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Life Is Good

I have to stay up tonight, because my sleep schedule has been wicked off (I lie awake in bed for hours, usually until 02:00 or so, only to naturally awaken at 0600 or so...), and I have found that an all-nighter is sufficient to reset my circadian rhythm such that regular sleep works again. Besides, a single night's missed sleep is not only tolerable but frequently seems to enhance my absorption of information.

The irregular sleep notwithstanding, life has been very good thus far this semester. My professors are personable, likable people who are good at their jobs, my classes are full of friends and acquaintances, I have devoted well over 90% of my fullest attention to the class (rather than other distractions which one can so easily find on a laptop that is ostensibly for taking notes) in every class, and my book bill has come in well under $300 for the first semester I can remember, from the Campus Bookstore no less!

Rusty made the mention after lunch yesterday that we (he and Krista and I) head over to the seventh floor of the EERC, where the main office for CECN is, to see if they were discarding anything. As it turns out, they were in fact doing just that, in great volume to boot. I ended up harvesting four PSUs, mostly 200-350W Antecs, four motherboards with PIVs and some DDR RAM, two ATi AGP cards with decent chipsets, and some assorted cables for my current rig and the PSUs. I fully intend to sell off most, if not all, of the working parts to help boost my bank account and more than recover the book money I just spent.

FIRST has been going well. I have a five-member programming team, though not all of them have shown up at the same meeting, and, despite the intricacies of the task that 857 has asked of us, I believe that we will deliver a solid base of code within a few weeks. To catch the reader up, the game this year is played with Delrin-coated wheels on a plastic surface specifically selected to have a ridiculously low coefficient of friction with the wheels (and, notably, only with the wheels--shoes have perfectly normal traction), to the extent that µS is but 0.04 and µK is 0.02. This means that, by some rough envelope calculations, the friction force available to a wheel on a 120# robot is roughly 1.2#...which works out to an extremely low maximum controllable acceleration (0.39m/s2). To this end, we have been asked, as well as learning LabVIEW and working with a brand-spanking-new (and AWESOME!) control system, to create an electronic traction control system (ETS), much like that found on many mid-range vehicles these days. After much discussion over the last few days with the programming team, we have determined that this is a feasible goal, especially with the addition of an additional control one of the other mentors came up with, affectionately dubbed the "Aaron Drive".

The Aaron Drive is composed of three to four 1.5" diameter PVC tubes, roughly 12-24" long, with a 1" stroke, 1.5" bore pneumatic piston in the bottom of each. Upon this piston's shaft rests an 8-10# mass, likely lead or steel. The operation of this system is rather simple in theory, and is shown graphically by a spreadsheet based on approximate numbers:

  1. One of the cylinders is extended by a blast of 60psi air, propelling the mass upwards several inches and creating an additional 110# of normal force (which is intimately related to friction as you may remember from physics) on the robot chassis for a brief instant. (ENHANCEMENT ONE)

  2. The mass enters freefall conditions, traveling upwards, and thus is no longer acting on the robot at all, thus causing a loss in normal force. (DEAD ZONE ONE)

  3. The mass hits apogee and begins to descend, accelerating due to gravity but not quite in a freefall due to sidewall friction, thus increasing normal force very slightly. (DEAD ZONE TWO)

  4. The mass hits the cylinder shaft, which has been vented on both sides, causing a (relatively) gradual conversion of kinetic energy into normal force. (ENHANCEMENT TWO)

  5. Other cylinders are fired to try to place Enhancements in the middle of Dead Zones, to bring an average increase in normal force, and thus an increase in control, however slight.

With the Aaron Drive, if it is legal, we would be able to give the ETS one more way to apply corrections to the robot's movements to more closely mimic the actual requested accelerations from the driver or autonomous code.

To summarize, life is good right now, and I hope to put last semester's mistakes firmly behind me and walk with my chin up and a lightness in my step, and get myself back on track.