Yaw errors, might this be a solution?

[Droning on and on...]

People share grainy indistinguishable photos of some black blob as "proof" of the existence of Sasquatch, or that aliens landed a flying saucer in their backyard. They may even in all sincerity believe it to be true.

Seriously man, it's stuff like this that just completely turns me away from spending time on this. Really?

If that's the degree of respect you have for other's claims, I simply don't have the patience to explain in detail how and why video posted by fellow members from their crashes isn't on par with alien flying saucer pictures.

Your assumption that, when I refer to another pilot's video I must also prove its not, "grainy indistinguishable photos of some black blob" is, for me, unreasonable.

We're not talking about an extraordinary claim about extraterrestrials. It's ridiculous to apply such a standard. Your proof requirements just to discuss this make me not want to.

 

[Droning on and on...]

In this day and age when everyone carries a cellphone equipped with a powerful camera, why has nobody ever captured a convincing definitive clear photo?

Not sure what you're saying here. The video, from the drone, has been posted. I've seen it. Are you saying I'm lying?

It was years ago. I spent a few minutes in search trying to find it and couldn't. Given how this exchange is unfolding, I'm not inclined to spend any more time searching.

I can accept your disbelief. If you insist it didn't happen because you didn't see it only you will miss out on the knowledge and understanding that then comes from examining the failure.

 

[Zbip57]

Seriously man, [...] If that's the degree of respect you have for other's claims, [...] Are you saying I'm lying? [...]
I can accept your disbelief. If you insist it didn't happen because you didn't see it only you will miss out on the knowledge and understanding that then comes from examining the failure.

Deep breath. Relax. Sasquatch and alien landings were merely an example. I put them on par with some people's belief that the moon landings never occurred and that the Earth is flat. There are people who passionately and sincerely believe these things to be true and will post all sorts of "evidence" trying to back up their beliefs. Whatever floats your boat...

There are things that I can accept on faith, even though I cannot actually prove for myself whether they're true. I'll never be a nuclear physicist or brain surgeon, but I trust there actually are people who understand those things and are qualified in those fields.

I'm merely questioning your statements about the behaviour of VPS.

This problem has been around since the beginning of VPS, and has resulted in loss of control and crashes. What's more because the drone is moving but the FC thinks it's holding a stationary position, people have reported wild, paradoxical response to control input, making it difficult to regain control.

It's reported by people who have experienced this error. By "loss of control" what is meant is drone is drifting forward following that leaf in the stream, the pilot pulls the stick back to try to stop the forward movement – the correct control input – and the drone goes full-throttle sideways, slamming into the shore.

Response unexpected and completely at odds with the control input. I consider this "out of control", response "paradoxical" to the control input, and I suspect many others see such control/response behavior this way too.

I posted a video example of my own where my Phantom responded in a completely unexpected manner that was at odds with my control input. I pulled the stick back, but the drone instead went further away from me. At that moment I too considered this response paradoxical and out of control. It was only much later, with the help of others, that we diagnosed what had actually occurred. The explanation made perfect sense. The drone was never "out of control", it responded exactly as it's programmed to do. It was my own mistake for not understanding that Home-lock doesn't work while Atti-mode is selected.

If you insist it didn't happen because you didn't see it only you will miss out on the knowledge and understanding that then comes from examining the failure.

But that's exactly my point. I am interested in learning and understanding the results that come from examining a failure. But you haven't offered any reasonable explanation for blaming it on the VPS. You merely claim that other people have "reported" pulling back on the control stick, whereupon the drone flew "full-throttle sideways, slamming into the shore."

If such a thing is possible under certain defined conditions (and verified with log files), then the response should be reliably reproducible whenever the same control inputs are repeated under equal conditions. That would certainly help our knowledge and understanding on how to avoid or resolve such a confusing response should we ever find ourselves in a similar situation.

But, you "simply don't have the patience to explain in detail how and why..." and you are "not inclined to spend any more time". That's the equivalent of claiming you have irrefutable proof the Earth is flat, but haven't the time or patience to explain a logical theory or produce an actual proof.

 

[Droning on and on...]

But that's exactly my point. I am interested in learning and understanding the results that come from examining a failure. But you haven't offered any reasonable explanation for blaming it on the VPS. You merely claim that other people have "reported" pulling back on the control stick, whereupon the drone flew "full-throttle sideways, slamming into the shore."

This is very frustrating.

