Flight time and efficiency

[daved20319]

Wow, Pat, if there was an awesome answer of the year award, that one would win it! Yes, the Pixhawk is an Arduino based FC, good call. And yes, I did see a calibration table, as well as a discussion of offsets from absolute zero reference. So I have a better understanding of why you and others are insisting the in-flight procedure is bogus.

So if Yuneec isn't the place to go for answers, what IS the correct procedure? It still feels like just parking it, turning it on, and telling it to do its thing is incomplete, maybe that's just a left over from my time spent building these things instead of going the RTF route. Later, and thanks!

Dave

 

[jandjfrench]

I'd like to apologize for possibly causing some confusion. In my initial post I said "calibrating the accelerometer". I should have said "the accelerometer calibration". I saw references in this thread to the original Typhoon H manual and the one for the Plus. I tried to locate these without success. I'd appreciate any help in finding these. There are various free hosting services to which they could be posted if links can't be found. I have a free account at Box and have never experienced any problems with it so I'll recommend it.

 

[Mrgs1]

Wow, Pat, if there was an awesome answer of the year award, that one would win it! Yes, the Pixhawk is an Arduino based FC, good call. And yes, I did see a calibration table, as well as a discussion of offsets from absolute zero reference. So I have a better understanding of why you and others are insisting the in-flight procedure is bogus.

So if Yuneec isn't the place to go for answers, what IS the correct procedure? It still feels like just parking it, turning it on, and telling it to do its thing is incomplete, maybe that's just a left over from my time spent building these things instead of going the RTF route. Later, and thanks!

Dave

Have you heard of the Upair one quadcopter? That's a lesson in how not to use Pixhawk. Px4 board.

 

[Eagle's Eye Video]

I'd like to apologize for possibly causing some confusion. In my initial post I said "calibrating the accelerometer". I should have said "the accelerometer calibration". I saw references in this thread to the original Typhoon H manual and the one for the Plus. I tried to locate these without success. I'd appreciate any help in finding these.

A recent addition to the resources of this board... in every model's "HowTo:" section, is a sticky thread titled "Documentation Library"... Contained in each of those threads is the OEM manual for that corresponding model, along with most recent firmware files.

 

[PatR]

I'd like to apologize for possibly causing some confusion. In my initial post I said "calibrating the accelerometer". I should have said "the accelerometer calibration". I saw references in this thread to the original Typhoon H manual and the one for the Plus. I tried to locate these without success. I'd appreciate any help in finding these. There are various free hosting services to which they could be posted if links can't be found. I have a free account at Box and have never experienced any problems with it so I'll recommend it.

V1.2 is the original H manual. V1.3 is the version that notes the hover calibration. Note the calibration process in V1.3 mentions failure to calibrate and needing to repeat the process.

Daved20319,

The original Typhoon H instructions, V1.2, have the calibration process on page 22. The later user manual document, V1.3, has them on page 21. Many of us obtained the H during the initial product release and still have the original document because of that.

 

[jandjfrench]

My thanks to Eagle's and Pat. That's nice to know about the manuals in the How to sections. It turns out that Google wasn't my friend.
I see that only the hover method is given in either H manual and no reference to Accelerometer calibration in the Plus manual. I'm guessing that they fixed the displaced CoG in the Plus.

 

[PatR]

Daved,

You brought up a good question about Pixhawk, Arduino, and H calibration differences. The H uses a version of restricted version of Pixhawk and logically should use the same calibration process.

Your question may have provided the cause of “toilet bowling” that has been experienced by some people. If the hover was used to calibrate the accelerometers the system may have been chasing a zero reference that didn’t, and could not exist.

If the calibration code had been revised to perform in a “conditional” format, something like “if x does this then y should do this, except when z does this then x, y should do this” there would be an enormous amount of error latitude built into the process.

Ideally, the aircraft should be rotated about its axis to establish zero refs. The problem with that is we don’t know how many or which axis Yuneec established in their system design.

Interestingly, there is no mention of an accelerometer calibration at all in H-920 manuals. Perhaps of greater interest is that a calibration process was provided for the Blade Chroma, made by Yuneec, marketed by Horizon Hobby, using most of the same flight control functions as the Typhoon H. The Chroma did use exactly the same flight control functions (and flight transmitter) as the Q-500 and Typhoon 4k. Horizon provided a video tutorial for calibrating the Chroma accelerometers.

Note the accelerometer calibration process is the same for the Q-500 and Typhoon 4K.

 

[PatR]

Perhaps the only thing we can depend on Yuneec for is "inconsistency".

 

[DCH]

Your question may have provided the cause of “toilet bowling” that has been experienced by some people. If the hover was used to calibrate the accelerometers the system may have been chasing a zero reference that didn’t, and could not exist.

A good thought, however we can rule out calibration -or miscalibration as the cause of TB. I never knew about the airborne method when I had issues with TB, I always calibrated it stationary. I chased TB as far as I could using two H480s by swapping components and narrowed it down to the main FC board. Both aircraft were fully calibrated (stationary) after each swap, and that is the only component that the TB Syndrome followed when swapped.

Inconsistency indeed! V1.2 doesn't even mention accelerometer calibration, or the hidden menu, and V1.3 tells you to take off and hover. I have no idea why Yuneec put this procedure in the manual, it's baffling. I still maintain an accelerometer must be calibrated with a zero reference. That can only found at rest.

