M200 flying off way off track on mapping mission

Today I was flying my M200 V1 for a couple of missions that I normally use the P4P on (thought it was about to rain). On the first mission I flew off track multiple times but only when flying south. I stopped it and had to refly with my P4P.

So I did another test at another site and the same thing happened only this time it only veared off when flying Northwest. I thought I grabbed a screen shot on the first mission but did not. I have a screenshot on the second mission. I did a compass calibration after the first occurance. There were NO error messages or warnings. Apparently the M200 series had compass problems several years back but that involved warning messages.

When I initiated Go HOME it came straight home and did not waiver at all. I have no idea if this is a compass issue, firmware issue, or some other issue. The M200 the latest firmware as do the batteries.

Any help will be appreciated.

How did the P4P perform? I think there is an issue going on with the compass and or the DroneDeploy heading.

@timmyd Hi Tim, thanks for sharing this. If you are on a premium subscription of DroneDeploy I recommend messaging into Support for more customized help. The team would love to take a look for you. Cheers.

The P4P was flawless. I just flew a small mission using DD and Pix and both were fine. I am headed out to do another construction site so I will test the M200 there using both and see if any errors occur and if so is it in both or just one app. I will keep you posted.


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Michael, this is the first flight with M200. I would lean towards this being an app issue because it does not seem that a compass failure would only be in one flight direction ??

Second image is flight with P4P.

Hi Andrew, I used to have a premium subscription but I now just have the free version.

So it looks like a little bit of the difference is the overlap in comparison to the processing area. The M200 left side is a little short or the rotation has caused it to have a shorter leg. As for the straying off path that is another issue entirely. I have been having a lot of trouble with my P4P flying at a skew which tells me that there is a heading or compass issue. I don’t think it’s the compass on the drone because it does not happen in any other flight software. You can see the thread about that. If it is related it may affect the M200 differently.

I went out and flew a rectangular mapping mission over the construction site that I was doing. there was no deviation whatsoever with the m200 today. it makes no sense whatsoever.

on the phantom 4 Pro I have posted in the past and had multiple problems where the drone is flying a straight line but the camera angle is not perpendicular to the flight path. it is almost as if the drone itself is rotated slightly as it is flying. I can go back and try to find the posts but the bottom line is I never got an answer. but the drone would be rotated opposite directions depending on which way it was going, so it does in fact cause some overlap problems when you’re processing your maps. but I finally gave up and just realized I will have to deal with it.

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one thing I never did, was take a phantom 4 Pro and fly it down a perfectly straight roadway down the center line for reference. then fly another drone over the top of it so that you can try and determine if the phantom 4 Pro is perpendicular to the line it’s flying and it is the camera gimbal that is slightly off angled in the yaw axis or if the drone itself is actually turned at an angle even though it is flying a straight path as dictated in the autonomous app being used.

Here’s my post. You would be the third person that I’ve heard of that is had this issue and I with the type of sites that I fly flight lines are definitely parallel with straight objects and it is easily visible as to what is happening. We have not gotten any feedback either. @Andrew_Fraser

Drone Heading Alignment

Here is my post from Feb 2019 with the same problem. This was on the DJI forum.

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Exactly. Not necessarily drifting, as would be consistent with poor GNSS, but incorrect yaw that would point towards the compass. Like I said before since it doesn’t happen in other programs I feel that it has to be something with the calculation of the heading. I am not for certain, but I feel that this may be happening in manual flight as well.

As for the drifting and the behaviour you experienced with the M200, it almost feels like a GNSS issue. Do you keep any logs of satellite status? It would be interesting to know what satellites there were and what their SnR values were at the time.

on the m200 issue, I don’t have a way to look at the GNSS log data. The m200 just has a built-in GPS antenna like the phantom 4. so there’s no way to really look at log data like we would on an external GPS receiver. I will just continue to watch it, and if I go back to the same location and fly again in the same thing happens, there has to be something at that specific site that could be causing extreme interference. so I will know as I do more test.

I went back in red my post of 2019 and its entirety. You had even posted at the end of that :slight_smile: what I think is causing the yawing is that the autonomous software is correcting the flight path by using a yaw command instead of a left and right r udder command which would be equivalent to the right stick on the controller. if the autonomous software is using a yaw function to keep the drone on the path, then it will cause it to yaw in the flight path and therefore the images are rotated just like you and I both have indicated in our previous post.

if the wind is blowing the drone off path, then the same problem can happen if the flight software is using yaw functionality to keep it on path. it would be very interesting to find out from a programmer within drone deploy how the actual flight path is maintained when there are external forces.

But it is very possible that this problem originates inside of the DJI SDK and therefore lies within DJI and not the various autonomous softwares. The post that I did it described how it was occurring in litchi so I do not think that it is restricted to just one particular autonomous flight app like drone deploy.

I would look for a good mobile GNSS tracking app and keep a screenshot for record of each flight, not the drone’s logs themselves. Examples like Skyview for iOS or Precise GPS for Android.

The issue I am seeing now only started occurring as of about 3 versions ago so I am trying to push a little further to see what the global view is. I have had any updates to any of our P4’s so I don’t think the DJI SDK is to blame unless it is something that DroneDeploy changed and can blame it on such.

And to take that one step further, if you have a fixed wing UAV that you have a camera mounted to, with a strong crosswind, the plane will half to yaw in order to stay on the flight path. And therefore angled images to the flight path should occur. but with any type of multi-rotor, instead of using a yaw functionality to stay on path it’s simply should use what I call left and right rudder (right stick on controller) to maintain the flight path and the heading should never change. but I suspect that is not the case.

now I understand where you’re coming from with the apps. I do have some apps for showing the GPS locations at any specific time. That is certainly a good idea to screenshot that and have a record for the flights. The only thing that doesn’t make sense is that the m200 had issues, then I flew the phantom 4 Pro within minutes with no issues so the satellites would have had very little movement and change. I have used the m200 for mapping before, and had nothing like this ever occur.

hopefully you can get to the bottom of the P4P yaw issue. I have also submitted a ticket to DJI on my m200 issue. so I will certainly report back if I ever get to the bottom of that

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If it was literally just a couple of minutes then yeah that doesn’t make sense, but I have seen shift in constellations in a matter of 30 minutes that made data go bad. The app that I am talking about is more related to the sky plot of where the satellites are, which ones they are and what the signal-to-noise ratios are. Is the M200 RTK or standard?

it is just standard and it is also the version one. so unfortunately I cannot even add The external GPS antenna. I’m going to do more mapping missions with it to see if the same situation ever occurs, then I’m going to go back over to where the problem occur red and see if it happens again.

I will also be sure to check the satellites and get the information you have recommended.