Setting up for first flight.
« on: April 29, 2019, 08:23:37 pm »
I am almost ready to fire up the drone and take her for the first flight.  Motor all turn, controller (FlySky) is talking to the quad, if I tilt her it reacts, gps works.  I think I am ready to go.  There are a few things.  I have been flying since first of the year on a commercial drone (HS700) and it is pretty idiot proof.
1) Is there a way to set the drone up for return to home? I would prefer not to lose the darn thing. The other question is does the drone mark the home position when it acquires a GPS fix or does it always have to be manually assigned?
2) How do I tune the quad so that it is super stable?  I can always increase the aggressiveness as I get more confident but I want to start conservatively.
3) How do I make it so that if I cut the throttle to zero it won't fall out of the sky while at the same time making sure that once armed it wont take off immediately.  The HS700, with the throttle all the way down will slowly lower.  It is pretty hard to crash it when landing.
4) Is there a way to automatically set it to hover?  My HS700 controller's throttle is spring loaded to return to hover.  The new one is not so it would be hard to just let go and have everything stop and hover.

All of this is geared toward not crashing and not losing the thing right away.  If it helps I made a DJI F450 like drone.  No camera on it yet but that's next.

Ed

 

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Re: Setting up for first flight.
« Reply #1 on: April 29, 2019, 08:43:27 pm »
I am almost ready to fire up the drone and take her for the first flight.  Motor all turn, controller (FlySky) is talking to the quad, if I tilt her it reacts, gps works.  I think I am ready to go.  There are a few things.  I have been flying since first of the year on a commercial drone (HS700) and it is pretty idiot proof.
1) Is there a way to set the drone up for return to home? I would prefer not to lose the darn thing. The other question is does the drone mark the home position when it acquires a GPS fix or does it always have to be manually assigned?

You shall set it to the arming location, not to a fixed one. It only arms with enough sats, so you can be sure the quad returns. Its described in the wiki.

2) How do I tune the quad so that it is super stable?  I can always increase the aggressiveness as I get more confident but I want to start conservatively.

I would try the default settings, normally they are beginners friendly. for nick an roll choose attitude stablilzation, for Yaw axis lock. If you increase the parameters too much, the quad may wobble and thats difficult to control.

3) How do I make it so that if I cut the throttle to zero it won't fall out of the sky while at the same time making sure that once armed it wont take off immediately.  The HS700, with the throttle all the way down will slowly lower.  It is pretty hard to crash it when landing.

Dont know how powerfull your new toy is, but what about a test run without props? so you can check if you can increase/decrease the power smooth.
 
4) Is there a way to automatically set it to hover?  My HS700 controller's throttle is spring loaded to return to hover.  The new one is not so it would be hard to just let go and have everything stop and hover.

VelocityRoam GPS mode helds with controls at neutral the current position. But normally attitude stabilization is very easy to control, my dad (78 years) was able to hover my eachine  racer in attitude mode after 5 minutes training.

All of this is geared toward not crashing and not losing the thing right away.  If it helps I made a DJI F450 like drone.  No camera on it yet but that's next.

Ed

Good luck !

Udo

Re: Setting up for first flight.
« Reply #2 on: April 29, 2019, 09:43:46 pm »
I was all excited that someone had replied!  Not the reply I was hoping for but at least someone besides me is encouraging me!!!  Thanks.

Re: Setting up for first flight.
« Reply #3 on: April 29, 2019, 10:20:33 pm »
gps works.
GPS flight modes are an advanced topic.  You should get it flying well in Atti, Atti, AxisLock, Manual(throttle) first.  The problem with that is that it drifts and you have to keep it from drifting away.  The GPS flight modes you are used to hold it right where it should be, even in wind.  You are used to a self driving car, and now you have to drive one that requires constant attention and corrections to not drive into the ditch.

1) Is there a way to set the drone up for return to home?
That is a GPS flight mode and in my opinion, should be done later.  The one thing you must do now is set your failsafe so that if it flies out of range, the motors stop.

The other question is does the drone mark the home position when it acquires a GPS fix or does it always have to be manually assigned?
Yes.  When you fly from a new field it will return to that field.

2) How do I tune the quad so that it is super stable?
As the other post said, use defaults.  They are fine.  You don't tune a car differently for a new driver...  :)  That means using defaults, not using a "cloud configuration."

