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Comprehensive Identification from FrEquency

1. Window m Cursor Size Display Options E Full Screen C Large Command History Buffer Size 50 2 Number of Buffers 4 IF Discard Old Duplicates IF QuickE dit Mode I Insert Mode Cancel Apply Figure 4 4 Enabling Ouick Edit Mode With this mode enabled you will be able to capture screen text into the paste buffer by depressing the left mouse button and dragging across the desired text to highlight it and then releasing the left mouse button to select the highlighted text Next you can capture the selected text by right clicking Captured text may be subsequently inserted at the cursor position by right clicking a second time This maneuver is very useful for duplicating complicated CIFER frequency response names To enable scrolling select the Layout tab of the Properties panel Figure 4 5 In the Screen Buffer Size pane enter a suitably large value e g 1000 lines for the Height however leave the Width set to 80 columns Next in the Window Size pane enter a number of lines sufficient to give the shell window the screen coverage you would like again do not alter the width of the window CasalCorp September 2005 Page 17 CIFER Software User s Manual There is one remaining customization which you may wish to consider when setting up your CIFER shortcuts As it is installed the CIFER shell will always launch with white actually grayish lettering di
2. The next figure is a plot of the resulting autospectra of one of the time histories GM40 from COMPOSITE and for the individual windows from FRESPID The figure clearly illustrates that the desired results have been obtained from COMPOSITE a smooth autospectra that tracks the autospectra from the longer windows at low frequencies and tracks the autospectra from the shorter windows at high frequencies COMPOSITE FRESPID sareeneneee 30 sec window T 20 sec window 15 sec window 10 sec window 5 sec window Gxx Mag dB 2 3 4 5 6 7 8 9 Frequency rad sec COMPOSITE and FRESPID input autospectra 7 3 The X15 Database A standard CIFER installation is delivered with a fully populated XV15 database with both hover and forward flight conditions represented This is used as a reference for both the detailed descriptions of CIFER Programs and Utilities that follow Section B of this Software User s Manual and for the lab exercises provided with CasalCorp s CIFER Training Series CD DVD set Please consult that Training Series manual for a complete description of the XV15 Test Cases and data bases CasalCorp September 2005 Page 31 CIFER Software User s Manual SECTION B CIFER PROGRAMS AND UTILITIES CasalCorp September 2005 Page 32
3. Design system subsystem assembly component In this section we provide examples to assist both the new user gain familiarity with CIFER features and the experienced user to refresh The reader is also promoted to periodically revisit CasalCorp s CIFER Support Area www casalcorp com for new examples document updates and related publications 7 1 Models and Components These examples are under construction and will be provided with a future version of this User s Manual See also the CIFER Primer publication pending 7 2 CIFER and Unstable or Nonlinear Systems Contributed by Dr Mark Tischler One of the most common misconceptions about frequency domain system identification in general is the notion that it can only be effective for stable mode systems In other words one assumes that the Bode diagram of an unstable system response has no meaning because of an erroneous belief that the techniques demand that any transients must decay or die out before a sinusoidal response results This conclusion is simply incorrect The source of the confusion is a common interpretation that the frequency response only has meaning when a constant sinusoidal input can produce a constant sinusoidal output This is a very simple way of thinking about the frequency response determination process for a stable system bit it is not how a frequency response is defined The frequency response IS defined and has complete meanin
4. Figure 1 4 CIFERTEXT file sample CTDIF Format CTDIF varies from the CIFERTEXT format only in the details of the header Record 1 User defined e g flight event references Record 2 User defined e g analysis specific keywords Record 3 User defined e g a text description of the file Record 4 A list of channel names separated by spaces and or tabs Record 5 Floating point values separated by spaces and or tabs Each line should contain as many values as there were channel names defined in Record 4 In CTDIF time is often one of the channels first column suggested for the DT reference lh sample_ctdif ctdif txt Notepad File Edit Format View Help 162501 18 80 TESTPLAN MNVRCODE TRANS 1 TEXTFILE HOV LNG FREQ SWEEP 1 2IN TIME_D80 COLLASIPD80 COLLASOPD80 COLSTKP1D80 EXCSIG_D80 HEAD18 0 0141000 0 5794747 59 58763 57 47087 0 02007741 28 381 0 0264480 0 5916601 59 88052 57 53711 0 02202033 28 485 0 0389520 0 5758191 59 60486 57 44076 0 02007741 28 443 0 0514680 0 5733821 59 29475 57 44678 0 01347145 28 257 lt gt Figure 1 5 CTDIF file sample To complete the THD files link for your analysis session when you select Types 5 or 8 for the time history source you will be presented with screen 3B not shown in the CIFER User s Manual but illustrated as Figure 1 6 On this screen you are asked to provide a filename for each flight number and event number combination that you ha
5. Page 10 Display j Matrix elements Page 11 Display T Matrix elements Page 12 Set up source of control channels time history data Page 13 Set up source of observer channels time history data Page 14 Modify control channel for this model record Page 15 Estimate bias for this element of the state equation Page 16 Model observer channel for this model record Page 17 Select part or all of the time history sample Page 18 Condition time histories Interactive calculation of low order transfer function calculation from high order transfer function or frequency response data 7 RMS Utility 8 Handling Qualities and Stability Margins 9 Frequency Response Arithmetic 14 Read ASCII Matrix File s 15 Read ASCII Response into the Database 19 QPLOT Plot Frequency Responses 20 Print Frequency Response Values 11 Change CIFER Defaults 12 Case Directory 13 Case or Response Delete Utility 16 Select Aircraft Analysis SIFDEF file 17 Create Aircraft Create new db or create SIFDEF for existing db 18 Search Frequency Response db 27 Database Case Copy 28 Database Share not available on WINTEL 29 Database Compress 31 Plot DERIVID Results 32 Plot VERIFY Results 33 Tabular DERIVID Reports 34 Tabular VERIFY Reports 35 Print DERIVID or VERIFY Results 36 Case Plotting Utility 37 DERIVID or VER
6. character character insert mode the character is inserted directly above the cursor moving the right portion of the line one character to the right backspace Deletes the character immediately to the left of the cursor and drags the right portion of the line one character to the left del Deletes the entire line even if the cursor is positioned in the interior of the line CasalCorp September 2005 Page 20 CIFER Software User s Manual 5 Getting Started Setting Up Databases and SIFDEF files This section will provide an overview of CIFER databases and the procedures for creating them SIFDEF files will be described and the relationship between databases and SIFDEF files will discussed Finally a detailed example of the creation of a user database and its associated SIFDEF file will be given 5 1 Organization and Content of CIFER Databases The CIFER package consists of a large number of independent utilities which interact by accessing information stored in a common database An individual CIFER user may have many such databases each dedicated to a particular project or even a particular engineering analysis within a project Each database is given a unique aircraft ID at the time that it is created An aircraft ID is a string of up to eight characters Valid characters include alpha numeric characters dashes and underscores blanks are not allowed Physically a database consists of a data file binary
7. 4 Set desired combinations of input output to compute incl ALL Page 5 Edit sensor coefficients alternate method Page 6 Name the responses used in the identification semi automatic Page 7 Name the responses used in the identification manual Page 8 Specify the terms of the M Matrix Page 9 Specify the terms of the F Matrix Page 10 Specify the terms of the G Matrix Page 11 Specify the terms of the T Matrix Page 12 Establish named derivatives in M Matrix Page 13 Establish named derivatives in F Matrix Page 14 Establish named derivatives in G Matrix Page 15 Establish named derivatives in T Matrix Page 16 Fix the H matrix and launch analysis Others Page 14 CIFER Software User s Manual VERIFY State Space Model Verification NAVFIT Frequency response analysis utilities Program Parameter utilities Database and Setup Utilities Results Utilities CasalCorp September 2005 Page 1 Select Case and Aircraft choose DERIVID or VERIFY Page 2 Set up links to matrix names M F G Tau H s Page 3 Present model parameters subset of DERIVID model parameters Page 4 Display sensor coefficients for all observer control combinations Page 5 Display M Matrix elements Page 6 Display F Matrix elements Page 7 Display G Matrix elements Page 8 Display H s Matrices output structure for VERIFY Page 9 Display H Matrix elements
8. PRODUCT PROMPTLY TO THE PLACE OF PURCHASE FOR A FULL REFUND OWNERSHIP OF THE SOFTWARE The Licensor software program identified above and the accompanying documentation are owned by Licensor and are protected by United States copyright laws by laws of other nations and by international treaties Licensor owns rights to all copyright trade secret patent and other proprietary rights in the Software This License gives you no rights to such content In addition under no circumstances is reverse engineering of the software program algorithms or features functions in whole or in part allowed LICENSE The Licensee is hereby granted a non exclusive license to use the Software for up to and including the number of seats specified in the accompanying ordering agreement Licensee may not a permit other individuals to use the Software except under the terms listed herein b use or permit others to use the Software for any commercial purpose c modify translate reverse engineer decompile disassemble except to the extent applicable laws specifically prohibit such restriction or create derivative work based on the Software d copy the Software except for back up purposes e rent lease transfer or otherwise transfer rights to the Software or f remove any copyright trademark or other proprietary notices or labels on the Software DISCLAIMER OF WARRANTY The software is licensed on an AS IS basis without warranty of any kind
