Compass Error Observations

[Drone_Video]

I have been messing with this TH Real Sense for the last few hours and have the following observations, and wondering if anyone else that has these brutal compass errors has noticed any of these things....

GREEN HOME DIRECTION ARROW:
When I power on the motors, before take off the home indication is pointed the wrong way, not back to where I am standing with the controller.

HOME ARROW POINTS BACK to CHINA:
The Home indication when I power on points back to the city of origin/build. While I can't perfectly test this, the arrow for sure is not pointed back to the true home position. I mapped out on google the direction the arrow was pointing and I had Telem data from my first drone from when they powered it on at the factory. The home arrow points the shortest route back to China and almost perfectly matches to the built factory where the GPS was first powered on. (based on eye balling the home location indicator and plotting it on google, so yes crude, but I had the time to imagine this as I could not fly it).

GPS LOCATION DATA:
Once a Compass error starts, the GPS satalights for the drone show 20, but the coordinates go to NA for both X & Y - however, if you turn off the GPS, the X, Y position appears again, but GPS off is displayed. tested this over 10 times and worked exactly the same way.

HOME LOCATION 180 DEGREES WRONG:
My first crash had the home arrow pointing what I thought was the opposite of where I was standing when it crashed, about 180 degrees away from my true home location. This 3rd copter seems to be doing the same thing, but the line goes all the way back to the factory in china

each time I was testing this, the home location was in fact about 180 degrees away from from me. Do you think its possible that the Compass sensor is installed incorrect or the software is written with a 180 degrees shift?

FLIGHT TRACKER ON PAD LOADS CHINA LOCATION
For those of us that used the Mapping Software that came with the ST16, it seemed to default to loading in China when you played back the Telem data also, not sure if thats related, but its suspect considering the other things I have noted as possible above

SOFTWARE NOT RECORDING STARTUP LOCATION CORRECT:
is it possible the software is somehow recalling the original startup location and it fails to update its home location on power on at its new home causing the Sensors to not match what its reading and then trigger this error?

BORDER SECURITY EFFECTS
The other thing to occurred to me that i could use some options on is if it could be possible that the process in which customs clears packages causes the sensors to fail. For example, are they using X-ray or something else that causes the sensors in these to fail? Maybe the security clearance procedure can effect this machine?

GRASPING AT STRAWS
I could be grasping at straws here, but its all I got left.... I want this machine to work. I got my RMA number today, and a the supplier offered a full credit for a new new drone if I want it (have to make a decision early next week)... I was really hoping to find a solution this problem. I can not imagine that this problem can not be solved...

Open to ideas

 

[Steak frites]

Are you sure you are interpreting the green arrow correctly ? It doesn't always point at the ST16. It depends on the orientation of the craft. If you are taking off with the head of the H facing you (ok, unusual ), the arrow will point up, away from you. I don't mean to be condescending, just making sure.

 

[Drone_Video]

Are you sure you are interpreting the green arrow correctly ? It doesn't always point at the ST16. It depends on the orientation of the craft. If you are taking off with the head of the H facing you (ok, unusual ), the arrow will point up, away from you. I don't mean to be condescending, just making sure.

Thats a fair question... What I saw for sure was the head of the craft and the green arrow NOT telling the same story. I would be be behind the craft and the nose of it was pointing mostly away from where I was standing. and the return to home indicator arrow was pointing in some non related direction, like 90 degree's away or 180.

The first time I saw this, the TH was flying the same direction as the arrow was indicting was home, but it was 180'ish degrees away from the true home. this was un controlled flight and there was a crash involved in that one.

I just looked at the video I recorded. There is a few spot where I am clearly being the craft, and and nose pointed away from me, and the arrow is pointed in sorta the same direction as the nose of the craft. basically, its pointing the opposite direction of where Im standing. In some parts of the same video, the home arrow points 90 degrees the wrong way and other parts is like 135 and at other spots its 180.

I'm truly surprised by this - maybe there is another explanation for why it does this.. but its for sure not doing what I think it is expected it to.... I will see if I can grab a few frame grabs from the video to show this condition.

