DJI O3 Air Unit User Manual

Page 9

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DJI O3 Air Unit

User Manual

❖

Video Image Shakes After Enabling RockSteady

Mechanical vibration at certain frequencies may result in abnormal EIS (electronic image stabilization)

performance of the DJI

O3 Air Unit.

Cause

IMU Resonance

The usual ESC (electronic speed control) PWM (pulse-width modulation) control frequency is

24 kHz by default, and the camera IMU frequency is around 24 to 30 kHz. If there is no effective

vibration absorbing measure, the motor vibration may be transmitted to the camera IMU, causing

resonance because the frequencies coincide. The resonance will affect the IMU data accuracy

and EIS performance of the video stabilization application.

[2]

As a result, the processed video

image shakes, but the liveview image is not affected.

Usually, aircraft frames with TPU or vibration absorbing rubber are not prone to the IMU resonance

issue.

[2] Video stabilization application: refers to either the DJI O3 Air Unit EIS function or a third-party video stabilization software.

Rolling Shutter Effect
If the rolling shutter effect appears in both the liveview and the video image, it is usually because

the propeller vibration (frequency is around a few hundred Hz) is transmitted to the camera

through the aircraft frame.

Troubleshooting and Tuning Guide

Follow the steps below to troubleshoot and fix the image stabilization issue:

Step 1: rule out the IMU resonance issue

1. Remove the propellers from the aircraft. Make sure that the camera is securely mounted and the

aircraft is placed stationary on the ground. Then enable RockSteady and start recording.

2. Start the motors and slowly push the throttle to the full position. Observe the liveview in the

goggles. If the liveview is not shaking, stop the motors and end the recording. Otherwise, check

the camera and make sure it is securely mounted.

3. Check the recorded video. If the video image shakes, the issue is most likely caused by the

resonance between the frame and the camera IMU. In this case, refer to the following solutions:

Solutions

a. Change the ESC PWM control frequency to 48 kHz or 96 kHz and test again.
b. If the video image shakes after the solution (a) is adopted, apply a softer vibration absorbing

structure between the camera and the aircraft frame. Repeat the above testing procedures

until the video image does not shake.

Step 2: rule out the rolling shutter effect issue

After ruling out the IMU resonance issue, check if the video image has the rolling shutter effect.
1. Install the propellers on the aircraft and make sure that the propellers are not damaged.
2. Fly the aircraft and start recording with RockSteady enabled. Check the video image after the

flight. If the video image has a rolling shutter effect, try the following solutions:
a. Adjust the vibration absorbing structure between the camera and the aircraft frame again.
b. Adjust the tightness of the screws that fasten the camera to the aircraft frame.

If the issue still exists after all the above methods are completed,

contact DJI for support

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