brake pressure [bar] Pressure increase [bar/s] Sound pressure(2) [Pa] Temperature [°C] Mass (e.g. total mass) [kg] Moment of inertia [kgm²] Time [s] Frequency [Hz] Angle (general, angle of rotation) [deg] Rotational Speed [rpm] Rel. humidity, axle load distribution, frequency etc. [%] Absolute humidity [g/m³] Damping (lining damping) [‰] Friction coefficient, efficiency [--] (without dimension) Electric Potential (voltage) [V] (1) The structure-borne sound is measured in [m/s²]. Structure-borne sound levels are always rms values in [m/s²]. (2) The sound pressure is measured in [Pa]. Sound pressure levels are displayed in dB or dB(A) (i.e. 20 log (prms/p0), with prms = rms value of the sound pressure signal in [Pa] and p0 = 2x10-5 Pa).


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4 Detailed description of the EEP file format The EEP file format is the main element for data transfer and is therefore required for every data transfer. It includes the identification (“EEP file ID”) of the file format, the file version and the language version in the first line of the file. The second line contains the specification of the unit system used (“Unit System”; this information always applies to all other files of a measurement). The header area (EEP header) begins in the third line, which may basically consist of any number of lines. The data table (“EEP data table”) with the summarized measurement results (one line per measurement) follows at the end of the file – indicated by the start line “part_data_begin” and the final line “part_data_end” – Structure of an EEP file:

4.1 EEP file ID

The first line contains the file ID (EEP file ID), which results from the string “eep_” and the version number multiplied with 100. The identifier for the language version is attached (see also Notes on the language version in chapter 3.1). Examples: eep_100_us meaning: EEP file format, version 1.0, language version: US English eep_100_de meaning: EEP file format, version 1.0, language version: German

4.2 Unit system definition

The second line contains the “unit_system” identifier with the value assigned to it. It defines the unit system used. So far, only the European unit system is defined with the “ekb_eu” value (see also chapter 3.4): unit_system, ekb_eu

EEP data table

EEP header

Unit system

EEP file ID


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4.3 EEP file header

The area of the EEP file header always begins in the third line of the EEP file and ends with the start of the “EEP Data Table” (table with measurement results, see chapter 4.5), which is indicated by the identifier “part_data_begin”, or at the end of the file (if the “EEP Data Table” is missing). Header data describe the boundary conditions for the set of measurements and define the type of parts measured. A header entry always consists of at least two column entries: the identifier and the assigned value. In addition, there are header entries with multiple values assigned to it. Since the files are always read line by line, if identical header entries are repeated, the last entry is valid (i.e. it overwrites the previous entry).

4.3.1 Description of the Measurement

company, <text> Specification of the company performing the set of measurements, as text. project, <text> Identification of the project (number, text or combination) to which this set of measurements belongs, as text. meas_name, <text> Identification of the set of measurements (number, text or combination) as text. This entry should correspond to the <measname> in the file name, if possible (see also chapter 2). meas_program, <text> Identification of the measurement program, circuit, procedure etc. as text (e.g. “EKB 2001” or similar). meas_options, <text> Optional elements of the measurement procedure, e.g. deviations from the standard, or similar. meas_rig, <text> Identification of the measurement rig or system used to conduct this set of measurements, as text or number (e.g. measurement rig name etc.). meas_modification, <text> Modifications made to the measured object before this set of measurements (as text). meas_motivation, <text> Reason / motivation for the conduction of this set of measurements (as text).