9. Update Selection of items on this menu may be made via the right or left arrow keys or by typing the first letter of the desired entry Once an entry has been selected depress F1 to accept Update is an exception Type T or F to enable or disable a database update respectively to be done after selection of an entry It is not possible to select this item via the arrow keys nor does typing U have any effect F3 This key is only used in specialized situations see for example Class Notes Vol 2 DERIVID operations screen 4 F4 Presents a secondary navigation menu of the form Go to to which the user may respond with a screen number followed by the Fl key or the RETURN key Screen numbers entered at this prompt may be outside of the range of actual screen numbers for the program e g 99 will take you to the end of the data entry segment for most of the CIFER utilities Table 4b QPLOT Augmented Data Entry Features Moves cursor to the left end of the current field CTRL A CTRL D Moves cursor to the right end of the current field CTRL G Moves cursor left by one character CTRL L Moves cursor right by one character CTRL O Enters character insert mode Any printable character typed will be inserted directly above the cursor lt ESC gt Exits character insert mode any printing In normal mode overwrites the character directly above the cursor In
10. after you have already used results from an earlier different version of the same case name For instance if you have already run FRESPID MISOSA and COMPOSITE for a particular window size and you then rerun FRESPID changing window parameters for an existing case and window you will probably cause yourself grief unless you continue on and rerun MISOSA and COMPOSITE using the new frequency responses As an example of the generation of frequency responses by CIFER consider this sample run of FRESPID MISOSA and COMPOSITE For a case involving two controls four outputs and five windows FRESPID creates the following 40 frequency responses XVLATSWP_FRE_A0000_AIL_P XVLATSWP_FRE_0B000_AIL_P XVLATSWP_FRE_00C00_AIL_P XVLATSWP_FRE_000D0_AIL_P XVLATSWP_FRE_0000E_AIL_P XVLATSWP_FRE_A0000_AIT _R XVLATSWP_FRE_0B000_AII _R XVLATSWP_FRE_00C00_AIL_R XVLATSWP_FRE_000D0_AIL_R XVLATSWP_FRE_0000E_AIL_R XVLATSWP_FRE_A0000_AIL_AY XVLATSWP_FRE_0B000_AII _AY XVLATSWP_FRE_00C00_AIL_AY XVLATSWP_FRE_000D0_AIL_AY XVLATSWP_FRE_0000E_AIL_AY XVLATSWP_FRE_A0000_AITI VDOT XVLATSWP_FRE_0B000_AIL_VDOT XVLATSWP_FRE_00C00_AIL_VDOT XVLATSWP_FRE_000D0_AIL_VDOT XVLATSWP_FRE_0000E_AIL_VDOT XVLATSWP_FRE_A0000_RUD_P XVLATSWP_FRE_0B000_RUD_P XVLATSWP_FRE_00C00_RUD_P XVLATSWP_FRE_000D0_RUD_P XVLATSWP_FRE_0000E_RUD_ XVLATSWP_FRE_A0000_RUD XVLATSWP_FRE_0B000_RUD_ P y CasalCorp September 2005 Page 11 CIFER Software User s Manual XVLA
11. data file is concerned this is most definitely not equivalent to the implied loop form READ lun data i i l npts 2 CIFER always assumes that data are equally spaced in time CasalCorp September 2005 Page 4 CIFER Software User s Manual 1 2 2 CIFERTEXT Type 5 or CTDIF Type 8 CIFER WINTEL now supports a more compact and exchangeable ASCII input format that combines all channels needed for an analysis These formats are similar with the only effective difference being the header information CIFERTEXT Format CIFERTEXT files follow this simple effective format Record 1 A floating point number representing the sampling period delta time Record 2 A list of channel names separated by spaces and or tabs Record 3 Floating point values separated by spaces and or tabs Each line should contain as many values as there were channel names defined in Record 2 Figure 1 4 shows a sample of a CIFERTEXT file sample_cifertext txt Notepad DER Fie Edit Format View Help 0 01 A COLLASIPD80 COLLASOPD80 COLSTKP1LD80 EXCSIG_D80 HEAD1801D80 LACCAF 5794747 59 58763 57 47087 0 02007741 28 38151 0 0082 5916601 59 88052 gy a kak 02202033 28 48517 0 0834 5758191 59 60486 44076 02007741 28 4437 p 1526 5733821 59 29475 44678 01347145 28 25712 0 0936 5697265 59 20861 42871 01347145 28 04979 0 0145 5660709 59 2603 42269 01424862 28 15345 0 1009 gt
12. in such a way that they can be read by the following simple FORTRAN code segment DO i 1 npts READ lun data i END DO Because Type 1 time history files contain only the data points themselves the user must enter the time step between samples in seconds in the corresponding field of FRESPID screen three Finally CIFER requires that Type 1 time history files must be stored in a specialized directory tree structure based upon flight number and event This tree is rooted at the location pointed to by the CIFER environment variable THLOC Figure 1 3 illustrates a typical directory tree containing Type 1 files Note the manner in which the flight and event numbers are encoded into the subdirectory names and file names In addition to the flight and event number parameters the file name itself encodes a third parameter the data channel name as follows lt channel gt E lt event no gt lt flight no gt Figure 1 3 Typical Type 1 Time History Directory Tree F Flight Number E Event Number The CIFER software system comes with a variety of utilities to assist the user in this file organization One of those is mvhistories which aids in creating this tree of CIFER time histories If all files are correctly named and reside in a single directory then invoking this utility will create subdirectories and move the files into their proper places Note that as far as the record structure of the
13. line should then read gt The active SIFDEF is MY_FLYER TH2 lt From this point forward you may designate one or the other of these files as the active SIFDEF file using utility 16 Select Aircraft Analysis SIFDEF file Advanced Topic The preceding discussion illustrated a relatively straightforward application of analysis tags to distinguish between two SIFDEF files which each target the same database The next logical extension of this scenario would be to the case where the user wished to store the results of his CIFER analyses for the two time history data sets in separate databases Since both data sets pertain to the same aircraft logic requires that we not use different aircraft IDs but on the other hand the aircraft ID is the sole determinant of the database file name the analysis tag does not enter into the database name Thus the only reasonable way to modify the above scenario to incorporate independent database files for each set of time history data would be to store the databases in separate directories This can be easily accomplished at the point when the databases are created i e when you run utility 17 Create Aircraft Create new database or create SIFDEF for existing db When you are asked to enter the directory in which to create the database simply choose a directory structure that reflects the analysis tag that will be associated with the SIFDEF file under construction For exa
14. machine and records are updated it is likely and acceptable that records of both endian will exist Remember that a database comprises a data file dat and an index file idx If ftp is used to transfer a database use binary mode This should go without saying for the binary data file but it is also important to use this mode for the index file Otherwise when an index file is copied to a Windows machine in ASCII mode a DOS end of record character is added to every line breaking the database software 1 3 Frequency Response Database amp Naming Conventions The core of the CIFER analysis technique is the generation conditioning fitting and combining of frequency responses from control and output time histories Frequency responses such as those produced by FRESPID are generated either as stand alone ASCII files or are written to the CIFER frequency response database The latter provides a more compact storage method and stores information about how the frequency response was generated However because of the file format the data is not directly human readable and can be accessed only via the CIFER software Note that the print frequency response utility allows generation of an ASCII file containing frequency response values from the database The format of these files is Record 1 Descriptive information about the frequency response Record 2 n Frequency magnitude phase coherence gxx gyy gxy real part of r
15. of a functioning READMIS routine examine the readmis TYP1 file for the language of your choice 1 2 4 Third Party Software Interfaces CIFER may be connected to data generated from 3 party software such as EXCEL MATLAB LabView OriginLab and the like This is best done by exporting the data sets from the external application into one of the ASCII formats just described CIFERTEXT or CTDIF Most modern analysis and simulation software is capable of this directly or using simple utilities Alternatively a READMIS DLL may be constructed specific to the as formatted data discussed next Finally if the data is already in binary channels as described in section 1 2 1 then these can be organized into the needed directory structure and linked by pointing to the directory through Setup Utilities Installing the MATLAB DLL Recognizing the widespread use of MATLAB in the engineering and science enterprises that CIFER supports a pre constructed MATLAB READMIS DLL is delivered with the standard installation Only one READMIS DLL may be attached at a time CasalCorp September 2005 Page 8 CIFER Software User s Manual Please note that standard MATLAB not binary data may be exchanged via simple extractions into CIFER s ASCII formats CIFERTEXT or CTDIF The purpose of this DLL is to provide the means to read MATLAB Binary data The MATLAB binary file must contain a time lower case array and arrays of the same size as time
16. sample READMIS code provided with this package see below however a few further comments about time history data organization are in order here As noted in the case of Type 1 time history data files described above CIFER regards time history data as organized around the parameters flight number event number and channel name And indeed the READMIS arguments flightNo eventNo and channel convey exactly this information into the READMIS module Once again when you select option 4 for the time history source you will be presented with screen 3B not shown in the CIFER User s Manual but illustrated here see Figure 1 6 On this screen you are asked to provide a filename for each flight number and event number combination that you have specified on previous screens This filename information will be made available to READMIS via the filename argument Of course your READMIS data may not reside in individual files at all it may be located in a database or grouped in some other fashion in container objects Thus it is important to realize that for Type 4 time history data CIFER makes no use of these various pieces of information other than to pass them to your READMIS routine You may encode any type of information into these parameters that will help you locate your data For example it may be more appropriate for your purposes to associate a directory path with each flight number and event number pai
