LibrePilot Forum
Users => Vehicles - Helicopters => Topic started by: daveapplemotors on January 19, 2016, 06:26:17 pm
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Today I should receive my long awaited Revo Nano and a GPS module from BG. I am excited because I have been trying to get one since last summer.
If the hardware fits a 250 heli I will learn altitude control, way point navigation, auto take off / landing, etc.
I wonder how much this will cost me? Wish me luck...
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You seem to already have a good grasp for setting up a heli. :)
Given that, the GPS stuff is quite doable. Twist your high current power wire pairs/triples, battery to ESC, ESC to motor.
Always have Attitude mode on your flight switch, take off and land with it. If there is a problem in the air, you can always switch to it.
Get it flying in Attitude mode first (same as CC3D), then change the Attitude Estimation Algorithm to INS13 and fly again, then add a flight mode with AltitudeVario throttle mode to test the baro, then add GPS and add a VelocityRoam flight mode. At that point, you have GPS flight mode working and you can branch out from there to waypoint, etc.
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Revo Nano came last night. Setup includes 'nose down and right side west' or 'left side down and nose south' for the magnetometer and / or accelerometer sections.
Thanks theothercliff for the note about emissions from my power wires. I will braid my ESC / motor wires :)
Since I didn't have the Revo installed into my heli yet I propped the unit on books and things to calibrate. It was probably positioned more accurately for each orientation than it will be in the heli. And I will redo calibrations to be accurate now the Revo is installed.
My board is not level when my heli is sitting on the skids and the mainshaft is not perpendicular to the heli base even if the skids were perfect. But the Revo board is perpendicular to the mainshaft and aligned well longitudinally.
questions:
Is it necessary to be as accurate as possible for all calibration orientations? Should I make a jig to hold the heli level and at right angles? I should calibrate based on orientation of the helicopter's mainshaft, que no?
What is the temperature compensation for? It failed to calibrate 3 times because it didn't vary 10 deg . It was about 15 degrees where I was and it reported nearly 30 degrees after a while. What causes the temperature change? Is it heated electrically?
Thanks,
Dave
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I have recently added some pages to Wiki, take a look here:
https://librepilot.atlassian.net/wiki/display/LPDOC/Sensor+calibration
Accel calibration is done without frame, it calibrate every axis for bias and scale assuming the gravity is 9.81
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The angles for calibration aren't super critical. I just eyeball it.
When it says stationary though, it must be completely still.
When you are doing the thermal calibration it also needs to be still. To get a good range that covers winter and summer, I:
- plug usb cable into just FC
- put FC in a sealed baggie in the freezer for 10 minutes, gets it down close to freezing.
- take it out of the freezer (leave baggie on till done) and immediately put it in a shoe box or similar on top of a hot light bulb
- immediately plug it into computer and start thermal calibration
- don't let it get over 70C, switch off light bulb way before that
When flying a true heli, the rotor won't even be level in stationary hover, you will probably want to adjust the rotate virtual roll a few degrees for that.
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I spend a lot of time adjusting, checking and test flying each helicopter so that with all three axes in "Rate" it's happy to hover a while hands-off. And I understand that eyeballing my three axes will get it flying pretty well because people are really good at eyeballing 90 degree. Furthermore the geometry of 88 or 89 degrees is very near 90 for our applications.
But, I want precision a little more so I will work on a "Device For More Precise Orientation During Setup" a bit which will be probably a wooden or cardboard box, some tape and a line on the field The "Aim the nose north" part is worth drawing a line anyway, que no?
Thermal Calibration: baggie in the freezer and then into a bowl of hot water at 69 degrees. Foolproof with saucer holding the important part of the baggie under water. Thanks, theothercliff, for the how-to which probably should go into the wiki verbatum.
And I must learn how much battery that first flight can use flying after it spends 20 minutes finding satellites.
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The angles no need to be perfect while calibrating Accelerometers, if board is 88° instead of 90° the error is very small.
