Auto missions and auto landing questions

I’m using an mRo Pixracer, Arduplane 3.8.5 and Mission Planner 1.3.56.

  1. In the beginning of a flight I launch in MANUAL mode and check the airplane to make sure it feels right and the systems are responding normally. Then I switch to AUTO mode to start a pre-programmed mission plan. Does the mission begin at the waypoint nearest to the airplane at the moment I switch to AUTO? Or, does the mission always start at the first waypoint?

  2. I often abort a landing by switching to MANUAL mode. Then I fly another approach. Then I switch back to AUTO when I’ve got the airplane back near to the final approach leg. The airplane usually resumes the auto-landing. I believe this is because when the abort is triggered by a switch to MANUAL mode the mission will go back to the DO_LAND_START if I switch to AUTO again. Is this correct?

  3. The reason I often have to abort a landing is because the airplane is overshooting the landing spot. The only time I came close was when I set the TECS_LAND_SPDWGT to -1. The airplane was forced down and landed near the spot but did not flare. I tried the same plan but with the TECS_LAND_SPDWGT set to 0.67 and it overshot by 200 feet again. I’m using an airspeed sensor and that seems to be working well and I have reasonable land and pre-flare airspeeds set for this particular airframe. Glideslopes are all between 3 and 7 percent when on base leg and final. What else can I try to get a nice flare closer to the landing spot?

Thanks,

Paul

  1. The mission always starts from the first waypoint provided that the waypoints are placed sufficiently spread out. Also check the waypoint radius isnt too big that it overlaps another waypoint. i usually place them well apart and input waypoint radius which shall be sufficient (depends upon ur aircraft’s flying characteristics).

2 & 3. I havent used auto landing before, so other people in the community would be the best bet.

  1. there i s a specific parameter to resume or start again the whole mission if aborted, sorry do not remember exactly wich one.

  2. Not much, basically after trying over 200 landings with airspeed sensor and Lidar I would say that landing mode do not take advantage of that hardware and Ardupilot landing is based more on a “ditching” strategy" where flare Alt or flare Sec is the most important parameter but a good tuning of TECS could help a lot

Suggestion: If you plane is tuned well, consider flying in FBWA more than manual mode. It’s just easier in my opinion.

#2: You’re probably right, the mission goes to DO_LAND_START. You can check the waypoint # that ardupilot is calling by looking below the mode in the mission planner HUD.

#3: You may want to change your Land_Flare_ALT or SEC as well as your airspeed to be close to stalling. There are a whole lot of parameters that you can take advantage of here: http://ardupilot.org/plane/docs/automatic-landing.html

Thanks all. I have never tuned the airplane with autotuning and will perform that operation next.

I’ll keep this thread posted if I have any breakthroughs.

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Did an autotuning flight. Made no difference later on in the landing performance.

I will try setting up the autolanding feature again from scratch with another airframe to try and figure out if it is me or the airframe.