CONDUIT® News

June 20, 2017

During the recent flight control course taught by Dr. Mark Tischler at the AIAA Aviation Conference, two bugs in CONDUIT version 5.5 for the Windows platform were brought to our attention and were quickly resolved.

** If you experience either of the two errors described below, the CONDUIT 5.5.1 upgrade is mandatory and must be applied immediately.**

Otherwise, this patch upgrade is optional, since these bug fixes and enhancements will be included in subsequent CONDUIT releases.

1. Error starting up CONDUIT while determining the associated Simulink version due to the order in which certain MATLAB toolboxes were installed.

  • Symptoms:
    • CONDUIT startup progress bar stalls at around 60%
    • When viewing the MATLAB Command Window, there are MATLAB errors related to "conver" and "GetVersions"

2. Batch Mode fails to find some specific MATLAB graphic handles due to Microsoft Windows display settings. Note:  This is more likely to occur in Windows 10 due to the default Windows display magnification/scaling settings.

  • Symptoms:
    • When creating a new Design Margin Optimization for a given CONDUIT problem, the Batch Mode GUI launches in Batch Setup Mode to set up the Batch cases, but stalls after only one case is created
    • When viewing the MATLAB Command Window, there are MATLAB errors related to "getViewport", "ButtonPress", and "ModeSelect"
    • In some cases, the Dependency Checker initialization waitbar stalls at around 90%

In addition to the two bug fixes, one minor enhancement is also implemented in this patch upgrade:

  • The ability to disable Batch databasing through the "Options" menu on the Batch GUI was added as an alternative shortcut for the existing feature in Batch Preferences GUI.

The upgrade is available immediately as a download by contacting STA_Support@usra.edu


May 8, 2017

The CONDUIT(R) team is proud to announce the release of CONDUIT version 5.5! In this major release, you will find a number of new features and improvements since the 5.4 release.
 
A major highlight of this release is the introduction of our first ever Student version of CONDUIT! The Student version was developed specifically as a companion to the AIAA flight control book, “Practical Methods for Aircraft and Rotorcraft Flight Control Design: An Optimization-Based Approach,” which is now available for purchase through AIAA, AHS, or Amazon. The Student version contains limited capabilities, and is available at no cost as a download from the AIAA website with the purchase of this book. For more information about the book, please visit: http://nams.usra.edu/flight-control/conduit/book/. To compare the difference between the Pro and the Student versions, please visit: http://nams.usra.edu/flight-control/conduit/pro-vs-student/.
 
We also want to remind our user community about the upcoming flight control course based on the new book and CONDUIT software, which will be held on June 3rd and 4th at the AIAA Aviation Conference (Denver, CO). It is a great opportunity to get some accelerated flight control and CONDUIT training for your team. For more details about the course, please visit: http://aviation.aiaa.org/PracticalMethodsFlightControlDesign/. Please take note of the Early Registration deadline of Monday, May 15, 2017.
 
