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.