Sujay D. Kadam

Roshan A. Chavan, Sujay D. Kadam, Abhijith Rajiv et al.

The idea of posing a command following or tracking control problem as an input reconstruction problem is explored in the paper. For a class of square MIMO systems with known dynamics, by pretending that reference commands are actual outputs of the system, input reconstruction methods can be used to determine control action that will result in a system following desired reference commands. A feedback controller which is a combination of an unbiased state estimator and an input reconstructor that ensures unbiased tracking of reference commands is proposed. Simulations and real-time implementation are presented to demonstrate utility of the proposed idea. Conditions under which proposed controller may be used for non-square systems are also discussed.

Sujay D. Kadam

The work presented here addresses the issue of tuning PD controllers for controlling integrating plus dead-time (IPDT) processes using settling time and gain and phase margin specifications. Tuning formulae are derived for PD controller being used for controlling IPDT processes. Simulations have been carried out to determine the effectiveness of the tuning formulae. Also, comparison between proposed and the other existing tuning methods with respect to performance indices, time domain specifications and the control effort expressed in terms of control signal energy has been done. Effects of gain margin and settling time specifications on process output responses have been discussed. A PD controller cannot account for load disturbances. So, a disturbance observer is suggested for use along with the PD controller. Regulatory and tracking responses are then compared with respect to performance indices and control effort.