A commonly used hardware in-the-loop environment is the dSPACE1 system, whose strength is aimed at high flexibility and processing speed, but involves rather costly hardware and software license fees. In our proposed paper we elaborate a scalable hardware platform running a low-cost RTLinux open source system of comparable processing speed.

There is a great variety of applications that need such rapid control prototyping systems. Especially developers of electromechanical plants are using rapid control prototyping systems to tune less known system parameters and controller settings. These needs are well covered by the software environment MATLAB/Simulink and the "Simulink Target for Real-Time Linux" (STRTL toolbox). STRTL was developed within the Ph.D. thesis of R. M. Garcia [1] on which our system is based upon.

Because of a bug in the parameter exchange function of STRTL and the desire to control our Simulink model via a website, we created an extension called strtl procctrl. This extension is a special driver that en- ables the user to exchange the MATLAB/Simulink model parameters via the linux build in proc-filesystem between the model and a website. Using this method it is quite easy to create a MATLAB/Simulink independent user interface. This interface can either be a command line application or a website that accesses the driver generated proc-file.

The paper is organized as follows:

First the requirement for this rapid control prototyping system and common drawbacks of the STRTL toolbox are detailed. Secondly the strtl procctrl driver is discussed in detail. Finally we demonstrate the usage of the driver by means of a small application. We conclude our paper with some remarks and the reference to our website where this extension can be downloaded freely.

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