So as most of you know, I've finally decided to develop a generic script that will be used to generate aerodynamic data using Digital DATCOM. It's been a long-winded process but I'm almost ready to do some testing on it.

So it turns out that I was very optimistic about just using a gain mixing of accelerometer rand gyros than computing a DCM matrix of the aircraft rotation. So I decided to overhaul the code by creating data structures that will hold the information requires for such computation. I must say that at the back of my mind I was really worried about the computational time that these calculations will take in the small Atmega328 micro. To my surprise, provided that one sticks with a minimum of division operands, float arithmetic is actually quite fast even in an 8-bit controller. Given that this application is for high L/D aircraft and who’s mission is mainly waypoint tracking, the slow changing dynamics can be reasonably captured with this environment. The bad part of the implementation was to discover how quickly the gyro drift (especially in the roll channel) hurts the computation of the Euler angles. (See the pics below), even-though all sensor are bias compensated fro...

We've been having quite bad (windy) weather that It has been almost impossible to get the glider up in the air to gather more flight data . But nonetheless, I managed to analyse the data that I have come to some interesting conclusion on the behaviour of the aircraft in flight. The post-filtering of the IMU euler angles prior to controller design only add approximately 4/10th of the second in lag (guestimate). The servo limiter which I set on all channels is which what a normal flight actuation is experienced (considering wind factors). It's quite clear from the graphs that GPS velocity is expected to change with aircraft pitch although the nature of the sensitivity over a 1Hz update was not expected. The noise factor in launch in both roll and pitch channels shows that an alternative method needs to be established for a take-off and landing autopilot mode. There seems to be a considerable lag in pitch servo input and pitch change. This makes sense for the fact that t...