I want to plan a long range survey flight, I will be using a skywalker x8 to do the test, but I am wondering what settings I should use on the APM for things like failsafes and loss of telemetry situations. I want to cover an area of around 1 square KM.
How should I set up the APM to continue with the Auto flight if I loose radio or telemetry?
What is the max range of 3DR radios at 900 mhz? should I expect loss of telemetry at max distance of 800m?
What about radio signal? I have a futaba 18mz supposed to have a range of around 2km, I think the furthest point on the flight plan is about 800m so I don't think I will loose signal, but has anyone done flying this far away?
What is a good WP radius setting?
Finally, the camera triggering, the flight plan was created with the mission planner survey tool, it said the distance between pics should be 78m, but I do not see a waypoint on the plan to set the CAM_TRIG_DIST, should I add this manually?
Thanks!
Replies
Thanks for your answers, I went ahead and made the test flight today. I was not able to complete the whole area, the battery started running low about half way and I decided to bring it back. But when I recharged the batteries they only took back 2000 mAh, so I think I still had some juice left (batteries are 3300 mAh). How low can you let a 3S battery go? I got time when the voltage was going down to 10V so thats why I decided to abort the flight plan.
Also on the log you can see the navigation controls may need some adjusting, there was a lot of oscillation on the flight path. I guess I have to work on that.
Unfortunately it seems the camera did not trigger and I did not get any pictures. I need to check why this happened because I made an earlier test where it did trigger. Strange. At the furthest point, the telemetry signal was still at 85%, and I never lost radio signal either, so it seems I was still well within range.
This is the track on google earth and I attached the tlog, the flight starts around 58%:
2014-01-29 11-12-54.tlog.zip
Since you have no responses, I'll answer what I can:
This flight plan is a walk in the park for an X8 and should only take about 20-25 mins.
Since you know this mission is well within battery range, you are safe to set failsafe to continue the mission. Under the failsafe tab, set FS_SHORT_ACTN and FS_LONG_ACTN to 0, but leave THR_FS to 1=enabled. This will allow the Throttle Failsafe to RTL in modes other than AUTO.
It really depends on too many variables, but that is getting close to their max range unless you add a directional antenna. The easiest way to extend range is to get a 900MHz patch antenna. That should get you around 5km for $50.
I don't use 2.4Ghz, so I can't advice, but it sounds like it should be ok if you have your failsafe set up properly. Pay careful attention to your Rx antenna installation/orientation. Make sure your handheld is not blocked by objects or someone's body.
Generally 2 secs of flying time for GPS lag, and roll rate. So for an X8, about 35m works well. Adjust to suit your desire to overfly wp versus stay on track.
CAM_TRIGG_DIST is a parameter you will find in the Full Parameter List. It is set automatically by the survey tool, but I never trust it. I always add into my flight plan a DO_SET_CAM_TRIGG_DIST which allows you to turn on the triggering at a specified WP, and turn it off again by setting it to 0 when your mission is over.
This is the flight plan I would like to do.