Thursday, February 19, 2009
We have integrated the OptiTrack camera system in QUARC so that the designer can use a simple set of QUARC blocks in Simulink to track individual markers or rigid bodies. To test the performance of the system, we wanted to see if it was possible to control a standard inverted pendulum experiment using visual feedback instead of the standard encoder feedback. To control the inverted pendulum you must be able to measure the pendulum base arm angle and the angle of pendulum. We placed refective markers on an inverted pendulum experiment and used a simple QUARC block to interface with the OptiTrack system to measure the marker positions. Knowing the marker positions, we can determine the angle of the pendulum base arm and the angle of the pendulum so that it can be controlled.
The following video shows the results of this experiment. As you can see, it is possible to stabilize the inverted pendulum using vision-based feedback. The OptiTrack system combined with QUARC is a powerful new control tool, opening up the possibility for many new control experiments. Objects that were previously difficult to track, such as indoor autonomous vehicles, can now be tracked by adding reflective markers.
Thursday, February 12, 2009
Tuesday, February 10, 2009
Quanser is soon releasing a new such product called the 3 DOF Gyroscope, depicted on the left. The device consists of a rotating disk mounted inside an inner gimbal which is in turn mounted inside a second outer gimbal. This whole structure is supported by a rectangular frame that is free to rotate about its vertical axis of symmetry. This scheme results in three degrees of freedom for the gyroscope disk. The structure is masterfully engineered to provide minimal friction on rotation axes. This makes the 3 DOF Gyroscope a great choice for research in spatial applications of gyroscopes as the zero friction of space is almost nearly achieved by the device! Each axis as well as the disk itself is actuated using a separate motor while digital position measurement on each of these axes is done via high resolution encoders. While both gimbals and the outer frame are free to rotate about their rotation axes, the frame and outer gimbal are designed such that they can be also be fixed on desire. Therefore a whole variety of experiments can be performed.
The 3 DOF Gyroscope also comes with an extensive curriculum that uses MATLAB and Quanser's QuaRC software to cover a variety of experimental tasks using the gyroscope plant such as stability analysis, root locus design, non-minimum phase effects, LQR state-feedback control and friction compensation schemes. In the video below, the plant is simulated using the Virtual Reality toolbox and QuaRC to perform position control on the gyroscope angle about the vertical axis. The yellow plot shows the reference applied in degrees while the purple plot is showing the output. Notice that as a direct result of the gyroscopic effect, the horizontal axis is actuated to control the angle about the vertical axis. That's the magic of gyroscopes!
(Note: 3 DOF Gyroscope is scheduled for release in March 2009)
This can also be used with the One-Floor Active Mass Damper in order to perform structural engineering analysis or develop a controller that reduces the deflections of the building while, for instance, the table is running an earthquake.
The Shake Table I -40 can be run on a PC with the QuaRC control software. This can be done either through Matlab/Simulink or using the STI-40 Software shown below. The STI-40 Software enables users to quickly get started and command signals such as sine wave, chirp, and sample earthquakes all through an easy-to-use GUI. Only QuaRC and the LabVIEW Run-Time Engine, which is free to download, are needed to run this program (no need for Matlab/Simulink). This software can even be published to a website for users to log on and control the table remotely.
- Mitch -
(Note: Shake Table I - 40 is scheduled for release in March 2009)
Monday, February 9, 2009
Wednesday, February 4, 2009
I recently had the good fortune of visiting India, a country beaming with youngsters who are on the cusp re-writing history. From the minute the airplane door swung open, I knew I was in for quite the experience. Over the two weeks I spent immersed in this colorful and vibrant culture, I was pleasantly taken aback by the array of mouth watering dishes and their assortment of appetizers and sweets.
The good people at Cybermotion, Quanser’s Indian distribution team, showered me with their warm hospitality and inspired me with their drive and dedication towards impacting the academic and industrial world of controls and automation. Anand and Praveen, two brothers spear-heading this ambitious team of more than 60 highly energetic and hard-working individuals, are visionaries in many respects. On several occasions, I couldn’t help but comment on the similarities between Quanser and Cybermotion.
During the week, we spent a great deal of time presenting to and working with professors from some of the top Universities in India such as IIT. The decisions made and the courses cultivated at these top institutions has an incredible impact on potentially hundreds of institutions around the country. It gave me a great sense of pride to present on behalf of Quanser and to see that our control solutions are found in labs all over the world!
Sunday, February 1, 2009
It was no surprise that both teams worked together pretty well - after all, we work together in a real life - and have a lot of fun! What did come as a surprise were the sharp-shooting skills of White shark (a.k.a. Derek Wight) who won the first game and ninja-like Sashimi (a.k.a. Luke Cho), a celebrated "bug collector" for the team Q.
Just as everyone was running out of ammunition - Zofo's (a.k.a. Paul Gilbert) presentation brought everyone to life. Zofo entered the room in true Bond style with the 007 theme song and a glass of Martini (shaken, not stirred). He outlined for the rest of the agents the goals and strategy of the whole Quanser team for this year. Agent Tut (a.k.a. Jacob Apkarian) who founded the company 20 years ago, added few words to highlight the success of the now adult Quanser. And of course, there was a cake (expertly cut by agent Tut) and cigars.