Drones use sophisticated technologies. However, they need calibration to ensure accuracy. Factors like a hard landing, varying magnetic pulls, and other factors can distort their sensors like the magnetometer and accelerometer. Thus, you must adjust them from time to time. This article will teach you how to calibrate a mini drone and why you have to do so.
Calibration corrects errors that cause the drone to make inaccurate sensor measurements. It manages adjustments based on a standard model. Calibration is the synchronization of sensor data with real physical data.
What is a Magnetometer?
The magnetometer serves as the drone’s compass. A microcontroller processes the magnetic field data in the area then provides the heading angle to the drone concerning the magnetic north. Thus, it is crucial that the magnetometer function properly for a safe flight.
Why You Need to Calibrate the Magnetometer
Because magnetic field varies depending on the location, your drone can misread its heading and fly a few degrees off tangent. It will lessen its efficiency and decrease the land area that it can map during its flight.
How to Know if the Magnetometer Needs Calibration
If you want to find out if you need to calibrate your drone’s magnetometer, you must point the drone’s part to a landmark. Search on Mission Planner if the icon of the drone is directing to the same marker. If it is off by a few degrees, it is a sign that you need to tweak the magnetometer.
Also, if you notice your drone flying in swirling and circular movements while trying to hold position, you need to regulate its magnetometer. Significant changes to the hardware like adding a camera gimbal or a larger battery can warrant recalibration of the magnetometer. The good news is that calibration only takes a maximum of five minutes.
What is the Inertial Measurement Unit (IMU) Calibration?
The IMU houses the drone’s various sensors like the accelerometer, barometer, gyroscope, thermometer, etc. You need to understand the IMU because some of its sensors require calibration.
What is an Accelerometer?
An accelerometer makes the drone balanced and stable when it flies. It measures the right acceleration relative to an observer at rest. The drone uses the data to determine velocity and transmits it to the central processor so you will know the drone’s speed and direction. The accelerator works with the gyroscope to identify altitude changes.
Why Do You need to Calibrate the Accelerometer?
Its non-calibration can cause unsafe and erratic flight. If the ground control station is slanting even if the drone is on a level surface, it needs calibration. If you feel that its trip is not right, you need to recalibrate the drone’s accelerometer.
Also, if the drone experiences sudden vibrations and shocks or if the temperature changes during transport, it demands calibration especially if it is on a plane. Often, you need to calibrate the accelerometer after fifty hours of flight or every six months. Also, if it experiences a massive jolt, it requires calibration.
What is a Gyroscope?
The gyroscope maintains the altitude of the drone — a small electromechanical structure interfaces with electronics. A flying drone can deal with various forces like wind, gravity, etc. that can affect the pitch, yaw, and roll.
The gyroscope detects any change in the drone’s position instantly. It sends this information to the motor control drivers to maintain the motors’ speed. The gyroscope is responsible for compensating any modification in position by readjusting the drone’s location. Thus, the drone can fly smoothly and tolerate winds.
Moreover, the gyroscope ensures the rotation of the drone at an exact angle determined by user controls. A drone with a gyroscope or accelerometer is beneficial in advanced applications like 3D imagery and photogrammetry.
Why You Need to Calibrate the Thermometer
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The thermometer senses every change in the drone temperature. The Inertial Measurement Unit has to warm up when you turn on your drone. It needs to warm it up to the last calibrated temperature.
For instance, you last calibrated the temperature at room temperature. If you bring your drone outside, the IMU needs to warm it up to room temperature before it can fly. You may feel frustrated if it takes longer for the IMU to warm up. This occurrence is typical if you last calibrated it at high temperature.
Thus, experts recommend that you remove the battery for 30 minutes before you perform calibration. This practice will cool your drone. Also, you can place it near an air conditioner vent if you want it to cool quickly.
Why You Need to Calibrate the Barometer
The barometer measures every shift in height; it converts the atmospheric pressure to altitude. The pressure sensor in the drone can determine the atmospheric pressure. Then, it guides the drone to achieve the appropriate height.
As such, calibrating the inertial measurement unit is necessary to provide accurate data for the drone’s flight control. It can help the drone balance itself based on the leveled value. Also, the drone can make accurate descends, ascends, and turns. Non-calibration of the IMU can cause flight issues.
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What are the Steps to Calibrate a Mini Drone?
The process of calibration is almost the same for all small drones. You need to pair it with the transmitter; then, place it on a level surface. Then, you need to follow the drone’s manual. However, for most drones, you need to move the stick up and the throttle down. Some of them will require you to move the throttle and the rod to the lower right corner. If the LED lights no longer blink, it means that your setting is successful.
If your drone has the trim button, you can stabilize it through this button. Search for the switch in your controller. For those with two buttons, you can trim backward or forward, and left or right. In case it has three buttons, the last one is for the yaw trim that you can use to stabilize your drone if it spins. You can trim while your drone flies.
A drone has many uses, but it needs calibration from time to time. You need to know how to calibrate a mini-drone to ensure that it flies safely and efficiently. It doesn’t take a lot of time and effort to do it.