1. New feature highlights:
 
  • Attention System Administrator for concurrent license users: This version of CONDUIT comes with an updated version of the concurrent license server (version 1.3). You will need to upgrade your existing license server to the new version. Please refer to the "Upgrading the CONDUIT License Manager" section of the installation chapter of the User's Guide for details.
  • The following specifications have been updated/added to this release of CONDUIT:
    • Yaw bandwidth and quickness specs with revised boundaries per upcoming ADS-33F: BnwYaH1, BnwYaH2, QikYaH1, and QikYaH2
    • New slung load bandwidth specs and outer-loop DRB specs based on upcoming ADS-33F: BnwSlH1, BnwSlH2, DrbPzH1, DrbVzH1, StkDyH1, and StkDyH2
    • New axis-specific minimum crossover specs: MnxPiH1, MnxPiL1, MnxRoD1, MnxRoH1, MnxVxH1, MnxVyH1, MnxVzH1, MnxYaD1, and MnxYaH1
    • New stick gradient specs: FspGsL1, FspGsL2, FspKtL1, FspKtL2, and FspKtL3
    • New pitch control power specs: MaxPiF1 and MaxPiF2
    • New turn coordination specs: TrnCrD1 and TrnCrD2
    • Other specs added since CONDUIT 5.4 (see individual spec info for description): BnwAtF3, FrqDrD6, FrqHeF1, GstRpG1, MaxMgG1, RofGaG1
    • Specs to accommodate the updated exercises: BnwAtX1, BnwYaX1, DrbRoX1, DrbRoX2, DrbYaX1, and DrbYaX2. Note that a new “XV15_Exercises” library has been added correspondingly.
  • A new set of Transfer Functions blocks has been added to the CONDUIT Blocks Library. This is a collection of commonly used transfer functions which are useful for control system design. The new block set includes transfer functions for second-order poles and for second-order notch, Butterworth, Bessel, washout, first-order lag, and first-order lead-lag filters. These transfer function blocks are also supported by CONDUIT's pre-linearization feature.
  • A new dependency checking tool "Dependency Checker" has been integrated with CONDUIT Batch mode, Save As, and a new Archive feature. Dependency Checker helps ensure that files required to run a CONDUIT problem are properly identified. This is essential so that when a CONDUIT problem is saved to new directory or when a Batch problem is created, all the dependency files are included and copied correctly. This addition also helps reduce Batch problem size by ensuring only files required for problem runtime are copied to Batch child folders.
  • A new "Archive" feature has been added to archive CONDUIT problems and their dependencies in directories outside the problem folder. Since archived problems contain all files needed to run a specific problem, it can be used to efficiently package CONDUIT problems for transfer to other CONDUIT users.
  • A new Preliminary Design mode has been added to Analysis Tools. Preliminary Design mode was designed to work with block diagrams whether or not they are associated with CONDUIT problems to provide maximum flexibility in early stage of control design. As such, it allows you to utilize Analysis Tools to analyze a block diagram whether or not it contains: design parameters, an initialization script/file, an external script, scenarios, or an associated CONDUIT problem. This feature can serve as the first step in building up a new CONDUIT problem.
  • Analysis Tools now scans for changes to initialization and external scripts as well as the block diagram and prompts you to rescan to ensure any changes are captured when generating plots.
  • Analysis Tools now includes a CIFER NAVFIT like option for LOES fit generation using a dynamically generated LOES profile.
  • Analysis Tools Transfer Function display now includes options for displaying the transfer functions in both coefficient form and shorthand notation. It also provides options for applying pole-zero cancellation and model reduction to the transfer function.
  • One-dimensional sensitivity analysis in Sensitivity Tools has been updated with new options to analyze the local or global topology of the design space, or to optionally customize the step size and number of steps.
  • The Batch mode GUI has been streamlined to provide more relevant mode specific information in batch.
  • Many other cumulative bug fixes and enhancements to the core system and tools since the 5.4 release.
2. Status of platforms supported
 
This version is available for Windows Vista/7/8/10 and Linux platforms, and is compatible with MATLAB versions R2012b through R2017a. Please note that this is the last version of CONDUIT that supports MATLAB R2012b through R2013b so plan your migration to newer versions of MATLAB accordingly.
 
For Linux, MATLAB R2012a was the last release on 32-bit Linux platform, and MathWorks no longer provided any software updates or technical support for 32-bit Linux OS beyond the summer of 2014. While we continue to distribute the 32-bit Linux version of CONDUIT for this release, no further 32-bit release and technical support will be provided by the next CONDUIT release, and only the 64-bit version will be supported on the Linux platform.

March 8, 2017

The AIAA short course, Practical Methods for Aircraft and Rotorcraft Flight Control Design and Hands-On Training Using CONDUIT®, will be held on the weekend of June 3-4, 2017 in Denver, CO in conjunction with the upcoming AIAA Aviation 2017 Forum. This is a unique opportunity to learn and review the methods and applications of aircraft and rotorcraft flight control design directly from Dr. Mark Tischler and Mr. Tom Berger.