17. screen you will be returned to the Database Utilities submenu Wj C CIFER_Pro bin setdefaults 3 gt Set logicals needed by CIFER CPress the PFi key to accept the screen JIHDE EEEE fircraft Analysis MY_FLYER default CIFER DB Location C CIFER_Pro data dh Units RAD CRAD or HZ Time history loc C CIFER_Pro data th Plot directory z C CIFER_Pro jobs plots Batch directory C CIFER_Pro jobs TRENDS database TRENDS tail id We Figure 5 2 Editing the Active SIFDEF File In order to complete the first portion of the setup the only remaining task is to change the name of the analysis from default as indicated by the status line to something suggestive of the origin of the time history data Note that it is unfortunately not possible to edit the analysis name from within the screen editor utility 11 To change the name of the analysis we will save the active SIFDEF as say SIFDEF MY_FLYER TH1 as follows You will be shown a list of available SIFDEF files for CasalCorp September 2005 Page 24 CIFER Software User s Manual aircraft MY_F LYER depress carriage return to dismiss the list and then type TH1 and effect the selection by depressing carriage return again Upon the completion of this operation we are returned to the submenu screen but the status line now reads gt The active SIFDEF is MY FLYER TH1 lt which is the desired result If this were
18. CASALCORP Comprehensive Identification from FrEquency Responses An interactive facility for system identification and verification CIFER WINTEL Software User s Manual Version 4 2 00 or later CasalCorp gratefully acknowledges the extraordinary contributions of Dr Mark Tischler and Mr Dexter Hermstad in the continuing success and growing capabilities found in the CIFER software system September 2005 CasalCorp USA CASALCORP SOFTWARE LICENSING AGREEMENT Comprehensive Identification from FrEquency Responses CIFER RECITAL CasalCorp HAS ACQUIRED FOR DISTRIBUTION SUPPORT AND REUSE UNIQUE ANALYSIS SOFTWARE FOR MODELING COMPLEX SYSTEM BEHAVIOR BASED UPON LIVE OR RECORDED DATA USING A TECHNIQUE CALLED SYSTEM IDENTIFICATION SOFTWARE IMPORTANT READ CAREFULLY This End User License Agreement EULA is a legal agreement between you either an individual or a single entity and CasalCorp for the above identified software and associated documentation Software By installing copying or otherwise using Software you agree to be bound by the terms of this EULA If you do not agree to the terms of this EULA do not install or use Software CasalCorp LICENSOR IS WILLING TO LICENSE SOFTWARE TO YOU LICENSEE ONLY IF YOU ACCEPT ALL OF THE TERMS IN THE LICENSE AGREEMENT IF YOU DO NOT AGREE TO THESE TERMS LICENSOR WILL NOT LICENSE THIS SOFTWARE TO YOU AND IN THAT CASE YOU SHOULD RETURN THIS
19. CIFER Modeting Partial Coherences Frequency domain system identification Identification Freq Response Algorithm Identification process Criterion Initial gt Mathematical Model Dynamic Behavior Derivatives Values lt lt and Time Delays Va Sensitivity Analysis Dissimilar Reference Data not used in RO Model Structure sar Le Fh gt Wenttication Determination Identification ANALYSIS APPLICATION interactive semi automated automated Figure 1 2 CIFER is based not only on sound science but on sound engineering Other important aspects of our use of CIFER s processing features in our approach include gt Tools and results exercised and proven over 14 years of use recognized as world best in class for applications addressing real world problems in real world conditions Y Significant relevant data and experience can be supplemented with minimal additional effort and cost to any future program s Non real time and real time analysis directly supported Directly relevant identification algorithms are highly exercised and tuned Flexible and interactive definition of identification model structures VV VV Non Parametric Modeling directly supported no a priori assumptions are needed about the system order structure or composition Y Fully automated weighting function selection based on frequency response accuracy Y Built in and reliable parameter accuracy me
20. ER graphics operations because it is necessary in two of the three WINTEL CIFER graphics configurations for the graphics window to have the focus before it can be dismissed CIFER graphics windows in configurations I and 2 are dismissed returning focus to the CIFER input screen by typing a carriage return while the graphics window has focus This means that if your mouse wanders away from the window boundary nothing will happen when you depress carriage return Also if the title bar of the plot window reads Hit RETURN to close amp continue do not dismiss the graphics window by clicking the window s close box because this will cause the parent CIFER utility to immediately exit Users familiar with Unix versions of CIFER will know that those systems support several operational modes which allow multiple plot windows and persistent plot windows Due to limitations inherent in the NuTCRACKER WINTEL interface these modes were only recently implemented in the WINTEL version The default WINTEL CIFER mode is to support a single plot window that must be dismissed by hitting the RETURN key before interacting with CIFER again You can select your preferred mode via utility 91 available in CIFER main menu Please note that on some systems plots do not automatically pop to the top when generated i e they can be obscured by other windows Check the Windows status bar if you don t see your plot the icon correspo
21. IFDEF file Remember this is only a copy of the parent SIFDEF file and hence it can be modified without concern for loss of existing data If you would like to use another SIFDEF file as the template you first must select it When you select utility 16 Select Aircraft Analysis Select SIFDEF file you will be shown a list of available SIFDEF files depress carriage return to dismiss the list and then choose the default selection by depressing carriage return again When you return to the submenu screen the status line may be shown in reverse video would indicate that another SIFDEF file is active if you had specified a different SIFDEF file Main menu utilities may be run from this menu also Each of these utilities may be run from the main menu also Database Utilities Change CIFER Defaults Case Directory Case or Response Delete Utility Select Aircraft Analysis SIFDEF file gt Create Aircraft Create new database or create SIFDEF for existing db Search Frequency Response D B Database Case Copy Database Share not available Database Compress gt The active SIFDEF is CIFERSTD DEFAULT lt Enter a number to select a utility Enter lt CR gt to return to main menu gt Input m Figure 5 1 CIFER Utility 10 Database Utilities Submenu CasalCorp September 2005 Page 23 CIFER Software User s Manual Next select the Create Aircraft Create new database or create SIFDEF fo
22. IFY Matrix Reports 38 Eigenvalue Utility 39 DERIVID Parameter Dump Page 15 CIFER Software User s Manual 4 Running CIFER Once you have completed the installation of the CIFER package made any necessary manual adjustments to the X Vision transport protocols see Section 3 of the CIFER Installation Guide and Release Notes IGRN and rebooted your machine you should be able to invoke CIFER either by double clicking the shortcut that the installer placed on your desktop or by selecting the START gt Programs gt Cifer gt CIFER Shell menu item Figure 4 1 Note that two different methods for starting CIFER may give you slightly different CIFER windows with different properties e g a CIFER window started via the desktop shortcut may be physically shorter than a CIFER window started from the Start menu ia Administrative Tools Common gt E New Unix Program H Run Unix Program icrosoft Visual C 5 0 CS NUTCRACKER 4 S Startup gt a CIFER NT Release Notes pdf gt a Implementing READMIS pdf Figure 4 1 Starting the CIFER Shell When you launch CIFER you are actually starting an MKS Korn shell which then ultimately executes the main CIFER script after first running several intermediate scripts to set up CIFER s environment This startup process is discussed at some length in Section 5 5 of the IGRN in connection with CIFER s environment variables Here it
23. ION FURTHERMORE SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES SO THIS LIMITATION AND EXCLUSION MAY NOT APPLY TO LICENSEE TERMINATION This License will terminate automatically if Licensee fails to comply with the limitations described above On termination Licensee must return all copies of the Software EXPORT CONTROLS None of the Software or underlying information or technology may be shipped transferred or exported into any country prohibited by the United States Export Administration Act or used for any purpose prohibited by the Act U S GOVERNMENT RESTRICTED RIGHTS Use duplication or disclosure by the Government is subject to restrictions set forth in subparagraphs a through d of the Commercial Computer Restricted Rights clause at FAR 52 227 19 when applicable or in subparagraph c 1 ii of the Rights in Technical Data and Computer Software clause at DFARS 252 227 7013 MISCELLANEOUS This Agreement represents the complete agreement concerning this license between the parties and supersedes all prior agreements and representations between them It may be amended only by a writing executed by both parties If any provision of this Agreement is held to be unenforceable for any reason such provision shall be reformed only to the extent necessary to make it enforceable Authors Paul W Salchak CasalCorp with contributions and revisions by Dexter L Hermstad UC Santa Cruz and revi
24. TSWP_FRE_00C00_RUD_ XVLATSWP_FRE_000D0_RUD_ XVLATSWP_FRE_0000E_RUD_ XVLATSWP_FRE_A0000_RUD_AY XVLATSWP_FRE_0B000_RUD_AY XVLATSWP_FRE_00C00_RUD_AY XVLATSWP_FRE_000D0_RUD_AY XVLATSWP_FRE_0000E_RUD_AY XVLATSWP_FRE_A0000_RUD_VDOT XVLATSWP_FRE_0B000_RUD_VDOT XVLATSWP_FRE_00C00_RUD_VDOT XVLATSWP_FRE_000D0_RUD_VDOT XVLATSWP_FRE_0000E_RUD_VDOT In addition if cross correlation of inputs is requested then the following responses are also computed you must generate these if you are going to run MISOSA XVLATSWP_FRE_A0000_ATL_RUD XVLATSWP_FRE_0B000_AIL_RUD XVLATSWP_FRE_00C00_ATL_RUD XVLATSWP_FRE_000D0_ATL_RUD XVLATSWP_FRE_0000E_AIL_RUD Running MISOSA to condition the AIL responses for RUD 20 responses one for each output and window generates XVLATSWP_MIS_A0000_AIL_P uses AIL_P AIL_RUD XVLATSWP_MIS_0B000_AIL_P etc XVLATSWP_MIS_A0000_AIL_R etc XVLATSWP_MIS_A0000_AIL_AY etc XVLATSWP_MIS_A0000_AIL_VDOT etc If you want to condition the responses for other inputs you must rerun MISOSA with a different primary input COMPOSITE will then combine frequency responses for the five windows XVLATSWP_COM_ABCDE_AIL_P XVLATSWP_COM_ABCDE_AIL_R XVLATSWP_COM_ABCDE_AIL_AY XVLATSWP_COM_ABCDE_AIL_VDOT y gt eo CasalCorp September 2005 Page 12 CIFER Software User s Manual System Requirements 2 1 Operating System This version of CIFER and its supporting components should run on any NT4 W2K or XP WINTEL wo
