Augmented feedforward and feedback control scheme for input tracking and vibration control

This paper presents an investigation into the development of an augmented control scheme for input tracking and vibration suppression in the vertical movement of a twin rotor multi-input multi-output system (TRMS). A parametric model of the TRMS in hovering mode employed for design and implementation of an augmented feedforward and feedback control law for vibration suppression and setpoint tracking. A PID controller is developed for control of rigid body motion. This is then extended to incorporate feedforward control for vibration suppression of the TRMS. A 4-impulse input shaper is used as a feedforward control method to pre-process the command signal to the system, based on the identified modes of vibration. Simulation results of the response of the TRMS with the controllers are presented in time and frequency domains. The performance of the proposed control scheme is assessed in terms of input tracking and level of vibration reduction. This is accomplished by comparing the system response to that without the feedfoward components. The approach has shown to result in satisfactory vibration reduction.