This course will be comprised of lectures interspersed with associated hands-on lab exercises (aircraft and rotorcraft) to be completed by the students on their own laptops using the newly released Student version of CONDUIT® that is provided for course participants. While our design approach is based on multi-objective parametric optimization, we intend that course attendees who use a different design method will still find the course a useful and comprehensive presentation of well validated flight-control principles and rules of thumb. This course should challenge the practicing engineer to consider where their flight-control processes can be improved or augmented. Also, while we make reference to the basic tenants of feedback control theory, our focus in this course is on reducing the theoretical methods of aircraft and rotorcraft flight control to design practice for students and working-level engineers.

This course is intended for aerospace engineering faculty, students, and for practicing aircraft and rotorcraft flight dynamics and control system engineers. A basic knowledge of flight dynamics and control fundamentals, methods, and flight control concepts is assumed. But, the attendee is not expected to be an expert, and the course will not contain advanced mathematics. This course will emphasize the design requirements and methods of simulation, design, and analysis as presented and illustrated herein.

Course participants will receive a complimentary copy of the newly published Practical Methods for Aircraft and Rotorcraft Flight Control Design: An Optimization-Based Approach (AIAA, 2017).

The registration link is https://www.aiaa-aviation.org/register/. Please take note of the Early Registration deadline of May 15, 2017. Please see the attached flyer or contact us for additional details.


February 3, 2015

 Dr. Tischler's short course, Rotorcraft Flight Dynamics Model Identification and Flight Control Design using CIFER® and CONDUIT®, will be held on May 4, 2015 in Virginia Beach, VA in conjunction with the upcoming AHS 71st Annual Forum. This is a unique opportunity to learn and review the methods and applications of aircraft and rotorcraft system identification and flight control design directly from Dr. Tischler.

This course will cover practical methods and applications of system identification methods to determine and validate flight dynamics models of rotorcraft from flight test and simulation data. It will also cover practical flight control design and optimization methods to meet modern handling-qualities and flight control specifications. Many flight application examples based on the instructor's broad experience base will be presented throughout the course to demonstrate the methods and results.

The course would be beneficial to new and experienced rotorcraft engineers, researchers, academia, flight test engineers and pilots, and managers interested in an overview of advanced rotorcraft flight dynamics modeling and flight control tools, typical results, and project payoffs. Participants will receive a notebook with all of the course slides and can purchase a signed copy of Dr. Tischler's book on Aircraft and Rotorcraft System Identification for a discounted price.

The registration link is https://vtol.org/annual-forum/registration-information. Please see the attached flyer or contact us for additional details.


May 15, 2014

The CONDUIT® team is proud to announce the release of version 5.4!