On six positions he try to adjust bias and scale assuming the gravity is 9.81
In practice, a board with a case and a box to maintain board perfectly still and vertical at some steps.
For thermal calibration no need 70°C max.
As an example, initial compensation from baro manufacturer only applies below 20°C. Assuming the sensor response is linear above 20°C.
Water is not a good idea because the pressure inside bag should change, not good for baro sensor (air temperature, water pressure)
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Weird problem:
If the tail servo is plugged in when I connect flight battery none the servos work. Disconnect the tail servo and the cyclics function then re-connect the tail servo and everything works. I will try another tail servo when I get time--maybe the E Flite DS76t again!** And maybe I get time to test fly this weekend but the weather report looks lousy. Note to self: shorten 13 wires to tidy up.
This Revolution Mini from BG doesn't have regular 3 pin outputs to servos. There is an 8-wire plug for outputs. I don't think it is possible to specify it in "Configuration " because it is default. The 8 output wires: red is + pos, black is ground; green = ESC ; White, Blue & Yellow are cyclics (1-3); gray is for the tail. Orange is unused so far. You must distribute power to the servos because they each need pos and neg. I used a couple of headers with the pins soldered together. (see photo on Google drive https://drive.google.com/drive/folders/0B5McJ3wwtyLxMnpDZHJ0NEtPYW8).
It acquired 7 satellites while at my kitchen table last night! Can't wait to fly!
**I tried this DS76t before but it overheated even when I lowered input frequency to 50.
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Weird Problem:
with USB:
If the USB is connected before or after flight battery then the servos work. If the USB is then disconnected afterwards they continue to work.
without USB:
If the heli is powered up without the USB cable connected the servos don't work unless the tail servo is disconnected when powering up then cyclics work and then reconnect the tail and everything works.
Any ideas?
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Check your +5v source.
Maybe there is a current spike with all servo connected, especially with your tail servo ?
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“From theOtherCliff:
Always have Attitude mode on your flight switch, take off and land with it. If there is a problem in the air, you can always switch to it.”
Got it Attitude Mode is easy. I have my DX7s set for 6 flight modes.
“Get it flying in Attitude mode first (same as CC3D), then change the Attitude Estimation Algorithm to
INS13”
Got it change in (System / RevoSettings / BaroTempCorrectionExtent / FusionAlgorithm)
“ and fly again, then add a flight mode with AltitudeVario throttle mode to test the baro,”
****EDIT
OK I found “Altitude Vario” and I notice it's linked to collective and that any setting will be in all three Settings Banks.
**That brings up two questions.
How do I invoke “Altitude Vario”?
Is this just to test baro because I notice that it will be same for all three settings banks?
“then add GPS”
More than in Configuration / Harware ?
“and add a VelocityRoam flight mode.”
Got it -- Configuration / Input / Flight Mode Switch Settings
“At that point, you have GPS flight mode working and you can branch out from there to waypoint, etc.”
Thanks.
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One step forward and ..
The servo problem cured by tining the connector pins with a little solder.
In preparation for autonomous flight I set a flight mode for "Attitude". With the heli on the bench and motor dis-armed the swash jumps about 20 degrees to the right going into "Attitude". That will crash. It jumps back when it is switched back into another mode.
I tried "Attitude" mode once on the CC3D board and very nearly crashed. I had to get out of "Attitude" mode quickly.
The other flight modes don't move the swash.
Anyone every fly a heli in "Attitude" mode?
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About attitude, check how is the PFD when level.
Bank the heli and see if PFD horizon react fine.
In flight: Take care about vibrations (Attitude state can be totally wrong due to vibrations), try a little fly in rate or manual mode almost level and check your PFD. You can log your flight: Tools > Record..
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G'day Laurent,
You are right on, thank you.
Redoing all the calibrations helps. Now the swash jumps aft a tiny bit when I engage "Attitude". When I get to the field I will calibrate again so that jump will probably disappear. But now I must wait for 30 cm of snow to melt.
