Hello, please help me.
I am trying to flight DJI S900 with PIXHAWK, but I have serious problem. RC controller is Futaba T18SZ. When I tried to take the drone off, it did not take off straightly, it leaned to the right side. However, once it took off (I controlled precisely to take off with problem), it looks fine to fly. I tried to take the drone off more than 10 times, but same problem happened.
I uploaded hexacopter firmware (APM:copter V3.3.3 Hexa) from Mission planner, and I calibrated accelerometer, magnetometer, RC, and ESC. I connected the motors with Pixhawk as below. I think I set up the drone correctly.
Pixhawk Motor-Out | S900 ESC |
1 | M6 |
2 | M3 |
3 | M2 |
4 | M5 |
5 | M1 |
6 | M4 |
Please see logs I attached. As seen in the first log, I did not control roll, pitch angles, but ROUT signals to motors have gap as I increased throttle. I tried in altitude hold mode, stabilize mode and the same problem occurred.
I also attached a top side picture of my drone. Is there anything I need to do more? Or I did wrong? Thanks for reading, and please give me advice.
Replies
I am sorry, I have been so busy for few weeks.
Please let me tell you my story. I will tell you the solution first. It was the problem of controlling the drone. I mean I was very careful to take the drone off and that was the problem. Thanks to Darrell, I punched the copter into the air and it worked. At the middle of throttle, I needed to raise the throttle quickly before the S900 leaned to side. I actually don't know why there is a problem about taking off if I tried to take the drone off slowly.
Thanks for replying all.
I cannot try the QgroundControl, because I need to some functions in Mission Planner. I followed the connection what Art gave me.
Now, I am thinking to try autotune.
I think I calibrated all I can do. I checked the balance, too
Thank you again.
Did any of the advice given help?
Give us an update please.
That reads like balance.
COG Centre of gravity.
If one side of the copter is heaver. I.e. Your centre of gravity is not in the centre of the copter.
Description:
On take off the copter would lift the light side first. The Flight Controller (FC) dose not know it is out of balance yet! Then one of the censers will tell the FC and the FC will try to level the copter by increasing the opposite motor. Half a second (probably a lot less, but I am not trying to be time accurate) in the air all is fine, FC controls it. But before you have flight power one side lifts.
One option: punch the copter into the air. Push a little harder on the power and get the copter to jump into the air. The FC will take control quick and the copter will fly.
The problem is, throughout the flight you will be using more power on one motor to maintain level flight.
Try moving something, like the battery, just a little. So the copter will balance.
All power off:
Holed the copter by the ends of two arms. If it tilts or leans one way. Make adjustment so it will stay level. Do this for both directions: e.g. forward backward, left right.
Really it can be very small adjustments.
I can move the battery up to 2 mm in any direction to make it better balanced.
Hope this helps.
Have you checked that all your motors are level?
I find the easiest way is to make sure the prop tips line up with the motors next to them.
Have you done a CompassMot calibration?
Just wondering as the Pixhawk is mounted very close to the PDB.
Your graphs show different power out for different motors so I am going with motor alignment as the first issue to look at.
I do this with all my maiden flights as a sure way to see if there are any problems:
On shortish grass/lawn, in an open area, carefully throttle up so the multirotor is just starting to "get light on the skids". Do not let it take off!
Now try to pitch forward gently, you should hear and see the rear motors speed up and the front slow down, the craft should also tilt forward a little bit.
Do the same for right roll - right motors slow down, left motors speed up, craft tilts right slightly.
If this doesn't work exactly like this then something is wrong so don't try take off!
In your case this test will show that everything is OK, but sometimes with the S800's/900's you have to get it off the ground fairly quickly or they do sometimes tilt over alarmingly.
You need to perform the autotune procedure. This should help your stability.
Read the Arudupilot Wiki on autotune and follow it carefully.
I uploaded the same question to Arducopter and Pixhawk forum because I don't know which forum is right for my question. Sorry about that.
Not a problem. I have a lot of question myself. Just remember if you are powering the FC on the power plug it is best to remove the power wire from the ESC to the Pixhawk..
Pixhawk does not like APM 3.3.3 from what I have read. I too like Mission Planner but have a problem with it recognizing my Pixhawk FC. I would recommend QGroundControl. Also you motor connections are not correct (see attached jpg)
hex motor layout.jpg