Hi to everyone,
I am using an IRIS quadrotor and I noticed already one thing that I don't like too much but I think there should be an explanation for that but I would like to know if someone of you knows more.
Why is it not possible to have a switch to disconnect the battery?
My question is driven by the impression that when I connect the battery the quadrotors does (after about 4 seconds) the calibration of the sensors and especially of the accelerometers. If it does that while the quadrotor is still inclined then the IRIS will see as horizontal direction a wrong one. The result will be that at beginning when it will fly , it will do pitching immediately in a certain direction which is relative to the inclination of the IRIS while calibrating.
For this reason I would like to know if there is a way to disconnect the battery with a switch, in this way I could insert the battery and only when the quadrotor is on a flat surface connect it to the drone.
Thanks for your help.
Fab.
Replies
Frabrizio,
Just one opinion - Nothing prevents you from installing a switch but remember that a fully equipped and loaded Iris pulls more than 20 amps DC. Installing an extremely reliable switch to handle that current is extra weight but most importantly is an extra point of failure in the power supply system. It's a potential reliability hit. For high current electric R/C stuff I gave up on switches years ago after several switch failures.
I have never had issues with this. I tilt it up with the front legs on the ground, plug in the battery, close the door and set it right back down within a few seconds. If you are having pitching issues I doubt they are from the power up unless you are having some compass interference.
One other thing, since I don't know your experience level, I always take of in Stabilize, verify proper attitude control, and then switch to whatever my desired mode is. I have seen a few strange things when these birds take off in other modes, especially auto mode.
mp
Thanks for the exhaustive reply. I think I will not put a switch, I didn't want to actually because I imagined something like that.
By the way, is it true that the IRIS make the calibration of the sensors just after the connection of the battery?
Thanks for your help,
fabrizio.
I am not sure whether the Iris does but I have had consumer copters that do gyro cals in the first few seconds after power and you have to set them down before it finishes. With the Pixhawk flight computer I have never had issues as long as I set it flat within about 5 seconds after powering up.
The accelerometers, gyros, compass are all pre-calibrated via the calibration routines in Mission Planner. Someone with more intimate knowledge of the Pixhawk firmware could probably tell us if there are any calibrations that happen right after power up?
mp
Thanks for the reply.
Fab.