I did some ‘passive’ test flights today going back to check the basics. Without the ESCs / motors powered up, I did a 12s pseudo-flight, where I picked Phoebe off the floor climbing to a meter in about 4 seconds; then I walked her forwards for 1m for about 4s again; finally I walked her left by about a meter again for 4s.

These are the three positive directions for the accelerometer so I should see positive spikes in acceleration at these points, a raised fixed velocity of each of the axes, and from the distance point of view 3, 1meter 4 second humps. So this came as a bit of a surprise:

Velocity is the clearest – it should be 3 positive bumps – Z axis first for take-off, then X axis for forward movement, and then Y axis for leftwards movement; each bump should be about the same size / shape!

Accelerometer readings worry me most though as this is (almost) raw data from the sensors with little tinkering from me: there should be a positive spike, followed by a negative spike roughly four seconds later. The spikes should be roughly the same height for each axis, and (for example), the positive spike in X acceleration should happen at the same time as the negative spike in the Z acceleration.

Just in case Phoebe’s sensor was duff, I did the same with Chloe and got almost exactly the same results.

Something is seriously wrong with my accelerometer averaging! At least that explains why Phoebe keeps crashing into walls.

P.S. Sorry for the change in graph styles – the death of my home computer has forced me to produce the graphs on my work computer running Excel 2007 instead of 2003, and as with everything from Microsoft, there’s a real quality problem between sequential releases; in this case Excel 2007 has chosen to completely change the default colour tablet making it almost impossible to use the same colours as my 2003 graphs, and frankly I don’t want to waste any more of my time than is possible fighting Microsoft ‘enhancements’ to Excel 2007.