LibrePilot Forum
Users => Vehicles - MultiRotors => Topic started by: weldon855 on November 30, 2015, 08:00:28 pm
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Hi,
I have recently got a quanum venture frame and put a revo ( clone with slightly different layout) controller in it. This is my first quad and its proving a little difficult to get it to lift evenly on take off. I am in attitude mode.I can get it to take off by adjusting the pitch and roll and once in the air I can continue to wrestle with it to keep it hovering before taking it down. I am using complentary filter at the minute because I have a mini ubx7 gps and onboard mags are not great. My question is what settings do i look to to balance the quad?
At the minute i have the neutral positions on the motors all locked to the same value should they be different?
I realise that alot of the questions that I have may have been asked a million times over ob the op forum as google keeps pointing me there but they appear to be no access to it anymore.
The escs are afro 20a.
The revo board is mounted upside down and facing forward and I have set the roll to 180 deg.(should i teeak these setting to compensate for ths imbalance?)
I have gone through all calibration and modelview shows correct orientation of the quad
Appreciate any help/advice
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Hi Weldon855, and welcome to LibrePilot :)
well, actually I can tell you, I started flying rc with those quads and what you write feels just like it felt to me. To get best results for the start, to my experience is best to setup:
- complementary
- attitude
using the vehicle setup wizard, select either default tuning or if available, a tuning special for you quad. Your quad should work straight away with either of your choice there. First I would like to ask you, if you have any experience with flying multicopters, rc planes or rc helicopters.
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I am in attitude mode.I can get it to take off by adjusting the pitch and roll and once in the air I can continue to wrestle with it to keep it hovering before taking it down. I am using complementary filter at the minute because I have a mini ubx7 gps and onboard mags are not great.
First start in Complementary Filter (Basic) that mode is using only Gyro and Accelerometer. If you want to use Magnetometer later on, and your flight controller (FC) is flipped, you will need also to flip magnetometer accordingly. This must be set in two place AttitudeSettings->BoardRoation and AuxMagSettings->BoardRotation
For now though, ignore that, and try to get your quad hovering in Complementary Basic.
At the minute i have the neutral positions on the motors all locked to the same value should they be different?
Most likely, in the vehicle wizard you go through the procedure which allows you to determine the lowest point props are spinning for each motor. The low and high end are found automatically in the step where you are asked to take off propellers, connect/disconnect battery to get ESC beeps. I have neutral points 1092,1097,1097,1097 so it's often same neutral point and that is fine.
The best thing is to start in Complementary Basic and Attitude.
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To Complementary and Attitude I would add that you need to follow the wizard directions carefully and completely and use high speed ESCs and and configure high speed ESC update rates (PwmSync / PWM 490 / OneShot125).
When you have that set up and working, you must calibrate your ESC's and THEN you must set the neutrals (individually) so to the lowest reliable motor RPM.
Don't just skip over something because you didn't understand it. :)
If you have all that, and you always fly with the tail pointed toward you the quad should actually be easy to learn to fly. First concentrate on maintaining a consistent altitude at knee level to eye level over some soft grass so you can slam the throttle down without hurting the quad.
Use default values! Do not start on a slope. Do not hold any roll/pitch/yaw while on the ground at all! After arming when you get ready, start the motors and immediately take off (jump up) to knee level. If you sit on the ground with the motors running, you give it time for the attitude stabilization to wind up and try to correct for small amounts of unlevel. It thinks it is flying and that it should be leveling out, so it tries harder and harder. When you finally get into the air, that "harder and harder" when it was held to that angle by the ground is suddenly way too much correction.
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I recall that during sensor calibration, GCS first sets all rotations to zero, then does calibration, then sets rotations back.
You do need BoardRotation if your board is flipped, and it doesn't matter if you set board rotation before or after calibration.
To clarify: f5soh reminds us that if you are using the vehicle wizard with a rotated flight controller, you must set the board rotation (Configuration -> Attitude -> Settings -> Rotate Virtual) before running the wizard...
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thanks guys, I have not had much time to tinker with it this evening due to weather.
ok so I will keep the board rotation setting
First start in Complementary Filter (Basic) that mode is using only Gyro and Accelerometer. If you want to use Magnetometer later on, and your flight controller (FC) is flipped, you will need also to flip magnetometer accordingly. This must be set in two place AttitudeSettings->BoardRoation and AuxMagSettings->BoardRotation
For now though, ignore that, and try to get your quad hovering in Complementary Basic.
the magnetometer is on the fc so I would calibration adjust this or will I need to correct it in AuxMagSettings->BoardRotation?.
I will reset to default and redo the calibrations to make sure I have not changed something I should not have.
And yes this is my first time flying anything my only other experience flying is on bf4 ;D
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Hi,
Be sure you setup the BoardRotation (180° roll) before Wizard or you will see weird results after Wizard level calibration.
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I am so new at this but one problem I had quad would hardly hover with out fighting it. When calibrating, I thought my desk was level I finally checked it with a level wow almost a full bubble off. Leveled the quad with playing cards.......Night and day difference at the hover hands off except for the normal drift.
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Some aircraft (helicopter, tricopter) are not level when they hover, even if perfectly built. Also, any small misalignment (e.g. crash damage) even on a quadcopter and it will not be level when it hovers either. Also the landing gear can be different lengths.
