Now we have the cut downs the flight computer needs to be aware of what its current status is. Traditionally the criteria for triggering a flight termination is exceeding a set altitude or leaving a certain geographic area.<\/p>\n
I felt neither of these are suitable, instead I wanted to terminate the flight based on the current rate of ascent. I quickly coded up some current rate of ascent calculations so the payload knows what its current vertical rate is.<\/p>\n
Based on this vertical rate it makes decisions about whether its Ascending, Decending, Floating or it has a leak.<\/p>\n
Ascent is defined by a Rate of Ascent (RoA) >1 m\/s
\nDescent is defined by a RoA < -2 m\/s
\nFloat is defined by a RoA between -1 and 1 m\/s
\nLeak is defined by a RoA < 0 but > -2 m\/s<\/p>\n
As a test I intend to fly the payload without a pyro but leave this code in so I can see what the payload thinks its RoA is and what decisions it takes based on this information. I’ve introduced a flight status code as follows :<\/p>\n
A = Ascending – Nominal Flight
\nD = Decending – Nominal Flight
\nL = Leak Condition Detected
\nF = Float Condition Detected
\nP = Pyro fired due to decent detection (i.e balloon has burst)
\nQ = Pyro fired due to detection of a float condition.
\nR = Pyro fired due to detection of a leak condition.
\nG = Ground mode prior to launch.
\nS = Landing mode (this is set when decending and altitude drops below 500m – possibly trigger siren or somthing)
\nN = No GPS lock<\/p>\n","protected":false},"excerpt":{"rendered":"
Now we have the cut downs the flight computer needs to be aware of what its current status is. Traditionally the criteria for triggering a flight termination is exceeding a set altitude or leaving a certain geographic area. I felt …<\/p>\n