About balancing:
I use Audacity software and an old earbud to balance all my helicopters including Blade nano tail rotors.
be well,
Dave
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Good weather yesterday. I tried to move my home position to the center of the soccer pitch instead of a sidewalk near some trees.
EDIT: I don't know how to move home position, Can anyone help me with this? --I got this.
On another note it appears the PIDs are treated differently in LP than they were in OP. I had to drastically reduce settings--notably pitch--on tow of the 250s. Settings that were smooth in OP make a bucking bronco in LP.
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Blackie, with the Revo Nano, is flying much better. Weather and work have interfered with my flying. In a few days I will get this one going autonomously, I hope. And maybe a video or two depending on booting my keychain camera properly.I know how to do a flight plan, now.
This is a Bangood Revo Nano clone that doesn't have an internal 433 mhz OPLink. I must buy another OPlink if I want to tune wirelessly and add more weight to my heli. Rats. I have been trying for almost a year now.
I still want to buy a real Revo Nano for an HK250.
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Hi,
Banggood doesn't have Revo Nano but a Revolution board redesigned by cloners with smaller pcb and external OPLink.
A Revolution Nano looks like that, smaller CPU, MPU9250, no oplink.
(https://librepilot.atlassian.net/wiki/download/thumbnails/5669002/gcs-board-nano.png)
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Merci Beaucoup, Laurent.
And I am becoming more confused.
When I purchased from Bangood I thought I was getting a Revo Nano. Since I can't get a real Revo Nano what is the next best flight controller that has an internal modem? Is there one that is light and about the same size ? Sparky?
If I keep what I have as well as the OPlink module that I can use with my laptop then I will need to purchase just the OPlink Air module. Does anyone know where I can purchase just that without having to purchase another one for my laptop? I would probably buy two; one for each HK250GT heli.
Thanks,
Dave
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Sparky is same size as Revo.
The small Revo, normal sized Revo are good choices.
There is no Revo Nano clones (at least in this size) and around 500 original sell in the world, minor some defects.
The good thing with this small revo: both modules have SMA connectors but i'm not sure you can found the "Air Oplink module" alone.
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hobby king has it..
http://www.hobbyking.com/hobbyking/store/__98334__Oplink_Mini_Air_Ground_Telemetry_for_Mini_CC3D_Revolution_Flight_Controller.html
or you can use 3DR radio set as well
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Description of using 3DR radio for OP / LP board described in this blog.
http://peterwedege.blogspot.com.au/2015/10/open-pilot-cc3d.html
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Thanks for the links. I want to get the lightest parts that work. Does anyone know what the OPlink Air masses? OPlink ground station part? 3DR radios?
I have two helis that could use the OPlink Air but I have not seen that part available separately without buying the OPlink base part, too, one of which I already have.
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If you want to use 3DR radio, no issue but this uses one Port with telemetry.
With the small Revo and Air Oplink, radio is already integrated and keep all ports free like a normal Revo.
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UPDATE on the GPS and OPlink enabled Nano Revolution:
OPlink works. I am just waiting for snow to clear from soccer field to calibrate. And to get time from work--how come is that? I am supposed to be retired!
I have calibration questions that I hope are addressed in the middle of the pitch by wireless calibration.
I removed the controller from the heli to start over with attitude calibration because the graphic in Configuration / Flight Data or Firmware shows the heli upside-down. Then I calibrate. But I notice that a couple of my axes are reversed--usually roll and yaw. When I tried correcting this situation by changing the sign on the individual axes in System / Settings / AccelGyroSettings / Accel_scale and Gyro_scale things get uglier. The graphics flip to inverted again.
I have gone to fly and found that a couple of axes were reversed, RUDELY one time when it scraped the tips. I reverse the Axes in System / Settings / AccelGyrosettings. It flies fine in "Rate" even if the graphics are inverted. Don't try "Rattiude" or "Attitude" though because it will want to tip.