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meas_start_date, <date> This value defines the start of the measurement process (date and time). meas_end_date, <date> This value defines the end of the measurement process (date and time). meas_time, <time> Duration of the measurement process (equivalent to the difference “meas_end_date – meas_start_date”) in the format (h)hh:mm:ss. meas_total_quantity, <num> Planned number of measurements to be executed. meas_actual_quantity, <num> The number of measurents actually included in this set (i.e. this eep file). meas_aborted, <num> Message in the event of a measurement abortion (0=no measurement abortion). Messages still need to be defined (reason for the abortion). meas_error, <num> Measurement status error (0=no error). Error numbers still need to be defined. The following header entries apply only if all (modal) measurements are performed using the same excitation and response points; otherwise the appropriate identifiers of the data table have to be used: meas_excitation_id, <num> Excitation point identifier for the (modal) measurement. meas_response_id, <num> Response point identifier for the (modal) measurement. Excitation and response point identifiers are defined as follows: <measurement point no><direction ID> The <measurement point no> is the integer number of the measurement point. The <direction ID> is “X”, “Y”, or “Z” for cartesian coordinates, “R”, “T”, or “Z” for cylindrical coordinates, and “R”, “T”, or “P” for spherical coordinates, where X is the X axis direction Y is the Y axis direction Z is the Z axis direction R is the Radial direction T is the direction of elevation angle Theta P is direction of radial angle Phi (a preceeding minus sign indicates negative coordinate direction)


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Examples for point and direction identifiers: 15X point number 15, positive x axis direction -33T point number 33, negative direction of angle theta 5R point number 5, positive radial direction

4.3.2 Description of the Part

part, <text> Identification of the part examined (e.g. the commercial name of the part). part_type, <enum> Part type identifier as described under <parttypeID> for the file name. The short (“di”, “dr”, “pa”, “br”, “sh”, “pi”, “kn”, or “ap”) or the long abbreviations (“disc”, “drum”, “pad”, “brake”, “shim”, “piston”, “knuckle”, or “any”) for the part type identifier may be used – as well as the appropriate abbreviations for additional detailed descriptions of part types (“-in”, “-ou”, “-ho”, “-ca”, “-po”, “-ri”, “-rw”, or “-fn”) or (“-inside”, “-outside”, “-housing”, “-carrier”, “-pot”, “-ring”, “-raw”, or “-finished”) -. The long versions are preferred for more (human) readability of the file. part_manufacturer, <text> Manufacturer name of the part. part_number_oem, <text> Part or drawing number of the OEM for the complete part. part_number_supplier, <text> Part or drawing number of the supplier for the complete part. part_number_oem_<n>, <text> Part or drawing number of the OEM for a single component of the complete part. part_number_supplier_<n>, <text> Part or drawing number of the supplier for a single component of the complete part. Example for part numbers: part_type, brake { complete floating caliper

= housing & carrier }

part_number_oem, “A168 421 00 12” { complete floating caliper = housing & carrier }

part_number_oem_1, “A168 430 00 12” { housing of floating caliper } part_number_oem_2, “A168 440 00 12” { carrier of floating caliper } part_number_supplier, “X463.260” { complete floating caliper

= housing & carrier } part_number_supplier_1, “X463.360” { housing of floating caliper } part_number_supplier_2, “X463.460” { carrier of floating caliper }


Copyright: VDA

part_version_number, <text> Evolution step or version number of the part (e.g. in the event of modifications to / deviations from the series or the drawing number). Specification of a unique version number or text information on changes. part_axle, <enum> Axle on which the part is located (e.g. “front” or “rear”). part_side, <enum> Side of the axle in driving direction on which the part is located (e.g. “left” or “right”). part_eigenfrequency_no, <num> Number of reference frequencies for the part (if omitted, the amount of values assigned to “part_eigenfrequency_values” is used for “part_eigenfrequency_no” instead) part_eigenfrequency_values, <num> List of reference frequency values for the part in [Hz]. part_eigenfrequency_minvalues, <num> List of lower limits in [Hz] for the reference frequencies listed above. part_eigenfrequency_maxvalues, <num> List of upper limits in [Hz] for the reference frequencies listed above. part_mode_descriptions, <text> List of mode descriptions part_mass, <num> Mass of the part in [kg]. part_material, <text> Description of the material of the part. part_condition, <text> Condition of the part (“new”, “little wear”, “wear > 10%”, …). Not applicable for all part types (e.g. for “disc” or “pad”). part_chamfers, <num> Chamfer description (or “yes”, “no”) for part type “pad”. (See also: identifier “pad_chamfers” in EKB 3008 / VDA 305). part_slots, <num> Slots description (or “yes”, “no”) for part type “pad”. (See also: identifier “pad_slots” in EKB 3008 / VDA 305). part_shim_used, <bool> Only for part type “pad”: indicate if a shim used (“yes” or “no”). (See also: identifer “pad_shim_used” in EKB 3008 / VDA 305).


