Stabilization of a mini rotorcraft with four rotors

F light control of unmanned helicopters is an area that poses interesting problems for control researchers. The classical control strategy for helicopters assumes a linear model obtained for a particular operating point. Applying modern nonlinear control theory can improve the performance of the controller and enable the tracking of aggressive trajectories, as demonstrated in [1] for a 5-ft diameter main rotor helicopter. Civil and military applications of autonomous flying vehicles have been steadily increasing over the last few years. Traffic surveillance, air pollution monitoring, area mapping, agricultural applications, and remote inspection require high maneuverability and robustness with respect to disturbances. Since rotary wing vehicles can take off and land in limited spaces and hover above targets, these vehicles have certain advantages over conventional fixed-wing aircraft for surveillance and inspection tasks. © DIGITAL VISION Experimental implementation of linear and nonlinear control laws