CARLTON

The Carlton Quadrocopter belongs to the class of Vertical Take-Off and Landing (VTOL) aerial vehicles. The main advantage of this type of aerial vehicle is the ability to launch from the stowing position without the need for complex launching facilities. In principle, it is also possible to return to a docking position without external intervention. Further, quadrocopters have a large number of degrees of freedom, and offer highly dynamic flight capabilities. The path that can be given to a quadrocopter is much less constrained than, for example, that of a fixed wing aerial vehicle. This flexibility comes at the cost of increased energy consumption. However, for the purpose of scouting (the activity of exploring the surrounding terrain), such vehicles are very well suited, as they can launch on demand and get to the short range target area quickly.

The Sikorsky layout is the classical helicopter configuration with one large main rotor and a smaller tail rotor. Upward thrust is produced by the main rotor, torque for pitch and roll is created by adjusting the pitch of the rotor blades depending on the position of the rotor. Yaw is controlled by altering the pitch of the tail-rotor blades. The quadrocopter uses four identically sized rotors, two of them counter-rotating. The torques for yaw, pitch and roll are controlled by altering the rotational velocity of the individual motors. The advantage of such an approach is its mechanical simplicity, as only four rotors, rotor-drives, and a frame are needed. This simplicity has the advantage of potentially lower costs for high-volumes and longer operating hours due to a lower probability of mechanical failures. As quadrocopters are less energy efficient compared to the Sikorsky layout when scaled-up in size, they are best suited to short range scouting tasks in multi-robot exploration scenarios.