1. New feature highlights:

  • New set of CONDUIT Engineering Blocks is added to the CONDUIT Blocks Library. These are a collection of engineering blocks that are very useful for control systems design. The new block set includes: a second order actuator model with user definable rate and position limits, a simple sensor model as a time delay and second order filter, a chirp signal generator, the CETI hover/low-speed turbulence model that simulates the effects of atmospheric turbulence on a helicopter, and a "To CIFER" block that couples with a built-in CONDUIT function for storing Simulink time simulation signals to CIFER-readable time history files for post-processing in the frequency domain.
  • In addition to the existing generic disturbance rejection bandwidth spec (DstBwG1) and disturbance rejection peak spec (DstPkG1), new axis- and loop-specific DRB and DRP specs (DrbPiH1, DrbRoH1, DrbYaH1, DrbVxH1, DrbVyH1, DrbPxH1, and DrbPyH1; DrpAvH1, DrpPoH1, DrbPiH1, and DrbPxH1) are added to the Rotor Hover Low Speed library, as based on several recent helicopter flight-test programs and as now included in the ADS-33 requirements.
  • A new State-Space Coupling Numerator Tool is now available in addition to the existing Coupling Numerator Tool. This allows a state-space model to be evaluated with selected degrees-of-freedom constrained. To better differentiate this new tool from the original Coupling Numerator Tool, the latter has been renamed to "Transfer Function Coupling Numerator Tool."
  • Design parameters can now be constrained as a fraction of the minimum crossover frequency spec (CrsMnG2) during optimization. Recall that the optimization process drives the design to rest on the minimum crossover boundary (i.e., "target crossover"). So, a common application of this feature is to constrain the integral feedback gain based on this target crossover frequency of the corresponding axis/loop, thereby fixing the phase lag contribution of the integrator and eliminating problems with poor definition of the integral gain values.
  • The user now has the ability to adjust the CONDUIT optimization step size tolerance as an exit criteria for the coarse optimization (delta Pcomb=0) option by defining a variable named StepSizeTolerance in the initialization file. The default value for this variable is 1.0e-5. Setting this variable to a larger value will terminate the coarse optimization sooner.
  • The figure toolbar in all supporting plots and analysis plots is now enabled for easy access to the MATLAB built-in plotting tools.
  • Additional option to save/export design parameters to MATLAB binary MAT files from the Design Parameter Window has been added.
  • In the HQ window, the user can now enable/disable design margin for a group of selected specs simultaneously, or to apply the same constraint type to a group of selected specs simultaneously.
  • A new HQ window context menu option is added to allow the user to move the Level 1/Level 2 boundary of a spec to an equivalent of a specified design margin percentage.
  • In Pre-Linearization, the ability to define a gain block as 1/DP is now supported.
  • The Design Margin Optimization plot option in Batch Mode is completely revamped to allow plotting of individual spec database variables and Pcomb values against design margin.
  • An option has been added to Batch Mode to terminate Design Margin Optimization for the remaining cases if three consecutive batch cases fail to reach Phase 3.
  • A Batch case can now be spawned from Batch Mode as a standalone CONDUIT problem on Windows platform. This feature was available previously only on Linux platform.
  • Batch Mode now provides the user the options to print/save HQ window and supporting plots to different file formats and different format options.
  • Users now have access to both the Design Parameter window and the Pcomb window in Batch Analysis mode.
  • New option is added in Batch Mode for saving the Batch run results as a MATLAB binary MAT file.
  • The user can now switch directly from Batch Setup mode to Batch Analysis mode to analyze previously ran cases without needing to first switch to Batch Run mode first.
  • Many other cumulative bug fixes and enhancements to the core system and tools since the 5.3 release.


Thank you for your continued interest and excellent feedback to our team on your CONDUIT experience. Many of your comments and suggestions have been incorporated in the latest release, so let us know how we have done in addressing your requirements.

2. Status of platforms supported:

This version is available for Windows XP/Vista/7/8 and Linux platforms, and is compatible with MATLAB versions R2010b through R2014a. Please note that this is the last version of CONDUIT that supports MATLAB R2010b through R2011b so plan your migration to newer versions of MATLAB accordingly.

Also, since Microsoft has ended support of Windows XP as of April 8, we will begin to phase out support of CONDUIT running under Windows XP. Since there are no Windows version dependent elements in CONDUIT, we believe the current release will continue to operate properly under Windows XP. However, please plan to upgrade your system to Windows 7 as we will officially remove Windows XP from our list of supported operating systems by the next release.

For Linux, MATLAB R2012a was the last release on 32-bit Linux platform, and MathWorks will no longer provide any bug fixes or technical support for 32-bit Linux OS beyond the summer of 2014. Therefore, we may also officially remove 32-bit Linux version and technical support by the next release. The 64-bit Linux platform, however, will continue to be supported.


December 11, 2012

The CONDUIT® team is proud to announce the release of CONDUIT version 5.3! This version is available for Windows XP/Vista/7/8 and Linux platforms, and is compatible with MATLAB versions R2008b through R2012b. Please note that this is the last version of CONDUIT that supports MATLAB R2008b through R2009b so plan your migration to newer versions of MATLAB accordingly.