25. Workflow A more complete and integrated set of utilities can be used such as higher end document processing applications like Adobe Acrobat which includes Distiller and Adobe Illustrator These commercial products provide a seamless path from CIFER s multi frame PostScript output files through plot preview frame extraction printing editing and encapsulation for document insertion Figure 6 2 illustrates the workflow as realized with these products Adobe Acrobat should not be confused with Adobe Acrobat Reader which is a free utility for viewing portable document format PDF files CasalCorp September 2005 Page 27 CIFER Software User s Manual The first step in this process utilizes the Acrobat Distiller utility to convert the raw PostScript graphics output file into a portable document format PDF file This is a fast operation taking generally only a few seconds even for relatively large files e g 150 plots As illustrated in Figure H 2 the resulting PDF file becomes the primary input source for either of two possible post processing scenarios a previewing extraction and or printing workflow or an editing document preparation workflow In addition once the raw graphics files have been converted to PDF format they can be easily shared with colleagues regardless of platform type since the free Acrobat Reader utility is available for every major platform and OS As an added advantage the PDF files are us
26. and an index file ASCII These files are named lt ARCRFT gt dat and lt ARCRFT gt idx respectively Here the symbol lt ARCRFT gt represents the aircraft ID For a detailed discussion of CIFER s files and associated environment variables see section four of this document CIFER databases can contain many types of data records The following list while not exhaustive describes some of the primary data types and the nomenclature associated with them e Frequency Responses Frequency responses FR are probably the single most common type of record in the database These records result from the analysis of time history data by CIFER utilities such as FRESPID COMPOSITE and MISOSA Utilities that deal with frequency responses as either input or output data elements rely on a specific naming convention to identify them in the database The basic format of an FR name is lt casename gt _ lt program gt _ lt windows gt _ lt input gt _ lt output gt where lt casename gt is a user defined alpha numeric string of up to eight characters lt program gt is a three character designator for the utility that created the data e g FRE gt FRESPID lt windows gt is a five character string that indicates which windows were active when the response was computed Each of the five positions corresponds to a specific window in order A E If a window is inactive not used in the computation a zero appears in its slot Thus the s
27. e next screen row Move data entry focus left by one field If currently in left most field of a screen row then wrap to right most field in the previous screen row left arrow Move data entry focus down to the most closely vertically aligned field in the next row When issued from the last line of the screen the focus will wrap to the top of the screen return enter down arrow Move data entry focus up to the most closely vertically aligned field in the previous row When issued from the top line of the screen the focus will wrap to the bottom of the screen up arrow any printing Appears in the data field as typed case sensitive character backspace Deletes the character to the left of the cursor del Deletes the entire content of the current data entry field Users familiar with the Unix version of CIFER will recall that keyboard mappings could be adjusted in order to compensate for the vagaries of the many keyboard types encountered on those platforms This type of customization is not required on Windows platforms since the mappings provided by NuTCRACKER are consistent across all systems CasalCorp September 2005 Page 19 CIFER Software User s Manual F1 Accepts the data on the current screen as entered and proceeds to the next screen F2 Presents a secondary navigation menu on the last line of the terminal screen The menu s options are Continue Backup Main Exit
28. egrate to their custom or proprietary data sets through a published intermediate format and template This supports ASCII telemetry encoded or even binary level data samples Frequency Response Identification FRESPID Frequency Response Fitting NAVFIT A Multi Input Conditioning MISOSA cc A i Av a Time Hi D Window Combination Figurel 1 ime History Data COMPOSITE The Ti op Level Plot and Report Utilities CIFER Derivative Identification Product a DERIVID Organization State Space Verification VERIFY Comprehensive Identification from FrEquency Responses CIFER FRESPID Frequency Response DERIVID Generalized Stability Derivative Screen Subsystem User Interface Identification Identification from frequency responses e Utilities Suite Special functions plotting MISOSA Multi Input i VERIFY State Space Model Verification conditioning etc Conditioning NAVEIT Calculates Low Order Transfer x DB Subsystem Raw Intermediate COMPOSITE Multi Window Function from hi order transfer function or Processed data and indexing Averaging frequency response data In the past CIFER s primary use has been for high performance aerodynamic systems controls modeling analysis test and optimization It has also been uniquely proven for handling qualities and related analyses particularly for frequency domain intensi
29. esponse imaginary part error one record per frequency value Related CIFER matrix sizes are defined as follows M ns x ns where ns number of states max of 40 F ns x ns no number of outputs max of 20 G ns x nc nc number of controls max of 10 Tau no x nc H no x ns Xi no x nc A frequency response then consists of a set of arrays and descriptive information The arrays contain the frequency values frequency response magnitude phase coherence etc The attributes summarize how and when the response was created In order to keep track of frequency responses the following naming system is used case_pgm_windows_inchan_outchan where CasalCorp September 2005 Page 10 CIFER Software User s Manual case is the case name typically up to 8 characters pgm is the source program always 3 characters FRE MIS COM DER VER or NAV DERIVID can also produce DTA as the program windows is the string indicating the window s used 5 characters inchan is the user defined control input channel up to 4 characters outchan is the user defined observer output channel up to 4 characters As the user progresses through the CIFER programs additional frequency responses are generated at each step All intermediate responses are kept Frequency responses are overwritten only when the user reruns a program using a previous case Note Consistency problems may result if you change case information
30. ew by Dr li Mark Tischler Army AFDD NASA ARC Some original sections by Gary Villere with revisions by Lawrence E Pierce Raytheon This Page Is Blank Authors Paul W Salchak CasalCorp with contributions and revisions by Dexter L Hermstad UC Santa Cruz and review by Dr Mark Tischler Army AFDD NASA ARC Some original sections by Gary Villere with revisions by Lawrence E Pierce Raytheon CIFER Software User s Manual CIFER WINTEL Software Users Manual Document Terms and Conditions This material is restricted to your Company or Agency use only under the terms of purchase and is for use only at your site It may be installed for execution on one system at a time for individual or group presentation Discs and supporting documents may be copied only upon prior approval This restriction includes prohibition from use by contractors or outside agents unless their sole use will be at your site Introduction CIFER is the world s premier System Identification solution The CIFER system shown in Figure 1 1 is a high performance interactive and complete software facility used for a wide range of systems synthesis optimization and validation While the software suite can be executed as a stand alone tool interface provisions are made for common external data sets on input e g Data Acquisition standards MATLAB and plotting reporting tools on output The capability also exists for individual users to int
31. for all channels to be read The DT delta time is the average of the time steps but each time step should be as near DT as possible Differences of up to two percent from DT are allowed This MATLAB binary file can be created via the MATLAB command save file mat time chan1 chan2 chans chann where is not the MATLAB continuation indicator but signifies channels 4 through n 1 by whatever name These files are portable between platforms The following instructions replace the default READMIS DLL with the MATLAB DLL The basic requirements to begin are The MATLAB DLL libreadmis dll matlab MATLAB libraries need to be known at run time if the MATLAB binary reader READMIS DLL is the active READMIS library If MATLAB libraries are not available the MATLAB binary reader READMIS DLL MUST not be the active READMIS library First save the current DLL Using the MKS Unix shell accessible directly or by launching CIFER then exiting leaving the Unix window open and active cd cifbin mv libreadmis dll libreadmis dll fstub Please Note If another libreadmis is already installed then save it to an appropriate name instead of libreadmis dll fstub e g libreadmis dll ctdif Remember that the ID is displayed on screen FRESPID 3 Next obtain the new MATLAB binary reader READMIS DLL and install again using the MKS Unix shell cd cifbin mv lt where you put the file gt libreadmis dll matlab libreadmis dll If you depo
32. form any other tasks for which you find a Unix like command line interface well suited You will find that most Unix tools and editors are available and that features such as pipes and background processing work as you would expect Furthermore all CIFER environment variables are defined and available for use making manipulations of CIFER directories and files quite straightforward To restart CIFER from within the shell type cifer lower case at the command prompt To exit the shell entirely type any one of exit logout or bye 4 1 Customizing the CIFER Shell Window As they are installed the CIFER shortcuts present a somewhat vanilla interface in which important features such as cut and paste and scrolling are disabled You will almost certainly find your CIFER user experience more productive if you take a few moments to enable some of these features Note however that the operations described in this section will require administrative privilege since you will be enabling these features for all users of these system wide shortcuts Begin by launching an instance of the CIFER shell from either the desktop or START menu shortcuts Right click on the title bar of the menu and select Properties Next select the Options tab Figure 4 4 Then check the box labeled Quick Edit Mode CIFER Properties lx General Shortcut Options Font Layout Colors Security
