HELICOPTER FLIGHT CONTROLLER-DESIGN USING NONLINEAR TRANSFORMATION

Synthesis of a helicopter trajectory controller is described in this s tudy using nonlinear transformation and singular perturbation theories . A non-iterative control law in the slow time scale has been develope d for the inverse nonlinear transformation. The problem of modeling er rors in the system with nonlinear inverse dynamics theory is investiga ted extensively. The errors examined include not only high frequency u ncertainties such as neglect of actuator dynamics, but low frequency o nes like aerodynamic modeling errors. The results of simulation studie s show that the control system could track commanded values under the presence of modeling errors and disturbances.