Hello,
I hope you are ready for a challenge. Once you start to get it right it is very rewarding. The first thing I can say is frame ragidity is most important. Check vibration levels using your logs. X and y axis should under 3 g's. The z axis should be less than 15 g's. Make sure your esc's are operating without flaw. Some firmwares do not like the torque and slow kv motors. Isolate electronic interference crop the gps/compass. Also I have noticed that once I reflashe'd the firmware on to the Pixhawk things improved.They to feduce the P rate for loiter to.7 or .8 to start. Thus may cause the quad to wonder a bit wider area where you set it to loiter but it is a good start until you get things figured out. Wind is not your friend in loiter. I am still working on that. I usually fly 50 to 60 minutes in loiter of position hold in winds of 3 to 5 mph. I am confident that most of the problem is frame rigity. The long booms with the large propellers can create twist and vibration isolation in the booms. I increased the wall thickness if the booms to a minimal 2mm thickness. The vibration isolation you use in the frame in between it and the Pixhawk is problematic. The isolation material needs to be soft enough to reduce the vibration but not so soft to alow unwanted movement of the Pixhawk. Check to make sure your wires into the Pixhawk are not transmitting vibrations into it. There should be at least 1 inch o wires that is free to move and none of them should be resting on the Pixhawk.
I've the same problem than William: my quad fly very well in stabilize mode (after a hard PID tuning work) and quite well in AltHold, but it's unstable in Loiter. My setup:
1100 mm motor to motor. T-Motor U8 135 kv. T-Motor 30A opto pro ESCs. 28" T-Motor Props 6s batteries Pixhawk APM:Copter v 3.1.5 Tranis + X8R
I tried to tune Loiter PIDs by diferent ways, but without sucess. Any tips for that tuning?
Would be great if you could share your params file or at least your PIDs.
I am running mine on 6 S batteries.the problems that I have been running in to have been stability while in loiter mode. It does not like wind while in loiter and will develop very aggressive over corrections to the point if I do not change modes it will flip. Have you encountered this problem, if so what have you come up with to resolve it. I know I need to adjust the P.I.D.'s but I have not found the right combination. Any help would be appreciated.
Comments
I hope you are ready for a challenge. Once you start to get it right it is very rewarding. The first thing I can say is frame ragidity is most important. Check vibration levels using your logs. X and y axis should under 3 g's. The z axis should be less than 15 g's. Make sure your esc's are operating without flaw. Some firmwares do not like the torque and slow kv motors. Isolate electronic interference crop the gps/compass. Also I have noticed that once I reflashe'd the firmware on to the Pixhawk things improved.They to feduce the P rate for loiter to.7 or .8 to start. Thus may cause the quad to wonder a bit wider area where you set it to loiter but it is a good start until you get things figured out. Wind is not your friend in loiter. I am still working on that. I usually fly 50 to 60 minutes in loiter of position hold in winds of 3 to 5 mph. I am confident that most of the problem is frame rigity. The long booms with the large propellers can create twist and vibration isolation in the booms. I increased the wall thickness if the booms to a minimal 2mm thickness. The vibration isolation you use in the frame in between it and the Pixhawk is problematic. The isolation material needs to be soft enough to reduce the vibration but not so soft to alow unwanted movement of the Pixhawk. Check to make sure your wires into the Pixhawk are not transmitting vibrations into it. There should be at least 1 inch o wires that is free to move and none of them should be resting on the Pixhawk.
I hope this helps.
William
Hey guys, I have the same setup that you and I'm having the same problems with tuning my pixhawk.
Could someone help us???
Thank you!
Hi, Enzo
I've the same problem than William: my quad fly very well in stabilize mode (after a hard PID tuning work) and quite well in AltHold, but it's unstable in Loiter.
My setup:
1100 mm motor to motor.
T-Motor U8 135 kv.
T-Motor 30A opto pro ESCs.
28" T-Motor Props
6s batteries
Pixhawk
APM:Copter v 3.1.5
Tranis + X8R
I tried to tune Loiter PIDs by diferent ways, but without sucess. Any tips for that tuning?
Would be great if you could share your params file or at least your PIDs.
Thanks.
1200 mm motor to motor frame.
Pixhawk Flight controller.
Castle Creations 50A ESC's
6s 15C Lipo Battery
U8 Tiger Motors
28" Tiger Props
Taranis 9XD Radio
please, give me your complete setup.
Enzo
yeah,
4 Tiger U8 pro
4 ESC T30 pro
Computer: pixhawk
Reveiver: Dragon Link
Radio modem: 3DR
Frame: tarot t 1000 octocopter but 4 arm less.
Motor mount: Tarot with base lifted with tarot spacers.
regards
Can you list the build components you used for this? I have been working on a simular project and I am running into some problems.
Thanks