There are several drone autopilot systems or more general control hardware for multicopters and planes available on the market. Since the start of Project ArchEye I used for the multicopters the hardware of the homonymous German Mikrokopter company. This hardware is elaborated and works very dependable. It basically consists of two ARM powered microcontroller-boards, one for the control of the flight attitude and motor control, the other for navigation purposes. With the additional GPS the multicopter is enabled to do a lot of tasks. On the image on the left, the complete setup of Mikrokopter boards is shown. On top in the circular frame part is the GPS Antenna, the red board below it is the navigation board and below this, the flight control board is visible (at least a little). For details see the Mikrokopter website.
The motors are driven by controllers also from Mikrokopter, but several other drivers can be used. Our large octocopter is using the “Herkules III“, developed by Andreas Bayer. Since most parts of the source code of the Mikrokopter project is open to public, alongside with good documentation and a very active internet-forum, it is a good choice – but limited to multicopters.
For the new hexacopter I was recommended by Frank Thiemig to use the so called “Pixhawk” drone autopilot system, developed by a team around Lorenz Meier at the ETH Zürich, Switzerland. This is a one-board solution in a quite neat housing with lots of interfaces. The only external parts are the GPS and compass as well as the telemetry device. In contrast to the Mikrokopter, the Pixhawk can control almost everything, no matter if rc controlled plane, multicopter, boat or car. It is completely open-source and open-hardware with a lot of additional sensors available. Especially the airspeed-sensor and the optical flow sensor are very interesting. A main advantage is the direct interface of the software to an onboard computer for different purposes.