AN H∞ based observer for disturbance rejection in TRMS decoupled with hadamard weights using LMI optimization

In this paper, the problem of disturbance rejection in Twin Rotor MIMO System (TRMS), which is a laboratory model of helicopter, is dealt with. The use of disturbance observers, without any additional sensors is an attractive method to attenuate the effects of disturbances as they are highly cost effective. This method uses a simple form of DOB, which does not need to solve the plant model inverse, and uses H_∞ control method using LMIs to design the Q-filter in the DOB. TRMS is decoupled using Hadamard weighting techniques and the design of DOB is accomplished for the two decoupled plants. The estimation capability of DOB is verified using simulation results in frequency domain as well as in time domain.