Plugger Lockett <[email protected]> writes: > Any advice in this area would be much appreciated folks.
How high is the flight expected to be? For flights "close" to 100k', you can use EasyMega pretty much as-is -- the kalman filter will use both baro and accel data up to the limits of the baro sensor (about 30km, or 100k'), and above that it switches to using only the accelerometer. What we've learned is that the firmware will often think that apogee happens before the actual apogee, so a fairly long delay can avoid putting the chute out early. Because the air density is so low, you can use a pretty long delay without any risk -- you'll be ballistic for a long time, even if the ejection system has deployed. At 130k', I've used 10 seconds several times. Of course, if you have a non-nominal flight that has apogee below 100k', you may not want this delay. There's no way, save changing the firmware, to do this from a single channel. However, you can wire up two channels in parallel and have one fire with no delay if height < 100k', and the other fire with a delay at any height. If you will be flying well above 100k', I don't have any great suggestions. What would be cool is to predict apogee by the speed estimate from below 100k' when the baro sensor is still working and the kalman filter is generating more accurate speed data. Divide the speed by 9.8m/s to get seconds until apogee. I should do some analysis of the recorded flight data I have here to see if this might be a reasonable plan... -- -keith
signature.asc
Description: PGP signature
_______________________________________________ altusmetrum mailing list [email protected] http://lists.gag.com/mailman/listinfo/altusmetrum