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part_compressvalue_inner, <num> Only for part type “pad”: inner pad compress value in [µm]. (See also: identifer “pad_compressvalue_inner” in EKB 3008 / VDA 305). part_compressvalue_outer, <num> Only for part type “pad”: outer pad compress value in [µm]. (See also: identifer “pad_compressvalue_outer” in EKB 3008 / VDA 305). part_compressvalue, <num> Only for part type “pad”: pad compress value in [µm]. Shall be used if “inner” or “outer” values are not applicable. part_compressvalue_type, <enum> Only for part type “pad”: type of compress value (“k3” or “k6”). Defines the type of compress values indicated by the above identifiers “part_compressvalue...” (See also: identifer “pad_compressvalue_type” in EKB 3008 / VDA 305). part_baseplate_type, <text> Only for part type “shim”: type of base plate used during shim measurements. (e.g. “SAE J3001 base plate”, “EKB base plate”, description of material and dimensions, and so on). The following header entries apply only if all parts are identical with respect to these entries; otherwise the appropriate identifiers of the data table have to be used: part_id_number, <text> Identification number for the individual part (e.g. “BB3489X001” or serial number of the actual part). part_batch_number, <text> (Any) batch number of the part. part_batchmold_number, <text> Molding batch number of the part. part_batchmach_number, <text> Machining batch number of the part. part_batchcomm_number, <text> Commercial batch number of the part. part_mold_number, <text> Mold number of the part (for casted parts, e.g. housings etc.). part_cavity_number, <text> Cavity number of the part (for casted parts, e.g. housings etc.).


Copyright: VDA

4.3.3 Other Header Entries

There is a direct link between the “EKB 3011 Part Data Exchange Format” described in this paper and the “EKB 3008 Test Data Exchange Format” desribed in VDA Recommendation 305. Therefore, header entries defined there and useful for measurement or part documentation, may also be used. Especially the analyzer settings should be documented in the EEP file header using the identifiers listed in VDA 305 Appendix I under “1.7.4 Analyzer Setup”. Other part related identifiers listed in VDA 305 Appendix I, like identifiers for suspension parts and brake parts may be used by exchanging the part type description by the keyword “part” (in VDA 308 (EKB 3011) the part type is defined by the identifier “part_type”). Examples: EKB 3008 Identifier (VDA 305) EKB 3011 Identifier (VDA 308) Examples for existing relationships: disc_manufacturer part_manufacturer (with part_type = disc) pad_manufacturer part_manufacturer (with part_type = pad) shim_manufacturer part_manufacturer (with part_type = shim) Examples for identifiers derived from EKB 3008: pad_compressvalue_type part_compressvalue_type (only for part_type = pad) pad_compressvalue_inner part_compressvalue_inner (only for part_type = pad) pad_compressvalue_outer part_compressvalue_outer (only for part_type = pad)

4.4 Comment block

One comment block can be added to the file. The line comment_begin is inserted before the comment block and the line comment_end is inserted after the comment block. The number and sequence of the comment entries inserted between “comment_begin” and “comment_end” can be chosen freely as desired. The entries are ignored by an evaluation software product. The comment block can be inserted after the first two lines of the EEP file (before the header area), within the header area, and before the start of the “EEP Data Table” (identified with “part_data_begin”). No comment blocks are permitted within and after the “EEP Data Table”.


