Disturbance Observer based Control of Integrating Processes with Dead-Time using PD controller

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.