3) How do I make it so that if I cut the throttle to zero it won't fall out of the sky while at the same time making sure that once armed it wont take off immediately.  The HS700, with the throttle all the way down will slowly lower.
Well what you want there is "Altitude Vario" thrust mode which is best switched to once flying, but again, start with Atti, Atti, AxisLock, Manual(throttle).  Zero throttle will stop the motors, but for now that is probably a safety feature that should be left active.  There is AlwaysStabilizeWhenArmed, but there are many cautions for it that should be researched.  Learning to hold a reasonable altitude with sensitive throttle stick is probably the first thing you must learn, even before learning to keep it from drifting away.

4) Is there a way to automatically set it to hover?  My HS700 controller's throttle is spring loaded to return to hover.  The new one is not so it would be hard to just let go and have everything stop and hover.
When you eventually set up "Altitude Vario" thrust mode, the center 20% of the stick is dead band, so anywhere close to center is exactly center.  For now, using Manual throttle, learning throttle should be your first concern.  You are doing well when you have found that this click on your detent throttle is slowly coming down and one click up is slowly climbing.  Then a hover is just clicking back and forth once in a while.

May I suggest that you read this:
https://forum.librepilot.org/index.php?topic=4408.0

Re: Setting up for first flight.
« Reply #4 on: April 30, 2019, 03:02:24 am »
Cliff

Thanks for the information.  It highlights how much I have to learn!  But it is fun to learn new stuff.

I took the drone out tonight and fired it up.  It did actually fly. I kept it low and very slow.  It was doing great until I tried to go forward.  It actually went backwards.  This totally freaked me out and I overdid the throttle and up it went, then I cut the throttle and it dropped like a rock, flipped over and hit the ground like a rock.  Broke the cheap plastic frame and propeller.  I am sure I am the only person this has ever happened to.   ;)

New frame on order.  In the mean time I will read the referenced material.

Thanks.

Re: Setting up for first flight.
« Reply #5 on: April 30, 2019, 03:44:30 am »
- Flight rule to keep in mind:  Always fly with the tail pointing toward you (nose away from you), so both you and the quad are facing the same way, like you are both in line (queue) waiting for checkout at the store."

It sounds like you had the nose pointing towards you.  It's important to know which is the nose.  :)

Re: Setting up for first flight.
« Reply #6 on: April 30, 2019, 01:59:45 pm »
That's what I thought, it happened so quick.  It was a nightmare.  The other thing I forgot to mention is that I designed the quad in eCal to be able to carry a camera on a gimble and a larger battery so as it is now it is very over powered.  Can I limit the amount of throttle I am allowed to apply?  Say 50% max. 

Also, I should have read your start guide BEFORE I fired the thing up!  Great write up and I probably violated every pointer.

Ed

Re: Setting up for first flight.
« Reply #7 on: May 01, 2019, 03:02:48 am »
Yea, you can reduce your Output page Maxes on all motors to say 1500 or even 1300 if it's really wild and you want to tone it way down.

With a tightly tuned (PIDs as high as possible without oscillations) quad, doing this might cause oscillations, but not in most cases, especially with just a default tune.

Re: Setting up for first flight.
« Reply #8 on: May 07, 2019, 10:23:03 pm »
Several updates.

1) Got the Optlink working so at least I can see what is happening remotely!

2) Everything is calibrated and the sensors are working.  The magnetometer had me thrown for a couple of hours because it getting really strange reading when it was just sitting on the ground.  The compass was way off and would jump around.  Turns out that I had a magnetic clasp on my Fitbit on the arm I was doing all the calibration.  All I can say is DUH!

3) I have the modes set up as Flight Mode 1: Atti, Atti, AxisLock; Manual: Flight Mode 2 Hold position with GPS assist; Flight mode 3: Return to home with GPS assist.  My controller only has a three position switch so I don't know how I would set more but I am not sure I need any more right now.

4) I am getting inconsistent arming of the quad.  It leads back to inconsistent lock on the GPS.  I cannot always get a GPS lock which keeps the drone from arming.  Still looking into that.

5) Toned down the max output from 2500 to 1300.  Everything ran but didn't have enough to take off.  Changed it 2000 and the quad flipped over and broke a prop.  My motors have a DJI type hub (has a dent on the side locking the prop to the hub...very unforgiving).
Moved the thrust to 1700 but ran into the lock issue again.  Called it a night.