I have tried/am trying different orientations in Configuration / Attitude / Settings / Board orientation. 180 correction on roll --upside down and -90,0, 90 & 180 corrections on yaw.
My board is upside down and the USB plug in on the right (starboard) side just like the board in attached drawing nose to the right looking down on it and USB plug aimed down.
Maybe I get time today to calibrate. Wish me luck.
What roll, pitch , and yaw orientation numbers should I use?
Thank you good people.
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Dave, that a Revo mini from cloner.
Look previous post for Revolution Nano (from OP) as reference.
Again, just to avoid mistakes about names and boards.
My board is upside down and the USB plug in on the right (starboard) side just like the board in attached drawing nose to the right looking down on it and USB plug aimed down.
So Revo Mini, if upside down and usb to the right, the arrow on case is on back and pointing rear ? try setting Pitch=180°
Put a picture how you mounted to be sure.
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I stand corrected. The revo mini - from cloner , doesn't get capital letters anymore either. I would like a real one...
My LP software will not allow me to rotate pitch more than 18 degrees. I did not find out where to edit the pitch rotate parameter in System yet as a work-around.
If I rotate yaw 180 & roll 180 it should be the same as rotate pitch 180, que no?
Can you ignore spaghetti wiring in photos?
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Just see you change manually Accel_scale and Gyro_scale with some '-1' value to revert.
You cannot get reliable changes in Attitude > board rotation if you change settings in both/all places.
And cannot help you, sadly.
If i remember you report some Radio input issues at some point ?
Can you refresh my memory ? Can't remember
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All is working except orientation. I got help w OPlink and Bluetooth on another heli so far.
I have been successfully altering Accel_scale and Gyro_scale since I first stated using OP about a year ago.
I try not to make changes in both places as I realize that could cause confusion. I re boot and then re calibrate everything after I change orientation.
merci, Laurent
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Why did you start using the scales instead of just using Attitude->board rotation? The rotation settings are much easier to use since they're in degrees and in the configuration screens instead of buried in settings.
I recommend you reset them back to the default and use board rotation instead. It makes it much easier not only for you but for people trying to help you or people you share uav files with. No one will think of looking at the scale settings when trying to help someone since they're not intended to be used this way.
edit: I just noticed in your pictures that the board you have has the "this way to front marker" arrow. It's the half white half black arrow head on the case.
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If you reset the *_scales to "normal" , Orientation should be 180° Pitch
Also consider calibrating the Accelerometers if you want to use INS13 at some point.
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Pitch does not go 180 degrees. Its limit is 18 degress in the GUI. Try it.
I got into the habit of using the System to change parameters because the GUI has flaws. I didn't know that there are rules to this road. I have been traveling it for almost a year with very little help.
There was no documentation on the board I bought. I had to guess at the output wiring.
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No one knew of the bug that limits it to 18 degrees. I've entered it in the open issues at https://librepilot.atlassian.net/browse/LP-266
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Thanks,
I didn't know if it was a bug or not. How could I? I thought the 18 degrees was designed-in so I reversed roll and yaw instead of pitch--in the board rotation part of the GUI.
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Just a limitation to -90° / 90° like Attitude readings.
In you case do Roll 180 + Yaw 180
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Yes , thanks.
I saved with with board orientation : Roll 180 and Yaw 180
Now that I re calibrated the graphics are again correct. BUT the servos react the wrong direction when I roll or yaw. Pitch is good. I have always used the Accel and Gyro Scales to rectify this problem. What is the CORRECT way to fix this?
I have seen this before and just changed the two scales and gone flying.
Sorry I am such a newb, but how do I reverse the helicopter's reactions?
BTW both Accel and Gyro Scale read -1. I did not change them.
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I have come to the conclusion that the (vehicle) setup wizard sets your control directions? But there is no helicopter setup wizard. I am pretty familiar with the GUI and have not found where I can reverse my control directions.
