Critical PREFLIGHT FAIL: EKF HIGH IMU ACCELEROMETER BIAS

[WTFDproject]

" relatively unstable", "When I yaw left or right, the drone does not just spin about it's vertical axis it actually makes a U-turn."

I do not own any to the Typhoon H drones. However, I offer these thoughts for your consideration:
On the older model drones, the behavior you described was one symptom of an IMU with a significant bias. The other big symptom was sudden flyaway. The only thing keeping the bird in check was GPS. If GPS dropped out, the bird would take off in a direction and at a rate corresponding to the IMU bias. Return to home would not work. Manual control would not work, because there was never enough time to realize what was happening and adjust your thinking for the course/rate it was trying to travel on it's own.
I suspect you have a bad IMU (or corroded contacts), and have now calibrated the bad readings into your flight control system.

It may be time to talk to a service center.

 

[fireflysolutions]

I do not own any to the Typhoon H drones. However, I offer these thoughts for your consideration:
On the older model drones, the behavior you described was one symptom of an IMU with a significant bias. The other big symptom was sudden flyaway. The only thing keeping the bird in check was GPS. If GPS dropped out, the bird would take off in a direction and at a rate corresponding to the IMU bias. Return to home would not work. Manual control would not work, because there was never enough time to realize what was happening and adjust your thinking for the course/rate it was trying to travel on it's own.
I suspect you have a bad IMU (or corroded contacts), and have now calibrated the bad readings into your flight control system.

It may be time to talk to a service center.

I think this is very likely because we did have a flyaway. I bought a replacement IMU which arrived yesterday. Going to swap that first and see if it does the trick, if it doesn't work then off to the service center it goes.

 

[fireflysolutions]

Change your mode to 2

flight mode 2?

 

[RPR]

flight mode 2?

Yeah, map that, as well as map mode 2. (Map=calibrated)

I think this is very likely because we did have a flyaway. I bought a replacement IMU which arrived yesterday. Going to swap that first and see if it does the trick, if it doesn't work then off to the service center it goes.

Did you buy the OEM IMU? Because I’m tempted to couple a new version of IMU.

I will also be doing an FCC approved RC antenna mod and replace all the antennas inside the RC to the newer paddle antennas. I know what parts to get, but I cannot decide of how much, I am willing to devote my time and money.

 

[RPR]

Also, if you are using the drone to do the IMU calibration and not through a computer. Make sure that calibration process has to be precise at Zero x,y,z Parameters. Because getting a zero reading on the H Plus is a bit hard and tricky without a gauge. Or a mechanical device such as a zeroed our wooden pegs on a wooden level board to help you gauge.

 

[arruntus]

I will also be doing an FCC approved RC antenna mod and replace all the antennas inside the RC to the newer paddle antennas. I know what parts to get, but I cannot decide of how much, I am willing to devote my time and money.

If in the end, you feel like doing the mod, take lots of photos, videos and whatever you want. Around here many, we will thank you to see how you have done it. See tests of performance, range, etc.. I personally like to do that kind of modifications ?

In a few months I run out of warranty, so I will have complete freedom to make modifications ?

 

[fireflysolutions]

Swapping the IMU did the trick! After that I followed all of RPRs calibration steps and the drone is much more stable and turning properly now. Didn't have a garage so I popped it in the fridge for 15 minutes for the cold calibration ?

Thanks all for your help!

 

[RPR]

Swapping the IMU did the trick! After that I followed all of RPRs calibration steps and the drone is much more stable and turning properly now. Didn't have a garage so I popped it in the fridge for 15 minutes for the cold calibration ?

Thanks all for your help!

Glad everything worked out.

 

[panthony]

I got this same error twice on the last to flights. I noticed the ST16S was sluggish so I decided to clean the file system. This seems to have corrected several problems with losing contact at less than 400' distance and I have not gotten the imu error. Tech support told me that my firmware is out of date however the updater says I'm OK. I think the controller was out of memory and had to swap during flight and was causing the issues.

Can somebody list the latest firmware (US) so I can match it up with mine to see if up to date...here is what I show with version information.

ST16S - 1.5.10.14

RC Version - 0.33.0

Camera Version - 1.0.61_A

Gimbal Version - 2.40.3

Flight Controller Version - 1.6.5

Vehicle ID - 54:00:3D:00:11:51:35:34

Hobbs Meter - 0014:02:46

 

[RPR]

I got this same error twice on the last to flights. I noticed the ST16S was sluggish so I decided to clean the file system. This seems to have corrected several problems with losing contact at less than 400' distance and I have not gotten the imu error. Tech support told me that my firmware is out of date however the updater says I'm OK. I think the controller was out of memory and had to swap during flight and was causing the issues.

Can somebody list the latest firmware (US) so I can match it up with mine to see if up to date...here is what I show with version information.

You can actually check your build/fw for yourself under ‘software updates’
Locate the sprocket wheel - 3 dots, and below the system version, you will find the ‘software updates’

 

[panthony]

@ RPR...thanks

the software updater Version is stated as 1.5.03 and I can only assume that this is the latest software update. The tech guy at Yuneek told me I am using outdated software.

Is the latest updater version 1.5.03 or not? That is my question.

 

[arruntus]

@ RPR...thanks

the software updater Version is stated as 1.5.03 and I can only assume that this is the latest software update. The tech guy at Yuneek told me I am using outdated software.

Is the latest updater version 1.5.03 or not? That is my question.

https://www.yuneec.com/en_GB/support/downloads/h520-en.html

The only thing that changes is the version of the camera, that instead of the American is the European, the version number is the same. You can compare yourself.