Tuesday, July 13, 2004

Armadillo Aerospace News: Electronics Failures

chabot imageWe set up for another captive hover test of the big vehicle on Tuesday. Everything proceeded well, but as I started the flight control software up to warm the engine, the self-test failed because one of the jet vane actuators was not responding. The automated self test on every startup now is a Very Good Thing, because I very likely would have missed this condition, as the vane position graphs aren’t on the first visible page of telemetry results. On the driver board, two actuator bit LED’s seemed to be stuck on We connected the ribbon cable to a brand new driver board, and found that they were still on, so the fault was in the AccessIO A/D + DIO board. We had moved to a Diamond A/D + DIO board for the A/D, since we had fried four of the AccessIO boards (probably from the motor inductive kicks, in hindsight), but the digital IO pinout was completely different, so we had been continuing to use the AccessIO board to run the motor drives, because the DIO part seemed to still be functioning fine, even though the A/D was fried. Apparently this wasn’t a great idea. It is odd that it seemed to give up sometime late in the vehicle pressurization, because I had started it and let it pass self test several times during the loading process. Read More

3 comments:

  1. Great article! Thanks.

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  2. Thanks for interesting article.

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