Hi DIYdrones,
I have been trying to nail down a problem with my arducopter. It seems like when I switch my flight mode to land, the motors simply disarm and the copter falls out of the air. I have now critically destroyed 2 air frames because of this. I thought the first failure was due to a dry solder failure causing the board to disarm the remaining 3 motors when one lost power, but it has now done this on a whole new build and a very solid power harness. I was very careful to make sure my solder connections were properly flowed and had no dry solder joints. I even used a linemans splice at the center of the harness and filled the whole joint with solder.
Has anyone else ween their copter fully disarm and fall out of the sky upon switching flight modes to land? or any other flight mode for that matter?
It is interesting that i was testing the RTL functionality when this happened. So I took off just fine with no apparent problems multiple times earlier in the day, and even used the RTL mode multiple times earlier in the day. So, i was flying around yada yada no problems. I switched it to RTL, and the copter takes off in some arbitrary direction clearly not coming back to the last place that it had armed the motors. (I THINK it is supposed to come back to the last place the motors were armed? even so - it wasnt headed back to any place where the motors were armed) Since it was headed in a seemingly un related direction and it was headed toward trees - I switched it to land. Thats when it just dropped out of the sky. Now - I had already turned the throttle all the way to the zero position on my controller.
Does the land flight mode behave like alt hold - where the throttle stick controls the altitude or the climb (descent) rate? I understood that the Lnad flight mode simply controlled the descent independent of any throttle control.
I have attached what i think is the log from this flight. How can I get the kml file - I would be able to confrim if this is the right log if i could see the kml file.
Edit - I found the gps files as .kmz after downloading. I Think I have now re-uploaded the correct log.
Can anyone help me interpret this log file? What happened here? I notice that the 'MOD' tag shows that it went from RTL to LAND to STABILIZE - at which time my throttle stick was at zero. But it never went to STABILIZE at my controller, only to land. It looks like the .kmz shows that the copter flew to a location that it never actually flew to. I never crossed the road and remained in the open grassy area of the park.
i need to learn to recover from these situations with the stabilize mode and throttle out of tough situations. I think from here I am going to set the simple stabilize mode to be on standby for these situations. its unfortunate that the learning process involves critical crashes and rebuilds.
Replies
So, I think I have at least figured out why My copter has fallen out of the sky upon switching to any auto mode (land in my case) -
I have also read reports of major GPS offsets and fly away copters. But I understood that only affected the cheaper NEO-6 GPS? I am using the UBLOX; Any reason other than simply loosing a sat that would cause a mad displacement in my .kmz track? After all, that is what I think caused my copter to fly off in an arbitraty direction that was not back to launch - and that is when I told it to land (with the throttle at zero)
Whenever I've used land, I leave my throttle alone until touch down, then I drop it to zero. I also rarely use auto land, I prefer to control my landings.