I know why your asking me this question, as its easy to mix up the indicator and how it works. But I am 100% certain I understand the feature, and I have documented video that'll show this the way I explained it.

 

[gwhuntoon]

Thats a fair question... What I saw for sure was the head of the craft and the green arrow NOT telling the same story. I would be be behind the craft and the nose of it was pointing mostly away from where I was standing. and the return to home indicator arrow was pointing in some non related direction, like 90 degree's away or 180.

The first time I saw this, the TH was flying the same direction as the arrow was indicting was home, but it was 180'ish degrees away from the true home. this was un controlled flight and there was a crash involved in that one.

I just looked at the video I recorded. There is a few spot where I am clearly being the craft, and and nose pointed away from me, and the arrow is pointed in sorta the same direction as the nose of the craft. basically, its pointing the opposite direction of where Im standing. In some parts of the same video, the home arrow points 90 degrees the wrong way and other parts is like 135 and at other spots its 180.

I'm truly surprised by this - maybe there is another explanation for why it does this.. but its for sure not doing what I think it is expected it to.... I will see if I can grab a few frame grabs from the video to show this condition.

I know why your asking me this question, as its easy to mix up the indicator and how it works. But I am 100% certain I understand the feature, and I have documented video that'll show this the way I explained it.

That would make me wonder but I would bet the compass module only goes in one way. I know others have said facing north doesn't matter when doing a compass calibration but all of the documentation I've seen says otherwise. On my Cheerson CX 20, I had to face north and hold the drone horizontal when starting calibration. Being around buildings, structures, or power lines when doing this is also problematic.

Regarding GPS, HDOP (GPS quality) must be 2.0 or better. Unfortunately on the ST16 you can't tell. Just because you get a get GPS 3D-Lock (7 or more satellites) doesn't mean HDOP is good enough to know your home position is so by default, home is assumed to be the mfg facility in China. I suspect in this instance when RTH is activated in smart mode, some of the H's seem to fly away because they are attempting to return to China. Usually the first flight of day will take the longest (due to the gps-almanac being updated). Knowing this, I've just been really patient when starting up even when I have what seems to be a good GPS lock. I wait so I feel confident the GPS also has a good fix and knows where home is (not China). If you are impatient, and I think most of us are, make sure to start in angle mode (which you should anyway) and fly around for at least 5 minutes before attempting to use smart mode, hopefully the gps-almanac will update in flight. I also feel that HDOP isn't the same everywhere. Some locations may take 5-10 minutes, others 1-2 minutes, then again still others may never get a good fix.

From the Wiki on GPS Almanac -
The almanac consists of coarse orbit and status information for each satellite in the constellation, an ionospheric model, and information to relate GPS derived time to Coordinated Universal Time (UTC). Each frame contains a part of the almanac (in subframes 4 and 5) and the complete almanac is transmitted by each satellite in 25 frames total (requiring 12.5 minutes). The almanac serves several purposes. The first is to assist in the acquisition of satellites at power-up by allowing the receiver to generate a list of visible satellites based on stored position and time, while an ephemeris from each satellite is needed to compute position fixes using that satellite. In older hardware, lack of an almanac in a new receiver would cause long delays before providing a valid position, because the search for each satellite was a slow process. Advances in hardware have made the acquisition process much faster, so not having an almanac is no longer an issue. NOTE: I think this last sentence applys more to a handheld or vehicle GPS. I believe the receivers in prosumer drones still need it to some degree especially when the mfgs are trying to cut costs.

 

[gwhuntoon]

I also just found out that if you have a Windows notebook in the field running the Typhoon H GUI, you could plug in the USB to see the compass settings and GPS Information in real time, including HDOP before you fly.

 

[Tuna]

For the green arrow to work, both the H *and* the ST-16 need to have accurate GPS lock, the H needs to have correct compass information and the ST-16 needs to be a reasonable distance away from the H (5 meters or more should probably do it). If you're standing near or under the H, then the green arrow will struggle. If the green arrow is pointing at some fixed location that *isn't* the ST-16, then the problem lies in the controller's GPS lock.

