Calibrations are important practices to perform occasionally with a drone to ensure optimal performance and accurate flight, and to reduce the risk of accidents
The calibration process is essentially the same for all current models of the DJI prosumer line, including:
- Mini 3 and 3 Pro
- Mini 4 Pro
- Flip
- Air 3 and 3s
- Mavic 4 Pro
In this video, I will show you how to calibrate the IMU, compass, gimbal, and remote controller, as well as when and why to do it
Other related articles you may find interesting:
IMU Calibration
IMU stands for Inertial Measurement Unit. It is a device capable of estimating and reporting specific dynamic states such as angular velocity and accelerations
From these measurements, other dynamic states can be inferred, such as attitude angles (roll and pitch), as well as velocity and position increments of the platform. The IMU utilizes several components of the aircraft, like the gyroscope, barometer, and accelerometer, to maintain a smooth, stable, and balanced flight
Since the IMU affects the aircraft’s behavior in flight, it may impact the safety of your unit. I perform a calibration of the IMU whenever I notice an unexpected flight behavior. If the aircraft cannot fly in a straight line, doesn’t maintain the altitude, drifts while hovering, or doesn’t respond appropriately to the sticks of the remote control, the first thing to do is to calibrate the IMU
Another occasion for calibration is when the DJI Fly app prompts to do so with an on-screen message. The calibration is also recommended after traveling more than 50 miles, after significant elevation changes, such as during a trip to the mountains, or when the temperature is drastically different from usual
For the calibration, choose an area far from metal and free from magnetic and electrical interferences. Place the aircraft on a level and flat surface. Ensure you have at least 50% battery life for both the drone and the remote controller
I will show how to do it with the Mini 4 Pro and the RC2 remote controller, but the procedure is the same with the other models. With the Flip, there are some small differences that I will illustrate
In the Safety tab of Settings, scroll down until you find IMU Normal, and hit Calibrate. We are presented with a screen that guides us through the different steps
We are asked to position the drone with folded wings in five different positions:
- In the first position, the aircraft sits laterally with the camera to the left. After hitting the Start button at the bottom of the screen, a ring shows the progress of the first step
- The second position is sitting on the left side of the aircraft, with the power switch facing us and the camera to the left
- Position three with the drone on its back and the camera to the right
- Position four with the aircraft on its right side and the camera to the right
- Position five with the drone standing on the back, showing us the right side
Finally, we place the drone in the first position, and the aircraft will restart. It is a bit like doing yoga
This short video shows the different positions; it should help to get them correctly. At the end, a message will confirm the outcome
If the calibration has failed, move to drone to a different location far from metal and magnetic interference, make sure that the surface is perfectly flat, and try again
IMU Calibrations with the Flip
With the Flip, from the on-screen instructions, it is not always clear what to do with the propeller guards. To simplify the process, let me show you some footage
We start by positioning it laterally with open wings and the camera facing to the left. The second position is sitting on the left side of the aircraft, with the DJI logo facing us and the camera to the left. The left wings are folded. Position three is with the drone on its back, all wings open, and the camera to the right. Position four with the aircraft on its right side, the right wings folded, and the camera facing the right. In position five, the drone stands on its back, showing us the right side, with the back wings folded
If you are using a smartphone or tablet, after connecting it to the Flip, tap the Settings icon on the lower right. Scroll down and tap More Settings. Scroll down again and tap IMU normal calibrate. The calibration window is displayed, and you can follow the same procedure described above
Compass Calibration
The compass keeps track of the aircraft’s position and the home point. If it is not calibrated properly, the drone might fly erratically or crash. It also plays an important role in the case of a Return to Home
We calibrate it when prompted by the app, or after the IMU calibration, if we still notice an unusual flight behavior
The procedure is simple. We find the option for Compass calibration in the tab Safety of the Settings, just above the one for the IMU
We choose an area free from metal and objects with an electrical charge; the calibration might fail in low light. The aircraft must be held at a height of about 1.5 meters, or 5 feet, more or less at shoulder height
After tapping the Start button, simply follow the on-screen instructions: rotate the drone 360 degrees horizontally, then turn it to a vertical position and do the same
The maneuver can be accomplished by simply rotating the hand holding the aircraft; no need to perform complex circular dances or other dangerous acrobatics. A prompt on the screen will show the result. In case of failure, try again further away from interferences
Gimbal Calibration
Unlike the IMU and the compass, the gimbal doesn’t impact the flight behavior but acts upon the alignment of the camera. When a drone is switched on, it operates a sort of basic gimbal calibration
We want to proceed with a gimbal calibration when the horizon is uneven, often after a small crash or a hard landing.
In Settings, we go to the Control tab and scroll down until we find Gimbal Calibration. There is a choice between Auto and Manual
For Auto calibration, the drone must be placed on a level surface with open wings. The calibration starts immediately after hitting the Auto button. The camera moves horizontally and then vertically for a few seconds, and the trick is done
A Manual calibration is generally performed while flying. If we notice that the horizon is uneven, we hit the button below Auto, and we are presented with two sliders. The first one is the rotation of the camera compared to the horizon, and the second is the horizontal alignment
Remote Controller Calibration
Remote controllers like the RC, RC2, and RC2 Pro contain a compass to detect their position. It works like the compass of the aircraft. On rare occasions, we may be prompted to calibrate the controller itself by a message on the upper left part of the screen of the RC controller.
The procedure is explained on screen. It consists of looping the controller into a figure of eight
With the RC 2 controller, it is possible to summon the controller calibration. To do that, we scroll down twice on the screen to reach the menu window. We hit the gear icon at the top right, and then we choose Compass Calibration