Hybrid modeling and control of a coaxial unmanned rotorcraft interacting with its environment through contact

A new type of coaxial-rotor unmanned helicopter capable of physically interacting with its environment is the subject of this paper. Its design is optimized in order to provide the means of robust environmental interaction through contact (e.g. docking and sliding on walls). Due to the rapid change of the dynamics from the free-flying helicopter to the helicopter subject to the forces and moments during contact a hybrid systems modeling approach is followed. This global model of the system's dynamics is the basis for the design of a hybrid model predictive controller that guarantees the stability of the hybrid system and provides the capability of controlled docking on walls as well as sliding on them. The capabilities of the platform and the efficiency of the control law are illustrated through experimental studies.