When you're flying, are you finding the arrow is 'stable but wrong' - i.e. consistently pointing at the wrong location for long periods of time, or 'inconsistent' - i.e. jumping around and pointing all over the place? The first would suggest the ST-16 is having problems sending it's location, the second would suggest the compass is sending incorrect information.

On my list of features is a 'controller location' marker on the map, so you can see in Flight Center where you were standing relative to the H (and things like error reports). There are unfortunately not enough hours in the day at the moment!

 

[Drone_Video]

I have been playing with the home location thing, and for me its more than 15 meters away and it starts to point the right direction.
I managed to get this thing in the air today for one battery. Th tony thing I did different was I borrowed a controller from someone in town and connected it. It worked just as poor as when I was using mine, but I did the calibrations with it anyway.

After those completed it still had compass warnings and the camera gamble was not coming back more than 50% to the forward looking position. I switched back to my controller and the issue persisted. I went into the ST16 calibrations menu (tapping the about controller a bunch of times) and that process allowed the gamble to flow full path of travel.

Before I did the gamble calibrations thats when I managed to fly one battery. it wasn't smooth, it was jittery and very touchy/grabby when making movements forward/back/up/down. This was the case even in turtle mode.

an in place rotation (left stick) caused it rotate, but it would increase the size of the rotation and it would not remain in place, it would grow the circle of rotation of that makes sense.

It would drift very slight to the right and stop with stick input. It would drift forward, and same thing stop with stick input. It would also climb in height on its own, but stick inout never made that stop, I would bring it down, and then it would go back up. Maybe the calibration of the ST16 ill solve that, I have to check that still.

Take off was smooth but abrupt at the start, landing was smooth in terms of no bounce or anything like that.

I did notice that the if you let go of the left sticks after it lands the bounce back however small will cause the motors to spin up and start flying on mine. I had to make sure I gentle let go of the sticks when it was in the zero position and not wiggle it at all or it would start to power up on me. Again, maybe the calibration for the ST16 resolves it.. I will find out shortly when I try to get a second battery of flight.

based on the feedback from gwhuntoon I let the TH and control sit powered on outside for 20 min before starting the flight today. My brother is a **** pilot and he said something similar about the GPS lock, but that it would take 5 min or so on average. Not sure if this helped but certainly didn't hurt to try.

Getting in the air, even with these quirks is better than the last few days.. so I will keep at it...

 

[Drone_Video]

I Went out to fly the next battery and compass errors returned.
I tried restarts and calibrations etc. still kept getting compass errors.

I then swapped out to my next battery, and there was no compass errors and it started to fly again.
I didn't change locations or any other variable on that test.

The driving was still there, but with more courage I went to about 50/60 feet in the air.
The Altitude on the controller seems to be random;y out by 2-3 meters
The TH hovered more stable.
Returning to the lower height, the hover started to drift again. Maybe its the IPS system?

The rotation left or right using the left stick stills wonders at any height

Landing gear up down I have been testing each time I get in the air, no interference to report

I turned on OA/Real Sense and it was working, no odd movements or anything, seems to be REALLY sensitive however and would not let me fly to stuff that was a good 20 feet away, but that doesn't even make it to my list of troubling shooting yet.

I made more erratic movements with it, and more multiple changes and it flew, new errors on the compass or lost GPS.

I had to stop because the controller battery was too low.

At this point, I'm marking the battery's used and if a compass error appears ay the same time or it flies good with that battery. I have 4 batteries and am I going to borrow someones for a few days so make it 6 to test with.

 

[Drone_Video]

Well, the battery thing is a dead end. I flew it again and the same battery with the compass error didn't generate a single compass error;

I did have a moment where it just about flew away on me again. It started to climb at full speed and when i checked the controller it said the altitude was -16.8 meters. I held the left stick down all the way and it crawled close enough to ground for me to cut the motor power. I tried once to back off and let the left stick at zero, but it started to climb at full speed the second I did that so I landed it.

