though not the nice kind Cilla Black used to host on prime time UK TV until the turn of the millenium.
Although angles have been ‘sorted’ for a long while now, I took a look at them from the last test flight to try to work out why Phoebe insisted on thinking she was drifting backwards, resulting in her real world compensation of drifting forwards.
Look at the 3 green lines – they start off well (she took off with her nose up by about 10°), but around 3 seconds, the gyro (i_pitch) and the accelerometer (e_pitch) clearly have a major disagreement. Net result of the complementary filter (c_pitch) is that Phoebe thinks her nose is pointing upwards, and as a result, she’s going to think she’s going backwards (which is exactly what yesterday’s graph shows), and so she compensates by dropping her nose, and hence start moving forwards, which is what happened yesterday in real life.
At a guess the complementary filter is now paying way too much heed to the gyro now I’ve got everything so beautiful tuned and averaged with the accelerometer readings.
Time to tweak tau in the complementary filter down from 0.5s to something a lot smaller, and see what happens although to be honest, that’s just a workaround / hack – I’d rather understand why the gyro and accelerometer suddenly disagree so much, but for the moment, I’m very short of ideas – perhaps it’s time to retire the gyro from angle calculations completely and instead use it solely for angular stability? Hmm now, there’s a thought.