APM 2.6 Auto Mission Crash with Video



Last Saturday I tried my first auto flight with my Bixler 2 and APM 2.6. This is my third autopilot. The first ended after a brown-out in a skywalker, the second was lost in a quadcopter crash when the APM GPS was too close to my 800 mW video Tx. So I figured I'd give this a try again. I started with some RTL and the results were perfect. The google files were great. Then a few days later I tried a basic autopilot mission. Four waypoint and an autoland. It hit the first waypoint and seemed like it couldn't make the turn for the second and hit a tree. I have attached a link to the video. (The quality is rough due to using a crappy camera).  I have also attached the kmz file and log. Any feedback would be helpful. Are my waypoint radius' to small? Are my waypoints to close? Thanks for the help.

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  • Flying very low, for tests. So close of the trees.

    Has no time enough to recovery if needed.

    Upload your tlog to droneshare: http://www.droneshare.com/view/pkulu2

    Has a warning about an incorrect parameter.

    • Thanks for taking a look. Yes I have learned that I need to fly higher on these autopilot missions. I researched the CDM_INDEX error and didn't find much information. What did you think about the way point radius? Are those too small and close? Thanks again for looking.

      • Yes, in my missions the radius they are 50~60m, in loiter are 90m.

        Please, take a look in full info abou this parameters.


        • Thanks for the response on this. In regards to the CMD_INDEX the complete parameter list says:

          Current mission command index (ArduPlane:CMD_INDEX)

          Note: This parameter is for advanced users

          The index of the currently running mission item. Do not change this manually.

          • Range: 1 255

          It says for advanced users. Should I change it to one? I will also try larger waypoint radius' for my next flight. Thanks

          • Moderator

            Ignore the CMD_INDEX error for now, it's not something to be changed manually and will not affect the outcome of your flights.

            Do you have any logs for your crash, .log and .tlog?

            • I did not have my telemetry plugged in so I do not have a .tlog but my .log is linked at the top of my first post. I appreciate you looking in to this. Any pointers or feedback is super helpful.

              • Moderator

                Ok got it, yes definitely flying too low, I set my waypoints at least twice as high as any obstacles that might be in the path of the plane. A bit of height also gives you a bit of a chance to take over if you observe something amiss, (ALWAYS be ready to take over in case you see something going wrong, I even do it now after 100's of flights)

                Your bixler was flying around 26mph just before the crash which is not too bad but perhaps a little fast, waypoints need to be a bit further apart at that speed. From your KMZ waypoint 2 would've needed to be 116m (308ft) away from 1 for the plane to make the turn.

                Waypoint radius could be a little larger, the plane will start to turn as soon as it hits the radius so will cut the corner but this makes it join up with the straight better.

                Your video shows massive vibration, the APM with it's gyro's and accelerometers doesn't like those kind of vibs so will have a hard time navigating, you'll need to get that really smooth by balancing prop and motor.

                Can't see too much else on the log, just bad luck though to have that tree in the way.

                Good luck on the next try!

                • Graham
                  Thanks for taking the time to review my log. I definitely will increase my altitude for future missions. Currently I'm using the Bixler Configuration I downloaded from the manual. The throttle setting is at 45%. I'm pretty sure I was on the downwind leg which caused a slightly higher airspeed which also contributed to a larger turning radius. How did you calculate the 308 feet between waypoints to make the turn? Is that based on the actual radius it flew? Good thinking on balancing the prop and motor. I fly a tbs discovery and that's one of the first things I did. I didn't even think to do it on my plane. I'm also not using a very good camera. It's a dice camera from nitro planes. I guess I have a hard time strapping my gopro on with such uncertainty with the apm at this point. Thanks again for the info. I'll keep you posted on the next flight. Winds at 15 knots gusting to 25 here in Colorado. We'll see what tomorrow brings. See ya
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