Hi All,
Has anyone experimented with having Altitude Hold always on? What I would like to accomplish is that the APM2.5 knows that the center position of the left stick (I fly mode 2) means "hold altitude" and that the spring is active in the throttle such that the stick returns to the center position when it is let go. I have managed to accomplish this with the MikroKopter platforms using "Vario" however have not seen any documentation on this type of feature with the APM.
I have heard all the downsides of flying in this way such as, letting go of the stick and the copter jumping from 0 to hover causing hops and also the fight that might occur when trying to land through the down draft but from my personal experience, it's quite easy to manage.
The advantages of flying this way is that nearly anyone can fly. One just needs to be in altitude hold (and if GPS is available, with GPS Hold on as well), arm the motors, move the stick slowly to the bottom center position, and then assist the spring in the throttle stick in making a steady and smooth motion to the center (or "hover" point) and from then on, getting it up as smoothly as possible to a safe altitude where the copter can calibrate its barometer readings and hover thrust needed to maintain altitude, then if GPS has not been engaged, engage it for full position hold.
Essentially, this is now not using "Throttle" but rather "Rate of Climb vs Rate of Descent" which for many is much easier and the learning curve to fly is drastically reduced.
If "Loiter" is engaged from the get go, then even my father can fly :-) and he's no RC fundi. If the Mikrokopter can do this, I hope that the APM can too. One of the best selling features of the Microdrone platform is that this is the standard flight mode and it's an option to use GPS or not.
So after that very long explaination and blabbeling, has anyone else thought of this or implemented it or have any ideas how to?
Kind regards,
Oliver Volkmann
Replies
I haven't been a member here long enough to know if others have tried this, but here are my thoughts on what you would want to do:
First, reduce the size deadzone on the throttle stick significantly. If spring centered, you don't need much of one... a slight (but intentional) stick push should give results.
Second, increase the authority of the throttle stick significantly. The max rate of climb command by default now is fairly low - which is fine for relatively stable flight when you can quickly switch back to Stabilize mode if you need full throttle authority. But if you're not planning to use Stabilize mode, you probably want to adjust the sensitivity in Alt. hold.
Third, implement a kill switch and get used to using it. You need to be able to turn the motors off in an instant when something goes wrong, and you need to not have a spring that is going to cause your motors to restart when you set the controller down. I don't think the current Arm/Disarm routine is good enough for this.
Probably some other stuff you'd want to do too, but that would be a start.