Closed Loop Vibrational Control: Theory and Applications

Abstract : In this project, a novel control technique, referred to as Closed Loop Vibrational Control, is developed and applied to the problem of fuselage vibrations suppression in helicopter dynamics. This technique is applicable to systems where the control input enters the open loop dynamics as an amplitude of a periodic, zero average function, and this amplitude can be chosen to depend on the systems outputs. An example of such a system is the helicopter with Higher Harmonic Control (HHC) where periodic feathering of rotor blades around a fixed pitch angle is introduced in order to suppress the fuselage vibrations. For systems with this structure, a number of control-theoretic problems, including - theoretic problems, including stabilizability, pole placement and robustness, have been solved, and the results are reported in this document. Vibrational control, Vibrational stabilizability, Robustness, Higher harmonic control.