Solution is to use
GCS -> Configuration -> Attitude -> Settings -> Rotate Virtual ...
to make Attitude mode hover in one place.
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As a total noob I don`t understand and I hate dumb questions but I cannot help it. On the attitude page I zeroed the Gyros and what else am I needing to do ... do I change any setting???? I am sorry but I am lost there.
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You really need to do them all; to avoid questions about "can I do this mode".
Press the help tab at the top. I know. Help? Is this the only place that has help? :)
There are 5 calibration steps, but 4 steps listed in help. The first step in help is both accels and mags.
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No NO No No I never noticed the HELP button I thought I scoured the whole page looking. Please take my sincere apologies and Thanks Again TheOtherCliff
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hello again so after reseting and recalibrating take off is a little more stable now.
weather is still really bad so cant test much.
Now I just need to adjust the throttle sensitivity to make it easier to hover.
the problem I am having now is that I am trying to connect a bluetooth module (HC-06) to the oplink for telemetry on the GCS.
I have changed the baud to 38400 and name of the the bluetooth module to confirm that the commands were successful.
I can connect to the bluetooth module on the GCS and it shows me the oplink icon with settings on the configuration tab and even shows the signal strength.
the oplink is also being used for control. any ideas when I am not getting the data?
it works if I plug the usb into the oplink obviously but I am trying to replace the usb cable with bluetooth so there is no cable.
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You have to set the boudrate to 57600 than this is the default for telemetrie.
I did so and was successful.
Also be shure the bluetooth is on mainport of the oplink ...
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You're right, telemetry ports are currently "hardcoded" at 57600 by mistake.
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You're right, telemetry ports are currently "hardcoded" at 57600 by mistake.
Is there a Jira for that? I didn't see one. :(
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There is a JIRA, PR and merge :)
https://bitbucket.org/librepilot/librepilot/pull-requests/122/lp-182-set-telemetry-port-baudrate/diff
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still no joy at 57600 same issue have changed baud on bluetooth +fc +oplink
any other ideas?
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If USB is connected i think the USB telemetry take priority ?
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no had usb disconnected and multiple attempts. its annoying me at the minute because I want to tidy up the transmitter so I can get rid of the usb.
it seems a bit more difficult to bind the fc and oplnk at 57600 so im not ruling out dodgy hardware.
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Perhaps you can try to swap rx and tx on the bluetooth device...
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fairly sure wiring is correct as I can see the oplink in the gcs once connected
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fairly sure wiring is correct as I can see the oplink in the gcs once connected
Not sure what you say... you can see the OPlink tab inside config, connected through Bluetooth ?
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yes but gcs receives no data
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Do you have the two small bar on bottom/right that says there is Tx and Rx data ?
Like file attached
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yes tx goes between ~24/48
rx between ~114/148
rx seq no. and rx rate B/s remain at 0 though.
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So GCS is talking with OPLM through Bluetooth and you can see OPLink tab.
Not a bluetooth issue but between OPLink and Revo.
Post Config > Oplink tab screenshots for Revo and another for Oplink
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Ok so problem solved thanks so much for your help you got me looking on the right track.
you were right the bluetooth to the oplink was working. but the problem was with the oplink to the revo.
So I noticed that when I connect power to the bluetooth module the revo would loose its connection with the oplink!!
It appears the voltage drops to much when powering both the oplink and the bluetooth module from my transmitter.
I will stick another reg in there as I just took a line of the existing 5v regulator beside the switch inside.
it wasnt an issue without the bluetooth module but obviously was at its limit.
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Hi again
so I am fairly happy with the way it flys in attitude mode now.
however I noticed today that although the GCS tells me that my GPS has a fix(7/8 satallites) the UAV location never moves on the map. It appears to be stuck 1 location.
If I rotate the quad the UAV rotates on the map though.
I dont think I was like this before becaue I remember leaving it sit for a while before and the UAV trail would jump around abit as it picked up more satellites.
any thought on what could cause this?
I really dont want to reset and start again as I am happy with how it flys now
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If you don't have any GPS guided flight modes, then it will let you arm and take off without a full GPS lock.
GPS needs 7 satellites and PDOP<3.5 to come fully online.
Simple way around that for now may be just to right click on map and enable "Show Diagnostics". You will get a green GPS trail of simple GPS coordinates.
Are you using Basic or INS13 for Attitude Algorithm?
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I had 7 sats and it was still in fixed position (in my house so it got some kind of lock)
with show diagnostics I now have a moving UAV but why does the other UAV marker remain fixed? or is it not meant to move
I am using basic algo .
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For GPS to move on map when using INS13 (not the default of Basic Attitude Estimation Algorithm) you must have satellites >= 7 and PDOP<3.5 and green MAG (and green ATTI and STAB) :) Mag is usually the hardest part.
PDOP value can only be seen in System -> Data Objects -> GPSPositionSensor
It's possible that it is something else. To be honest, I am really only familiar with Revo and INS13.
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thanks
I have been focusing on getting it steady with basic as I only have the on board mags on the revo.
So I probably wait for external mag support before I switch over to INS13.
I was just curious as to why the UAV was not moving but I can see it with view diagnostics so I am happy for now