It's been nearly two months since I last flew the Skywalker X5 (been busy working on the house and garden) so I took her up for a re-familiarisation flight to see how rusty I was after such a long break. It was like riding a bike, no problems at all. :)
Now that the airframe tuned for basic RC it's now time to work on the auto-tune function to get the APM working efficiently. So today the task at hand was to get started on the auto-tuning function.
I started by assigning three flights modes, manual, stabilize and FBWA to see how they performed. Stabilize seemed to work quite nicely, it took the edge off flying the 'squirrelly' X5 and the FBWA mode seemed to work with the bank limiting obvious. Once these flight modes were tested I bought her in and re-assigned the stabilise mode to Auto-tune and FBWA mode to RTL.
Thing's didn't go too smoothly this time around. The auto-tune mode was extremely tough to get any response from, when I changed into the mode the X5 became extremely sluggish and almost impossible to manoeuvre. I moved the control surfaces hard left, hard right and it took several seconds before the X5 could turn around. The speed at which the X5 flies across in front of me meant that I could only attempt an auto-tune mode for about 12-15 seconds before turning it off to do a 180 and fly back in the other direction.
I really wasn't sure if I was getting any 'tuning' done so thought I'd see what happened when I flicked to RTL. The first time I tried it seemed to work, with the X5 changing direction and heading over roughly to where the RTL point on the Mission Planner was set, however it overshot the position, did a slight turn and started to fly away. I panicked and switched back to manual mode.
When I tried RTL again instead of heading to waypoint, the X5 pitched up, did a hard turn and then nosed hard down and increased throttle. I switched back to manual immediately and bought her in.
It seems that auto-tuning was going to be a little tricky.