33. g and validity for stable or unstable systems The definition is simply the substitution of s gt jw There is a huge amount of literature published on this point from as far back as the 1940s addressing frequency response methods that include unstable systems Bode Nichols Nyquist and many others All helicopters and most modern aircraft have unstable modes This just means that there is a gain reduction margin and a gain increase margin in the control system Part of the problem is that current standard control systems don t address this very much CasalCorp September 2005 Page 29 CIFER Software User s Manual So yes frequency methods are appropriate for both stable and unstable systems That is the point the only requirement is to ensure that the output does not blow up This means that the excitation source pilot SAS simulation must regulate the input to be sure that the response is bounded That is an easy requirement to meet but disallows a steady sine wave input to an unstable system since this would indeed result in an unbounded response a nuance that is another aspect of the common confusion on this point Many examples of frequency response methods for design and analysis of flight vehicles that contain unstable modes are thus to be found in the literature X 29 is a particularly good reference since it is highly unstable real time frequency response methods were used to validate stability margins in flight That sa
34. hese time histories can come from a variety of sources and schemes but the most common are e CIFER Binary individual files containing one channel of data associated with one parameter e CIFERTEXT or CTDIF comma or space delimited text file with header and a matrix of parameters and their data e Site specific data formats and exchange mechanisms linked via READMIS e A third party application EXCEL and MATLAB directly supported We discuss each of these next There remain several NASA specific time history schemes including TRENDS and FLYTE but these are no longer widely used so are not discussed further Please note that CIFER does NOT rewrite time histories back to the originating source A time history is uniquely identified by the aircraft flight event and channel name Start and stop time within the time history record may also be specified Depending on the format this may be in the file itself or via a CIFER Program screen Given these items and a code indicating which database scheme to use the time history interfaces can go read the correct file s records s and return an array of data CasalCorp September 2005 Page 3 CIFER Software User s Manual 1 2 1 CIFER Binary Type 1 File This corresponds to a simple binary data file format of the type used in the sample time history files distributed with the CIFER package These files consist of a single vector of floating point data structured
35. id it is critical to take care with plotting and interpreting the Bode plots for systems that have either zeroes or poles in the right half plane The danger is that many engineering packages such as MATLAB produce a plot that needs to be shifted by 360 degrees Also depending on the pole zero configuration the right plane situation aka no minimum phase transfer function will require the use of the zero degree crossing as the criterion rather than the 180 Again MATLAB s plotting routines are not smart enough to pick this up If instead you use a root locus plot in conjunction with the Bode plot on even a simple example e g 1 s 1 this will be clear In short as with most engineering challenges the unstable systems DO have an impact on the design of experiments and testing methods Again they do NOT invalidate in any way the meaning of the frequency response results or methods 7 3 Using CIFER as a Signal Processor Contributed by Dr Jeff Lusardi Dr Mark Tischler and Dexter Hermstad One of the least utilized and most powerful aspects of the CIFER software system is its use as a signal processor for feature observation extraction or trending In many applications of CIFER s analysis facilities the user seeks to extract a mathematical description of the response dynamics of a vehicle from flight test data For such applications the COMPOSITE program combines the individual window results to achieve a set of cons
36. including without limitation the warranties of merchantability fitness for a particular purpose and non infringement The entire risk as to the quality and performance of the Software is borne by Licensee Should the Software prove defective Licensee and not CasalCorp assumes the entire cost of any service and repair In addition the security mechanism implemented by the Software has inherent limitations and Licensee must determine that the Software sufficiently meets Licensee s requirements This disclaimer of warranty constitutes an essential part of the agreement SOME STATES DO NOT ALLOW EXCLUSIONS OF AN IMPLIED WARRANTY SO THIS DISCLAIMER MAY NOT APPLY TO LICENSEE YOU MAY HAVE OTHER LEGAL RIGHTS THAT VARY FROM STATE TO STATE OR BY JURISDICTION LIMITATION OF LIABILITY UNDER NO CIRCUMSTANCES AND UNDER NO LEGAL THEORY TORT CONTRACT OR OTHERWISE SHALL CASALCORP OR ITS SUPPLIERS BE LIABLE TO LICENSEE OR ANY OTHER PERSON FOR ANY INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY CHARACTER INCLUDING WITHOUT LIMITATION DAMAGES FOR LOSS OF GOODWILL WORK STOPPAGE COMPUTER FAILURE OR MALFUNCTION OR ANY AND ALL OTHER COMMERICAL DAMAGES OR LOSSES IN NO EVENT WILL CASALCORP BE LIABLE FOR ANY DAMAGES EVEN IF CASALCORP SHALL HAVE BEEN INFORMED OF THE POSSIBILITY OF SUCH DAMAGES OR FOR ANY CLAIM BY ANY OTHER PARTY THE LIMITATION OF LIABILITY SHALL NOT APPLY FOR DEATH OR PERSONAL INJURY TO THE EXTENT APPLICABLE LAW PROHIBITS SUCH LIMITAT
37. ional READMIS program will generate a DLL that duplicates the operation of the Type 1 option That is it will read Type 1 time history files from the directory tree rooted at THLOC in exactly the same manner as would be the case if option one were selected in response to the Time history source query on screen three All of these modules both the templates and the code for the Type 1 READMIS samples are meticulously documented Each is a self contained tutorial covering everything you will need to know in order to implement your own READMIS code However as you approach the task of constructing your READMIS module please realize that it is precisely because of the depth of this documentation that these programs may seem somewhat formidable appearances notwithstanding though there is actually very little coding required to produce a usable routine Organization of the Project Directories The READMIS projects are located in the directory cifroot source readmis in the folders readmis f90 and readmis_c The directory structure of each is identical the structure of the readmis_c directory tree for the MATLAB Binary READMIS library is shown in Figure 1 7 fs libreadmismat JEK File Edit View Favorites Tools Help Bak 3 Pi J Search ie Folders E Address C CIFER _Pro sourceyeadmisyeadmis_c ibreadmismat Folders x Name Type E readmis ORelease File Folder 2 readmis_c libreadmis dsp DSP File B lbreadmis
38. is sufficient to note that you will see a screen similar to the one shown in Figure 4 2 the CIFER splash screen Depressing carriage return will then take you to CIFER s main menu screen Figure 4 3 from which you may selectively execute individual CIFER utilities EEEEE RRRRR E R R RRRRR RR nt with the p und f and and the National Aeronautics and Enter F or f for 4 1 00 features Enter lt or main menu Figure 4 2 CIFER Splash Screen Computational progra ESPID 1 FRES 4 DERIVID vameter Utilities I Matrix Fil I the D B Values lt Enter a Input number to select a program or utility gt when finished gt Figure 4 3 CIFER Main Menu When you have finished your CIFER session you will find your cursor at the input prompt of the CIFER main menu screen To exit CIFER simply enter a carriage return and you will be returned to the Korn shell from which CIFER was initiated This is a useful If you do not wish to have the CIFER shortcut on your desktop it may be safely deleted It is not the purpose of this document to discuss in detail the operation of CIFER s various components For an introduction to these programs please see volumes 1 and 2 of the CIFER Class Notes CasalCorp September 2005 Page 16 CIFER Software User s Manual environment from which to manipulate CIFER output files re launch CIFER or per
39. istent spectral functions Gxx Gyy and Gxy that together yield a frequency response of minimum random error and that track the coherence of the most reliable frequency response data By contrast signal processing applications require an accurate estimate of the autospectra of an isolated signal and the coherence of input to output pairs is not a consideration This is accomplished by specifying the input equal to the output in FRESPID For this case COMPOSITE does not use coherence weighting but the weighting due to window length is retained This is illustrated in the following signal processing example where estimates of the autospectra of four time histories GMXA GM05 GM20 and GM40 are desired The figure shows the input output pairings for this case from FRESPID screen 6 CasalCorp September 2005 Page 30 CIFER Software User s Manual 3 C CIFER_Pro bin frespusr A11 lt Y N Clear gt 3 FRESPID 6 GMXA GM S GM26 GM49 GMXA GMOS GN26 GN46 FRESPID screen 6 with input output pairing for signal processing The FRESPID frequency responses are then combined in COMPOSITE where both the coherence and random error are calculated for each window With the input equal to the output as per the figure all the windows will have unity coherence at all frequencies and weighting based on coherence is not used by the algorithms in COMPOSITE but the benefit of averaging based on window length is retained
40. lt ANALYSIS gt where lt ARCRF T gt is a file name extension string which is equivalent to the aircraft ID declared in the SIFDEF file Similarly lt ANALYSIS gt is an extension string formed from the definition of the ANALYSIS environment variable contained in the file Of course there can be only one active SIFDEF file at any given time during a CIFER session This file is uniquely named SIFDEF without any extensions This active SIFDEF file is a copy of one of the available parent files i e one of the SIFDEF files that is named according to the convention described above CIFER is installed with a special set of vanilla active and parent SIFDEF files called the default default SIFDEF files These files set the aircraft ID string to default and the analysis string to default One of the first tasks a new user must accomplish is the customization of these files for his own use To this end CIFER provides the utilities under Database Utilities main menu item 10 see Figure 10 below which can be used to modify the contents of SIFDEF files FRESPID COMPOSITE and MISOSA casenames may be up to eight alpha numeric characters DERIVID and VERIFY casenames may be up to 12 characters in length CasalCorp September 2005 Page 22 CIFER Software User s Manual It is important to understand that these utilities never make changes directly to the parent SIFDEF file