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4.5 Table with result data

An overview of measurement results (“EEP Data Table”) can be inserted in the EEP file, which contains one line per measurement (number of lines = number of measurements). The data sector with the measurement results directly follows the previously described header data and starts with the line: part_data_begin A line with column identifiers follows directly as the next line. The number of identifiers defines the number of columns. The identifiers themselves clearly define the values in the columns and their physical units. Such a line could e.g. be as follows: measid, partid, measdate, tpart, excitid, respid, frq_1, frq_2, coh_1, coh_2, ... Two lines follow this identifier line, which are not evaluated and which may therefore include comments. However, they shall include just as many fields (columns) as corresponds to the number of previously defined column identifiers; they should be used for the improved legibility of the table and contain column headings and the physical units in plain text. Similar to the previous example, the lines could be e.g. as follows: Meas-No, Part, Date, Temp, Excit, Resp, Freq1, Freq2, Coh1, Coh2,... ---, ---, ---, °C, ---, ---, Hz, Hz, ---, ---, ... These three lines with the table heading (column identifier, column heading, unit text) are followed by the corresponding data lines: one line per measurement. Example: 1, BB3489X001, 07/11/2013 08:15:00, 25.0, 1X, 2Y, 813, 1765, 0.89, 0.92 2, BB3489X001, 07/11/2013 08:22:00, 30.4, 1X, 2Y, 811, 1762, 0.91, 0.85 3, BB3489X001, 07/11/2013 09:35:00, 34.9, 1X, 2Y, 819, 1772, 0.87, 0.84 4, BB3489X001, 07/11/2013 11:10:00, 40.2, 1X, 2Y, 807, 1759, 0.82, 0.91 Note: Since the first line after “part_data_begin” defines the sequence and number of columns, all subsequent lines shall have the same number of columns. That is also the case if the first line in a field contains an unknown identifier or a blank field. Empty columns or special columns can thus also be created with signals not defined here. For example, if an empty column is to be inserted instead of the column for “measdate” / “Measurement Date”, the table example above would look like as follows:


Copyright: VDA

measid, partid, , tpart, excitid, respid, frq_1, frq_2, coh_1, coh_2 Meas-No, Part, , Temp, Excit, Resp, Freq1, Freq2, Coh1, Coh2 ---, ---, , °C, ---, ---, Hz, Hz, ---, --- 1, BB3489X001, ,25.0, 1X, 2Y, 813, 1765, 0.89, 0.92 2, BB3489X001, ,30.4, 1X, 2Y, 811, 1762, 0.91, 0.85 3, BB3489X001, ,34.9, 1X, 2Y, 819, 1772, 0.87, 0.84 4, BB3489X001, ,40.2, 1X, 2Y, 807, 1759, 0.82, 0.91 To indicate user-defined identifiers (and to ensure that they can never collide with identifiers defined in VDA 308 (EKB 3011)), they should be indicated by a leading “@” character. The following example shows this: measid, partid, @MyID, tpart, excitid, respid, frq_1, frq_2, coh_1, coh_2 Meas-No, Part, MyValue, Temp, Excit, Resp, Freq1, Freq2, Coh1, Coh2 ---, ---, ??, °C, ---, ---, Hz, Hz, ---, ---... 1, BB3489X001, 4711,25.0, 1X, 2Y, 813, 1765, 0.89, 0.92 2, BB3489X001, 4712,30.4, 1X, 2Y, 811, 1762, 0.91, 0.85 3, BB3489X001, 4713,34.9, 1X, 2Y, 819, 1772, 0.87, 0.84 4, BB3489X001, 4714,40.2, 1X, 2Y, 807, 1759, 0.82, 0.91 The list of data lines is completed with the line part_data_end All of the following entries are then ignored by the reading program. EEP Data Table Column Identifiers The values in the individual columns have the following meaning, depending on the column identifier selected: measid <num> Integer number (>0) to identify the measurement (not the part itself). Start and end values may be freely selected – ascending order is recommended. In addition, the “measid” is used to identify the measurement data file (<measID>). Example how “measid” identifies a measurement: It is assumed that the set of measurements is listed in the EEP file named “mypart_di_eep.csv”. If, for example, the “measid” of a single measurement equals to 215 the FRF measurement belonging to this measurement can be found in the file “mypart_di_nr00215_frf.uff” (if modal measurement data files are available). partid <text> Part identification number (identifier for the individual part or serial number of the part, e.g. “BB3489X001”). Equivalent with header identifier “part_id_number”; header settings will be overwritten by table entries.


