OpenMaG — A Simple Gimbal for UAV Mapping
Drones (UAVs) are being used for new applications every day. Most common uses such as photography and cinematography require cameras mounted on the UAVs. These cameras need to be stabilized to compensate for the UAV’s movements and vibrations caused by the motors. Most off-the-shelf camera drones come with 3 Axis gimbals which can stabilize the camera in all 3 axes.
UAV based mapping and surveying is an emerging area where traditional ground surveying techniques are being replaced with sophisticated autonomous mapping solutions that leverage the high resolution and convenience of these camera drones to achieve phenomenal results.
In this article we will explore the design goals for a single-axis gimbal system. ‘OpenMaG’, is an Open-source mapping gimbal designed for use with custom multi-rotors. Built around the Sony RX0 camera, OpenMaG uses a single servo motor to stabilize the camera in the pitch axis. The idea was to build a minimalistic mechanism that can be easily printed with a desktop FDM printed.
The intention behind using a single axis gimbal for mapping is that most UAVs move in a single direction when mapping mode, hence deviation in camera angle is observed in only that direction. In most cases the UAV moves about the pitch axis, therefore OpenMaG aims to stabilize the camera in the pitch axis.
OpenMaG is an extremely simple design. With only two 3D printed parts and a single servo motor the gimbal can be assembled in a matter of minutes. It can be mounted on a pair of rails and can be printed with a desktop FDM printer.
As OpenMaG was designed to be used with custom UAVs, it can be driven with a PX4 based flight controller or any flight controller which can drive servos for gimbal stabilization. The system uses an MG995 or equivalent servo that can be driven with a PWM signal and 5–6V of power.
Since OpenMaG is intended to be completely open source, the servo mount can be modified for use with brushless gimbal motors for smoother movements. The STLs can be found here, the design files will be made available soon!
OpenMaG is being extensively tested on a custom built quadcopter. Preliminary results show that it performs adequately in various mapping missions. Follow me as I will be sharing results and sample data as soon as testing is done!
