The x, z-axes of the spatial frame are pointing north and down. The body x-axis is defined from the center of gravity to the nose of the helicopter, and body z-axis is pointing down from the center of gravity (CG). The motion of the helicopter is controlled by the main rotor thrust, and the longitudinal tilt path angle.
Flight modes represent different modes of operation of the helicopter and they correspond to controlling different variables in the dynamic. We define the following flight modes: Hover, Cruise, Acc/ALH, Dec/ALH, Climb, and Descend, where ALH stands for "ALtitude Hold."
The control uses approximate feedback linearization and pole placement. The top level system looks like.
The climb action consists of a sequence of flight modes. Inside the controller block is the FSM domain, where each FSM state represents a flight mode. Each flight mode is further refined into a continuous time controller. The model inside the controller is shown below.
Last Updated: $Date: 2004/04/12 00:12:48 $