Tuesday, April 14, 2009

QUARC: Hard-Real-Time Performance on a Windows PC

The next major release of QuaRC, version 2.0 which is currently under development, will support an additional target operating system, called INtime, in order to provide hard-real-time performance in a "one-PC solution", in which the user interface components and hard-real-time control are integrated on a single PC platform. INtime is a Real-Time Operating System (RTOS) developed by TenAsys which provides deterministic hard-real-time performance under Microsoft Windows.

The upcoming QUARC 2.0 is a result of Quanser's new partnership with TenAsys. QUARC's support for INtime has just been showcased during a Quanser-TenAsys joined demonstration at the TenAsys booth at the Embedded World 2009 Exhibition & Conference show in Nuremberg, Germany, at the beginning of March 2009.

The QUARC-INtime demonstration actually consisted of two fully-featured hard-real-time QUARC controllers running in INtime and interfacing to Windows on the same PC.

QuaRC-INtime demonstrations: LBS and 2-DOF Planar Robot

The first demonstrated system consisted of Quanser's Laser Beam Stabilization (LBS) unit, whose QUARC controller was solidly running at a 10-kHz sample rate while communicating with its corresponding Simulink model in Windows using external mode and updating on-the-fly, among others, a X-Y graph and a VRML 3-D graphical scene, both representing the laser beam regulated position.

The other demonstrated system was Quanser's latest state-of-the-art robotic device: the 2 DOF Planar Robot. The 2 DOF Planar Robot interfaced to the demo PC using a Q4 HIL card passed to INtime. It had its QUARC controller model running at 1 kHz in INtime and executing in parallel to the LBS, on the same PC. As an external user interface, a USB drawing tablet (a.k.a., pen pad) with stylus input was also connected to the PC. A Windows C# user application could collect the handwritten data and send it as position commands to the 2 DOF Planar Robot equipped with a pen end-effector, so that the captured handwriting (or signature) could be duplicated on an actual sheet of paper. The communication between the Windows user-developed C# application and the QUAaRC controller running in INtime was easily implemented using the QUARC Stream API.

Both LBS and 2 DOF Planar Robot models ran side-by-side using the INtime system timer and have proven themselves to be very stable during the 3-day long Embedded World conference. Preliminary performance measurements indicated observed latencies of ± 5 microseconds for both 10-kHz (LBS) and 1-kHz (2-DOF Planar Robot) controllers.

Therefore, QUARC for the INtime target has been demonstrated to give extremely promising hard-real-time performance while running alongside Microsoft Windows on the same PC.


Florin said...

Good work!
ANy idea when this will be available? Any specifications? How fast can you run with more complex models? CPU load?

Florin Nae
Automotive Application Engineer

Hervé Lacheray said...

Hello Florin,

Thank you for your interest. The QuaRC with INtime support release date still has to be firmed up (before the end of the year I would assume, but this is partly depending on external constraints as well). Some benchmarking results will also be released at that time. All I can say for now is that performance data look very promising! Please feel free to contact us directly for more information about QuaRC and our upcoming INtime support.