41. mple when creating the database for the first SIFDEF above you might choose the directory E cifer data db MY_FLYER TH1 instead of accepting the default Remember though database directories must already exist or creation will fail Finally it may also be worth noting that utility 17 will automatically update the database location field in the active SIFDEF whenever you enter something other than the default directory while creating a new database file CasalCorp September 2005 Page 25 CIFER Software User s Manual Working with CIFER Graphics Output 6 1 Hints and Tips for On Screen Graphics As has already been mentioned in this guide WINTEL CIFER s on screen graphics are generated via an X Window display server A key concept in the X Window paradigm is focus that is which screen object usually a window will receive any user generated input e g keystrokes mouse clicks etc The default focusing method for the SCO X server distributed with CIFER is termed implicit focus which means that the cursor need only be located within the boundary of the X window in order for it to have the focus or conversely the cursor need only wander away from the window for it to lose focus This stands in contrast to regular WINTEL windows which operate by explicit focus wherein the user is required to click within the window in order to activate it The concept of focus is important in WINTEL CIF
42. n portions of the primary System Variables CIFER directory structure in order to provide segregated areas for the A w ccthome DACIFER_LT n storage of user data In these installations the cifroot environment PORRU dee variable will point to the primary CIFER directory as created during lee installation while the cifhome environment variable will point to the eze Yaz root of each individual user s CIFER directory tree These per user J twana Li directory trees are mor subtrees of the primary CIFER directory but oe Se rather are usually located in the user s own directory For a more v complete explanation including specific instructions on creating these Hera men user directories see the CIFER Installation Guide and Release Notes rs Hesan rn Version 4 1 00 or later Figure 2 1 Environment Tab of the WINTEL System Applet CasalCorp September 2005 Page 13 CIFER Software User s Manual Summary of CIFER Programs CIFER for the WINTEL platform is distributed as a set of executable Programs scripts and data As already introduced the main Programs consist of FRESPID MISOSA COMPOSITE DERIVID NAVFIT VERIFY and a range of specialized utilities administrative analytical This section provides a brief overview of each Each of these programs and utilities is completely described later in this document FRESPID Frequency Resp
43. n software EPS artwork files es Multi frame a N Multi frame PostScript Acrobat PDF plot file plot file Distiller Save selected frames or frame groups to format files Adobe Acrobat can be used for previewing and extracti Print selected frames Figure 6 2 CIFER Graphics Workflow Using Adobe Distiller Acrobat and Illustrator 10 Although plots can be rotated easily in both Adobe Illustrator and Acrobat you may wish to consider selecting Portrait mode on CIFER s plot setup screens Landscape mode is the default when generating large numbers of plots for publication CasalCorp September 2005 Page 28 CIFER Software User s Manual 7 Examples A wide range of examples of CIFER use have been published A benchmark book on Frequency Domain System Identification by Dr Mark Tischler will also be available from AIAA in 2006 the reader is promoted to watch for this important and valuable tool Typical Frequency Response Analysis Applications for Airborne Systems GTRI NATO Research amp Tech Org Madrid Spain 1998 Vibration Spectral Safety amp Aircraft Analysis Reliability Dynamics Handling Simulation Qualities Validation System x Excitation e g Sweeps FREQUENCY RESPONSE Structural DATABASE Dynamics e g as provided by CIFER Aeroelastic Transfer Function Models Analysis system subsystem Control System State Space Models assembly component
44. nding to the plot should appear in the status bar if so you can click on it to bring the plot forward Working with plot windows Although it may not be apparent at first glance CIFER plot windows are resizable Simply move the cursor to the border of the window and it will change into a bi directional arrow indicating that resizing is available Once you finish the resizing be sure to return the cursor to the interior of the window in order to retain focus After you have resized a plot window there are several keyboard commands which are available for manipulating the aspect ratio remember the plot window must have focus These controls are defined in Table 6a If you are using an WINTEL CIFER graphics configuration that allows multiple plots to appear on the screen configurations 2 and 3 allow this then plots can accumulate quickly If you wish to close all of your plot windows quickly you can type the following at the Unix command prompt PERL S cifscripts close_all_xplots CasalCorp September 2005 Page 26 CIFER Software User s Manual Table 6a Graphics Window Aspect Ratio Adjustment Controls R Restores the graphics window to default size Makes one dimension of the window smaller in order to restore the default aspect ratio Makes one dimension of the window larger in order to restore the default aspect ratio 6 2 Hints and Tips for PostScript Graphics In addition to the
45. on screen graphics CIFER generates using the X Window system most CIFER utilities produce graphical output in PostScript form as well These files can be quite large and can consume significant amounts of time and printer resources if they are printed directly For that reason you may wish to develop a capability for previewing them and extracting the frames of interest for printing You may even wish to move beyond this simple capability and develop techniques for editing individual plot frames in order to render them suitable for publication This section will offer some suggestions for utilities that may be of use in addressing these issues A diagram of the idealized post CIFER execution graphics workflow is depicted in Figure 6 1 Of course the degree to which the real world workflow matches this schematic will depend significantly upon one s choice of software Possible software candidates for performing the first of the operations previewing plots depicted in Figure 6 1 are Ghostscript and GSview freely downloadable packages maintained by GNU and Aladdin Ghostview is included with the CIFER software system installation for versions 4 0 05a or later Multi frame Save selected gt Data Store PostScript Single Frame frames or Software to edit plot file previewing and frame groups individual frames extraction software and save them in document ready formats Print selected frames Figure 6 1 Idealized Graphics
46. onse IDentification MISOSA Multi Input Conditioning COMPOSITE Multi window Averaging DERIVID Generalized Stability Derivative Identification from Frequency Responses CasalCorp September 2005 Page 1 Select Case and Aircraft session indexes Page 2 Enter Controls up to 10 inputs and Observers up to 20 outputs Page 3 Enter flights and events to be analysed start stop times optional Page 4 Define composite control input channels and units Page 5 Define composite observers output channels and units Page 6 Set desired combinations of input output to compute incl ALL Page 7 Condition input time histories Page 8 Set up window parameters manual or automatic Page 9 Set plotting options Page 10 Launch frequency responses calculations Page 1 Select Case and Aircraft session indexes Page 2 Check Change session setup incl controls outputs and windows Page 3 Set desired combinations of input output to compute incl ALL Page 4 Set up plots Page Select Case and Aircraft session indexes Page 2 Check Change session setup incl controls outputs and windows Page 3 Set desired combinations of input output to compute incl ALL Page 4 Set up plots Page 1 Select Case and Aircraft session indexes Page 2 Set up links to matrix names M F G Tau H s Page 3 Present model parameters state names observers controls Page
47. r rather than a file name Or you may choose to enter nothing at all it is not necessary to enter file names if you have no need for an additional qualifier Case XVLATSWP FRESPID 3B Comments Lateral frequency sweep for XV 15 in hover Evnt Flt File Name 883 150 mydata fu 884 150 mydata bar 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Figure 1 6 FRESPID Screen 3B CasalCorp September 2005 Page 6 CIFER Software User s Manual The READMIS DLL Projects In order to generate a READMIS DLL for use with the CIFER package the user will need to have access to an integrated development environment IDE capable of building standard Win32 DLL modules Although any IDE with this capability may be used the CIFER package is distributed with sample projects for two common WINTEL IDE s Visual C C and Digital Equipment Corporation s Visual Fortran 90 If you have either of these IDE s you need only open the appropriate project insert code specific to your data access requirements into the READMIS template or stub and select Rebuild All from the Build menu If you wish to use an IDE other than one of these you may still be able to use the template modules as a starting point for your development efforts In addition to the template modules each project contains an actual working sample READMIS program which may be substituted for the READMIS stub code when building the project This fully funct
48. r existing db utility 17 You will be asked first to enter the directory in which the database files are to be created You may choose any directory that already exists and for which you have write permission For now simply accept the defaults and proceed to enter the name of the aircraft MY FLYER at the next prompt A final carriage return will bring you once again to the Database Utilities submenu screen The status line will now read gt The active SIFDEF is MY FLYER default lt Note that the Create Aircraft Create new database or create SIFDEF for existing db utility has changed the aircraft portion of the SIFDEF file name extension It is important to realize that the status line shows only where the active SIFDEF file was saved this does not mean that the extension of the original parent file has been altered But before using the new SIFDFF file we must adjust the location of the time history data since one of the goals of this example is to set up analyses that draw from two distinct sets of time history data Proceed by selecting utility 11 Change CIFER Defaults You will next see a screen from which you can edit the contents of the active SIFDEF file Figure 5 2 your actual settings and paths may vary Navigate to the Time history loc field and enter the directory path to your data in this example E cifer data th Set_1 When you are satisfied press the F1 key to accept the
