UAV Update: Autopilot kablooey

Saturday, October 31. 2009
Everything seemed to be ready to go for the first test of the autopilot board. Infact, an initial test showed it worked perfectly! Servos were moving, everything seemed happy. Then I hooked up an additional, fateful wiring harness to the R/C receiver's battery input port.

Because of a wording/phrasing ambiguity in the manual for the PPM encoder board, I did the opposite of what I was supposed to do. (I seriously can only take half the responsibility here - it was terribly worded and quite ambiguous.) Unfortunately, the AP board went kablooey. More specifically, the PTH08080 linear voltage regulator died. You can see it, somewhat fuzzily, in the photo - just click on it. Sorry, I didn't put my macro lens on, the standard walkaround was acceptable enough. Fortunately, the part is easy to replace, and not expensive (about $8) and I've already ordered a replacement from DigiKey. However, this will mean more delays. At least know I know that the interfacing works properly, and we should be in the air shortly!
Posted by Adrian Lauf in Research at 01:50 | Comments (0) | Trackbacks (0)

A look one year back

Tuesday, October 27. 2009
On October 27th, 2008 at around 11AM, my life nearly changed permanently - and nearly in a bad way. After weighing the advantages (and in my mind, at the time, the disadvantages) of patiently waiting for a truck to slowly accelerate to speed right before an on-ramp to I-40 Eastbound, I decided, poorly, to pass the slow-moving vehicle in my 2006 Civic on the left right before crossing infront of it to make the relatively sharp curve onto the highway onramp. Needless to say, the maneuver resulted in massive oversteer. I couldn't correct early, for risk of flipping my car over an island. Instead, I chose to wait out the slide, but it was too late. I helplessly mashed the brake pedal, but my tires found no purchase and I smashed into an embankment at nearly 65MPH.

My luck turned for the better, as the embankment was sloped instead of a flat wall. After taking off the front bumper, deploying the airbag and flattening the lower half of the engine bay, I ramped off the embankment instead of smashing full-force into it. Because of the angle, the momentum caused the car to flip over, and I continued the rest of the journey on the roof of the car, sliding backwards.

I will never forget the smells, the pops, crunches, smashes, and shattering noises that I smelled, felt, and heard that day. I am lucky and grateful to be alive to tell this story, yet I never suffered a single injury other than airbag burn. While it is obivous that, had the car been equipped with Electronic Stability Control (see an amazing demo here) that the oversteer would not have happened. Yet, this is no excuse. I learned a very hard, but valuable lesson that rides with me every day that I drive. Today, I happily drive a 2009 Jetta TDI with Electronic Stability Control (called ESP for Electronic Stabilisation Programme). I strive every day to be safer, to be patient, and to be thankful that I wasn't hurt, and that I hurt nobody else.

So, today I think back, solemnly, yet gratefully, and continue to make the promise of patience to myself and others. Thanks for reading.
Posted by Adrian Lauf in Thoughts at 01:39 | Comment (1) | Trackbacks (0)

Fun with a bouncy-ball @1000FPS

Monday, October 19. 2009


This is an entirely non-research related post - I purchased a giant, fluid-and-sparkly-filled bouncy ball at Walmart. The poor fellow was sitting alone on a clearance aisle, no pricetag, and it seemed to be the last of its kind. It is precisely what I went in to get. In the clip, you can see it deform vertically about 25-30% (!) as it hits the ground from about 4 feet.

In research news, I'm waiting for a few more parts to come in from Mouser and Newark before the autopilot will be completely integrated into the airframe. The autopilot is working (the board boots) and my airframe and radio configuration files are essentially complete. More later.
Posted by Adrian Lauf in Slow-motion at 03:07 | Comment (1) | Trackbacks (0)
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