Past Projects of Norg Consulting


24 years of hands-on experience working on a variety of controls related projects. Most of the projects Norg Consulting has executed for its clients are confidential, but some of the spin-off, and a few older projects are listed below:

 Tripod Floater v2.2: For this latest installment of "Active Magnetic Bearing"-setup experiments (see below for earlier versions), we replaced the power cable with a LiPo Image for "Tripod Floater v2.p"battery, allowing for several hours of undisturbed wireless experimenting. Also, in order to enable communication with the floater, we added a Zigbee network (see www.Digi.com). Using the Matlab serial interface, we can obtain real time sensor information from the floater at about 30 samples per second, and use that to feed an animation, showing real-time floater movements. Enjoy the movie. Here you can find the partslist, schematics and an ASPE 2010 paper on the subject .

  Tripod Floater v2.0: (see below for v1.0). For this "Active Magnetic Bearing"-setup we challenged ourselves to place all electronics plus the controller on board of the module. A TI Image for "Tripod Floater v2 Explained" micro-controller (TMS230F28335) runs 3 PID controllers plus a coordinate transformation at 10 kHz. This controller interfaces with an custom built PCB for line-filtering, 3 small but capable PWM amplifiers (www.Pololu.com) and sensor signal conditioning. The only cable this 13 lb module requires is a 12 V power supply. In rest, less than 1 A is required to run the module of which only 0.3 A is actually used by the amplifiers to maintain a positioning stability of less than 10 µm. Enjoy the movie.

  •3D moving bodies simulation engine. Based on the work of Chris Hecker, we developed a 3D rigid body simulation engine in Matlab. In order to improve interaction between simulated objects, interaction-models (e.g. stiffness, damping, friction) were used instead of Newton’s law of Restitution. Using this tool, we were able to determine specific process parameters by comparing simulated results with real measurements, while improving our client’s understanding on the behavior of specific flying and bouncing objects. As illustration, a simulation and animation of Newton’s Cradle shows the interaction between 5 balls. Notice the real-life behavior of the balls when they start to swing in-sync towards the end of the simulation. Another illustration is a bucket with two balls and a swinging lamp. Watch the balls as they bounce around and slowly come to a halt.

  Tripod Floater v1.0 : 3 Degree of Freedom Active Magnetic Bearing demonstrator. Image for "Tripod Floater Explained"Watch the movie explaining the Tripod Floater, filmed in our Laboratory.

The setup exists of ‘the stage’, with 3 actuators and 3 non-collocated sensors, a controller implemented in dSpace and a linear current amplifier. In the controller, the gaps between the AMBs and the plate are calculated using the 3 sensor readings. The controller keeps those gaps at a certain value.

Tripod Floater AnimationIn some situations, it’s hard to evaluate synchronous data. In the Tripod’s case, there are only 3 dimensions, but in case of (e.g.) a 6DoF free floating stage, evaluating 6 measurements with position data can be tricky and cumbersome. An animation visualizes the Tripod Floater's movement during an approx. 20 mrad step-response. The yellow element represents the Tripod Floater (with the rectangular blocks being the AMB and the cylinders representing the sensors), the plate it is hanging from is not drawn, and the blue cross in the center is the setpoint for the position controller. Watch the orientation of the setpoint change, and the stage follow.

  • 6 Degree of Freedom free floating Semiconductor stages using Active Magnetic Bearings. During a SPAWAR funded project, the compatibility of a 6 Degree of Freedom free floating stage (equipped with Active Magnetic Bearings) and the Imprint Lithography process was shown. For a more elaborate description, see ASPE paper.

  • Piezo-electric motors (a.k.a. Fred Flintstone motors). These motors, used in a Scanning Electron Microscope application, have many advantages, like stiffness, large dynamic range, non magnetic, etcetera. From a controls point of view, their biggest disadvantage is their non-linear behavior, making smooth moves at µm/s velocities and settling difficult. To improve this behavior, non-linear controller elements were designed, allowing for smooth stage moves and increase setting performance.

  • Motor control algorithm design for Sonicare Toothbrushes.

  • During a 1997 project at Philips Research, shock sensitivity of Hard Disk Drives and Car-CD-COM players was investigated. The aim was to improve shock sensitivity of these devices, without changing the current controller implementation. Only being allowed to add controller elements parallel to the existing controller, an 'Adrenaline Controller' was designed, basically increasing the controller effort only when needed, analogue to the behavior of a dozing driver when he hits the warning-bumps as he drifts off the road.

  • Conceived a graphical controller design tool, allowing simultaneous analysis in Time- and multiple Frequency domains, using Matlab. This program (in rewritten form) is still in use during Control System Tuning courses;

  • Designed an Animation Tool, visualizing captured position data of 6 degree of freedom floating stage, simplifying tuning and debugging and explaining complex technical matters to management;