Copyright: VDA

batch <text> (Any) batch number of the part. Equivalent with header identifier “part_batch_number”; header settings will be overwritten by table entries. batchmold <text> Molding batch number of the part. Equivalent with header identifier “part_batchmold_number”; header settings will be overwritten by table entries. batchmach <text> Machining batch number of the part. Equivalent with header identifier “part_batchmach_number”; header settings will be overwritten by table entries. batchcomm <text> Commercial batch number of the part. Equivalent with header identifier “part_batchcomm_number”; header settings will be overwritten by table entries. mold <text> Mold number of the (casted) part. Equivalent with header identifier “part_mold_number”; header settings will be overwritten by table entries. cavity <text> Cavity number of the (casted) part. Equivalent with header identifier “part_cavity_number”; header settings will be overwritten by table entries. tamb <num> Ambient temperature during measurement in [°C]. tpart <num> Part temperature during measurement in [°C]. humrel <num> or Relative humidity during measurement in [%]. humabs <num> Absolute humidity during measurement in [g/m³]. castdate <date> Casting date and time of the part. measdate <date> Measurement date and time. excitid <text> Excitation point identification as text (e.g. “1X”). Equivalent with header identifier “meas_excitation_id”; header settings will be overwritten by table entries. respid <text> Response point identification as text (e.g. “2Y”). Equivalent with header identifier “meas_response_id”; header settings will be overwritten by table entries.


Copyright: VDA

EEP Data Table Column Identifiers for Modal Measurement Results frq_<n> <num> Measured (resonant) frequency <n> in [Hz] (n = 1, .. , part_eigenfrequency_no). If there is no value available for the appropriate reference frequency the table cell remains empty. frqdev_<n> <num> Deviation of measured frequency <n> from reference in [Hz] (n = 1, .. , part_eigenfrequency_no). If there is no value available for the appropriate reference frequency the table cell remains empty. coh_<n> <num> Coherence at frq_<n> in [--] (n = 1, .. , part_eigenfrequency_no). If there is no value available for the appropriate reference frequency the table cell remains empty. dlf_<n> <num> Damping (loss factor) at frq_<n> in [--] (n = 1, .. , part_eigenfrequency_no). If there is no value available for the appropriate reference frequency the table cell remains empty. Notes: If reference frequencies are defined (see header entry “part_eigenfrequency_values”) measured values have to be assigned to table entries in the order specified by the header entry. For example, if there are three reference frequencies defined (e.g. “part_eigenfrequency_values, 800, 1100, 1600”), the table entry for “frq_1” contains the measured resonant frequency for the reference of 800 Hz, the table entry for “frq_2” contains the measured resonant frequency for the reference of 1100 Hz, and the table entry for “frq_3” contains the measured resonant frequency for the reference of 1600 Hz. If the measured value does not match the reference frequency (see also: “part_eigenfrequency_minvalues”, “part_eigenfrequency_maxvalues”) the appropriate table cell remains empty. In addition, it is advisable to use the second line of the table header (column headings) to indicate the reference frequencies (e.g. like “f1=800”, “f2=1100”, “f3=1600”, etc.). Example (three reference frequencies and three table entries): part_eigenfrequency_values , 800,1100,1600 part_data_begin measid, partid, frq_1, dlf_1, frq_2, dlf_2, frq_3, dlf_3, Meas-ID, Part-ID, “f1=800 Hz”, LF(f1), “f2=1100 Hz”, LF(f2), “f3=1600 Hz”, LF(f3), ---, ---, Hz, ---, Hz, ---, Hz, ---, 1, X001, n/a, n/a, 1161.0, 0.0375, 1667.3, 0.0283 { f1 not found } 2, X002, 808.2, 0.0522, 1148.3, 0.0368, 1634.0, 0.0265 3, X003, 814.0, 0.0489, n/a, n/a, 1652.8, 0.0278 { f2 not found } 4, X004, 785.5, 0.0557, 1076.7, 0.0422, 1594.3, 0.0272 part_data_end


