Gimbal Control – The Principle and Application

Camera stabilizing gimbals have emerged with a boom. The first 2-axis gimbals were servo-controlled and mounted on multi-rotors to stabilize the video or FPV (First Person View) camera. Since then the technology has advanced drastically and brushless gimbal motors are a common sight on the market. The whole point of a gimbal is to keep a payload stable and in the same orientation independent of what its mounting platform is doing.

The video below demonstrates the principle:

That was a handheld brushless camera stabilization rig, I am designing a 3-axis brushless gimbal that is going to be mounted on a multi-rotor, most probably a quadcopter.

The idea behind the whole thesis is that it can be used for SAR (Search and Rescue) purposes. As a member of a SAR party, you want a unobstructed view of your surrounding environment, but a additional pair of eyes in the sky could be very helpful as well. Google Glass is one of the few available HUD (Head Up Display) platforms that gives you the ability to view a HUD screen whilst still having a unobstructed view of your surrounding. The screen doesn’t have to be very big if the camera payload is a infrared camera that looks for someone’s heat signature, something like that would be easily identifiable on the Google Glass’ screen.

The idea is to have a quadcopter that is flying above you, and you can control the gimbal simply by moving your head around. Additionally a position lock function would be very useful. Now this is no simple task, but it is something I would like to add to the whole system. The control algorithm will be based on a trigonometric mathematical model of the orientation of the gimbal, the heading of the quadcopter and the direction in which the gimbal is facing. All of this information will be provided by a GPS, Pressure sensor and compass, and the base controller will be a Arduino Mega 2560.

When a position lock is activated, the gimbal should face the camera lens so that the general area below the quadcopter stays in view, despite the movements of the quadcopter. Naturally the head movements of the controller will have no effective input to the system in this state. The controller then has a visible image of a certain area without having to maintain head control over the gimbal.

If this project is successful, it could prove to be a basis on which UAV (Unmanned Aerial Vehicle) assisted SAR operations are conducted and can be improved.

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