Any advice is more than welcome (on any of the issues). 

My biggest fear is 1) runaway drone then 2) killing the throttle and having it drop from the sky like a rock.  As TheOtherCliff said I am used to an autonomous car so the switch to manual is a big change.  My flight modes are selected to learn how to control it first, but to be able to throw a panic button of hold in place or return to home in case of emergency.  Is there something in the middle of full auto and full "manual"?

Also the big change for me is the throttle.  I feel really uncomfortable with cutting the throttle all the way leads to 0 output.  To me this can never be a good option.  When would I ever want to cut the throttle of off? For a plane a get it, it can glide, but for a quad it is a rock.  Is there a way to say once off the ground zero throttle means 20% output or whatever I need to keep it from rocking?

Ed

Re: Setting up for first flight.
« Reply #9 on: May 08, 2019, 05:06:06 am »
3) I have the modes set up as Flight Mode 1: Atti, Atti, AxisLock; Manual: Flight Mode 2 Hold position with GPS assist; Flight mode 3: Return to home with GPS assist.  My controller only has a three position switch so I don't know how I would set more but I am not sure I need any more right now.
GPS Assist is only for use with non-GPS modes and basically just does a GPS Position Hold when the sticks are centered.  May I suggest that you use Velocity Roam instead of Position Hold.  They are the same if the sticks are in the middle, but VR lets you move it around too; just release the sticks and it stops where it is.  The throttle stick has 20% deadband (+-10%) so anything close to the middle means "maintain this altitude".

4) I am getting inconsistent arming of the quad.  It leads back to inconsistent lock on the GPS.  I cannot always get a GPS lock which keeps the drone from arming.  Still looking into that.
Some GPSs don't do well inside some buildings.  Also, you don't want to be between tall buildings.  You should be able to see the horizon (or trees).

5) Toned down the max output from 2500 to 1300.  Everything ran but didn't have enough to take off.  Changed it 2000 and the quad flipped over and broke a prop.  My motors have a DJI type hub (has a dent on the side locking the prop to the hub...very unforgiving).
Moved the thrust to 1700 but ran into the lock issue again.  Called it a night.
https://forum.librepilot.org/index.php?topic=4408.0

My biggest fear is 1) runaway drone then 2) killing the throttle and having it drop from the sky like a rock.  As TheOtherCliff said I am used to an autonomous car so the switch to manual is a big change.  My flight modes are selected to learn how to control it first, but to be able to throw a panic button of hold in place or return to home in case of emergency.  Is there something in the middle of full auto and full "manual"?
Yes.  Attitude (/ Rattitude / Rate) mode with GPS Assist (not sure all those are allowed with GPS Assist).  Attitude / Rattitude / Rate are "manual" and when you center the sticks, you get a GPS Position Hold.

When would I ever want to cut the throttle of off? For a plane a get it, it can glide, but for a quad it is a rock.  Is there a way to say once off the ground zero throttle means 20% output or whatever I need to keep it from rocking?
When it is eating you or your friend with more stitches needed every second.  :(  If I am really good with the disarming switch, I figure it takes me about a half second longer to hit the disarming switch than to reduce the throttle.  Yea, I remember having a hard time not zeroing the throttle in a crisis.  ASWA Always Stabilize When Armed will do what you want.  The motors always run.  There are down sides.  It always stabilizes.  When on the ground in Attitude mode one or two motors will run way up, trying to correct the slight tilt.

Re: Setting up for first flight.
« Reply #10 on: May 09, 2019, 05:18:16 pm »
This hobby is hilarious.  So last night I fire up the drone and it works perfectly, on the ground.  GPS lock, arms through a switch, props spin!!!  Still falls over.  Did get it off the ground with a quick burst then it flew straight left and into a bush.  Hilarious.

Finally figured out that the drone thinks it is tilted to the right even though it is level.  Re-calibrated everything (a couple of times), outside with GPS lock, but that didn't resolve it.  The only thing I can think of is electrical interference.  I have the FC mounted next to the GPS on one side and next to the receiver on the other.  The Optlink antenna is right in front of the GPS.  I just purchased a GPS stand to get it away from the FC.

Any other thoughts?

Re: Setting up for first flight.
« Reply #11 on: May 09, 2019, 06:23:52 pm »
Tilted how much to the right?  Just a few degrees or like ... 90 degrees?

