My Easy Star (modified rudder+elev) does FBW-A great. However, i'm trying to do RTL and it only loiters around in a clockwise circle at its current location whenever RTL mode is turned on. I send it off away at a random direction and switch RTL on, but It never attempts to head towards me, the Home location (60 ft altitude), despite the orange line in the HUD pointing towards the Home waypoint.
I've varied the Roll Nav P gains from 0.1, 0.5, 5, 10, 20, etc. nothing works. I've also tried changing the Loiter radius from 30 to 10, 15, 20.
Xtrack (cm) is always set at 0.0 and Xtrack angle at 15 degs all the time untouched. I didn't really touch the Pitch Nav gains as it doesn't appear to really change in altitude so it's left at 0.600 for both AS and Alt. I don't have the pitot static tube set up.
What am I missing?
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I haven't been able to get the aircraft to RTL or waypoint flight for months now kicking myself for being crappy on gain tuning, but as it turns out it wasn't the fault of the gains. The flight location I have flying in is only around 200 feet width box pattern, with a low altitude around 100-200 feet. The Easy Star airframe was simply not able to fly this "tight" course with just rudder and elevator despite trying excessive nav gain ranges. Using the Easy Star 1.7x model in X-Plane I confirmed this and remodeled two versions -one being with ailerons and it flew the waypoints in X-Plane. This change was then implemented into the real Easy Star and i was able to achieve autonomous flight on this small box pattern. I believe the current APM control laws is not robust enough to handle small courses like these when the aircraft doesn't have much roll authority (despite it easily done by human pilot).
Would trimming the control surfaces during flight on the radio affect the calibration in the Mission Planner?
I've been through the tuning process and it flies great in FBW-A and maintains altitude no matter what bank i give it.
I have been able to recreate this issue in X-Plane using a different aircraft model (w/ ailerons and rudder) by turning the Roll Servo gain to 0.0, essentially turning off the ailerons. The plane just keeps spiraling in the air like my real life Easy Star which also has no ailerons. Is this due to the APM firmware somewhat being dependent on turning with ailerons and can't operate well using just Elevators and Rudder? Do I need to add ailerons to my Easy Star just to make it fly RTL/Waypoints?
Maybe you don't have GPS lock?