Hello everyone
I'm quite new in the multirotor business and therefore a rookie. I performed some sucessful flights with no bigger problems, most in stabilize mode. The aim of the latest flight was to check other flight modes too. During this test flight the behavior of the copter was strange and not as expected.
Following there is a description of the flight regarding parameter changes and behavior:
Prior to the flight I set CH7 to "simple mode" in MissionPlanner to be able to activate simple mode for each flight mode I choose with the three position switch. After arming the copter CH7 was switched on to activate "simple mode" in combination to "stabilize". Unfortunately it seemd that the "simple mode" was not working after take-off and hovering around.
After landing and disarming the configuration was changed that the "simple" checkbox was ticked in MissionPlanner for "stabilize" mode. Therefore the "simple mode" shoud always be active in "stabilize" mode. After take-off the copter was not acting like "simple mode" should. Moving forward and backward was dependent of the orientation of the copter.
Furthermore I tried the "alt hold" mode at about 5m height, but the copter was quite unstable. It was changing the height a lot, which is unclear for me.
Checking the "loiter" mode showed also a strange behavior according the altitude. When I was activating the "loiter" mode the copter was quite stable for some seconds. After a certain time it began to change the altitude quite fast, moving down and up and after some time it was hitting the ground softly ("loiter" always on). As I noticed it will going down quite fast I switched back to "stabilize" and after hitting the ground I got it back into the air without problems.
I would really appreciate any assistance from experienced members in this regard!
I have attached the flight log files of MissionPlanner to hopefully better understand what was going on.
My copter's specs are:
- ArduCopter 3DR Hexa
- ArduCopter 2.9.1
- uBlox LEA-6 GPS
- Sonar sensor
- 3DR Radio
Thanks, any help would be greatly appreciated!
Replies
Thanks a lot for your valuable help instructions. The point of deactivating the sonar sensor improved the behavior on "alt hold" significantly. Also the "loiter" works quite well. Sometimes the copter wants to correct the altitude a bit too fast from my point of view which results in a slight bouncing. It seems that modifications of the PID parameters could help on that. If you have a good point to start with that would be appreciated.
But there is still a problem with "simple mode" which is probably related to the compass. I turned on the COMPASS_LEARN as suggested by Tim but it did not help much. So if I activate the "simple mode" on "stabilize" the forward direction of my Hexa frame woud be between two frame legs. But it seems that the forward direction is a bit shifted toward a frame leg. Do you have suggestions how to solve that issue? I have added another log file of a flight.
2013-03-03 17-34 5.log
Hi Randy there was no reply below your post but I looked for first time at the planner data and read these numbers! I never changed anything in there and it had flown ok. I hope it calibrates if I enter the right attitude but are the other numbers legit or corrupted as well?
S
Did you balance your props and mount your APM to remove vibration? Altitude hold only works well when there is little or no vibration to the APM.