Copyright: VDA

If there are no reference frequencies defined measured values are assigned to table entries in no specific order (preferred: ordered by frequency). Example (no reference frequencies and three table entries): part_eigenfrequency_values , n/a part_data_begin measid, partid, frq_1, dlf_1, frq_2, dlf_2, frq_3, dlf_3, Meas-ID, Part-ID, “1

st Frequ.”, LF(f1), “2

nd Frequ.”, LF(f2), “3

rd Frequ.”, LF(f3),

---, ---, Hz, ---, Hz, ---, Hz, ---, 1, X001, 1161.0, 0.0375, 1667.3, 0.0283 2, X002, 808.2, 0.0522, 1148.3, 0.0368, 1634.0, 0.0265 3, X003, 814.0, 0.0489, 1652.8, 0.0278 4, X004, 785.5, 0.0557, 1076.7, 0.0422, 1594.3, 0.0272 part_data_end

If there are more table entries than the number of reference frequencies a measured value which does not match any reference frequency may be added (behind the entries for reference frequencies with no specific order or ordered by frequency). Example (two reference frequencies and three table entries): part_eigenfrequency_values , 800,1100 part_data_begin measid, partid, frq_1, dlf_1, frq_2, dlf_2, frq_3, dlf_3, Meas-ID, Part-ID, “f1=800 Hz”, LF(f1), “2

nd Frequ.”, LF(f2), “3

rd Frequ.”, LF(f3),

---, ---, Hz, ---, Hz, ---, Hz, ---, 1, X001, n/a, n/a, 1161.0, 0.0375, 1667.3, 0.0283 { f1 not found } 2, X002, 808.2, 0.0522, 1148.3, 0.0368, 1634.0, 0.0265 3, X003, 814.0, 0.0489, 1652.8, 0.0278 4, X004, 785.5, 0.0557, 1076.7, 0.0422, 1594.3, 0.0272 part_data_end


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5 Example of an EEP file { EEP file header:} eep_100_us unit_system , ekb_eu company , ABC Brake Testing Inc. project , Brake Development 0815 meas_program , SAE J3001 meas_start_date , 09/21/2008 15:49:15 meas_end_date , 09/22/2008 18:35:07 meas_total_quantity , 100 meas_actual_quantity , 100 meas_aborted , 0 meas_error , 0 { - this is a comment - } part_eigenfrequency_values , 810,1725,2376 part_type , shim part_number_oem , “A168 421 00 12” part_number_oem_1 , “A168 430 00 12” part_number_oem_2 , “A168 440 00 12” part_number_supplier , “X463.260” part_number_supplier_1 , “X463.360” part_number_supplier_2 , “X463.460” { more header entries may be added } { Optional comment block:} comment_begin : -- any number of free comment lines – : comment_end { Overview of measurement results: } part_data_begin measid, partid, measdate, tpart, excitid, respid, frq_1, frq_2, frq_3, coh_1, coh_2, coh_3 Meas-No, Part, Date, Temp, Excit, Resp, “f1=810”, “f2=1725”, f3=2376”, Coh1, Coh2, Coh3 ---, ---, ---, °C, ---, ---, Hz, Hz, Hz, ---, ---, --- 1, BB3489X001, 07/11/2013 08:15:00, 25.0, 1X, 2Y, 813, 1765, 2125, 0.96, 0.92, 0.95 2, BB3489X002, 07/11/2013 08:22:00, 30.4, 1X, 2Y, 811, 1762, 2118, 0.91, 0.98, 0.91 3, BB3489X003, 07/11/2013 09:35:00, 34.9, 1X, 2Y, 819, 1772, 2131, 0.93, 0.94, 0.89 4, BB3489X004, 07/11/2013 11:10:00, 40.2, 1X, 2Y, 807, 1759, 2114, 0.87, 0.91, 0.90 : -- in this example, 96 more value lines follow (one line per measurement) – : 100, BB3489X100, 07/11/2013 21:05:00, 120.8, 1X, 2Y, 799, 1732, 2096, 0.97, 0.91, 0.93 part_data_end

vda ekb 3011 - part data exchange format...the illustration in the following figures gives an...

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