As far as the camera causing an imbalance when lifted by the two side motor pods, this is minimal and the FC has no problem compensating for it using its zero reference from a stationary calibration. This is why we do not need/or have the trim functions. There are no reports of Typhoon H series drifting because of the camera position. I don't think this is something to be concerned with. There are too many other things involved with these systems to worry about, might be best to let this one go.

 

[daved20319]

V1.2 is the original H manual. V1.3 is the version that notes the hover calibration. Note the calibration process in V1.3 mentions failure to calibrate and needing to repeat the process.

Daved20319,

The original Typhoon H instructions, V1.2, have the calibration process on page 22. The later user manual document, V1.3, has them on page 21. Many of us obtained the H during the initial product release and still have the original document because of that.

I'm starting to think the manual version numbers are arbitrary, I just downloaded what's supposedly the current version, and it's listed as 1.2 and has the hover method. Still waiting on my bird, just hear from Fed Ex, they're now saying it'll be here tomorrow. Will do some experimenting when it arrives. Later.

Dave

 

[jandjfrench]

I got my H in flying condition, had the side prop arms rest on 2 open cabinet doors, which were the right spacing, and did the calibration. Now that I've hit on what is indisputably the world's best accelerometer calibration procedure I'm satisfied and never want to think about it again. Amen.

 

[TyphoonPete]

I would imagine it is only a few lines of code for the bird to "self-calibrate" on start-up.
Maybe that is relevant to the newer models
Also, surely it would need information as to current air movement at the place of flight, not in a draftless room.
I would have thought a baseline in a driftless room would be different to a baseline at a flying field where any number of different conditions come into play when starting up.
Altitude, temperature, wind, humidity all have an effect on how the bird flies.
Getting back to the beginning....given identical data, flying a bird high in the Rockies should have better flight time than on the beach in LA...No?????
Just thinking out loud
I'll go get another glass of red and be quiet now
cheers

 

[AH-1G]

I calibrated mine on my perfectly level table two years ago.
NEVER, NEVER any issues. Oh I didn't loose any sleep over it !

 

[Photo]

I would imagine it is only a few lines of code for the bird to "self-calibrate" on start-up.
Maybe that is relevant to the newer models
Also, surely it would need information as to current air movement at the place of flight, not in a draftless room.
I would have thought a baseline in a driftless room would be different to a baseline at a flying field where any number of different conditions come into play when starting up.
Altitude, temperature, wind, humidity all have an effect on how the bird flies.
Getting back to the beginning....given identical data, flying a bird high in the Rockies should have better flight time than on the beach in LA...No?????
Just thinking out loud
I'll go get another glass of red and be quiet now
cheers

TyphonnPete.. you wrote: "given identical data, flying a bird high in the Rockies should have better flight time than on the beach in LA." I think you´re very wrong. It will end up in shorter flight time as the props/motors have to fight much harder in thin air high in the Rockies.

 

[AH-1G]

TyphonnPete.. you wrote: "given identical data, flying a bird high in the Rockies should have better flight time than on the beach in LA." I think you´re very wrong. It will end up in shorter flight time as the props/motors have to fight much harder in thin air high in the Rockies.

You are correct @Photo.
I was stationed At Ft. Carson, Butts Army Airfield and also flew to Leadville.
You also have to take into consideration of "density altitude and high density altitude" no matter where you are
High altitude, thin margins - AOPA

 

[Eagle's Eye Video]

TyphonnPete.. you wrote: "given identical data, flying a bird high in the Rockies should have better flight time than on the beach in LA." I think you´re very wrong. It will end up in shorter flight time as the props/motors have to fight much harder in thin air high in the Rockies.

This has certainly been my experience, flying around 5000-5500 feet ASL, in New Mexico.

 

[DoomMeister]

I would imagine it is only a few lines of code for the bird to "self-calibrate" on start-up.
Maybe that is relevant to the newer models
Also, surely it would need information as to current air movement at the place of flight, not in a draftless room.
I would have thought a baseline in a driftless room would be different to a baseline at a flying field where any number of different conditions come into play when starting up.
Altitude, temperature, wind, humidity all have an effect on how the bird flies.
Getting back to the beginning....given identical data, flying a bird high in the Rockies should have better flight time than on the beach in LA...No?????
Just thinking out loud
I'll go get another glass of red and be quiet now
cheers

No!

The air is more rarified at altitude therefore less lift.

Just think of mountain climbers needing oxygen at higher altitudes or planes with unpressurized cabins needing oxygen masks when being flown at or above 14K feet.

 

[DCH]

Getting back to the beginning....given identical data, flying a bird high in the Rockies should have better flight time than on the beach in LA...No?????

In reality, the smog is so bad in LA, I'm guessing the drag on the aircraft in every direction, even decending, would be so great that you would actually get longer flight times in thin air of the Rockies!

 

[PatR]

You think it’s bad now you should have seen it in the late 50’s and 60’s[emoji33]

 

[DCH]

You think it’s bad now you should have seen it in the late 50’s and 60’s

I did! I lived that American Dream in the 50s & 60s, I know first hand what the smog was like, can NEVER forget!

FYI, I lived less than one mile from LAX when the 1st Boeing 707 landed and took off. Yes, people use to live -and go to school (Airport Junior High School) that close to LAX. All that is parking and industrial complexes now. We were the first generation who had to learn to get use to commercial jet noise, and also those annoying Friday "Air Raid Alerts". LOL, like hiding under your desk is going to afford protection from a nuclear blast! .