I’m new to Ardupilot, so please bear with me.
As I understand it Arduplane does not use computed wind direction to crab into the wind in order to maintain a straight course between waypoints. Instead it heads directly to the next waypoint. Is this the case? If so, what is the reasoning?
Arduplane does crab to maintain course. There have been several threads about some planes that fly in a slip while on an auto mission. It tends to be aircraft with large propellers, like the Skywalkers with 12” props. The issue is related to the propeller torque or spiraling slip stream hitting the vertical stabilizer. It requires a lot of rudder trim to correct, but then it flies in a slip when gliding. This was all several years ago and I don’t know if the code has been modified to correct this since. It was an intermittent problem that only affected some aircraft.
This is technically correct; the crab angle is not calculated from the wind vector. HOWEVER arduplane’s waypoint navigation uses a tunable controller that trims out deviation from the waypoint path and ultimately corrects for the wind perfectly. I’ve seen as much as 55 degrees of “crab” to maintain the waypoint path with extreme crosswind. Arduplane will maintain a course directly from one waypoint to the other as long as your airspeed is greater than the wind speed.
Thanks for the explanations folks. I appreciate the feedback.