An adaptive multivariable disturbance rejection algorithm for helicopter turbulence compensation control

Helicopter turbulence compensation control is studied through using an adaptive disturbance rejection algorithm for uncertain multivariable systems with unmatched input disturbances. The helicopter system model is first analyzed, including its infinite zero structure and high frequency gain matrix. With relative degree conditions from control and disturbance systems, a nominal state feedback control design is then studied to ensure desired system performances. To deal with the uncertainties of the high frequency gain matrix, its SDU decomposition is employed to parametrize an error system model in terms of the parameter and tracking errors, for the design of an adaptive parameter update law with reduced system knowledge. All closed-loop system signals are bounded and the system output tracks a reference output asymptotically despite the system and disturbance parameter uncertainties. Simulation results of a helicopter flight control system with adaptive turbulence compensation are presented to show the desired system disturbance rejection performance.