Today's system test at Portland International Raceway went as all of our system tests seem to go: something went wrong in the morning, then we eventually fixed everything, and at the very end of the day we got to test what we wanted to test in the first place.
In the morning:
- We had lots of interfering wifi traffic from PIR (WHAT is PIR doing with high power wifi traffic?! talking to racecars?) which caused a lot of packet loss. We switched the field server Host AP to Chanel 6 and that seemed to solve our problems.
- Our true sine wave inverter blew up. Still don't know why, but it blows fuses. We switched to a modified sine wave inverter, and after some initial surge current problems, everything seemed to work. Looks like we'll just pick up a few high power modified-sine inverters to replace the true sine one: the pansat ATV receiver uses linear supplies, so bad switching wave forms shouldn't make a difference to that.
- Once again, we forgot to turn on the wifi poweramps before setting up the rocket.
But once again, we got everything fixed by the mid afternoon and then, surprisingly, the test had a twist to it that we've never really seen before: everything seemed to.... work. We were tired, sunburned, dehydrated, and after this morning's problems, a bit demoralized - but we all agreed, everything seems to work and we could have actually launched the rocket this afternoon.
We found issues as we expected, and we'll be polishing up some things over the next week, but we really are ready to go.
And just to be paranoid, we decided that one more system test day is a Good Thing. So we're going to do a formal system test day a week from today, Saturday August 13th. And we're going to start early in the morning, so we can still have time after fixing whatever goes terribly wrong at the start of the morning ;)
- The APS Battery voltage in rocketview is incorrect (0V), but seems correct in the ATV display.
- When forcing launch detect by removing the umbilical and setting the accelerometer to test mode a chute pyro deployed within about 30s. (Which pyro fired and exactly how long after launch detect?) This behavior was deemed acceptable since the launch detect criterion was met (>= 2 independent detections) and the altimeter and IMU agreed we were slow i.e. probably at apogee.
- When emergency powering down via the recovery node (DTMF code 46) the FC rebooted into Recovery-Wait state, which seems correct.
- ATV reception from the repeater on the KGON tower was good (P4?). Not as good at all times from the rocket. This problem is believed to be transient and related to the particular test geometry.
- DTMF reception attempting to activate the pyros was good and actuation was successful.
- All launch detect tests were successful. Timers etc. seemed correct.
- Communications were lost, effectively after the end of testing, including ssh to the FC, why?
- Glenn will measure battery recharge current to estimate charge consumption during the ~3hours of testing.
- Need to get several 5A "ATM"-type auto cartridge fuses
- LCD flat panel display is acceptable but requires sunshade
- Should measure ATV transmitter power output to verify proper operation.
- Must test effect of communications link loss on rocket during launch/flight sequence. This can be a lab test.
- Need an IBM logo on LV2 by launch time
- May be able to test with "fake" sensors on the CAN bus by reassigning CAN ids in the FC.
- In subsequent sensor designs a hardware "override" mode could allow test inputs on the bench for system evaluation (duh).
- Success criterion for the final test prior to Aug.20 launch must be set.
A lot of us are going to the Portland Area Robotics Society monthly meeting, since it's directly applicable to some of the things we're doing:
Paul Verhage, President of the Boise Robotics Group (the BoRG), will be in town and has volunteered to share his projects with us. Perhaps you've seen his articles in Nuts & Volts and Servo... Near-Space Exploration with high-altitude balloons (Sending BASIC stamps to 100,000 ft): Not necessarily a robot as we usually think of them, but the avionics use many of the same components. Paul will show video from 90,000ft. Read Paul's book and Nuts & Volts articles at http://www.parallax.com/html_pages/resources/custapps/app_nearspace.asp Near-Earth Asteroid (NEA) Micro-Lander: See Paul's article in the July issue of Servo -- the first in a series on making your own micro-lander robot. Come to the meeting to see the rovers in action. Why let NASA have all the fun?"
The meeting is Saturday from 10:30am to around noon at PSU's "PCAT" building (1800 SW 6th Avenue) in room 28. We'll blow out right after the lecture (missing the cool show and tell, I'm afraid) and head right to PIR.
The PSAS full system test will be Saturday August 6th, 1:00pm - 7:00pm.
Basically, from Portland:
- Take I-5 north
- Exit Hayden Meadows Rd
- Take a left after the exit onto N Vistory Blvd.
- Take a right at the T onto N Expo Rd.
- Take a left Broadacre Dr
- The field to your RIGHT is where we'll be; if you can't find us, call Andrew at 503.708.7711
Full PSAS system test, WITHOUT the launch tower, with a focus on flight computer software. Here are our integration test goals:
- Full-Rate Communication Links (2500 IMU messages per second, plus other normal packets)
We expect this includes no unexplained losses in logging, network, etc.
- Test seemed to pass. Reasonably stringent 1/4second? 2500? messages per second test repeatedly passes, although it did occasionally fail, but not at the end of the test day with all tweaks in place.
- Smooth and convincing demonstration of the launch procedure, from setup to rocket-ready relay click to launch detect using umbilical and IMU test setting. This means no debug mode overrides or other abnormal measures.
- Test passed. Setup time was reasonable (~3 hours). All observed behavior deemed acceptable.
- Clean log files. We want to do a post-mortem on our tests to see if any abnormalities exist.
- Status unknown.
- Record the ATV video. This will allow review similar to the previous goal.
- No one wanted to do this...
- Repetitive successes: run the full gamut three times.
- Test passed.