49. requency response names When all variables are set to the user s satisfaction the program submits a job to the batch queue to do the computations The name of the batch job is the case name preceded by a 3 character code specifying the parent program For example a FRESPID job computing frequency responses for the XVLATSWP case will be called FRE XVLATSWP The user will be notified when the job completes and a log file will be created Files of the form progr_case COM next and progr_case OUT next will be produced and saved in the batch directory identified by the active SIFDEF file see Section 5 For example FRE_XVLATSWP COM 01 and FRE_XVLATSWP OUT O1 1 2 Time History Data THD Files and CIFER Databases It is essential to recognize the distinction between THD files upon which CIFER operates and frequency response databases produced by those operations The frameworks for each are produced with installation Pointers to the databases dat and idx and to type dependent time history files such as ct or mat for a given analysis or session are formed via the SIFDEF construction discussed later in this manual sections 1 3 and 5 The usual first step in using CIFER is the analysis of time history data with the FRESPID utility CIFER implements four built in mechanisms for accessing time history data files The user selects between these methods via his response to the Time history source query on FRESPID screen three T
50. rkstation or server system CIFER is also available with equivalent functionality for Unix Operating Systems Solaris IRIX Linux and MAC O99 requires 3 party software No attempt has been made to test CIFER on Windows 95 98 or ME and no representation is made as to CIFER s suitability for use on such systems 2 2 Program Versions You may see some differences between actual program utility screens shown in this manual and the actual displays Some of the Program User descriptions provided in this manual are for earlier versions of the CIFER software version The purpose and functionality of each program utility screen is generally unchanged 2 3 Single and Multiple User CIFER Systems A single user CIFER installation is one in which only one person of the perhaps many people with accounts on the system actually uses CIFER On such a system if is recommended but unnecessary to create separate user configurations and directory structures in order to segregate the operational environments of multiple users If the standard setup is retained you will create databases and customized data input routines directly within the primary CIFER directory tree without fear of impacting others However you must then ensure that this data is saved and restored properly when applying any future CIFER version updates However on systems which support multiple CIFER users it is necessary to duplicate on a per user basis certai
51. rom that shortcut You should then launch CIFER from the other of the two shortcuts installed by the setup and repeat these steps to establish the proper defaults for it as well 4 2 The CIFER Keyboard Interface Many CIFER utilities interact with the user via a series of data entry screens that make use of cursor addressing Each screen contains a number of data input fields interspersed with descriptive text The user can navigate from field to field within a screen using combinations of the arrow tab and return keys Once the data content of a screen s fields is satisfactory the user can proceed to the next screen by depressing the F1 key CIFER does not make use of the computer s pointing device mouse CasalCorp September 2005 Page 18 CIFER Software User s Manual Table 4a summarizes the functions on a typical keyboard of the various navigational keys used by CIFER Data Entry Once the user has navigated to a field the procedure for data entry is straightforward In general all printable characters will appear in the field as they are typed It is important to remember that casenames control names and the like i e names of things must match exactly from use to use including case In addition please recognize that in this version some CIFER command and option selections remain case sensitive However the authors are removing this restriction and this should be a minimal encounter for the current
52. s only the active SIFDEF file is modified Then once the changes are complete the modified active SIFDEF file is saved back into the parent file Furthermore this arrangement means that the only way to create a new aircraft analysis pair i e a new SIFDEF parent file is to edit the currently active SIFDEF file and then save it as a new file This process will be illustrated in the next section 5 3 EXAMPLE Creating A Database and Associated SIFDEF Files In this section we will create a database for the example aircraft MY FLYER We will assume that two separate time history data sets for this aircraft are to be analyzed Assuming further that each of these data sets resides in its own separate directory tree we will create two SIFDEF files one for each data set Finally we will discuss the modifications which would be required in this scheme if the results of each analysis were to be stored in a separate database The Procedure After starting CIFER select utility 10 from the main CIFER menu screen You will then see a screen similar to the one shown in Figure 5 1 active SIFDEF may vary depending upon your normal settings The first step will be to create the database for MY FLYER Since the Create Aircraft Create new database or create SIFDEF for existing db utility 17 will store information into the SIFDEF file pertaining to the new database we will use the currently active SIFDEF file as a template for this new S
53. s which deal directly with time domain data Information on the time history data formats was provided earlier in this document Section 1 2 and is not repeated here 5 2 The Purpose of the SIFDEF file The SIFDEF file is a Korn shell script file which is executed during the CIFER startup process see section 5 5 It provides definitions for several environment variables Table 3b which inform CIFER component utilities of the locations of the database time history data files batch and plot output directories and the units in which on screen results should be displayed From the user s point of view the SIFDEF file provides a mechanism for grouping together the files associated with a particular project This is because in addition to the items described above the SIFDEF file defines the ARCRFT environment variable which contains the aircraft ID mentioned in section 7 1 and an associated ANALYSIS environment variable which contains a user supplied string This string is limited by the same rules that govern the aircraft ID see above These two quantities uniquely identify the SIFDEF file and therefore become a shorthand label for its contents A CIFER user may have several SIFDEF files each of which can be used to set up the CIFER environment for work with a particular aircraft analysis combination To distinguish among these files CIFER names each file according to the scheme SIFDEF lt ARCRFT gt
54. sited the file directly into cifbin mv libreadmis dll matlab libreadmis dll Add MATLAB DLLs to the runtime environment again using the MKS Unix shell export PATH PATH lt your MATLAB directory gt bin Example export PATH PATH C MATLABR11 bin Note It may be desirable to change the PATH environment variable as shown in the Installation Guide and Release Notes so the MATLAB DLLs are available every time a CIFER shell is started CasalCorp September 2005 Page 9 CIFER Software User s Manual 1 2 5 Byte Swapping Big Endian Little Endian Conversions Some CIFER users must migrate their databases and analyses between Unix and WINTEL platforms To facilitate such exchanges the needed databases now are portable among Unix and WINTEL CIFER version 4 1 00 and above Before these versions the generally big endian architecture of most Unix systems and the little endian architecture of PCs running either Windows or Linux meant that data created on one could not be read by CIFER on the other Byte swapping software has been added to overcome this problem No matter where or when the database was created or last modified it is portable between platforms as long as the installed version of CIFER used to read the database meets the version 4 1 00 requirements Swapping is done transparently when records are read from the database records are always written without swapping As a database is copied between the two types of
55. splayed on a black background This arrangement can be modified to any desired combination e g black lettering on a white background by making suitable adjustments in the Colors tab of the property panel Figure 4 6 CIFER Properties BEI General Shortcut Options Font Layout Colors Security Window Preview r Screen Buffer Size Width fz Height joox m Window Size Width feo Height fro 2 TREE Left p4 Options Font Layout Colors Ter HES Seren an Selected Color Values I Let system position window Si ound Red 255 Popup Text Green fess 2J Popup Background Blue oss 2 E EE B BR Ti BIR B D Cancel Apply m Selected Screen Colors C WINNT gt dir z eee SYSTEM lt DIR gt 83 81 92 3 11 Figure 4 5 Enabling Scrolling in the CIFER Shell SYSTEM32 lt DIR gt 83 81 92 3 11 Lite com 9ca c MI A aa 2 41 Selected Popup Colors Cz WINNT gt dir IR gt 63 61 92 3 141 SYSTEM32 lt DIR gt 63 61 92 Litas com ac aoc ad_ai_as ow se E Figure 4 6 Setting CIFE R Shell Background and Foreground Colors Finally click OK to close the property panel When you do so a dialog will appear asking if you wish to apply the changes only to the current window or to the shortcut that launched the window You should select the latter in order to have the changes take effect for all subsequent launches of CIFER f
56. the extent of the task that we had set for ourselves in this example we could end here by depressing a carriage return to take us back to the main CIFER menu screen and we could begin our analysis of the data However we originally set out in this example to construct a single database and two SIFDEF files one for each of two sets of time history data In order to complete that example we must now create a second SIFDEF file Work done while this second SIFDEF file is active will use the same aircraft database MY_FLYER but will take its time history data from a second set of files located in say E cifer data th Set_2 In this case we will use the aircraft analysis combination MY_FLYER TH2 as the SIFDEF name So instead of depressing the carriage return to return to the main menu we immediately select utility 11 Change CIFER Defaults and again edit the Time history loc field Only this time we insert the path to the second set of time history data Note that the Aircraft Analysis field will still show MY_FLYER TH1 at this point This is of no concern since we will change the analysis name when we save the edited SIFDEF file Remember too we are only editing the active copy of MY_F LYER TH1 the original has not been modified After accepting the edited screen by depressing F1 dismiss the list of SIFDEF files and save the modified file with an analysis name of TH2 The status