In this major release, you will find a number of new features since the 5.2 release. Here are some of the highlights:

  • New Parallel Computing capability, which allows distribution of spec evaluations and linearization across available CPUs on a local multi-core system, thereby improving the overall computational efficiency of complex flight-ready block diagrams. Note that this feature will require MathWorks' Parallel Computing Toolbox.
  • Improved pre-linearization capability to optionally take advantage of the new Parallel Computing feature to further improve computational efficiency.
  • Improvements to Batch Mode to more efficiently handle large scale problems.  The Batch Mode GUI has been updated to address rendering issues associated with large scale problems, and is now faster and more responsive to user interactions. The Batch back-end is also improved to run cases more efficiently and includes safeguard to monitor Java heap memory usage and prevent crashes due to MATLAB memory leaks.
  • Native 64-bit support. Now users can associate CONDUIT with 64-bit MATLAB installs on both Windows and Linux platforms. Note that if you are using CIFER-dependent features, like CONDUIT/CIFER integration and Linearization Validation Tools, you will have to continue to associate CONDUIT with 32-bit MATLAB installs under 64-bit OSes.
  • Support for Windows 8 operating system.
  • Cumulative bug fixes and enhancements to the core system and tools since the 5.2 release.
  • The CONDUIT license server is also updated to version 1.2. To ensure full compatibility with CONDUIT 5.3, please update the current CONDUIT license server at your site accordingly.

November 19, 2010

CONDUIT® 5.2 is released, with support of MATLAB R2010b family.


May 6, 2009

CONDUIT® 5.1.1 is released, with support of MATLAB R2009b family.


February 5, 2009

The CONDUIT® team is having a 3-day training course from March 24 to 26, 2009 at the Hyatt Regency Santa Clara.

It's been over seven years since our last CONDUIT® training class. Since then, we have made many improvements to the engineering methods and software based on excellent suggestions from our (growing) user community and our own applications. This 3-day, hands-on training course will cover the flight control engineering and optimization concepts of CONDUIT® software functionality, and illustrative results from several detailed case studies.

Seats for the class will be limited to current CONDUIT® license holders only, and will be made available on a first come, first serve basis. We are currently planning for no more than 2 attendees per site, and will try to accommodate more on a space available basis if seats are available. If you are interested in, or are in the process of, acquiring the software, please try to expedite the procurement in order to be qualified for attending the class.


December 3, 2008

CONDUIT® 5.1 is released, with support of MATLAB R2008b family. It is also available now for both US and International distribution.


October 12, 2007

CONDUIT® 5.0 is released, with additional support of Windows Vista and support of MATLAB R2007b family.


October 29, 2004

CONDUIT® 4.2 is released, with support of MATLAB Release 14 product family.


July 31, 2003

CONDUIT® 4.1 is released, with additional concurrent licensing option available.


July 11, 2002

CONDUIT® 4.0 is released, with additional support for Red Hat Linux platform.


December 11, 2001

CONDUIT® 3.1 is released, which included the beta version of batch mode.


June 15, 2001

The Windows NT/2000 version of CONDUIT® is released! For pricing and availability please contact us.


March 2, 2001

The 4-day CONDUIT® training course was held at the Hyatt Hotel in San Jose, California. It turned out to be a high success! About 20 people from various US aerospace companies, government agencies, and universities attended the event.


October 1, 2000

CONDUIT® 3.0 beta is released, with drastic enhancements to the system and added support of Sun Solaris platform.


December 15, 1999

CONDUIT® 2.0.3 is released, which included miscellanous enhanacements and bug fixes to the system.


June 9, 1999

CONDUIT® 2.0.2 is released, which included the beta release of the SystemBuild plug-in to CONDUIT® to allow the user to perform analyses on ISI's SystemBuild block diagrams. This version also included a new Sensitivity tool, which provides insight into the behavior of the optimization process, and also offers metrics that can help the user select compatible design parameters and specifications for a CONDUIT® problem.


May 25-27, 1999

The CONDUIT® team presented a paper on helicopter case studies using CONDUIT® at the AHS Forum at Montreal.


February 16, 1999

CONDUIT® 2.0.1 is released, which included a newly improved Analysis Tool.


September 30, 1998

CONDUIT® 2.0 is released. This version is compatible with MATLAB 5.1 and above.


February 23-27, 1998

CONDUIT® short course held at the University of Maryland Inn and Conference Center.