I'm done testing it. In conversations with Yuneec they are going to send me a new Compass/Gps/Barometer board. They offered to me to send them the unit and they would replace it, but I opted t swap it myself. I'm not going to test this anymore this was too much of a close call and I don't want to take any more chances.

The good news is this is progress, its getting off the ground now, compass errors are mostly gone at this point. if its just this one faulty part and it works fine after this I'll be happy again and can keep this TH....

 

[Drone_Video]

not that it matters, but still messing with this thing.
I have noticed that tapping up the air vents makes the altitude more stable, and it doesn't climb/sink at all.
NO PROGRESS whats so ever so far. Waiting for a new compass/gps board next week to swap it out.

 

[ArnhemAnt]

I have noticed that tapping up the air vents makes the altitude more stable, and it doesn't climb/sink at all.

Sounds like a barometer issue. These guys (Baro) are sensitive to light and air - by taping the vents, you are helping to eliminate this.

Haven't noticed this with my H.

 

[Photo]

Sounds like a barometer issue. These guys (Baro) are sensitive to light and air - by taping the vents, you are helping to eliminate this.

Haven't noticed this with my H.

Hi! What does "by taping the vents" mean??

 

[ArnhemAnt]

Hi! What does "by taping the vents" mean??

Putting tape, or covering up, the vents/holes/spacers in the frame that can let air or light into the flight controller.

The other way to get around this is to cover the baro with some soft foam - done this before...

 

[Graham]

There is something very odd about the start up location. I had noticed that when loading telemetry files into Helmut Elsner's programme that the distance graph didn't make sense. It seems to be showing the distance to home point to be 14 000 000m. The diameter of the Earth is 12 742 000m appx. The x axis doesn't make sense either. It should be showing time of day. I have no idea what this means, but distance graphs from before the recent update did make sense.
Also, GPS on, I haven't seen a relationship between compass errors and number of satellites.
D_V, I hadn't noticed your Green Arrow observations and nothing has come to me in a Flash.

 

[Drone_Video]

I don't have any other ideas right now to try. And there is next to nothing for real deep trouble shooting for this product.

My guy says there is an error in software on how to creates persistent data and how the system manages changes in data points. There is no software code that says if my altitude is 2.4 meters and suddenly changes to -17 meters that maybe that's not real. That if the drone accelerometer shows no moment but the gps speed goes from 0.1 km/h to 10km/h within the .25 seconds or 4 times per second update rate that this machine has got gps and then back down to near zero to ignore that data.

Basically it's hard to trust this machine.

And Yuneec constant everything is fine there is only 5 people with issues storey is getting really old.

I'm exhausted with this situation.

 

[glider]

One must distinguish been GPS "lock" and and the GPS attaining an accurate position estimate; they are two totally different things. This has been addressed multiple times concerning Pixhawk powered copters. In fact, IIRC is now part of the pre-flight checks.

Many complain about waiting 2-3 minutes before takeoff. I always wait 5+ minutes after the controller says "Ready". The same for any other copter I have.

It's becoming clear, at least in my view, the H's code is nowhere near as sophisticated as Arducopter which is constantly comparing all sensor data, then uses EKF (Extended Kalman Filter) and reports in real time the health of the FC system.

OTOH, I've yet to experience any flight issues with my H related to GPS/compass/barometer and flies exceptionally well. Call it luck, and I'll knock on wood.

 

[Drone_Video]

Glider
I understand what you mean - about the GPS Lock and accurate position. in my trouble shooting steps I have left the TH in the open, powered on for 15 min + and the same bouncing of speed and altitude is reflected at what appears to be a 4/second refresh rate of this hardware. The GPS coordinates themselves actually don't change. So the software is written to update the GPS X,Y slower (once every second) and thus one can not see the location information change as that appears to change to some far out number for one of the 4 reads per second.