Please tell me how to correct my swash. It moves the wrong direction when I roll the aircraft. If I roll left it rolls further left.
Help?
Please tell me how to correct my tail rotor. It will increase yaw left if the aircraft yaws left. Help?
To be clear the sticks work the servos fine. The gyros/accelerometers don't.
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Thanks to hwh the swash works correctly. I remounted the board so the writing is up and the little arrow points forward.
The PFD (flight display) works opposite on roll to what I thought it should. When you bank in to a turn the horizon tilts opposite to what I thought. Bank left and see more ground on the left side just like in a real cockpit.
I have included a photo of Blackie all chock full of gadgets. I may remove the OPlink when I meet my goals with waypoint navigation.
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NEW PROBLEM!
Blackie woke up from paralysis confused. Servos work fine with TX but react wrongly. Pitch is backwards. And when I yaw the aircraft (manually turn the heli) the swash tilts. When I tilt the heli the rudder moves. Board rotation is still 0,0,0 and Accel and Gyro Scales are set at 1.
Either someone broke into my house and reprogrammed Blackie last night and ran off laughing OR something weird is going on.
I will try wipe the board and try to start with a fresh UAV. But that might be a problem because (with no heli setup wizard) I use an existing UAV to get started and who knows what little booby traps are already loaded into a file. It may have been started with the OP software and modified to work somewhat with LP.
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Blackie woke up confused and but is napping again. I must have disturbed him too much. I calibrated sensors with OPlink plug disconnected through USB. Saved. Checked that OPlink was enabled, reconnected OPlink plug, reconnected flight battery and Blackie doesn't budge. No bind, no servo wiggle, no USB and no OPlink. oh well. reload firmware again...
Hank mentioned that if the board is set up for OPlink data then it won't communicate via USB. Yup. And it gets you into a bind if somehow OPlink doesn't work. No way to communicate. Rats!
Then I reload the firmware and reload an old UAV (I have tried different ones).
1. Calibrate with USB cable.
2. Make sure it's set up for OPlink.
or reverse 1 and 2 and calibrate sensors with OPlink connected (since I installed OPlink to get accurate mag calibration).
I have done this a few times and I wonder if there is a CLEAN helicopter UAV available anywhere?
Does anyone know how to bypass the reload firmware and UAV step?
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...Hank mentioned that if the board is set up for OPlink data then it won't communicate via USB.
It should still work for usb with the oplink setup and connected. I said that if the oplink was configured and then the oplink was unplugged from the revo-mini the revo-mini wouldn't boot.
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I am using Ubuntu 15.10 and recently ran into a problem* that I cured only by going backwards to the Libre Pilot release for 14.04 Ubuntu. I was using the ppa for Ubuntu 15.04+ until I couldn't use it anymore.
*Problem:
the top menu bar in Libre Pilot that shows "FILE" when you put your mouse pointer near the top does not appear. I tried every key stroke and combination I could think of but I could not get a top menu. There is no way to Import, Export, etc. I used the program many times before it failed.
I uninstalled Libre Pilot 15.04+ which require downloading Synaptic, a superior Ubuntu (un)installer tool. The "description missing" detail in the latest release required this, I guess. I reinstalled the 15.04+ version a few times to be sure, re-flashed the board and reloaded the oldest UAV that I have that used a satellite--way before OPLink. But each time the menu bar would not appear. It had been working before...
I have been having a devil of a time with OPlink staying connected. I had it working a few times but since it seems the source of some of my frustrations I removed OPlink, too.
Frustration, hair loss, grouchiness, missing flying time, blah, blah, I wanna fly my toy, bwah! I must go put in a few hours machining some TI to relax.
note to Hank re previous post: if it doesn't recognize the OPlink although plugged in, powered up, and configured properly then the mini-revo won't boot up in that case, too. Awkward--reflash, import, try something else, and pray.