What flight mode was it in when it went left?

About what bank angle do you think it was when it was going left?

I assume that you were in Attitude mode when this happened.  Attitude mode will drift, depending on how well the sensors are calibrated.  This is like your car.  If the front end is aligned badly, it will immediately head for the ditch when you take your hands off the wheel (fingers off the stick for a quad).  If it is aligned very well, it will still go for the ditch, but will take longer.  With your quad, you must constantly keep it out of the ditch.  That is Attitude mode (Atti, Atti, Rate/AxisLock, Anything).  If you add GPS Assist to that, it will stay in one place when you release the sticks, but if it is badly calibrated, it is like your car front end is badly aligned, but it is a self driving car and can correct that.  It will still drift when you touch the sticks.

Accel Calibration is supposed to be done with the board out of the aircraft, but could be done with it in aircraft in a pinch.  Board Level cal is done with board mounted in the aircraft.  Accel first then Board.  Both of these need to be done well to minimize drift.

Your transmitter trims should be in the same place as when you did transmitter wizard.  With battery in and USB plugged in and transmitter on, you can go to "Input - RC Input" page and verify that the readings match your Neutrals, +- 1.

So finally, Velocity Roam is like your other GPS quads.  Attitude mode with GPS Assist is "manual" flying with a position hold when you release sticks.  VR is easiest to fly, but as I recall, you can't arm in VR and shouldn't take off in VR (use Atti) until you understand the issue with GPS drift while it is sitting on the ground.

For GPS to work best, you should wait 12 minutes with it powered up (and in the open) before first flight of the day and wait 2 minutes for later flights that day.

Re: Setting up for first flight.
« Reply #12 on: May 11, 2019, 05:16:53 am »
The tilt is just a few degrees, not a lot but enough.  It was in Atti, Atti, Axislock, manual flight mode 1. Mode 2 is position hold with GPS assist and Mode 3 return to base.  I haven't gotten far enough for mode 2 or 3.  :)

I haven't touched the trims. 

The behavior is for it to just tip over as soon as it starts to spin up the motors. It did this heading north and flipped it heading south.  Both times it tipped left so I am sure that it is something in the setup.

I am surprised to hear about the long time to GPS fix.


Re: Setting up for first flight.
« Reply #13 on: May 11, 2019, 07:33:25 am »
The tilt is just a few degrees, not a lot but enough.  It was in Atti, Atti, Axislock, manual flight mode 1. Mode 2 is position hold with GPS assist and Mode 3 return to base.  I haven't gotten far enough for mode 2 or 3.  :)

I haven't touched the trims. 

The behavior is for it to just tip over as soon as it starts to spin up the motors. It did this heading north and flipped it heading south.  Both times it tipped left so I am sure that it is something in the setup.
I asked because this should be it's angle when it flew left into the bush.  We can fix that angle and make it zero.  Did you read the "first take off" post?  There are several things that may help you like "Stabilization->ZeroTheIntegral must be enabled" and don't touch anything but the throttle, etc.

I am surprised to hear about the long time to GPS fix.
The initial GPS fix often happens within a minute or two.  The 12 minutes is the time required to download the almanac so it knows what to listen for in case it missed a sat when simply scanning for them.  This gives the best lock, and also minimizes the small but annoying GPS jumps you get when adding or removing a sat.

Quote
About what bank angle do you think it was when it was going left?
Do you think this matches the tilt you see in the GCS?

Do those recalibrations and see if the GCS looks more level.  If so, try flying again.  There is a procedure to trim out the remaining Attitude mode drift and get it as small as possible.

Re: Setting up for first flight.
« Reply #14 on: May 14, 2019, 05:28:21 pm »
I did read the first take off post but in fact missed the zero the integral part.  I will re-read diligently!  I have triple checked the motors and prop orientation but I will check again.

GPS is fixing in a minute or two with 12 or 13 satellites.  The tilt of the drone doesn't appear to match the GCS tilt however I went back and look at the video in the Wiki and followed what he did exactly and it is much better.

Last night I tried again and jumped the drone up off of the ground. Unfortunately it jumped about 30 feet up and again went straight side ways, fast!. Fortunately it ran into a  tree before I cut the throttle (I tried to bring it down in controlled fashion).  The tree cushioned the fall no damage.

My wife and neighbors think I am an idiot but I won't give up!!!