GPS Denied Navigation

ArduCopter
1

Have the settings for GPS disabled, optical flow enabled, and only EKF2 enabled.
What is it that I am doing wrong ? (Do I need to provide anything further to diagnose at a first look ?)

[ INFO] [1720206326.150276059, 1058.301000000]: FCU: Arming motors
[ERROR] [1720206330.840700293, 1059.152000000]: FCU: NavEKF2: lane switch 1
[ WARN] [1720206330.874996406, 1059.156000000]: FCU: EKF primary changed:1
[ERROR] [1720206331.315869511, 1059.252000000]: FCU: EKF variance
[ERROR] [1720206331.318061329, 1059.252000000]: FCU: EKF Failsafe: changed to LAND Mode
[ INFO] [1720206335.895639488, 1060.303000000]: FCU: Disarming motors

Thanks !
GPS_Denied_1.param (43.8 KB)

2

At a first quick look the EkF2 should be disabled and EKF3 enabled

2 Likes
3

Thanks @amilcarlucas !

I am getting this message now. I have set the origin, and Optical Flow parameters.

PositionTargetGlobal failed because no origin
FCU: PreArm: Need Position Estimate

Why do these appear in spite of setting, please point me in the right direction.
Thanks for the reply.

4

Hey @amilcarlucas !
Just happened to read this from chatGPT :
'The EK3 (Extended Kalman Filter 3) in ArduPilot does not directly support optical flow navigation in a GPS-denied configuration. The EK3 primarily focuses on GPS-based navigation and state estimation, whereas the EKF2 (Extended Kalman Filter 2) is the module designed to handle vision-based navigation, including optical flow sensors.

A bit unsteady with this now. Please help me understand.

Thanks in advance !!

5

Chatgpt has no clue in this case. That information is three years old, and extremely outdated.

Do not thrust everything an AI writes.

2 Likes
6

I am getting this errorpersistently with EKF3. IS there any resource online, that I could methodically follow to get this configuration in SITL ? Or could you please illuminate on what needs to be set right here ?

7

What an awful use case for ChatGPT! Don’t even bother asking ChatGPT such technically specific questions. At best, you’ll get a quote from an outdated website. At worst, it will make just enough sense out of nonsense to cause you to trust it…and crash your copter.

2 Likes
8

Speaking of methodical configuration, have you configured this vehicle using the ArduPilot methodic configurator software? You should.

9

Boy ! Never knew of that. Thought you were kidding !
Sure, let me take a look.

Thanks again !

10

Hi @Iqua,

You’ve probably seen it already but here is our wiki section for setting up optical flow.

I’m surprised that ChatGPT gave such a poor response. I suspect it wasn’t ChatGPT4 which has been updated within the last year.

1 Like
11

Nope, @rmackay9 ,
it was the normal ChatGPT. Quite unsettling gotta admit.

12

Again, it’s a bad use case. LLM GPTs are trained on historical data to give you a pleasing answer - essentially, they tell you what you want to hear based on data that’s only as recent as the last training cycle and what amounts to a statistical analysis of word frequency and order, given a context. They are not bound by fact. There are amazing use cases for the technology, but asking highly specific, technical questions is not one of them. I would never configure ArduPilot parameters based on a ChatGPT query.

A broader question, like asking it to explain how EKF works, might be a better use case, but the response should only help frame further research rather than being taken as 100% fact.

I often use it to write code snippets (or repetitive declarations, like array literals). It often excels at that, but I never ask it to write code for something I don’t understand, and I almost always refine the result to some degree. It tends to be (predictably) TERRIBLE at arithmetic.

3 Likes
13

Good observation, Yuri. Puts a perspective on these ‘Intelligent’ tools.