I have a harsh landing the other day during a Stabilize flight we are doing for tuning of the 3 blade setup.
Because we were playing with the throttle the RSC mode was 1.
on our last try the heli took off with no issues and moment later RC1-2 stopped functioning, with the help of the gusts the heli started to swing quite fast as we only able to make RC 3-4 movements which is not able to make the heli come to us.
Following a series of wrong decisions due to panic we crashed. I know why we crashed but what I don’t know is why RC 1-2 stopped.
The RC signal was healthy during that.
I am not a pro at analyzing logs but this is what I saw from the RCIN logs that explains what we experienced. This could be from the PPM encoder or the transmitter I am not so sure.
Next run I will use SBUS connection and change the ESC servo to SERVO6 so I don’t need to use the PPM encoder.
Just want to get some feedback from the masters about the flight performance in terms of the PID settings I managed a smooth flight
Cheers,
Tolga trex700-355-flyingversion.param (13.5 KB)
ok further analysis of the logs what actually happened is not related with RC 1-2.
Right after take off alt reading dropped and pixhawk gavefull collective due to this drop. The alt reading is going minus levels but it was in the air at that moment. due to this reading pixhawk gave full collective and start climbing. Our collective on the radio was same during this period and oncewe saw heli is flying away from us we tried to maintain thec control and at one point it seems responding then we shut the RC andit started decent fast and we open RC again then not sure why heli gave full negative and crash to ground.
I am kind of confused now i think the transmitterI am using mulfunctioned and caused all this trouble.
The altitude reading should have no influence on the behaviour in Stabilize mode.
I can’t check the log from here, so can’t offer any other feedback right now, but try to compare RCIN with RCOUT.
Would have to see the log from this flight to see what’s going on. If you are using some sort of mix in the RC to control throttle this can create all sorts of problems if you shut the RC off in flight or lost RC signal.
Well i thought i uploaded the log but now i see it didn’t. I will try to upload again.
There was no mix on the radio actually. We shıt the radio as it already got out off control and not getting rc inputs. With the gusts heli flew away so we had to to shut rc and turn it on while it is in air as it was 70 mt high.
Those you will also see at the logs by tomorrow as laptop is not with me.
Yeah, it really sounds like a RC problem. And in your configs I see the RC calibrations are less than consistent. Which points to an old radio with bad pots.
The RC failsafe should’ve kicked in. And it looks like the collective was set ok, assuming the RC drops to no packets on loss of signal. But you have to set the rest of the channels to hold last known value, especially the throttle channel. I can’t see if that was done from your params.
What I see is that your collective went up and the helicopter went up. Then the throttle went wild - basically to wide freaking open.
I see the collective being pulled all the way to the bottom and the altitude does come down a bit. But then the collective goes all the way back up and the altitude starts going up again. The throttle came down a bit when the pitch was dropped. But then the throttle goes back to wide open again. Then the collective goes all the way to the bottom and the helicopter dropped like a rock.
If you didn’t make these control inputs then your RC malfunctioned.
Chris if you check the alt reading there ia a drop before that peak but there were no altitude loss during the flight. If you check the altitude reading goes negative. So i checkwd if vibration is causing this. Vibe y goes above minimum treshold. Not sure if that is the cause of the anomaly.
We will change our rc which was spektrum dx7s to radiolink of frsky taranis x9.
Yeah, I saw that but there was no clips on the IMU’s. And all the sensors agree. It looks like the controller just quit when it hit the ground. Everything stops. If it hit the ground that hard I wouldn’t expect the final readings to be too accurate.
