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The official order in which to perform the calibrations

PingSpike

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Everywhere I look I seem to find a different order in which to perform the three calibrations.

I contacted Autel yesterday, seeking a definitive response.

TL;DR

> IMU, Gimbal, Compass


Long version:

Thank you for contacting Autel Robotics Support.

When users power on the aircraft, it does an IMU calibration, but it only calibrates the gyroscope offset and accelerometer bias. When the aircraft is on the ground, the bias value is less accurate. If users take off the aircraft from a non-static surface, this IMU calibration may not work properly. The new comprehensive IMU calibration collects 6-axis measurement data based on the current sensor status and gives the IMU a manual correction. The calibrated data is more accurate.

When do users need to perform an IMU, Gimbal, and/or Compass Calibration?

When you receive your Evo II unit for the first time, we suggest performing all three calibrations in this order: IMU, Gimbal, then Compass.

After that, we suggest that users perform the IMU, gimbal, and compass calibrations if they experience unstable flights, gimbal drifts, sideways flight, and/or non-straight flight paths.

Best,

Jay S

Customer Service Agent

www.AutelDrones.com

844.692.8835
 
I'm beginning to think that each Customer Service Agent has their own favorite sequence of doing the calibrations. I think we've heard of every order possible. It would be nice if an engineer for the Evo 2 could address this issue on the forum or at least send a tech note explaining what happens and why...
 
I'm also wondering if the exact orientation of the aircraft during IMU calibration has any effect. Is hand holding/spinning the aircraft in approximately vertical or approximately horizontal orientation good enough? Also, the diagrams that are supposed to tell us which way to hold and rotate the aircraft are very confusing. Are they plan views or elevation views? Or mixed? It seems as though the IMU may be smart enough to ignore grossly incorrect orientations.
 
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I'm also wondering if the exact orientation of the aircraft during IMU calibration has any effect. Is hand holding/spinning the aircraft in approximately vertical or approximately horizontal orientation good enough? Also, the diagrams that are supposed to tell us which way to hold and rotate the aircraft are very confusing. Are they plan views or elevation views? Or mixed? It seems as though the IMU may be smart enough to ignore grossly incorrect orientations.
For IMU calibration, the aircraft has to be sitting still, on a perfectly flat surface AND with no propellers attached. ?
 
I'm also wondering if the exact orientation of the aircraft during IMU calibration has any effect. Is hand holding/spinning the aircraft in approximately vertical or approximately horizontal orientation good enough? Also, the diagrams that are supposed to tell us which way to hold and rotate the aircraft are very confusing. Are they plan views or elevation views? Or mixed? It seems as though the IMU may be smart enough to ignore grossly incorrect orientations.
you are thinking of compass calibration
 
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Have you guys not done the IMU calibration in v2.5.11 yet? The drone needs to be oriented in 6 different positions and held still (by hand) until it beeps. Is v2.5.12 different?
 
Have you guys not done the IMU calibration in v2.5.11 yet? The drone needs to be oriented in 6 different positions and held still (by hand) until it beeps. Is v2.5.12 different?
You can download an Obstacle Avoidance Calibration Tool direct from Autel. You run it from your PC/Mac while your drone is stationary. ?
 
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I'm confused. I just downloaded the OA Calibration Tool and watched the instruction video. First, it appears to be for calibrating the OA sensors, not the IMU. Second, it certainly requires the drone to be handled and pointed at the computer screen in various orientations. Definitely not stationary or sitting on level surface. What am I missing?
 
Yes. Exactly right because you're calibrating the Obstacle Avoidance (OA) sensors, hence OA Calibration tool. IMU calibration is done in the Explorer App. You follow the prompts on your device through the App to perform the IMU calibration. Never a bad idea to calibrate the OA sensors if you have never before anyways. That’s why you are confused. Hope this helps. Adios!
 
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Yes. Exactly right because you're calibrating the Obstacle Avoidance (OA) sensors, hence OA Calibration tool. IMU calibration is done in the Explorer App. You follow the prompts on your device through the App to perform the IMU calibration. Never a bad idea to calibrate the OA sensors if you have never before anyways. That’s why you are confused. Hope this helps. Adios!
Thanks. Got it.
 
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I'm confused. I just downloaded the OA Calibration Tool and watched the instruction video. First, it appears to be for calibrating the OA sensors, not the IMU. Second, it certainly requires the drone to be handled and pointed at the computer screen in various orientations. Definitely not stationary or sitting on level surface. What am I missing?
Sorry for the confusion, yes the OA tool is only for obstacle avoidance. When I ran it, there were no requests for movement etc, perhaps because mine settings were correct when delivered?
 
Everywhere I look I seem to find a different order in which to perform the three calibrations.

I contacted Autel yesterday, seeking a definitive response.

TL;DR

> IMU, Gimbal, Compass


Long version:
You are awesome thank you - same here no one seems to have the correct guess.
 
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PING SPIKE IS 100% Correct but for doubters - Autel response today was

Hello Bob

What is the new IMU Calibration in the Autel Explorer app?

When users power on the aircraft, it does an IMU calibration, but it only calibrates the gyroscope offset and accelerometer bias. When the aircraft is on the ground, the bias value is less accurate. If users take off the aircraft from a non-static surface, this IMU calibration may not work properly. The new comprehensive IMU calibration collects 6-axis measurement data based on the current sensor status and gives the IMU a manual correction. The calibrated data is more accurate.

When do users need to perform an IMU, Gimbal, and/or Compass Calibration?
When you receive your Evo II unit for the first time, we suggest performing all three calibrations in this order: IMU, Gimbal, then Compass. After that, we suggest that users perform the IMU, gimbal, and compass calibrations if they experience unstable flights, gimbal drifts, sideways flight, and/or non-straight flight paths.

Regards,

Thomas K.
Customer Support Agent
AUTEL ROBOTICS
 
Sorry for reviving a dead thread but I saw this from Autel today.

True Level: The REAL Way to Fix that Tilted Horizon

This says that is is very important to calibrate in the following order:
  1. IMU
  2. Compass
  3. Gimbal
So it sounds like they have either changed something or their initial claim was just wrong. Or maybe this blog post is wrong?
 
Sorry for reviving a dead thread but I saw this from Autel today.

True Level: The REAL Way to Fix that Tilted Horizon

This says that is is very important to calibrate in the following order:
  1. IMU
  2. Compass
  3. Gimbal
So it sounds like they have either changed something or their initial claim was just wrong. Or maybe this blog post is wrong?
That is the correct order . Helped someone out already, here are the results: Facebook Groups

I also had them remove a user video of imu calibration and replace with the current. NEVER HOLD the drone on the first step or even when you flip it over.
 
Last edited:
You can do a compass calibration without doing all 3. The above procedures is only needed if you start seeing a wonky horizon.

Can I ask why you would want to do a compass calibration after having a known good one and not experiencing any issues?
 
This is old school thinking to be honest. indications if this is necessary would be toilet bowl during hover and or jhooks while going straight. It would never cause a fly away. Most FC these days have a look up table that take this into account.

what causes most flyaways is people not understand the surface they fly off of. Once the craft breaks this influence that’s when all hell breaks loose. 2nd is improper calibrations around unknown influences. This is why it’s safer for standard user to stay with a known valid calibration rather than possibly introducing a bad calibration from external influences.
 

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