Active control of a frequency varying tonal disturbance by a nonlinear optimal controller with frequency tracking

In this paper a method for suppressing frequency varying tonal disturbances is presented. In most of such processes additional components are required to be installed within the process to measure the disturbance frequency. The proposed nonlinear optimal controller is combined with an RLS-based frequency tracking algorithm. The resulting controller is adaptive in terms of the disturbance frequency and can act as a stand-alone solution for the suppression of tonal disturbances, requiring only measurements from the process output. The performance of the resulting controller is validated by implementation on a process emulating the problem of isolating vibration using flexible raft structures.