Hello all,
I have built a quadrocopter with a custom frame and I have been testing it over the past month and I have an issue with the altitude I am hoping someone can help with.
The main problem is getting the copter to fly at a fairly low altitude of a couple of meters, I can move around about 2 to 3 feet of the ground without much trouble but if I try and go higher it climbs significantly I then have to lower the throttle to drop it and then increase it again, unlike when its very low to the ground it wont maintain a relatively constant height.
The second problem I am having is when I switch it into altitude hold, or loiter mode, in both these situations the copter slowly drops to the ground, I have tried starting from various heights and the same thing happens. I have a sonar sensor and I have tried it with just the barometer, behaviour is the same.
These may both be separate issues but hopefully someone will be able to comment on that.
I have attached a couple of log files which include general flying and switching into altitude hold or loiter mode, hopefully someone better than me can take a look and let me know what might be wrong.
Thank you
Replies
Arthur,
Could be vibration. Try setting your INS_MPU6K_FILTER to 20 but I think you may also need to put some more vibration dampening foam or moon gel between your APM and the frame or look for other sources of vibration including bent motor shafts or prop mounts. If you look at the accel Z values below (in red) you'll see they move outside the acceptable range which is -500 ~ -1500 quite often.