An update for the FOMCON toolbox has been released: version 0.41 beta. With this release we bring you an important bug fix which was causing problems when simulating fractional-order controllers with $\lambda=\mu=1$. This was due to incorrect calls to toproper() function which are now corrected.

In addition, several new features have been implemented. The most important ones are related to the fractional-order PID optimization tool and are as follows:

• All FOMCON options related to FOPID optimization are now saved and restored with the optimization project (“Save/load configuration” menu items in fpid_optim).
• It is now possible to specify the desired crossover frequency $\omega_c$ of the control system in the constraints panel without requesting the robustness criterion (which is “phase response is flat at crossover frequency”). To use this feature, set $\omega_{high}$ to $-1$. The same goes for the command line tool fpid_optimize().

It is our pleasure to announce the immediate release of a FOMCON toolbox update. Although some changes in the API are still possible in future versions, the core of the toolbox is now quite stable. Bearing this in mind, we have moved the project to the beta stage.

### New features

• New analog implementation module added; please see [1] for some hands-on examples of using it. A GUI for this feature will be implemented and included in a toolbox update.
• Several fractional-order transfer function analysis tools added, including fractional-order root locus analysis tool;
• Global and local function configuration options have been made available further enhancing the flexibility of the toolbox; in particular, it is now possible to save and restore all the configuration parameters in the fpid_optim() tool, a useful feature to effectively handle the abundance of available optimization options;
• All graphical user interfaces reworked to further facilitate the workflow, e.g. the fotfid() tool now fully supports FO process model identification; several new components added;
• New fractional-order transfer function blocks in Simulink: in these, model coefficients and exponents are entered numerically, so they can be used as building blocks for more complex systems.

### Bug fixes

• NB! The calling sequence to the fractional-order transfer function identification function fid() has changed! Please see the documentation for further details;
• Numerous bugs fixed, see the bug tracker for a list of major closed bugs.

The toolbox is available for download in the corresponding section of the website. The documentation has been updated as well. Please clean the FOMCON website page cache if you have any problems with viewing it. Legacy documentation is still available at http://docs.fomcon.net/legacy/

We also hope, that the release cycle for the toolbox will be shorter from now on. Kindly report any bugs you may encounter!

Note on upgrading the FOMCON toolbox: please overwrite existing files with the new ones.

### References

 [1] A. Tepljakov, E. Petlenkov, and J. Belikov, “Efficient analog implementations of fractional-order controllers,” in Proc. of the 14th International Carpathian Control Conference (ICCC), 2013, pp. 377–382.
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## Paper to be presented at MSC’2013 conference

A FOMCON project related paper will be presented this summer at the 2013 Multiconference on Systems and Control (MSC’2013) held in Hyderabad International Convention Centre, India, August 28-30. The paper is entitled “Fractional-order Controller Design and Digital Implementation using FOMCON Toolbox for MATLAB”. In this work, we describe the process of implementation of a fractional PID controller for a particular laboratory heating system. You will also learn about the new developments in the FOMCON project. The talk will be given by Aleksei Tepljakov.

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## Paper to be presented at MIXDES’2013 conference

A paper dedicated to fractional-order control of a position servo will be presented at the MIXDES’2013 conference in June. The talk will be given by Sergei Astapov.

## Paper to be presented at ICCC’2013 conference

A paper will be presented at the end of May at the International Carpathian Control Conference 2013 held in Rytro, Poland. The talk will be devoted to the new developments in FOMCON project, namely to the analog approximations module allowing to quickly obtain fractance circuits for a given fractional-order system or controller. Presenter is Aleksei Tepljakov.

## Paper to be presented at ACC’2013 conference

A FOMCON project related paper will be presented this summer at the 2013 American Control Conference held in Washington, DC, USA, June 17-19. The paper is entitled “Design and Implementation of Fractional-Order PID Controllers for a Fluid Tank System”. In this work, we design and implement a digital fractional-order PID controller for a system of coupled fluid tanks. Presenter is Aleksei Tepljakov.

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## Tutorial: Fractional-order PID Controller Design for a System with Input-output Delay

In this tutorial, we shall illustrate the use of the FOMCON toolbox in connection with the problem of designing a controller for a system with a significant input-output delay. For this purpose, a fractional-order first-order plus dead time (FO FOPDT) system is considered. We treat the continuous-time case.

Posted in Tutorials | | 44 Comments

## Forums now available

Support forums are now available. Please use them if you need help with a particular feature of the toolbox.

## Introductory materials completed

Basic introductory materials have been completed and are available under the “Fractional Calculus” menu entry. These materials will be updated once relevant FOMCON project developments are done. Further developments will also be devoted to creating thorough toolbox documentation.

Today, we are glad to announce the release of the next preview version of the FOMCON toolbox for MATLAB: version 0.3-alpha. This release, some features are added and some important issues are fixed.

### New features

• Fractional-order PID optimization tool fpid_optim now supports running Simulations in Simulink.
• Fractional-order transfer function identification in the frequency can now also be used for identifying systems with apparent input-output delays.
• An experimental tool impid has been added which can facilitate fractional-order PID controller digital implementation.

The toolbox is available for download in the corresponding section of the website.

In other news:

• An online reference manual for the FOMCON toolbox is now available. A more thorough PDF user manual will be published later.
• A bug tracker for the toolbox has also been set up. Please report any bugs you may encounter!

Note on upgrading the FOMCON toolbox: please overwrite existing files with the new ones.