I seem to have reached a point of rrrrrgghhhhh and need help. If I could find someone in the West Palm Beach or Central Florida area that has a working knowledge of this software and could help a guy out I sure could use some help and advice.
I have an ArduCopter that was assembled and tested by jDrones. It seemed a little unstable when I got it. Not sure if it was me or what but I never flew the copter more than 5 feet off the ground so I decided to install the latest version of software with the Mission Planner which to a newbie is a big advancement in a user friendly interface. :-)
The copter is very unstable and tries to flip over when getting about a foot off the ground. I broke a blade on the last attempt. I am struggling with trying to figure out what is wrong and where to go from here.
A little background.I was advised when switching to this software to move the magnetometer from a component side up to component side down and this is the only change I have made to the copter other than the software since I got it, about 6 months ago.I do well with my T-rex 500 electric so I do have some ability.
I went thru the troubleshooting (http://code.google.com/p/arducopter/wiki/AC2_Troubleshooting) steps for the "Arducopter tilts over or wobbles crazily when I try and take off steps" and everything seems to be correct in steps 1-6 as far as I can tell.
#1.Is the APM board facing forward and in the direction of forward motion (towards the forward arm in + mode and between the arms in x mode)?
APM board is facing forward towards the front motor in + configuration. It came this way.
#2 Have you set your quad orientation right in the setup process: + or x?
It is setup in + orientation. I have loaded the software 3 times and verified this each time.
#3 Have you run the Motors command in the CLI Setup to ensure that all the motors are hooked up right, turning the right way and the pusher/puller props are on the right motors and oriented the right way?
Front and rear motors (3,4) turn CW and have the pusher blades. The left and right motors (1,2) turn CCW and are normal props.
#4 Was the quad stable and flat for the whole calibration routine at startup? Was it stable and flat during the setup process? (If need be, do it again)
Quad was stable sitting on the floor all three times I installed the software.
#5 Did you calibrate your ESCs? They should all start together when you advance the throttle. If need be, do it again manually, as described in the second process here.
I calibrated the esc's and using the mission planner raw data, radio viewer it shows everything working correctly. All esc's are in unison. I did notice that after going to the max and back, two of the esc's are slightly off from the other two by a little but I am not sure if this means anything it is so slight.
#6 Did you setup and test your radio? Run test/radio to see. Pitch, Roll, Throttle and Yaw should all be 0 or near zero (60 or less).
The radio seems to be doing what it should and the throttle, pitch, roll and yaw all seem to be acting correctly according to the data seen in the mission planner.
#7 Have you checked all your sensors in the Mission Planner or CLI Test/IMU menu to make sure the hardware is working right?
I watch the data coming from the quad. There are three columns of data and this is where I get lost.
The numbers start at (-1, -2, 0) The numbers do not remain steady. Column 1 goes from -1 to -74 to 1786 and then back down to negative numbers again. Column #2 goes from -2 to -55 to +1038 to -371, etc. Column 3 goes from 0 to 35982 and usually stays around 35xxx then goes to 211 to 1006 back to 35875 but never goes negative. I thought these numbers are to be fairly stable if the copter is just static, sitting on the floor? Am I headed in the right direction for figuring out what is going on?
In the IMU test, it should definitely not change that much when not moving the quad (at least while not moving the quad/APM), but it is normal behavior when moving the quad/APM shield.
At least, thats my case, just after leveling (i did a setup->level in the CLI (command line interface)), i get -5 to 5 for the first and second column, and constant 338xx on the third column WITHOUT moving my quad. Obviously, if i move my quad, those numbers start jumping to different positive/negative values depending how i move my quad.
Have you tried the hand test to feel how the quad reacts to movement and see if it wants to stay stable? i found that test very valuable for me while i was still learning and building my quad.
Thanks for the reply. When I can today, I will do the level command and check the IMU again just to verify the output data. I am not familiar with the hand test. I would think that it is done with a little throttle with no props, correct?
Thanks. I will look into that tonight. I use a 6' USB cable so it sits on the floor flat all the time but I will pay attention to what you say. I will let you all know what happens. Thanks again.
OK, I ran level and got IMU
Gyro offsets: -8.31, -5.00, 14.00
Accel offsets: 8.14, -9.03, -7.30
I ran the IMU test again. The numbers change incrementally by a few digits at a time.
Col 1 goes from -8 to -57 then back down to 0 then to +38 and back down to -33 over and over.
Col 2 goes rom -16 to +12 over and over.
Col 3 goes from 907 to 1007.
I then rolled the quad by hand in all directions.
Col 1 went from -17,983 to +17,798.
Col 2 -2416 to 6790.
Col 3 235 to 33,340.
I put the quad back on the floor and saw the numbers change to:
Col 1 0 to 3
Col 2 -2 to -17
Col 3 520 to 556. I then repeated the same sequence and the numbers did not stabilize as well the second time. It sounds like what is wrong is almost becoming clear, lol.
I have not tried the hand test because seeing these type numbers, I am not sure it will be meaningful but I will try later.
Any insightful thoughts?
OK, I just finished doing the hand test. Whoa, that was exciting. The forward backward pitch, I could hear the motors fighting my change. The yaw CCW and CW I could feel the motors fighting back. Doing the roll left and right I did not feel too much fighting back of the motors. Hmmmm, is that what the response should be? It was hard to tell which motor was responding other than feeling it fighting back, in fact the roll was way different that pitch and yaw which seemed to want to twist back out of my hand. Being as hot as it has been, it was a nice breeze, lol.
Thanks Sam for the thoughts. I decided to calibrate all of the ESC's manually. One of the roll ESC's would not calibrate. It would not give the correct tones. I did the other three and came back to that one and it calibrated correctly that time. That is telling me that things aren't right with it. There are no bullet connectors so that part does not come into play. I would guess the motor has nothing to do with it either as the ESC should calibrate with or without a motor. Am I headed in the right direction?
And BTW, the props throw air downward as they should.
Mikey, have you changed any of your PID settings? You could try following PID settings on your stabilize modes.
P: 2.3 - 2.4
I : 0.015
Few people has reported that these will make ArduCopter with bigger motors a lot more stable than current default settings. After you upload latest software all earlier settings are wiped out too so your ArduCopter is back on smaller motor/prop combination setting.
Jani, thanks. I will try those settings tonight. As I said, I did get the ESC to calibrate but I accidentally turned off the brake setting. What are the settings of the ESC's so I can turn it back on. Also, I came across some 8" props. It wouldn't hurt to use those while I get things straightened out or should I stick with the 12" props.
Jani, the quad flies pretty good for once. It is finally a good day in West Palm Beach. I am gathering all of my problems stemmed from the one ESC not calibrating correctly, heavy sigh. I was flying it with 8" props and I haven't changed the PID settings. I will do that in a little while the battery is charging. I would still like to replace that ESC and get some spares. I also would like to know the settings for the ESC so I can turn the brake back on.
I was getting ready to change the PID values.
Old: P=4.5, I=0.025 D=0 INT=50 until I get to the YAW values, they were and still are P=4.5 (I can change that, I=0.1 (I will leave it alone) but the INT is 1500, and changing that one to a 40 does not seem like a good idea. Please let me know your thoughts on that one.
Thanks for the help and patience everyone. :)
Jani, would you e-mail me at firstname.lastname@example.org so we get the parts straightened out?