Join Jim Heid for an in-depth discussion in this video What's going on during warmup?, part of DJI Mavic Pro: Tips, Tricks, & Techniques.
- When you hear your drone make that startup sound, what you're hearing is part of the drone's power-up sequence. Understanding what's going on during that entire sequence will help you fly safely and also give you an appreciation for the technology that's built into these things. Some parts of the power-on sequence you can see for yourself. The props jiggle a little as the drone tests each motor. The gimbal goes through its full range of motion. If something is blocking the gimbal, or if you've forgotten to remove the plastic gimbal clamp, an error message appears on the DJI Go app and the remote controller.
Other parts of the power-on sequence happen under the hood. Inside the drone is a component called the inertial measurement unit, or IMU for short. Think of the IMU as a very sophisticated version of the accelerometer in your phone. That thing that lets your phone know whether it's vertical, horizontal or in between. The IMU in a drone lets the drone know how it's moving. Tilting back and forth, that's called pitch. Tilting left or right, that's called roll, and turning left or right, that's called yaw.
To perform all these measurements, the IMU uses a combination of accelerometers and gyroscopes. These are tiny, electromechanical components that use little moving grids to detect motion. To perform their measurements accurately, these components need to be at a known temperature. I'll talk about what that is near the end of this course. The drone contains a thermometer that checks the IMU to make sure that it's reached that known temperature. That's the warmup process, and the DJI Go app lets you know when it's happening.
While all this is going on, the GPS receivers in the drone are trying to pick up as many global positioning satellites as they can. GPS plays a huge role in modern drones. It helps the drone know where it is, to hold its position, to find its way home and to stay steady in flight. All of this sounds complex enough, but there's even more. Also in the drone, there's a barometer that measures air pressure and helps the drone report and maintain its altitude relative to your takeoff point. And there's a compass that works together with the GPS receiver to let the drone and you know which direction the drone is pointing.
All of these components are part of what's called the flight controller, and I'm describing them here for a couple of reasons. First, because they're cool, but second, because sometimes things go wrong. A nasty crash or even very aggressive flying can knock the IMU out of calibration. Flying too close to a strong magnetic field can cause the compass to get confused, and losing GPS lock because you're under a forest canopy or you're indoors, can suddenly cause the drone to respond and handle differently. When your drone seems to be flying erratically especially if you've crashed recently or roughed up the drone in some other way, there's a good chance the IMU or some other component needs to be calibrated.
We'll take a look at that process near the end of this course. Knowing how these components work explains why the drone takes some time to warm up before it's ready to fly. It's very important to give the drone time to ready itself. Don't move it around. Give it a chance to get its bearings. That all gets back to the point I made in the previous video, be patient after you power up and don't rush to get your drone into the air.
- Safety checks
- App settings
- Startup, takeoff, and landing
- In-flight data displays
- DJI GO tips
- Flight modes
- Streaming live
- Adjusting focus
- Exposure and white balance
- Still photography and panoramas
- Shutter speed
- Aerial video
- Using the gimbal
- Using the remote controller