The code running on these machines may in fact be flawed or the sensors send it data that the software doesn't know how to handle because they are broken sensors. It appears that there is no safety check on the data to see if its within "expect" ranges based on other factors. such as motors off, accelerometer shows no moment and Compass shows no variation - why would altitude and g-speed change? Not saying I have the formula worked out... but there is something funny about the way this software makes decisions.

In my mind, its poorly written, not self checking code possible combined with hardware variances that are out of spec from damage in shipping or possible the inspection process of moving it across boarders. The x-rays or what ever they are using to scan packages damaging the sensor of this equipment is also possible.

I plan to take a very close look at the existing GPS board in the TH I have, compared to the one they sending me to see if I can spot a difference. The other thing at play may be that shipping a whole unit with a LIPO battery gets a whole lot of extra attention with the X-ray machines (or what ever they use) but sending the GPS/Compass module in small paper envelope doesn't get it scanned and thus doesn't damage the sensors.

I literally am making up stuff right now with some 'logic' applied within my limited scope of the actual hardware function and design.

It is clear to me with so many new units shipped to me, using the same shipping company, and the same route into Canada (via Vancouver) which is one of the busiest in the country and the highest for smuggling - that the procedures for checking for illegal activities may be elevated compared to other shipping routes - that I may be suffering from issues related to that process against a hardware version that doesn't like being attacked by prolonged X-ray exposure and damages the sensors. I will be the first to admit that my battle seems to be the same every time I get a a new one from them. The last one said "flys great, enjoy!) and yet the compass error / GPS errors all start showing up within minutes.

At the end of the day if it turns out to be an issue with security procedures crossing boarders for example, I don't think anyone is taking these machines traveling with them because they might fall out of the sky when you start them up on the other side of the security screening. There is not enough people available to collect any data points right now with the tools we have (this forum) - this has to be done at the manufacture layer and they need to use post failure engineering teams to look at this gear and see whats common to them all.

I work for a very large technology company, and we have a team of people that do nothing all day but look at broken parts and see why they fail. We then use that to test new products for same conditions before they get integrated into new build products, and that team also changes manufacture process to avoid the same condition that caused the failed part. I admit we are a massive (50 billion plus) company and can afford to do that - but Yuneec needs to figure this out as reputation of not only their brand but for the hobby and the people who depend on drones for camera work etc are in fact (long term) at stake.

if the public starts to see these falling out of the sky and crashing all over the place there will be more resistance to them or more controls. It is very bad that there is a significant number of these that are doing this. It is like the early days of powered flight, yes - but we have the ability to build these better. I feel Yuneec is treating this machines like toys.

They need to get series about the problems. There is a real chance that a 'fly away' will in fact hit a person. I saw first hand with the one I had - the speed at which it takes off on its own, and the impact force of the carbon fiber motor arm splitting into a sharp tube and wedging into dry solid dirt almost 6 inches.

These issues need to be understood and correct - not just for us owners, but for the public. I would be very surprised if anyone reading this forum, even with no current issues, doesn't in the back of there mind have a concern about the air worthiness of this product right now. It might not be everyone, but there is something under all this smoke we are seeing.

 

[dinglehead]

Where are you getting this idea that x-ray scanning is damaging the magnetometer or GPS board?

 

[Drone_Video]

Where are you getting this idea that x-ray scanning is damaging the magnetometer or GPS board?

I said it here "I am literally making up stuff right now with some 'logic' applied within my limited scope of the actual hardware function and design."

It is largely a fishing expedition as stated at the start of my position -

The following link and what it contains is what caused me to position the question and shaped my interested in knowing if it does in fact have an effect on the compass/gps for example....

Cargo scanning - Wikipedia, the free encyclopedia

I can't find anything that says these methods used are in fact for sure capable of doing damage or not in some or any cases.

It really is a fishing expedition - I'm sure someone knows.

I suspect the ones they use are the airport are no where near as powerful as the ones used for shipping containers that can penetrate 18cm of steel!

 

[Graham]

I had no issues before the recent update, but since then there has been a rash of issues reported here. The problem lies with the firmware.