I have done far more than "merely claim that other people have 'reported' pulling back on the control stick". I provided a detailed, lengthy explanation of the operation of the Flight Controller, and how it's function resulted in the reported behavior.

You completely ignored it.

Honestly, if you sincerely desire a dialog about this and are open-minded about learning, then engage, ask meaningful questions, and I will too.

If the only thing that has any validity to you is logs, then we're done... I don't have them.

Ignoring detailed explanations of exactly what we're trying to understand is not engaging in discussion. My answers to your questions have been met with dismissive responses like, "you haven't offered any reasonable explanation".

Got it. You find my detailed discussion of how the FC behaved the way it did with bad VPS data to be "unreasonable".

So what's the point in spending the time and effort to explain my understanding of this? Even more, since in your view I'm unreasonable and peddling the equivalent of alien hysteria, why are you bothering?

You can have the last word. This discussion has ceased being of any value to me, and I strongly suspect pretty much everyone else.

 

[Zbip57]

I provided a detailed, lengthy explanation of the operation of the Flight Controller, and how its function resulted in the reported behavior.

You explained that the flight controller adjusts for a crosswind, tailwind, or headwind to hold a steady course direction, and how it limits the drone's groundspeed. You did not explain how pulling back on the control stick resulted in the drone flying "full-throttle sideways, slamming into the shore."

You completely ignored it.

I certainly did not ignore it. Please re-read my response to your explanation in post #38 in which I asked for clarification specifically about your Flight Controller explanations.

In particular, how is the drone measuring groundspeed? If it is using the VPS, then the apparent groundspeed would be zero while the drone maintains a constant fixed position over the drifting leaf. Or, if GPS is being used, the drone would be measuring some finite groundspeed while following the motion of the drifting leaf.

In either scenario, I asked how pulling back on the control stick would ever result in the flight controller paradoxically shooting the drone at "full-throttle sideways, slamming into the shore"?

By what logic does the discrepancy between the zero groundspeed seen by the VPS, versus some measured groundspeed determined by change in GPS location, cause the drone to fly sideways at full-throttle instead of rearward as commanded by the control stick input?

Honestly, if you sincerely desire a dialog about this and are open-minded about learning, then engage, ask meaningful questions, and I will too.

I did ask questions (as repeated above), to which your repeated response has been that you don't have the patience and can't be bothered to come up with further explanations.

My answers to your questions have been met with dismissive responses like, "you haven't offered any reasonable explanation".

I think I also used the word, "irrelevant". How does the Flight Controller, when trying to hold a straight course line automatically compensating for crosswinds, or by imposing a maximum limit on groundspeed, result in the drone shooting off sideways when commanded to go rearward?

Honestly, if you sincerely desire a dialog about this and are open-minded about learning, then engage, ask meaningful questions, and I will too.

Begin by answering my meaningful questions.

I'll even give another video example illustrating how my old P1 Phantom actually could produce an unexpected "wild, paradoxical response to control input". After my alarming experience with the near runaway of my Phantom, I did a bunch of tests to better familiarize myself with the differences in behaviour of Home-Lock versus Course-Lock. There were some surprising quirks.

In this example, pulling back on the stick in Home-Lock would bring the drone back toward me exactly as expected, but only until reaching a point 10m from the recorded Home Point. At that point, even though I continued to hold the stick in the exact same rearward position, the Phantom would suddenly and paradoxically change course and shoot 90° sideways off to the left. This sounds a lot like the scenario you described.

The reason for this was the Phantom cannot operate in Home-Lock mode any closer than 10m from the Home Point. Within 10m, even if Home-Lock was selected, the drone would automatically switch itself to Course-Lock mode.

If you'd never read that section of the User Manual, you'd be in for a big surprise if you ever encountered this scenario during flight. You might even be tempted to call it a sudden "loss of control". But even if it looks confusing, the drone was reacting predictably and exactly as programmed, and as documented in the User Manual.

Here I show how Course-Lock works, then Home-Lock, and at 9:30 I demonstrate how it switches itself between modes upon encountering the 10m range limit. I encouraged people to repeat this experiment for themselves using their own P1 Phantom, to verify that this will happen every time in exactly the same manner, because that is how the drone is programmed to behave.

It's only a "loss of control" or paradoxical behaviour if you weren't expecting it to behave this way. But it's still pilot error if you haven't read the manual and weren't aware that this is how it's programmed to respond under these circumstances.