I don't suppose the "gizmo on a stick" idea would still be a useful tool here...
Bill > On Sat, 2004-11-06 at 21:17, David Masten wrote: > > We have gizmo moving around under control now. > Unfortunately it is still > > too unstable to really control. > > > > Monday we dove straight into flight testing. It > didn't work at all. We > > pulled out the multi-meter and oscilloscope to > troubleshoot. After > > spending a considerable amount of time trying to > find what was wrong > > someone noticed the fuses on the motor leads were > toast. We all went out > > to our cars to grab our spare fuses. Several cars > are using the mini > > fuses now, but we managed to find enough 30-amp > fuses. Flights were more > > as expected than the crash a few weeks ago. Gizmo > got into a slow roll > > and a definite +x translation whithout command. I > was able to land it > > quickly enough. We took video, I'll post links as > soon as the video is > > put up. We did two flights, with similar results. > > > > I did some more test flights today. Knowing that > there was a tendency to > > roll (we define roll as rotation around the > vertical axis), I tried > > compensating for the roll while keeping one of > gizmo's gear on the > > ground. I was able to control it fairly well > though the response was a > > bit slow. That tells me I need to up the control > constants a bit. I also > > tried full flight. It did an immediate translation > but appeared to not > > get any worse, indicating that the response was > not fast enough, but > > that it did zero out the rotation. It also pointed > out that it is > > sufficiently small enough and unstable enough that > I am not quick enough > > to really bring it under control. I ended up > shutting down the motors > > just as I noticed that I was entering into pilot > induced oscillation. > > All of which occurred really fast, each flight was > probably 1 or 2 > > seconds from the time the gear left the ground. > > > > Todo items: > > > > - buy a good digital video camera. It would be > useful to watch video > > rather than my internal memory. > > - Tweak the control constants > > - add higher level control code. We are only > controlling rotational > > rates right now. We need to add in a PID loop for > rotational > > position/translational velocity. > > > > Dave _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