57. tine As noted above the sample and template READMIS files are completely documented and should provide all the information that you will need to implement a site specific version This section provides only a brief overview of the issues which must be addressed during that process they are as follows e You will be required to provide a 14 character ident string which will be used to identify the READMIS DLL on FRESPID screen three This string may contain any information you wish Its purpose is to serve as a mnemonic aid to help you determine at runtime which DLL you are using e The READMIS routine will be called in two different modes as CIFER executes The mode is indicated by the value of the mode argument to the READMIS call If mode 1 CIFER expects READMIS to return in the DELTAT argument the time step between data elements It is important that no actual time history data be returned when mode 1 When READMIS is entered with mode 2 CIFER will expect it to return the actual time history data in the ARRAY argument The number of data points provided must be returned in the NPTS argument and this number must be less than or equal to the maximum array size as given by the arraysiz argument This dimension is nominally 100 000 points although implementation may vary from platform to platform The areas of the template file which must be modified to meet these requirements are clearly marked To see an actual example
58. trics provides added confidence in results over spectral region of interest and importance gt Integrated procedure for identification and model structure determination gt Time domain verification of models including identification of offsets and biases 1 1 Case Methodology As discussed in this User s Manual the term case refers to all of the user inputs required for a single execution of any program FRESPID MISOSA and so on A complete set of inputs is saved and can later be retrieved via a user defined case name This mechanism is implemented for all the major computational programs in the CIFER software system except NAVFIT CasalCorp September 2005 Page 2 CIFER Software User s Manual Case information is contained in various commons and is read from or written as records on the database The parameters for DERIVID and VERIFY were divided into several sub categories e g MODel parameters SENsor coefficients F matrix values etc Each subcategory is stored in a separate file used by both DERIVID and VERIFY Specialized utility programs also use these data records as needed Case names may be up to 8 characters although DERIVID allows 12 characters Since case names are used as the prefix of various file names DO NOT use names with any character which will cause a file naming error when an extension is added Also DO NOT use underscores in case names since underscores are added by the software to create f
59. tring AB000 would indicate that only windows A and B were used to compute the response lt input gt is a user defined string that identifies the input control four character maximum lt output gt is a user defined string that identifies the output control four character maximum 7 Of course CIFER is not restricted to the analysis of aircraft data CIFER originated as an engineering facility for the design of aircraft control and stability augmentation systems As a result much of the nomenclature used in the CIFER interface is based on aircraft engineering terminology CasalCorp September 2005 Page 21 CIFER Software User s Manual e Case Data When performing an analysis with a CIFER utility the user will assign a casename to the analysis Then as he enters data on the utility s various input screens it will be saved to the database under that name This case data allows CIFER programs to recall the user s input parameters thereby minimizing the amount of re keying required to modify and rerun a case e Model Matrices The database contains the various matrices M F G H and Tau used to describe DERIVID models e DERIVID and VERIFY Results It is probably worth mentioning at this point that raw time history data is not stored in the CIFER database CIFER provides a set of built in hooks for inputting time history data directly into FRESPID and VERIFY the only two CIFER program
60. tz libreadmis dsw DSW File a amp E libreadmis ncb NCB File oe Release gt mi libreadmis opt OPT File E readmis_f90 E libreadmis plg PLG File libreadmis E readmis c CFile sweepGenerator v lt Figure 1 7 READMIS Directory Tree In the case of the C language project the files readmis c STUB and readmis c TYP1 located in the Scifroot readmis readmis_c directory contain respectively the code for the template READMIS routine and the sample Type 1 emulation READMIS routine 2 Some files may appear with different icons on other machines CasalCorp September 2005 Page 7 CIFER Software User s Manual To build either of these modules using the predefined project simply copy the desired file into the Scifroot readmis readmis_c libreadmis directory and rename it to readmis c The procedure is analogous for the Fortran project The corresponding files are readmis for STUB and readmis for TYP1 The IDE may be launched by double clicking on the file Libreadmis dsw located in the Scifroot readmis readmis_c libreadmis directory Selecting Rebuild all from the Build menu will compile link and install the resulting DLL into the CIFER bin directory Should it become necessary to perform the installation manually the DLL may be found in the Scifroot readmis readmis_c libreadmis Release directory once the build operation has been successfully completed Implementing a READMIS Rou
61. ually 50 70 smaller than the original PostScript plot files making them easier to transmit electronically In general the easiest way to prepare a CIFER plot for insertion into desktop or web publishing documents e g documents prepared with Microsoft Word PowerPoint or other page layout presentation software is to convert it to an encapsulated PostScript EPS document An EPS format file is a special type of PostScript file that can contain only a single page image which is specially encapsulated to allow it to be placed and rendered within another PostScript page This file format is the format preferred by most page layout programs for use when importing figures and illustrations into PostScript documents Adobe Illustrator will allow you to read any frame of interest from a multi frame PDF plot file and save it as an encapsulated PostScript file Of course in addition to this simple format conversion you can make various editing changes as might be required to meet your publication constraints Using Illustrator s editing features you can for example scale and or rotate the plot change any or all label fonts and add or delete labels and annotations Adobe Illustrator can be EPS files containing used to read individual single plot frames can frames from a multi be imported inot MS frame PDF file and Word PowerPoint or create single page other page layout or encapsulated PostScript presentatio
62. user Finally along with the standard numeric keys on most keyboards the numerical keypad can also be used for data entry provided the Num Lock has been set The double width Backspace key located above the return key see Figure 6 7 is the character rubout key it will delete the character immediately to the left of the cursor The small Delete key located in the six key cluster above the arrow keys can be used to delete the entire contents of a field NOTE A very important change was implemented for CIFER Version NT12 Except in the extended editing features described immediately below the first keystroke in a field will wipe out that field This is the behavior of the Unix version and some users who were familiar with it requested that it be implemented in the Windows version also Extended Editing Features One CIFER utility the QPLOT program utility 19 has an optional data entry protocol which is designed to provide additional editing features in order to facilitate the entry of long frequency response names These features are only available in screen one of QPLOT In this situation all of the descriptions given in Table 4a remain valid but the additional capabilities described in Table 4b also apply Table 4a CIFER Keyboard Navigation and Data Entry Move data entry focus right by one field If currently in right most field tab right arrow HIRE of a screen row then wrap to left most field in th
63. ve ADS 33 referenced specification and testing Vibration analysis flutter analysis wind tunnel and flight test characterizations and simulator development validation and optimization are just a few of its other past and continuing uses Other high value CIFER adaptations are not based on how it has been used though Rather it is based on what CIFER does For any measurable system excitation response set time or frequency domain CIFER assesses the frequency content and produces an accurate mathematical description of that system s complex dynamic behaviors With its strong basis in proven signal processing and analysis techniques CIFER uses extend well beyond the flight vehicle development and test regime CasalCorp September 2005 Page 1 CIFER Software User s Manual Figure 1 2 depicts the overall CIFER process This is an empirically based technique operating on measured excitation data continuous or pulse and system responses For our purposes the system subsystem component can be of any size or domain so long as it can be instrumented to collect the needed signal data Frequency Raw Response Data Compatibility Multi variable Inputs gt Collection gt amp State Estimation gt Spectral Analysis Stimulus Events Conditioned Transfer Function Frequency Responses SSS The
64. ve specified on previous screens CasalCorp September 2005 Page 5 CIFER Software User s Manual 1 2 3 READMIS Type 4 The formats of this type time history files are completely user defined In order to access these files CIFER will call a user supplied routine named READMIS an acronym for READ MlScellaneous data formats In the WINTEL version of CIFER the READMIS routine must be structured as a Dynamic Link Library DLL This library may be compiled independently of the CIFER code and need only be placed in the CIFER bin directory in order to become available to CIFER at runtime Because a user who works with several types of time history files could easily forget exactly which READMIS DLL was currently in use the READMIS library must also implement a READMIS IDENT function which when queried by CIFER will provide a user defined identification string This string will be displayed on CIFER screen three next to option 4 in place of the word READMIS Beyond these requirements CIFER places no restrictions on the structure of the READMIS library or the manner in which the time history data itself is accessed or stored In particular there is no requirement that the data be stored in files which are named and arranged in a directory hierarchy such as was one shown in Figure 1 3 The call arguments for the READMIS routine are well documented in the header block for the READMIS stub a

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